This post is a follow-up to my recent post about measles and MMR vaccine. The purpose of this post is to compare the risk of adverse effects from the MMR vaccine to other risks that we take with our children every day.
Annual Deaths of children under 18
In the US 37,000 children under the age of 18 die every year. In 2022, the last year for which we have complete data, 604 children were killed in automobile accidents. This figure includes those killed as passengers, walking to school or in their neighborhoods, or riding their bicycles. Here is a table from the New England Journal of Medicine showing the most common causes of death of children since 1999.
As you can see from the graph, motor vehicle deaths of children have gone down significantly since 1999, but are still the second leading cause of death in children. Firearm injuries have now surpassed motor vehicle deaths as the leading cause of death in children.
All of these risks are small, the highest being 4.5 deaths per 100,000 Children. These are risks we take with our children every day. There is a risk when they ride in your car. There is a risk when they walk in their neighborhoods. There is a risk when they ride their bicycles. There is a risk that they will be killed by a mass murderer when they go to school. The risks of adverse reactions to vaccines are actually lower than the risks that we take with our children every day. Adverse reactions to vaccines almost never kill children
Deaths of children due to MMR vaccine
There have been only two documented deaths due to MMR vaccine in the 62 years it has been available. Both of these deaths were in children with Severe Combined Immunodeficiency Syndrome (SCIDS). You may remember a movie about a child with this syndrome. It was called “The Boy in the Bubble.” These children should never have received a live virus vaccine, such as MMR.
MMR Vaccine and Autism
Robert F. Kennedy Jr, the current head of HHS, has contended that MMR vaccine causes autism. There was a paper published by Andrew Wakefield in the medical journal, the Lancet, that studied 12 children and concluded that MMR vaccine was linked to autism. It was later discovered that he had falsified his results and the paper was retracted by the Lancet. This discredited paper, plus another one by the same author are still cited by people, including our current head of HHS, as evidence that MMR vaccine causes autism.
Study by Brent and Taylor
Brent and Taylor and colleagues examined the records of 498 children with autism. Cases were identified before and after MMR vaccine became available in the UK. They compared the incidence of autism in vaccinated and unvaccinated children and found no difference.
Study by Madsden and Colleagues
Madsden and colleagues did one one of the best and most rigorous studies. The study included 537,303 children representing 2,129,864 person-years of study. Approximately 82% of children had received the MMR vaccine. The risk of autism in the group of vaccinated children was the same as that in unvaccinated children. Furthermore, there was no association between the age at the time of vaccination, the time since vaccination, or the date of vaccination and the development of autism.
Other studies
Many other well designed studies have shown no association between the MMR vaccine and autism.
Bottom Line
We daily accept small risks of injury and death of our children. There are no activities involving children that are without some risk. The risks of MMR vaccine side effects (or any other vaccine) are no larger than the risks we take with our children every day. See my last post for a list of possible side effects of MMR vaccine. Severe side effects of MMR vaccine are very rare. When given appropriately to children with normal immune systems, death is not one of the risks. The one study by Andrew Wakefield that showed a connection with MMR vaccine and autism was shown to be fraudulent and was retracted. Multiple well designed studies have definitively shown that MMR vaccine does not cause autism.
The benefit of cancer screening tests like pap smears, colonoscopy, mammography and others are reported in two ways. The most common way is the relative risk reduction. This is a ratio of the risk in the screened group divided by the risk in the non-screened group. Relative risk does not take into account the baseline risk in the whole population. The other way of reporting benefit of a screening test is called absolute risk reduction. Absolute risk reduction is the risk in the non screened group minus the risk in the screened group. Relative risk reduction always looks a lot bigger than absolute risk reduction because it does not take into account the baseline risk. Absolute risk reduction is what you really want to know. Absolute risk reduction lets you know how much your risk is reduced by taking the screening test. It is always a lot lower than the relative risk reduction. Absolute risk reduction of the most common cancer screening tests is very low, usually 1% or less.
Here are some examples:
Mammography: Relative breast cancer death risk reduction 30%; Absolute cancer death risk reduction 1%
Colonoscopy: Relative colon cancer death risk reduction 50%; Absolute death risk reduction 0.15%
Pap Smear: Relative cervical cancer death risk reduction 80%; Absolute cervical cancer risk reduction .08%
Another number that can be helpful is called Number Needed to Screen (NNS). NNS is the number of people who need to be screened to prevent 1 death from the disease. NNS is just 1 divided by the absolute death risk reduction for the screening test. Here are the NNS’s for the examples above.
Mammography: NNS 1/.01= 100 (this is mammograms every 2 years from age 50-75 so the the 100 patients means about 1100 mammograms).
Colonoscopy: NNS 1/.15=667
Pap Smear: NNS 1/.08=1,440
PSA: NNS 1/.09 =1,111
Sensitivity and Specificity
Any test, including cancer screening tests have a certain sensitivity and specificity.
Sensitivity
The sensitivity of a test is the probability that the test will detect the disease if it is present. In other words it measures how likely it is to get a falsenegative test. The higher the sensitivity, the less likely the test will be negative if the person has the disease being tested for. It is expressed as a percentage.
Specificity
The specificity of a test is the probability that a person with a positive test will have the disease. In other words it measures how likely it is to get a falsepositive test. The higher the specificity, the more likely a person with a positive test will have the disease. It is also expressed as a percentage
An ideal test has both a high sensitivity and specificity. Lets look at the sensitivity and specificity of our cancer screening tests.
Mammography: sensitivity 72%; specificity 98%
Colonoscopy: sensitivity 85%; specificity 90%
Pap Smear with HPV testing: sensitivity 95%; specificity 97%
PSA: Sensitivity 30%; Specificity 91%
Bayes Formula
All of these cancer screening tests have high specificity but somewhat less sensitivity except for Pap smears with HPV testing, which have high sensitivity and high specificity. So why are the absolute death reductions so low? Part of it has to do with something called Bayes Formula. It turns out that the chance of a false positive has to do not just with the specificity, but also the frequency of the disease in the population being screened. If the frequency of the disease in the population being screened is low, then even with a test that has high specificity, the chance of a positive test being a false positive is higher than than the specificity would suggest. The frequency of all of the above cancers is low in any 1 year in the population so that means that false positive cancer screening screening tests are common. Below are population frequencies for each cancer per year.
Breast cancer: annual prevalence in women 0.13%. Chance of a positive mammogram being a true positive: 28%. This means that a positive mammogram has 72% chance of being a false positive. On the other hand, a negative mammogram has an 8.7% chance of being a false negative, that is of missing a breast cancer
Colorectal cancer: annual prevalence in population .03%. Chance of a positive colonoscopy being a true positive: 2.5%. That means that a colonoscopy that finds something only has a 2.5% chance of being cancer. On the other hand, a negative colonoscopy has only a .005% chance of being a false negative. That means a negative colonoscopy has only a tiny chance of missing a cancer.
Cervical Cancer: annual prevalence in population 0.0077%. Chance of a positive pap smear being cancer: 0.24%. That means that 99.86% of positive pap smears with HPV testing will not be cervical cancer. On the other hand the chance that a negative pap smear with HPV testing will be a false negative is .00041%. Obviously a negative pap smear with HPV has an infinitesimally small chance of missing a cervical cancer. Although the chance of finding a cervical cancer is very low, the pap smear with HPV also finds precancerous changes in the cervix. Treatment of these precancerous cells prevents cervical cancer from developing. That is a big reason why the prevalence of cervical cancer is so low.
Prostate Cancer: annual prevalence in men .66%. Chance of a positive PSA (>4) being a true positive 2.18%. That means a PSA of >4.0 has a 98% chance that no prostate cancer is present. On the other hand a PSA of <4.0 has a 5.1% chance of missing a prostate cancer.
The somewhat lower sensitivity of mammography, colonoscopy and especially PSA means that false negatives are fairly common, for these tests.
The combination of false positives, false negatives and low prevalence of these cancers in the population all contribute to the small absolute death risk reduction for all four of these cancer screening tests. For patients at substantially higher risk, such as strong family history of breast or colon cancer, the screening tests perform much better, because the high risk population has a much greater disease prevalence than the general population.
Over Diagnosis
Another problem with cancer screening tests is over diagnosis. Over diagnosis means that a positive test finds a cancer, but the cancer grows so slowly or spontaneously disappears so that it never would have caused any symptoms in the person. Over diagnosis then leads to unnecessary treatment. So let’s look at the over diagnosis rate for our four cancer screening tests.
Mammography: Over diagnosis rate for women 40 and over is 12%. This means the 12% of women diagnosed with breast cancer by mammography will be treated for cancer unnecessarily.
Colonoscopy: The over diagnosis problem with colonoscopy results from the removal of polyps. All visible polyps are removed during colonoscopy. The polyps that have some chance of turning into cancer are called adenomatous polyps. Only 8% of these turn into invasive colon cancer over 10 years. That suggests that 92% of the adenomatous polyps removed at colonoscopy would never turn into cancer. Removal of all adenomatous polyps does prevent some colon cancers. It is not possible to know at the time of removal which polyps are going to progress. The cost of prevention of some colorectal cancers is substantial over diagnosis.
Pap Smear with HPV: Overdiagnosis of precancerous cervical lesions is high. We now know that cervical cancer is caused almost exclusively by the HPV virus. On the other hand, women often clear an HPV infection on their own without treatment. This is particularly the case with young women, which is why pap smears and HPV testing are not recommended before age 21. Precancerous cervical lesions are graded CIN1-CIN3, CIN3 being the most severe. Overdiagnosis rates are higher for the lower grade lesions, which most often clear on their own. The figures for over diagnosis over women’s lifetime were 70.6% for CIN1+, 63.2% for CIN2+, and 50.0% CIN3+.
PSA test for prostate cancer: Low grade prostate cancer is common as men age. Many of these cancers would never cause symptoms during the lifetime of the men. Current estimates are that 60% of prostate cancers detected by PSA would never cause symptoms or death from prostate cancer. Treatment of prostate cancer often results in permanent urinary incontinence and/or sexual dysfunction. This very large over diagnosis and therefore unnecessary treatment is why PSA testing is so controversial. There are certain populations of men who are at high risk of aggresive prostate cancer and these men are probably the only ones who should have routine PSA testing. Here is a link to a risk calculator for prostate cancer: PCPT Risk Calculator.
Bottom Line
Despite the high specificity of cancer screening tests, Bayes Formula shows that false positive tests will be more frequent than true positive tests. For mammograms, colonoscopy and PSA the somewhat low sensitivity means that there will be some false negative tests. In other words, they will miss a few cancers. Pap smear with HPV has the lowest chance of missing a cancer. Over diagnosis is a problem with all cancer screening tests, resulting in unnecessary treatment. This is particularly a problem for breast cancer and especially prostate cancer. The low absolute death risk reduction values and the over diagnosis problems for these tests do not mean you should not be screened, especially if you are in a higher risk population due to family history or other causes of higher cancer risk. All of these screening tests save lives, just not as many as the relative risk values suggest. The vast majority of people will not benefit from these tests and some will be harmed by unnecessary treatment, but a small but substantial number will have their lives saved.
Longevity is the newest health buzzword. There are an increasing number of so-called longevity experts. They say, just read my book and follow my instructions and you can live past 100 years. Some of these “experts” focus on health span. They say follow my instructions and you will stay healthy and die suddenly at an advanced age. As of 4/21/2024 there are 34 books on longevity listed on Amazon.
In this post I will do my best to distinguish the hype from the science with regard to living a long and healthy life.
Hype
Calorie restricted diets – Some people have extrapolated mouse and rat experiments that show that animals fed restricted calorie diets live a lot longer than animals fed a normal diet. There is not one shred of evidence that this works with humans, and is more likely to lead to diseases of malnourishment.
Nutrtional supplements – Recommendations range from vitamins, to protein powder, to collagen powder, to herbal preparations, to encapsulated fruits and vegetables. There is absolutely no evidence that any of these things or any other supplements including multivitamins work to extend your life. Anecdotal reports of feeling better on these supplements are almost certainly a placebo effect
Anti-aging medicines – reservetrol, metformin, rapamycin have all been shown to prolong life in some experimental animals. In humans Metformin and reservetrol decrease the ability to exercise and rapamycin suppresses the immune system. There is no evidence whatever that these compounds increase life or health span in humans.
Extensive lab tests – Other than lipid (cholesterol) tests, there is no evidence that otherwise healthy non-obese people benefit from any blood tests. More about screening tests later.
Imaging tests – One of the most popular longevity “experts” ,Dr. Peter Attia, recommends full body MRI scans for his patients. Imaging tests in people who have no symptoms are much more likely to lead to over diagnosis and unnecessary treatment than to find things that really need to be treated,
Very intense exercise regimens – The only thing very intense exercise regimens accomplish that moderate exercise regimens do not is that the intense regimens are more likely to cause injury.
Science
Genetics
Up until into the 80’s, lifestyle is the major contributor to healthy aging. There are some people, however who remain healthy well into their 90’s and a few to past 100. Genetics is the main contributor to these “super centenarians.” There is not a single or even a few aging genes. Super aging is caused by hundreds of genetic variants called SNP’s (single nucleotide polymorphisms). We cannot alter our genes (yet), so there are no lifestyle changes you can make in order to live to 100 if you don’t have the rare combination of all these genetic variants.
That is not to say that lifestyle is not important to healthy aging. In the US, the average person’s last birthday in good health is age 65! Lifestyle changes will almost certainly help you do better than that.
Exercise
Regular exercise decreases your risk of chronic disease and therefore increases your chance of living healthier longer. To accomplish the maximum health benefit the CDC recommends 150 minutes of moderate exercise per week. Brisk walking or cycling at a moderate pace on level ground would qualify. If you choose high intensity exercise like jogging or running or high intensity cycling, you only need to do 75 minutes a week according to the CDC. The CDC also recommends activity to strengthen your muscles two days a week. For a population of adults doing this exercise regimen the risk of death is decreased by 17%. This regimen decreases the risk of heart disease, diabetes, certain cancers and decreases the risk of hospitalization or death from infectious diseases like COVID, flu and pneumonia. This regimen also increases bone and muscle strength and thus decreases the risk of falls and fractures. This exercise regimen also helps maintain a healthy weight.
Any amount of walking or activity decreases risk somewhat. The CDC recommended regimen decreases risk the most.
Nutrition
Eat mostly unprocessed foods and avoid ultra-processed foods. The best way to identify ultra-processed foods is to look at the ingredients label. If there are more than four ingredients, and/or if there are some you don’t recognize, then put that food back on the shelf. It is best to keep nutrition advice simple. The most concise recommendation I know comes from author Michael Pollan. “Eat food (food is anything your grandmother would have recognized as food), not too much, mostly plants.” I can’t do much better than that. Most of the evidence about the beneficial effects of good nutrition come from studies of the Mediterranean style diet. The Mediterranean diet adheres to Michal Pollan’s advice. It has lots of fruits, vegetables, fish, olive oil and very little meat. Adherence to this type of diet showed a 46% increase in living healthfully until 70 or greater.
Social Connectedness
The CDC defines social connectedness as the degree to which people have and perceive a desired number, quality, and diversity of relationships that create a sense of belonging, and being cared for, valued, and supported. An analysis of multiple studies showed that high social connectedness as defined above decreases the risk of premature death by 50%! High social connectedness also decreases the risk of heart disease, stroke and dementia.
Social Determinants of Health
The main reason that the US average health span is 65 years is the tremendous inequity of resources in the US. People who live in substandard housing (or no housing at all) do not have the opportunity or resources to do all of the things above that tend to extend life. That is why life expectancy at birth is related to zip code more than any other factor. My feeling is that we should expend our resources working on improving health equity, which will increase both life and health span for everyone rather than focusing on helping wealthy people live to 100.
Screening Tests
There are a few screening tests recommended by the US Preventive Care Task Force for healthy people. These tests are meant to find disease, especially cancer early so it can be more successfully treated and thus prolong healthy life. The absolute risk reduction of death for these tests is small, most around 1%, but that ends up saving a lot of people when you apply it to the whole US population. The recommended screening tests are listed below.
Mammograms for women beginning at age 50. Recommended every two years. Absolute risk reduction about 1%.
Pap Smears beginning at age 21 every 3 years through age 29 and then every 5 years from age 30 to 65. The absolute death risk reduction is .0009%, which means your would need to do pap smears on 11140 women to prevent one death from cervical cancer.
Colorectal cancer screening. There are three different tests: colonoscopy, the most invasive (recommended every 10 years), Cologuard (a stool sent to a lab in a box recommended every 3 years) and fecal immunochemical test (done on a stool sample and either tested at home or sent to lab recommended every year). All three tests reduce deaths from colon cancer with an absolute risk reduction of around 0.6%. Only colonoscopy can prevent some cancers by removing precancerous polyps.
Vaccines
There is no question that vaccines save lives by preventing some serious life threatening diseases, or making them less severe. Vaccines are especially important for infants and children, who are most at risk from the infectious diseases prevented by vaccines. Childhood vaccines prevent diptheria, whooping cough, tetanus, measles, mumps, rubella, polio, rotavirus (which causes severe diarrhea and dehydration in infants), hemophilus influenza (which caused joint infections and meningitis), hepatitis b, RSV (which causes severe respiratory illness), pneumonia caused by strep (the most common kind of bacterial pnuemonia), COVID (also for adults), meningitis, chicken pox, and HPV (the virus that causes cervical cancer in women).
Adults can get any of these vaccines, but also a vaccine to prevent shingles.
Bottom Line
Living in good health to past 100 depends on genetics, not lifestyle. Many things recommended by so called longevity experts do nothing to prolong life and may increase risk. There are a number of lifestyle changes including exercise, good nutrition, social connectedness, certain screening tests and vaccines that increase you chances of remaining healthy well into your eighties. The main cause of early death in the US is poverty, homelessness and systemic racism. Addressing these inequities is a lot more important than helping wealthy people try to live to 100.
We have all been told for years that the main dietary risk factor for heart disease and stroke is how much saturated fat we eat. We have also been told that eating foods high in cholesterol also increases risk of heart disease and stroke. Evidence is accumulating that consumption of saturated fat increases risk of heart disease and stroke little if at all. Since your body makes cholesterol itself, eating cholesterol rich foods has almost no effect on serum cholesterol. Other aspects of diet have a much greater effect on increasing the risk of heart disease and stroke. In this post I will summarize the evidence and spend some time discussing things we eat and drink that do substantially increase the risk of heart disease, stroke and other chronic diseases.
The Seven Country Study
The most famous study that led to the saturated fat hypothesis was carried out by Ancel Keys. The study started in 1956 and was published in 1978. He looked at the dietary patterns of 7 different countries. The countries included Finland, Greece, US, Italy, Yugoslavia, Netherlands and Japan. He found that saturated fat intake was correlated with increased risk of heart attack and stroke. The country with the lowest saturated fat intake was Crete in Italy, which also had the lowest incidence of heart disease and stroke of the 7 countries. The diet of Crete is the basis for the famous Mediterranean Diet.
Diets of free living humans are notoriously difficult to measure. Keys did his best to accurately determine diet. He had a subset of his subjects in each country weigh their food for a number of days, which is considered the gold standard for dietary studies. The problem with any population study like this is that populations in different countries differ in lots of other ways besides diet. Also diets are complex, so some other factor or factors in diet could account for the low heart disease incidence in Crete. Another problem was that diet was measured in Crete during Lent, when most people did not eat meat. All Keys could really say was that saturated fat intake was associated with heart disease, but he could not say that saturated fat caused heart disease.
People who adhered to the Mediterranean Diet did reduce their population risk of heart disease, but there is a lot more to the Mediterranean Diet than reduced saturated fats. It also includes little added sugar, lots of vegetables and fruit and mostly unprocessed foods. It is not clear that reduction in saturated fat is responsible for the health benefits of the Mediterranean Diet.
The Framingham Study
The next big population study was the Framingham Study. A large group of people in Framingham Massachusetts was followed over many years with surveys about diet, activity, smoking and laboratory measurements of total cholesterol, LDL, HDL and triglyerides among other measurements. Heart attacks, strokes, death from either of these things and death from any cause were recorded in the study group. This was the first large study that implicated cigarette smoking as a cause of cardiovascular disease and cancer. It was also found that the higher the total cholesterol and especially the higher the LDL (low density lipoprotein) the higher the risk of cardiovascular disease. It was also one of the first studies that showed that the higher the blood pressure, the greater the risk of cardiovascular disease. This was a tremendously important and well done study.
The Diet-Heart Hypothesis
The diet-heart hypothesis is that saturated fat is the main dietary cause of cardiovascular disease. It has been very influential over 60 years and is still promoted by the American Heart Association and many cardiologists. Here is the train of thought. The 7 country study implicated saturated fat as associated with cardiovascular disease. It has been found through multiple studies that saturated fat intake raises LDL (so called bad cholesterol). The Framingham study showed that increased LDL was a major risk factor for cardiovascular disease. Since saturated fat raises LDL, therefore saturated fat must cause cardiovascular disease.
That makes perfect sense, so many randomized trials were carried out to nail down the diet-heart hypothesis. Unfortunately, as is often the case with beautiful theories, further randomized trials did not consistently show the expected increase in heart disease from eating saturated fat. The other part of the hypothesis was that eating polyunsaturated fats would decrease the population risk of heart disease. That was based on the observation that consuming polyunsaturated fats decreased LDL levels. Randomized trials have generally failed to consistently show that eating polyunsaturated fats reduces the risk of cardiovascular disease.
Reduced Risk of Cardiovascular Disease in US
Heart disease was epidemic in the US, peaking in the 60’s. Since then, the incidence of heart disease in the US and most other developed countries has decreased by 60%! Scientists debate the cause for this decline. Although saturated fat consumption decreased some, Americans still eat much more saturated fat than the 5% of fat recommended by the American Heart Association. So the fact that we eat somewhat less saturated fat does not explain the remarkable decline in heart disease over the last 60 years. What else changed?
Cigarette Smoking
In the 1940’s half of all Americans said they smoked cigarettes. Smoking began to decline in the US in the 60’s and today only 11.5% of Americans smoke tobacco! This has to be a major factor in the decline of cardiovascular disease (and lung cancer).
High Blood Pressure
High blood pressure is a major risk factor for heart disease. The number of people with high blood pressure successfully controlled on medicine has more than doubled since 1960. This is clearly another major factor in the decline of cardiovascular disease
Trans Fats
The rise of trans fat consumption was an unintended consequence of the heart-diet hypothesis. Because animal fat (mostly saturated fat) was postulated to cause heart disease, the food industry started figuring out how to use vegetable oil to replace lard and butter, which were high in saturated fats. They needed something that would be solid, not liquid at room temperature. They discovered that if they partially hydrogenated vegetable oil, then it would be solid at room temperature and could substitute for lard and butter. They marketed these products as healthier because they were only partially saturated fats, not saturated fats. The medical establishment bought this story and recommended margarine as a substitute for butter and Crisco (the most successfully marketed shortening substitute) as healthier alternatives. I have been unable to find statistics on trans fat consumption in the US, but it was very large.
It turns out that consumption of trans fats markedly increased the risk of cardiovascular disease. For every 2% increase in the consumption of trans fats, heart disease increased by 23%. This is a shocking number! The consumption of trans fats certainly contributed to the epidemic of heart disease in the 50’s and 60’s. The FDA essentially banned the addition of trans fats to food in June of 1978. The elimination of trans fats is almost certainly another major factor in the decline of heart disease.
Interesterification
Since trans fats have been banned, food companies have come up with a new way to make vegetable oil solid and spreadable. It is called interesterification. It is complicated, but the simplest explanation is that it involves changing the arrangement of fatty acids on a glycerol backbone. These are fully hydrogenated fats, so are not trans fats. We know very little about how these new industrial fats affect human health, but the information we do have suggests that these new products may be just as bad for you as trans fats. You would do best to avoid them until we know more. More about how to do this later in this post.
Do we need to limit red meat consumption?
The main risk of consumption of any food is eating too much of it. It is total calorie intake that makes us fat, and being fat increases the risk of cardiovascular disease, diabetes and some cancers. Eating red meat by itself is very unlikely to increase your risk of heart disease as long as your total calorie intake is equal to the calories you burn up. So there is very little health risk to you in eating red meat, but there is a big risk to the environment. Cattle raising worldwide contributes about 16% of greenhouse gas emissions. Here is a link to a balanced discussion of greenhouse gas emissions from cattle raising: Livestock Don’t Contribute 14.5% of Global Greenhouse Gas Emissions.
The other thing to think about when consuming any meat product, including chicken is that almost all the meat you buy in the grocery store comes from giant factory farms, where animals are treated very inhumanely. That in itself is bad enough, but raising all those animals together increases risk of spreading disease to the people who eat them. Antibiotics are used in many factory farms to keep animals from getting sick. This contributes to the evolution of bacteria that are resistant to most antibiotics.
If you are not willing to give up eating meat entirely, try to find locally raised beef, pork and poultry. Farmer’s Markets are a good place to find meat from locally raised animals. It may be a little more expensive, but likely a lot safer.
What about eating fish?
If you are at high risk of cardiovascular disease or have cardiovascular disease then eating oily fish (salmon, sardines, anchovies, herring, mackerel, tuna, swordfish) twice a week reduces your risk of a heart attack by 50%. If you are at average risk, these fish don’t have unusual health benefits but if you like them, it’s fine to eat them. Because most of these fish contain some mercury they should probably be avoided by pregnant women and children. If you get canned tuna, get Pacific Island Tuna at Walmart. It is sustainably caught. Here is a link to an article from the Nature Conservancy about it: The Nature Conservancy. By the way taking fish oil is not nearly as good for you as eating fish.
Highly Processed Foods
There are convincing data that consumption of lots of highly processed foods leads to health concerns ranging from increased risk of obesity, high blood pressure, breast and colorectal cancer, to dying prematurely from all causes.These foods all also contain additives whose health effects have never been adequately tested. How do you recognize them? Just look at the label where the ingredients are listed. If there are more than two things you don’t recognize, put it back on the shelf. Here is an example of an ingredients list from a loaf of bread!
This is not bread you would want to eat! If you mostly stay out of the central aisles of the grocery store you will avoid most highly processed foods. Just be sure to look at the ingredients label before you buy anything.
It is all well and good for me to make these recommendations, but highly processed foods and factory farmed meat are cheap. People who are poor cannot afford to buy anything else. This is only one of the things that have led to the major health inequities that are present in this richest country in the world.
Foods that decrease risk of cardiovascular disease
Fiber
Increased dietary fiber has been shown to decrease risk of cardiovascular disease. This may well have to do with promoting a healthy microbiome in the intestine. Sources of fiber that promote growth of healthy gut bacteria are ones that contain inulin. The highest sources of inulin are leeks, asparagus, onions, wheat, garlic, chicory, oats, soybeans, and Jerusalem artichoke. Sourdough bread (no added sugar, honey, or high fructose corn syrup) is also a good source of fiber. Whole grains, fruits, nuts and vegetables are also good sources of fiber.
Fresh Fruits
Fresh fruits are a good source of fiber and also contain many beneficial nutrients including vitamins and antioxidants. Data from multiple studies show that eating fresh fruit daily reduces risk of cardiovascular disease.
Nuts
Eating a handful of nuts per day reduces your risk of heart disease by 20%. Peanuts are technically of legume, not a nut, but legumes reduce the risk of cardiovascular disease as well. Unsalted nuts are better for you than salted.
Whole grains
Whole grains are also a good source of fiber and other beneficial nutrients. Eating whole grains most days is associated with decreased obesity, diabetes and heart disease. Examples of whole grains are
Barley.
Bulgur, also called cracked wheat.
Farro.
Millet.
Quinoa.
Black rice.
Brown rice.
Red rice.
Wild rice.
Oatmeal.
Popcorn.
Whole-wheat flour.
Whole-grain breakfast cereals.
Whole-wheat bread, pasta or crackers.
Make sure to read the ingredients label for cereals and crackers. Don’t buy anything that has more than two ingredients you don’t recognize.
Fresh Vegetables
Fresh vegetables are also a good source of fiber. Sorry folks, but potato chips and french fries do not count as fresh vegetables! Once again eating fresh vegetables daily significantly lowers your risk of cardiovascular disease.
Bottom Line
Eating red meat and saturated fats does very little to increase your risk of heart disease, but it also does not reduce your risk. Raising livestock on factory farms causes significant harm to the environment and puts people at risk of infectious disease. Eating meat from locally raised animals is safer.
Eating high fiber foods, whole grains, nuts, fruits and vegetable does substantially reduce your risk of cardiovascular disease as well as cancer.
Eating highly processed foods, and this includes the new industrial fats made by interesterfication increases your risk of cardiovascular disease and cancer. The biggest risk of these is probably because they encourage people to eat more calories than they need and have almost certainly led to the epidemic of obesity.
The most concise recommendation for a healthy diet comes from author Michael Poulin: “Eat food (food is anything your grandmother would have recognized as food), mostly plants, not too much.”
All mammals, including humans have an innate response to perceived threat or stress. The more common name for it is the “flight or fight” response. Our remote ancestors faced many real threats. Let’s say for example one encountered a saber tooth tiger. As soon as he (or she) saw the tiger, several things happened. Epinephrine and norepinephrine were released, speeding up the heart rate in preparation for running away. A surge of cortisol was also released, which increased glucose in the bloodstream for fuel for muscles and the brain. Cortisol also increases mental alertness. Inflammatory molecules were released to promote wound healing should that be needed.
This kind of acute stress response is a good thing. People or animals with this kind of response were more likely to survive and reproduce. Once the acute threat was over, all the hormones and neurotransmitters quickly returned to their baseline levels.
In today’s world, threats from predators are not a problem for the vast majority of people. The threats we perceive are things like poor work conditions; experiencing discrimination, hate, or abuse; poverty; homelessness; divorce or other family discord; having little control over outcomes; feeling overwhelmed.
These are all things that produce the stress response, but unlike our remote ancestors, these threats are chronic. They are either lifelong or at least last a long time. Instead of returning to normal, the stress hormones and neurotransmitters stay elevated for long periods of time. A chronic stress response is definitely not a good thing!
Allostatic Load
The medical term for the acute stress response is called allostasis. Here is the definition of allostasis from Wikipedia: “Allostasis is the efficient regulation required to prepare the body to satisfy its needs before they arise by budgeting those needed resources such as oxygen, insulin etc., as opposed to homeostasis, in which the goal is a steady state.” Allostasis is an adaptive response to acute stress. Allostatic load on the other hand is the long-term result of failed allostasis, resulting in dysregulation (abnormal function) of multiple systems including the neuroendocrine, cardiovascular, immune, and metabolic systems.
Allostatic load is measured traditionally by 10 indicators of chronic stress. Primary indicators are the hormones and neurotransmitters released by stress. Secondary outcomes are measurements of the systemic effects of the primary indicators. All of these indicators are associated with the perception of stress. Below is a table showing the 10 indicators, how they are measured, and which body systems are affected. Here is a link to the full article from which this table comes: Allostatic Load: Importance, Markers, and Score Determination in Minority and Disparity Populations
Category
Marker
Functional purpose
Primary mediators
Dehydroepiandrosterone sulfate (DHEA), serum
Secreted by the adrenal glands. When high with stress it tends to lower cortisol and be protective in the stress response.
Cortisol, urinary
Integrated measure of 12-hour hypothalamic–pituitary–adrenal axis activity. Secreted by the adrenal glands. Has multiple effects in stress response.
Epinephrine, urinary
Integrated indices of 12-hour sympathetic nervous system activity. Sympathetic nervous system activation increases heart rate and blood pressure.
Norepinephrine, urinary
Secondary outcomes
Systolic blood pressure
Indices of cardiovascular activity and major risk factor for vascular disease
Index of long-term levels of metabolism and adipose (fat) tissue deposition. High value means fat around internal organs which increases inflammation and increases LDL (bad cholesterol) and triglycerides.
High-density lipoprotein cholesterol
Index of atherosclerotic risk protection. Low value increases risk of heart disease.
Total cholesterol
Index of long-term atherosclerotic risk
Hemoglobin A1C
Integrated measure of high blood sugar over 2–3 months
Each indicator that is a certain distance out of the normal range counts as one point. The score can range from zero to ten. The higher the score, the greater the risk of illness or death.
Other Indicators
Although the ten indicators were the ones described in the original papers about allostatic load, other indicators have been used as well.
Heart rate variability is the normal beat to beat variability in the heart rate. In a healthy heart there is slight variation in the timing of one heartbeat to the next. Chronic stress reduces or even eliminates this beat to beat variation.
High sensitivity C-reactive protein (CRP). This is a measure of systemic inflammation that can result from chronic stress.
How is the stress reaction triggered?
The stress reaction begins in the brain. Something in the environment is perceived in a part of the front of the brain called the prefrontal cortex. This is the executive decision maker in the brain. If the prefrontal cortex perceives something in the environment as a threat, then it sends messages to the limbic system (the part of the brain that is involved with emotions). It also sends messages to centers lower in the brain, especially the hypothalamus. The hypothalamus sends messages to the adrenal glands which secrete cortisone, norepinephrine and epinephrine. The hypothalamus secretes DHEA. Messages from the hypothalamus are also sent to the white blood cells which secrete inflammatory chemicals called cytokines. All of this prepares the body to deal with the perceived threat. Different people may perceive different things as a threat. It is the reaction to perceived threats that causes allostatic load. If another person experiences the same thing in the environment as not a threat, then there is no stress reaction.
Diseases associated with high allostatic load (high chronic stress)
A high allostatic load score is not disease in itself, but if chronic stress continues then disease in the cardiac, metabolic, neuroendocrine and immune system can occur. Here is a list of diseases associated with persistent high allostatic load.
Heart disease, primarily progressive blockage of the coronary arteries. This can lead to angina and/or heart attack. Congestive heart failure and arrhythmia like atrial fibrillation can also occur
Peripheral arterial disease. That is blockage in arteries in the legs and sometime fingers.
High blood pressure
Stroke
Autoimmune diseases like rheumatoid arthritis or lupus
Diabetes
Fibromyalgia
Chronic Fatigue Syndrome
Dementia or decreased cognitive function
Depression
PTSD
Cancer, particularly breast and ovarian cancer. The increase in cancer is probably related to decreased immune system function
Allostatic Load and Mortality
Many studies have shown that people with persistently hight allostatic load have about a 25% higher premature death rate than people with low allostatic load.
Disparities in Health Outcomes
The response to chronic stress (allostatic load) may explain some of the disparities we see in health outcomes. We know, for example that Adverse Childhood Events (ACE), which include things like abandonment and abuse, increase the risk of many chronic diseases in adulthood. Studies have shown that adults with a history of ACE have high allostatic load scores.
African Americans have higher incidence of many cancers, as well as poorer outcomes from those cancers. They also have worse outcomes from heart disease, high blood pressure and diabetes. While a good portion of these poorer outcomes are related to lack of access to health care, these disparities persist to some degree even in middle class and upper middle class African Americans. Almost all African Americans have experienced or still experience racism on a chronic basis. African Americans of all social classes have higher allostatic load scores than caucasians. Chronic stress and response to it may be the common denominator for these disparities as well as for health outcome disparities in other marginalized populations.
How to reduce allostatic load
There is typically a long time between the presence of indicators of allostatic load and illness and death caused by diseases associated with these indicators. That presents an opportunity to reduce allostatic load before the chronic stress response leads to illness and death. So how do we reduce allostatic load?
Some of the things that cause allostatic load can only be reduced by societal changes. Things like poverty, structural racism and homelessness cannot be decreased by individual effort. Even these causes, though, can respond to the mind body methods discussed below. On the other hand, if you don’t have enough to eat, have no home, or have a job that gives you no control of your life, it is not likely that you will have the energy or the will, or the financial means to do many of the mind body methods discussed below. We should not be distracted from working to decrease the inequities that are responsible for societal causes of chronic stress.
Mind-Body Medicine
Remember that an external threat is first received by the peripheral nervous system and transmitted to the pre-frontal cortex. In order to reduce allostatic load we can either reduce the threat perception in the prefrontal cortex (top down) or reduce the transmission of threat in the peripheral nerves (bottom up).
Top Down Treatments
Top down treatments start with intentional activity in the prefrontal cortex. The idea is to decrease activation of the limbic system and the hypothalamus. This can be accomplished by mindfulness meditation, hypnosis (including self hypnosis), mental imagery and progressive muscle relaxation. All of these techniques when done regularly have been found to decrease allostatic load indicators and to reduce the risk of stress related illnesses.
Bottom Up Treatments
Bottom up treatments decrease the threat transmission to the prefrontal cortex. They include yoga, Tai Chi, massage and biofeedback. These treatments have also been shown to decrease allostatic load and to reduce stress related illness.
Bottom up and top down are somewhat of an oversimplification. All of these treatments have some aspects of both top down and bottom up. Yoga, for example includes aspects of meditation. The same goes for Tai Chi. Biofeedback involves some attention from the prefrontal cortex. Massage also includes progressive muscle relaxation.
Bottom Line
The body’s reaction to a perceived threat includes a complex cascade of messages from the executive center in the prefrontal cortex to multiple body systems including the nervous system, the endocrine system, the cardiovascular system and the immune system. All of these things prepare the body to deal with the threat. As long as the threat is short term the stress response is very useful to the organism.
Perception of chronic stress leads to continuous secretion of all the stress hormones and inflammatory cytokines and this leads to dysfunction of multiple body systems and eventually to illness and death.
Mind body treatments, both top down and bottom up can reduce the allostatic load (chronic stress response) and reduce the risk of stress induced illness and death.
Many causes of chronic stress have to do with the structure of our society, such as poverty, homelessness and structural racism. Individual effort is not likely to ameliorate the effect of these causes of chronic stress. All of us should be working toward societal change to reduce chronic stress response in marginalized populations.
Although we talk about cancer as if it were one disease, it is actually many different diseases. Some are common, and some are rare. In this post I’m going to write about the five most common cancers in the United States. I will focus on incidence (how common they are in the population), risk factors for these cancers, and especially risk factors that can be reduced or eliminated. I will not talk about screening for cancer. That will be the subject for another post
Breast Cancer
Breast cancer is the most common cancer in the U.S. The incidence of breast cancer in the U.S. is 128 new cases per 100,00 women per year (men get breast cancer too, but at a much lower rate). That means that one tenth of one percent of women in the U.S get breast cancer every year. The population risk increases with age. The lifetime risk of developing breast cancer is 13 per cent, or about one in eight women. The majority of that risk is in women over the age of 65. Overall, 20% of women with breast cancer eventually die from it. That means the cure rate is 80%.
Things you can do to reduce your risk of getting breast cancer
Eat a high fiber diet with lots of vegetables and avoid lots of red meat, animal fat and processed foods. Studies have shown that this kind diet reduces the risk of getting breast cancer. Of course this kind of diet also reduces the risk of heart disease and stroke as well, as I have written about in previous posts.
Be physically active. Women who are not physically active have a higher risk of getting breast cancer. There are lots of ways to be physically active. Take at least one flight of stairs instead of taking the elevator. Park as far as you can from the store when you are shopping. Take some long walks in your neighborhood if that is safe where you live. If not, drive or take the bus to a nearby park to walk.
Maintain a healthy body weight. Older women who are overweight or have obesity have a higher risk of getting breast cancer than those at a healthy weight.
Don’t take hormones (if you can help it). If you do need hormones for menopausal symptoms, take estrogen only, not estrogen and progesterone and take it for less than 5 years if possible. Some forms of hormone replacement therapy (those that include both estrogen and progesterone) taken during menopause can raise risk for breast cancer when taken for more than five years. Certain oral contraceptives (birth control pills) also have been found to raise breast cancer risk.
Reproductive decisions. Have your first pregnancy before age 30 if possible, and breast feed for as long as is practical whatever age you have children. Having a first pregnancy after age 30, not breastfeeding, and never having a full-term pregnancy can raise breast cancer risk.
Don’t drink alcohol or have no more than one drink per day. Studies show that a woman’s risk for breast cancer increases with the more alcohol she drinks.
Don’t smoke, or quit if you do: Studies show that smoking cigarettes increases women’s risk for breast cancer
Risk Factors for Breast Cancer You Can’t Change
Getting older. The risk for breast cancer increases with age. Most breast cancers are diagnosed after age 50.
Genetic mutations. Women who have inherited changes (mutations) to certain genes, such as BRCA1 and BRCA2, are at higher risk of breast and ovarian cancer.
Reproductive history. Starting menstrual periods before age 12 and starting menopause after age 55 expose women to hormones longer, raising their risk of getting breast cancer.
Having dense breasts.Dense breasts have more connective tissue than fatty tissue, which can sometimes make it hard to see tumors on a mammogram. Women with dense breasts are more likely to get breast cancer.
Personal history of breast cancer or certain non-cancerous breast diseases. Women who have had breast cancer are more likely to get breast cancer a second time. Some non-cancerous breast diseases such as atypical hyperplasia or lobular carcinoma in situ are associated with a higher risk of getting breast cancer.
Family history of breast or ovarian cancer. A woman’s risk for breast cancer is higher if she has a mother, sister, or daughter (first-degree relative) or multiple family members on either her mother’s or father’s side of the family who have had breast or ovarian cancer. Having a first-degree male relative with breast cancer also raises a woman’s risk.
Previous treatment using radiation therapy. Women who had radiation therapy to the chest or breasts (for instance, treatment of Hodgkin’s lymphoma) before age 30 have a higher risk of getting breast cancer later in life.
Exposure to the drug diethylstilbestrol (DES). DES was given to some pregnant women in the United States between 1940 and 1971 to prevent miscarriage. Women who took DES, or whose mothers took DES while pregnant with them, have a higher risk of getting breast cancer.
Hormonal changes from night shift work: Some studies have shown that night shift work may increase the risk of breast cancer.
There is no point in worrying about things you can’t change, but if you are at increased risk for breast cancer from one or more of these risk factors, that might affect your decisions about whether and when to get screening mammograms. More about screening in another post.
Prostate Cancer
Prostate cancer is the second most common cancer in the U.S. It is the most common cancer in men. The incidence of prostate cancer in the U.S. is 113 per 100,00 men per year. That means, like breast cancer for women, about one tenth of one per cent of men will be diagnosed with prostate cancer every year. Like breast cancer, the population risk increases with age. The lifetime risk of developing prostate cancer for a male is 13 per cent or about 1 in 8. That is about the same lifetime risk risk for women for breast cancer. Overall 3.2% of men will eventually die from prostate cancer. That is a cure rate of 96.2%, much higher than for breast cancer. Part of the reason for the low death rate is that many prostate cancers grow so slowly that more men die with prostate cancer than from prostate cancer.
Risk Factors for Prostate Cancer
Things you can do to reduce your population risk of getting prostate cancer
Diet: Once again, a diet low in animal fat, high in unprocessed and high fiber foods, especially cruciferous vegetables like broccoli and cauliflower seem to be especially protective. Tomato based products, which are high in lycopene also seem to reduce population risk of prostate cancer. Soy intake as well as drinking coffee also seems to be protective.
Alcohol. Alcohol intake does not seem to be a a risk factor for prostate cancer. It is a risk factor for some other cancers that I will write about later.
Don’t smoke cigarettes (or marijuana). Smoking both cigarettes and marijuana increase the risk of prostate cancer
Maintain a normal body weight. Like for breast cancer, obesity increases the risk for prostate cancer.
Exercise. While exercise is good for you in lots of ways, it does not seem to decrease the population risk for prostate cancer.
Risk Factors for prostate cancer you can’t change
Age. Prostate cancer rarely occurs before the age of 40, but peaks between age 65 and 74. Autopsy studies have shown that low grade prostate cancer, never diagnosed during life, is extremely common as age increases. In men 71-80 it can be up to 73%! These low grade prostate cancers never caused any symptoms and the men in the autopsy studies died from something else.
Heredity. If family members have had prostate cancer, especially first degree relatives (father, grandfather) your population risk for prostate cancer is substantially increased
Race. Black men are more likely to get prostate cancer and also more aggressive prostate cancer.
Chemical exposure. Exposure to certain chemicals, especially the herbicide agent orange increase the population risk of prostate cancer.
Once again, there is no point in worrying about things you can’t change. Screening for prostate cancer is very controversial. More about that in another post.
Lung Cancer
Lung cancer is the third most common cancer in the U.S. The incidence of lung cancer is 52 per 100,000 per year, which translates to five one hundredths of 1 per cent of the U.S. population per year that will be diagnosed with lung cancer. The lifetime risk of lung cancer is about 6% of people in the U.S. Of those diagnosed with lung cancer, only 23% will live 5 years after diagnosis. That is a much lower cure rate than for breast cancer and prostate cancer.
Smoking. Smoking cigarettes or cigars or smoking a pipe are the biggest risk factor for lung cancer. People who quit smoking before age 40 have a 90% reduction in smoking related diseases including lung cancer. People who quit smoking by age 54 reduce their risk by two thirds. The risk of lung cancer is still somewhat increased for former smokers as compared to never smokers even 30 years after quitting smoking.
Second Hand Smoke. Breathing other smoker’s smoke also increases your risk of getting lung cancer by 20-30%.
Radon. Radon is the second leading cause of lung cancer after smoking. Radon is a naturally occurring gas that forms in rocks, soil, and water. It cannot be seen, tasted, or smelled. It can accumulate in buildings, especially basements. Homes can be tested for Radon and a simple ventilation fan can decrease radon to safe levels. If your house has not been tested for Radon, it should be. You can buy Radon test kits at a hardware store or on Amazon.
Asbestos Exposure. People who have been exposed to asbestos have an increased risk of lung cancer. Asbestos used to be used as insulation in buildings, but has been banned for years. Asbestos is still in some homes. It is of no risk to residents of those homes as long as it is not disturbed. The risk comes when houses that contain asbestos are torn down or re-modeled.
Other Workplace Exposures.
Other carcinogens (cancer-causing agents) found in some workplaces that can increase lung cancer risk include:
Radioactive ores such as uranium
Inhaled chemicals such as arsenic, beryllium, cadmium, silica, vinyl chloride, nickel compounds, chromium compounds, coal products, mustard gas, and chloromethyl ethers
People who have had radiation therapy to the chest for other cancers are at higher risk for lung cancer, particularly if they smoke. Examples include people who have been treated for Hodgkin disease or women who get chest radiation after a mastectomy for breast cancer. Women who have radiation therapy to the breast after a lumpectomy do not appear to have a higher than expected risk of lung cancer.
Air pollution: in cities, air pollution (especially near heavily trafficked roads) appears to raise the risk of lung cancer slightly. This risk is far less than the risk caused by smoking, but some researchers estimate that worldwide about 5% of all deaths from lung cancer may be due to outdoor air pollution.
Personal or family history of lung cancer
If you have had lung cancer, you have a higher risk of developing another lung cancer.
Brothers, sisters, and children of people who have had lung cancer may have a slightly higher risk of lung cancer themselves, especially if the relative was diagnosed at a younger age. It’s not clear how much of this risk might be due to shared genes among family members and how much might be from shared household exposures (such as tobacco smoke or radon).
Researchers have found that genetics seems to play a role in some families with a strong history of lung cancer.
Once again, there is no point in worrying about risk factors you cannot change. There is a screening test for lung cancer for people who are current or former smokers. More about that in another post.
Colorectal Cancer
Colorectal cancer is the fourth most common cancer in the U.S. The incidence of colorectal cancer is about 38 per 100,000 people per year in the U.S. This means that 4 one hundredths of one per cent of people in the U.S. get colorectal cancer every year. The lifetime risk of getting colorectal cancer is about 4% of people in the U.S. Overall, 35% of people who have colorectal cancer eventually die from it giving an overall cure rate of 65%. The risk of death from colorectal cancer is very dependent on the stage of cancer when it is diagnosed. If colorectal cancer is diagnosed when it is localized, the cure rate is 91%. If it is diagnosed when it has already spread to other parts of the body, the cure rate is 15%.
These are exactly the same modifiable risk factors for breast cancer and prostate cancer. Improving diet, maintaining a normal weight, limiting or eliminating alcohol consumption, and not smoking or quitting smoking decreases population risk of three different cancers.
Risk Factors you cannot change
Age. Almost all colorectal cancers occur after the age of 45 and the vast majority of these occur over the age of 50..
Because chance of cure of colorectal cancer is so much greater when diagnosed at an early stage, screening for colorectal cancer can make a big difference. More about this in another post.
Melanoma Skin Cancer
Melanoma of the skin is the 5th most common cancer in the U.S. It is necessary to specify melanoma of the skin, because melanoma can also occur in the retina of the eye or in any other organ that contains melanocytes (pigment cells). These non-skin melanomas are fortunately rare. The incidence of melanoma of the skin is about 23 per 100,000 people per year or 2 one hundredths of 1 per cent per year. Of those people who develop melanoma of the skin, 6.3% eventually die from it, giving a cure rate of 93.7%. The lifetime risk of getting melanoma is about 2 per cent of people in the U.S.
What do skin melanomas look like?
Warning Signs
a new spot on the skin or a spot that is changing in size, shape, or color.
a spot that looks different from all of the other spots on your skin (known as the ugly duckling sign).
The ABCDE rule.
A is for Asymmetry: One half of a mole or birthmark does not match the other.
B is for Border:The edges are irregular, ragged, notched, or blurred.
C is for Color:The color is not the same all over and may include different shades of brown or black, or sometimes with patches of pink, red, white, or blue.
D is for Diameter:The spot is larger than 6 millimeters across (about ¼ inch – the size of a pencil eraser), although melanomas can sometimes be smaller than this.
E is for Evolving: The mole is changing in size, shape, or color.
Exposure to ultraviolet (UV) rays is a major risk factor for most melanomas. Sunlight is the main source of UV rays. Tanning beds and sun lamps are also sources of UV rays.While UV rays make up only a very small portion of the sun’s rays, they are the main cause of the damaging effects of the sun on the skin. UV rays damage the DNA (genes) inside skin cells. Skin cancers can begin when this damage affects the DNA of genes that control skin cell growth.
The pattern and timing of the UV exposure may play a role in melanoma development. For example, melanoma on the trunk (chest and back) and legs has been linked to frequent sunburns (especially in childhood). This might also have something to do with the fact that these areas aren’t constantly exposed to UV light. Some evidence suggests that melanomas that start in these areas are different from those that start on the face, neck, and arms, where the sun exposure is more constant.
Sunscreen
High protection value sunscreens do prevent sunburn, but paradoxically, people who use high protection sunscreens have an increased risk of skin melanoma. Does that mean sunscreens cause melanoma? No, it means that people who use high protective value sunscreens and apply them frequently are more likely to purposely spend time in the sun (sun bathing). The increased ultraviolet exposure overwhelms the protective value of the sun screen. Avoiding sun bathing and using high protective sun screen when you are working outdoors, as well as wearing a hat and protective clothing is the best way to reduce your population risk of skin melanoma (as well as other types of skin cancers.
Be Vigilant
Be aware of the warning signs above. If you have a mole or a skin lesion that meets any of the warning sign criteria, it is worth a trip to the doctor to check it out.
Risk Factors you can’t do anything about
Moles
A mole (also known as a nevus) is a benign (non-cancerous) pigmented tumor. Babies are not usually born with moles; they often begin to appear in children and young adults.
Having many moles: Most moles will never cause any problems, but someone who has many moles is more likely to develop melanoma.
Atypical moles (dysplastic nevi): These moles look a little like normal moles but also have some features of melanoma. They are often larger than other moles and have an abnormal shape or color. (See Signs and Symptoms of Melanoma Skin Cancer for descriptions of how moles and melanomas look.) They can appear on skin that is exposed to the sun as well as skin that is usually covered, such as on the buttocks or scalp. Dysplastic nevi often run in families. A small percentage of dysplastic nevi may develop into melanomas. But most dysplastic nevi never become cancer, and many melanomas seem to arise without a pre-existing dysplastic nevus.
Dysplastic nevus syndrome (atypical mole syndrome): People with this inherited condition have many dysplastic nevi. If at least one close relative has had melanoma, this condition is referred to as familial atypical multiple mole and melanoma syndrome, or FAMMM. People with this condition have a very high lifetime risk of melanoma, so they need to have very thorough, regular skin exams by a dermatologist (a doctor who specializes in skin problems). Sometimes full body photos are taken to help the doctor recognize if moles are changing and growing. Many doctors recommend that these patients be taught to do monthly skin self-exams as well.
Congenital melanocytic nevi: Moles present at birth are called congenital melanocytic nevi. The lifetime risk of melanoma developing in congenital melanocytic nevi is estimated to be between 0 and 5%, depending on the size of the nevus. People with very large congenital nevi have a higher risk, while the risk is lower for those with small nevi. For example, the risk for melanoma is very low in congenital nevi smaller than the palm of the hand, while those that cover large portions of back and buttocks (“bathing trunk nevi”) have significantly higher risks
Lots of irregular or large moles. The chance of any single mole turning into cancer is very low. However, anyone with lots of irregular or large moles has an increased risk for melanoma.
Fair skin, freckling, and light hair
The risk of melanoma is much higher for whites than for African Americans. Whites with red or blond hair, blue or green eyes, or fair skin that freckles or burns easily are at increased risk.
Family history of melanoma
Your risk of melanoma is higher if one or more of your first-degree relatives (parents, brothers, sisters, or children) has had melanoma. Around 10% of all people with melanoma have a family history of the disease.
Personal history of melanoma or other skin cancers
A person who has already had melanoma has a higher risk of getting melanoma again. People who have had basal or squamous cell skin cancers are also at increased risk of getting melanoma.
Having a weakened immune system
A person’s immune system helps fight cancers of the skin and other organs. People with weakened immune systems (from certain diseases or medical treatments) are more likely to develop many types of skin cancer, including melanoma.
Being older
Melanoma is more likely to occur in older people, but it is also found in younger people. In fact, melanoma is one of the most common cancers in people younger than 30 (especially younger women). Melanoma that runs in families may occur at a younger age.
Being male
In the United States, men have a higher rate of melanoma than women, although this varies by age. Before age 50, the risk is higher for women; after age 50 the risk is higher in men.
Xeroderma pigmentosum
Xeroderma pigmentosum (XP) is a rare, inherited condition that affects skin cells’ ability to repair damage to their DNA. People with XP have a high risk of developing melanoma and other skin cancers when they are young, especially on sun-exposed areas of their skin.
Bottom Line
These five cancers account for half of the cancer diagnoses made every year in the U.S. There are other less common types of cancer, only a few of which have screening tests to detect them early. I will write about some of those cancers in my coming post on screening for cancer. While everyone worries about cancer, the majority of people in the U.S. will never get cancer. The lifetime overall population risk for a U.S.male of getting any kind of cancer other than skin cancer is 40%. For women, that lifetime risk is 39%. These risks average together people at high risk and people at low risk. Your population risk could be substantially lower (or higher) than this average risk.
SARS-COV-2 is an RNA virus which means it’s genetic code is RNA rather than DNA. The genetic code for SARS-COV-2 is a long chain made up of four different bases. We can think of the four bases as an alphabet that consists of only four letters. These “letters” are A (which stands for adenine), C (which stands for cytosine), U (which stands for uracil and G (which stands for guanine).
Normally SARS-COV-2 makes exact copies of itself inside a human cell and these copies go on to make new virus particles. Very rarely the RNA of the virus makes a mistake when copying itself. An A might be substituted for a G, for example. These mistakes are called mutations. Almost all of these mutations make the virus function less well and they quickly disappear. Once in a great while a mutation occurs that makes the virus work better. When this happens viruses with the mutation spread faster and if they make the virus much more infectious, then the virus with the mutation quickly replaces the old form of the virus without the mutation.
That is exactly what has happened with the Delta variant. It is a mutation that makes the SARS-COV-2 virus much more contagious. Instead of each infected person infecting around 2 others, the Delta variant mutation causes each infected person to infect 5 other people. Because it is so infectious it has spread very quickly and is now the dominant form of the virus in the United States. If you get COVID today, there is a very high probability that you are infected with the Delta variant. There therefore is no need to test any individual infected person for the Delta variant.
Fortunately although the Delta variant of SARS-COV-2 is much more contagious, it does not seem to cause any more serious disease than the old form of the virus, but having a lot more people infected means that a lot more people will get very sick and require hospitalization.
I have already had COVID. Am I protected against the Delta variant?
There is some protection, but probably not very much. Even if you have already had COVID you can get infected again with the Delta variant and you might be much sicker than you were the first time.
I have been fully vaccinated. How protected am I against the Delta variant?
All of the vaccines in the United State that have FDA emergency approval (Pfizer, Moderna and Johnson & Johnson) provide about 80% protection from infection with the Delta variant. That means that out of 100 fully vaccinated people exposed to the virus, 20 will likely get infected. Those twenty people will tend to have no or mild symptoms and will not need to be admitted to the hospital. Very rarely a fully vaccinated person will get very sick and might even die. Rarely means about 1 person out of 1000 fully vaccinated people are hospitalized for COVID and nine out of ten hospitalized patients recover.
Being fully vaccinated makes you much less likely to get infected with the Delta variant and if you do get infected you are likely to have no or very mild symptoms. Vaccination means you have 99.99% protection from severe COVID requiring hospitalization. If everyone wears a mask indoors, the rate of infection for vaccinated people approaches zero. Even if most people are not masking indoors (though they should be) vaccinated people should still wear masks indoors because if they are infected with the Delta variant, even if they have no or mild symptoms, they could still pass the virus on to others.
I am not vaccinated. What is my risk of getting infected with the Delta variant?
If you are exposed to an infected unmasked person indoors and you are not wearing a mask then your chance of infection with the Delta variant is close to 100%. If infected you have a 20% chance of being hospitalized and a 1% chance of dying. That means that of 100 unvaccinated people exposed to the virus almost all of them will get infected. Twenty of those people will be so sick that they have to be hospitalized and one will die. Wearing a mask indoors protects you a little bit, but if everyone wears a mask indoors, your chance of being infected is much less. Obviously, you can’t control what other people do, and in states with low vaccination rates, there are also many fewer people who mask indoors. Your best shot at protecting yourself from getting very sick and perhaps dying is to get vaccinated as soon as you can. In the meantime avoid closed indoor spaces, especially where people are talking loudly or singing. Always wear a mask indoors.
Hospitalization rates are very high in states and counties where vaccination rates are low. Hospitals in those states and counties are almost out of ICU beds and are short on staff to care for desperately ill people. That means that those hospitals may not be able to take care of people who have heart attacks, car accidents or other serious illnesses. Some of those people will die because care is delayed. Although these deaths are not directly caused by COVID, these deaths would not happen if hospitals were not overwhelmed with COVID patients. Therefore another reason to get vaccinated is to take some of the stress off hospital workers who are exhausted and burning out.
Do I need a booster shot if I have been fully immunized?
Good immunity from the vaccines lasts for at least 8 months and probably longer. There is some evidence that immunity from all of the vaccines starts to decrease after 8 to 9 months. Booster shots will be available in mid September, and people who had their second vaccine 8 months or more ago probably should get a booster.
Vaccine Side Effects
By far the most common side effects of all COVID vaccines are fatigue, headache, fever and sore arm. These side effects go away within 24 to 48 hours.
Myocarditis and Pericarditis
The Pfizer and Moderna vaccines rarely cause some heart inflammation. This happens in about 12 people per million vaccinated. It is always mild and almost never requires hospitalization. All cases so far have gone away on their own and there have been no deaths.
Central Vein Thrombosis
The Johnson & Johnson vaccine rarely causes blood clots in a central vein in the brain. This happens in about 7 people per million vaccinated. This is the rate for women under 50. Men and women over 50 have an even lower risk. This can cause death, but if recognized in time can be treated and cured.
To put this risk in perspective, your chance of dying every time you drive a car is about one in one hundred. Almost everyone who drives is willing to accept this level of risk, which is way higher than your risk of death or disability from any COVID vaccine
Vaccine Misinformation
COVID vaccines do not cause infertility in women or men. COVID vaccines do not cause or make you more susceptible to getting COVID. COVID vaccines do not change your DNA. COVID vaccines do not put microcomputers in your body. There have been no unsafe shortcuts in the development of any of the COVID vaccines in use in the United States.
Bottom Line
All COVID vaccines available in the United States are safe and effective. They markedly decrease the risk of infection with the Delta variant and while breakthrough infections do occur, they tend to have no or mild symptoms. Current vaccines give 99.99% protection against getting sick enough to need hospitalization. Severe vaccine side effects do occur but are exceedingly rare and all are curable. The risk of infection with the Delta variant in unvaccinated people is very high as is the risk of hospitalization.
Hope is in the air. Effective vaccines came sooner than anyone thought possible, and it is likely that the United States will reach herd immunity sometime in mid summer. That means that people will be able to gather again, travel on mass transit and airlines safely again, be able to hug our grandparents. This has been described as returning to normal. Many people seem to think that life will be just like it was before the pandemic. Nothing could be further from the truth.
Deaths
There are more than 500,000 families in the US who have lost loved ones to the pandemic. That is a staggering number and is in some ways incomprehensible to us. We have never experienced in our lifetimes death on this scale, not even in world wars. The numbers are so large that they begin to make us numb. We cannot allow that numbness to take over. One out of three people in the U.S know someone who has died from COVID-19. Each one of those 500,000 families lives with the existential reality that their loved ones are gone from their lives forever. They have holes in their hearts that will scar over with time (lots of time) but that will never disappear. Even if you believe in an afterlife, these families will live the rest of their lives with the knowledge that they will never see their loved ones again in this life. What makes these deaths even more traumatic for families is that their loved ones died alone. They could not be at the beside holding their hands. Those who got to say goodbye at all had to do it via FaceTime or Zoom. Nor is the death toll over. Over 1400 people died of COVID-19 yesterday.
These are our friends, our neighbors and it is our responsibility to do what we can to ease their suffering as best we can. Mostly that means just being there and listening to their stories. It is easy to turn away or to offer platitudes about healing. Seeing someone else suffer is painful, but we must not turn away. Instead of asking how we can help, we just need to help, to be there, to be present.
Sometimes poetry is the best way to truth. Over 400 years ago John Donne wrote a poem about how death affects a community. Bubonic plague (the Black Death) had decimated England with ongoing and recurring epidemics for years. We would do well to pay attention to his words today:
No Man is an Island No man is an island entire of itself; every man is a piece of the continent, a part of the main; if a clod be washed away by the sea, Europe is the less well as if a promontory were, as well as any manner of thy friends or of thine own were; any man’s death diminishes me, because I am involved in mankind. And therefore never send to know for whom the bell tolls; it tolls for thee.
Post-COVID Syndrome
Of those who have survived COVID-19, up to 30% have something called post-COVID syndrome. This occurs more frequently in women. It is characterized by shortness of breath, brain fog, episodes of rapid heartbeat with minimal exertion and severe fatigue. This can occur even when the symptoms of the acute COVID were mild. It is becoming clear that it affects hundreds of thousands of people who have had COVID. Many of these people are so sick that they are unable to work. This syndrome can last for months. There is an excellent article in The Atlantic that describes this syndrome and how devastating it can be.
PTSD among Health Care Workers
Health care workers have worked tirelessly to care for desperately ill people in hospitals. Three thousand of them have died from COVID-19 as a result. They have had to watch many of their patients die and have had to serve as the stand-ins for family who could not be there. They worked until they were exhausted and came back the next day to do it again. This is a recipe for PTSD and 1 in 4 of them are suffering from classic symptoms of PTSD. This is unfortunately the new normal for them.
The Unequal Economic Impact
Some of us have suffered very little economic impact from the pandemic. Low wage workers, who are disproportionally people of color have lost their jobs in large numbers. Many of them worked in the hard hit hospitality sector. These low wage workers are not likely to get their jobs back for 2-3 years. They have continuing food insecurity and are likely to become homeless in large numbers.
Our New Normal
Even with a successful vaccination campaign that frees us from our enforced physical isolation, many people will continue to suffer. It essential for those of who have escaped COVID-19 and who have avoided financial ruin to step up and help those who have and continue to suffer. We must contribute in every way we can both financially and by volunteering our time and expertise.
All of us have suffered from the pandemic in one way or another, even if we have escaped having COVID. As we emerge from our enforced isolation the experience of the past year should remind us that life is precious and transient and that our relationships with others are even more precious. Our political differences are small potatoes compared to this.
The severity of any disease, especially a new pathogen like SARS-COV-2 is important to measure, especially it’s ability to cause death, which is the ultimate measure of severity. There are two ways to measure mortality from any infection.
Fatility Infection Ratio (IFR)
The proportion of deaths among all infected individuals. To measure IFR one has to know accurately the total number of infections as well as all deaths caused by, the disease. In the midst of a pandemic, with testing variably available and deaths often occurring at home it is impossible to accurately measure IFR.
Case Fatality Rate (CFR)
The proportion of deaths among identified cases. In the early stages of the pandemic, most cases are identified by surveillance and often only the most severe cases are tested. This leads to wide variation in estimates of CFR ranging from 0.1% to as much as 25%.
In fact, it is only possible to accurately measure either one of these fatality rates in retrospect, long after the initial stages of the epidemic. The number of deaths attributed to COVID-19 is almost certainly an underestimate. On the other hand, the number of people who have been infected is also certainly an underestimate. People with mild or asymptomatic infection are unlikely to get tested.
Another problem is that fatality rates from COVID19 are not uniform. Certain groups of people have an increased risk of mortality from COVID-19, so mortality is not uniform across people who are infected.
Excess Mortality
One way to deal with the first problem is to look at excess total mortality rates compared to historical mortality rates. It is very likely that excess mortality during the pandemic reflects the impact on mortality of COVID-19. Even if all of these deaths are not directly attributable to COVID-19, some may reflect unavailability of care at hospitals overwhelmed by COVID patients.
Excess mortality statistics are available through the first 30 months of 2020, which takes us through July 25 of this year. Because of the delay in reporting of death certificates, data for August and September are incomplete. For the US as a whole, there were 207,000 excess deaths for the first 30 months of 2020. This figure suggests that we passed 200,000 deaths from COVID-19 by the end of July whereas the number of reported deaths from COVID-19 at the end of July was 150,000. This was clearly an underestimate. It is also clear from these excess mortality numbers that the mortality from COVID-19 is much higher than from influenza.
Here is a graph of weekly recorded deaths from all causes for the first 30 weeks of 2020. The dark line represent excess mortality for 2020. The gray lines underneath are death rates from the previous 5 years. The spike in the beginning of the top gray line represents the H1N1 influenza epidemic. You can clearly see that even this spike is dwarfed by the excess mortality for the first 30 months of 2020. Here is a link to the website which has these data
Mortality by race/ethnicity
Another way to look at mortality data is to look at mortality by race and ethnicity. The mortality rate for african americans from COVID-19 is twice as high as for non hispanic whites. For native americans the death rate is 1.4 times as high and for hispanics the death rate is 1.1 times as high. These increased death rates by race and ethnicity have nothing to do with genetics. People of color have all sorts of socioeconomic factors that increase their risk of underlying conditions as well as living in crowded housing that make social distancing difficult or impossible. Many have low wage jobs that increase risk of contact with multiple people.
Mortality by age
Risk of dying from COVID-19 increases dramatically with age. Taking age 18-29 as the reference group, here are data from the CDC.
30-39 Risk of death four times higher
40-49 Risk of death ten times higher
50-64 Risk of death thirty times higher
65-74 Risk of death 90 times higher
75-84 Risk of death 220 times higher
85+ Risk of death 630 times higher
Mortality by underlying condition
According to the CDC, 94% of COVID-19 deaths had at least one underlying health condition. These include obesity, chronic lung disease, diabetes, poorly controlled high blood pressure, asthma as well as conditions or medicines that suppress the immune system.
Bottom Line
Mortality from COVID-19 is complicated. Traditional measures of mortality are impossible to obtain in the midst of the pandemic. Excess mortality is the best way to assess the impact of COVID-19 on death rates. Measurements of mortality are also not uniform and are markedly increased in older people, people of color, and those with underlying conditions. Excess mortality statistics clearly demonstrate that the death rate caused directly or indirectly by COVID-19 far exceeds influenza epidemics in recent years. The only pandemic that had similar or worse mortality was the 1918 influenza epidemic.
