Gut Check

Over the past few weeks there has been a lot of media coverage on the new guidelines for mammograms and breast self exams. Analysis of scientific research indicates that mammograms can do more harm than good. This is not what anti-breast cancer crusaders like the Susan G. Komen Foundation want to hear. Women are worried and confused because they have been told that they must have mammograms to detect and prevent breast cancer. Now the scientists are saying that is not the case and that, in fact, they can be counter-productive.

For every women correctly diagnosed with cancer after a mammogram there are significantly more women who endure the trauma of a false positive reading. They have no disease but undergo what turn out to be needless breast biopsies where they run the risk of a lung puncture from a poorly-performed needle biopsy. Unless a woman has a family/genetic history of breast cancer, the odds of her getting it prior to age 70 are actually quite low.

No one wants to be the one to tell the average 40-year-old woman without a family history of breast cancer to stop getting mammograms and then find out 3 years later that she developed breast cancer. But, again, the odds of her developing it are low. The cancer foundations and some health professionals appear to be operating under the “better safe than sorry” mantra while ignoring the fact that false positives can also lead to a sorry situation.

In 2002, Gerd Gigerenzer, author of Calculated Risks: How to Know When Numbers Deceive You, pointed out that the general public and many medical professionals do not really understand statistics. This lack of understanding leads them to judge inaccurately the actual risks and benefits of health screenings.

According to Gigerenzer, the vast majority of physicians who participated in the research described in his book cannot accurately determine risks and benefits when these are presented in the form of probabilities. (e.g. There is a 25% risk reduction in death from breast cancer with mammography.) Only when the results are presented in the form of natural frequencies do the risks and benefits become clear. (e.g. 1000 women got mammograms each year for 10 years and 1000 women did not. At the end of 10 years, 3 women in the first group and 4 women in the second group died of breast cancer.) If we and our physicians cannot accurately determine risks and benefits when they are presented as probabilities, we could be unnecessarily risking our health. How many of the 997 women who got mammograms each year for 10 years also had false positives during that time? How many experienced the trauma, pain, and potential negative outcomes of the additional testing required to rectify that false positive?

Rather than relying on mammograms (and other types of screenings) to safeguard their health, it would be better for women in their 40s and 50s to actively employ measures that we know can help prevent cancer. These measures include eating plenty of richly-colored fruits and vegetables; eliminating dairy and other saturated fats; getting plenty of exercise; sleeping around 8 hours each night; and taking a minimum supplement of 1000 IU/day of vitamin D3. More vitamin D supplementation may be required to get the blood levels of 25 OHD to the optimal level of 50 ng/mL.

By following these preventive measures all women, even those with a family history of breast cancer, will reduce their odds of developing the disease. And those without a family history will be able to ignore their guts and go with their brains in accepting the scientific data which states that we in the United States have been over-using mammograms. Look at the natural frequency data. Mammograms haven’t been as much help as we thought. Eat right, exercise, sleep well, and take vitamin D. That’s where the science is.

Eat for Health: A Review

Dr. Joel Fuhrman (Eat for Health) is one of the major proponents of a predominantly vegetarian diet he calls nutritarian. At first blush, his diet is very similar to that which I have long promoted: eat lots of fruits, vegetables, and tree nuts while eliminating dairy and grain-based foods. Dr. Fuhrman also allows very limited amounts of eggs, fish/shellfish, and poultry, but would essentially eliminate red meat. It is at the level of protein intake that Dr. Fuhrman and Dr. Fuller differ. Dr. Fuhrman wants proteins to be essentially vegetable-based, while Dr. Fuller knows that humans also need animal-based proteins.

Both of us recognize that humans are primates and that chimpanzees are our closest living relatives. Therefore, we both look to the chimpanzee diet for guidelines as to what our ancient ancestors ate. However, Dr. Fuhrman seems to conflate the diet of the gorilla with that of the chimpanzee. He also ignores a major difference we have with our fellow apes and the implication that has for human diets: our much larger brains.

Gorillas eat a lot of leafy vegetation; they are vegetarians. Chimps eat very little leafy vegetation. The major components of the chimp diet are fruits and nuts, but they also eat as much animal-based protein as they can find: ants, termites, eggs, monkeys, bush pigs, etc. Dr. Fuhrman combines the gorilla’s leafy diet with the chimp’s fruits and nuts and concludes that this is the proper diet for humans. In the wild, generally the only time chimps eat leaves is when they eat meat (except for certain unpalatable leaves eaten to remove intestinal parasites). Chimps and humans do not have the same ability that gorillas have to process large quantities of leafy vegetation through their guts.

Archaeological evidence shows that hominin (humans and their ancient ancestors) brains did not begin to enlarge until animal-based protein (primarily fish/shellfish and water fowl eggs) became a larger component of the diet. These foods are excellent sources of omega-3 fatty acids, necessary for proper brain growth, development, and function. Some plant-based foods such as tree nuts and flax seeds do provide omega-3 fatty acids, but research shows that these are not a good source: humans (and other mammals) cannot efficiently convert the plant-based fatty acids into the forms required for use in the brain. With the development of agriculture and an increasing reliance on plants in human diets, the size of human brains has actually decreased over the past 10,000 years.

In chapter 13 of Eat for Health, Dr. Fuhrman has an entire section inveighing against eating fish and shellfish because of mercury contamination. Mercury is a problem in large, long-lived fish. However, it is not a problem in shrimp and sardines, and other small, short-lived varieties. Is it worth relegating fish and shellfish to a very minor part of your diet if it also means that you are not providing your brain with enough omega-3 fatty acids?

Overall, Dr. Fuhrman’s book is full of good advice for those who are overweight and have chronic health problems. However, his nutritarian program is too close to that of a vegetarian/vegan if you want to have an optimally functioning brain. A few modifications will bring Dr. Fuhrman’s plan into line with Dr. Fuller’s Premier Nutrition Plan [http://www.anthrohealth.net/AHNews%20V6N7.htm]: a plan that keeps you healthy and brainy.