Several years ago, Professor Ajit Varki of the University of California, San Diego discovered a molecule called Neu5Gc that appears in the tissues of every mammal except humans (Proceedings of the National Academy of Sciences, September 29, 2003). Now he has put together the pieces of a puzzle that may explain why humans evolved with large brains and why, if we want to live into old age, we should probably avoid eating meat from any other mammals (Science, October 31, 2008).
His theory depends on evolution. Living creatures on earth started as one-celled organisms, progressed to 2 cells, and eventually to fish and birds. A mutation occurred in progressing to mammals, who developed the gene to make Neu5Gc. Mammals progressed to apes and Neanderthals, and as humans evolved, Neu5Gc added a single oxygen atom to become a different molecule called Neu5Ac. So Neu5Gc is found in all mammals and their milks except humans. It is not in fish or birds. Interestingly, the Neu5Ac molecule explains why humans are the only mammal to suffer from malaria. The malaria parasite cannot enter a cell until it grabs onto the Neu5Ac on the surface of human cells.
Many epidemiological studies show that people who eat red meat are at increased risk for heart attacks, strokes, at least 17 different cancers, diabetes, autoimmune diseases, arthritis and asthma. Scientists have blamed saturated fats or burnt fats, but this does not explain why red meat is linked to all of these diseases while poultry, fish or saturated fats from plants are not.
Dr. Varki proposes another theory. When humans ingest the flesh or milk of any mammal, they absorb Neu5Gc and treat it the same way as an invading germ, so they make antibodies against it. This turns on their immunity and keeps it active so it eventually attacks the host itself, the human body. This is called chronic inflammation, which can lead to heart attacks, strokes, cancers and so forth.
Since humans cannot make Neu5Gc, any amount found in human cells come from the mammals that they have eaten. Neu5Gc is found in high levels in tumors, with the highest levels in metastasizing tumors. In our food supply, Dr. Varki found very high levels of Neu5Gc in beef, pork, lamb and goat, and moderately high amounts in milk and cheese. Low levels are found in turkey, duck, chicken and eggs; and negligible amounts occur in plants and seafood.
I stopped eating meat many years ago, and this report makes me even more convinced that it should be avoided. I eat lots of fruits, vegetables, whole grains, beans and nuts, as well as fish and shellfish. Eggs, long thought to be a harmful high- cholesterol food, now appear to be a healthful dietary staple. While poultry appears to be a healthful food according to Dr. Varki’s theory, I still do not eat it. I do not drink milk and now plan to limit cheese as well.
Dear Dr. Mirkin: What time of day should blood pressure be measured?
If you have your own blood pressure cuff, most doctors recommend using it in the evening, just before you go to sleep. More than 91 percent of Americans can expect to develop high blood pressure which markedly increases risk for heart attacks, strokes, and kidney damage. However, not all people with hypertension suffer premature death from these diseases. Those whose blood pressure does not drop in the early evening and rises too high in the early morning are the ones most likely to suffer premature death.
Blood pressure usually decreases during sleep and rises on awakening. It can also spike with increased activity, exercise, and external stimuli such as taking in caffeine or salty foods. Therefore, it drops to its lowest levels in the early evening just before you go to bed and surges in the early morning. Those who take mid-day siestas also benefit from a mid-day drop in high blood pressure. The early-morning surge in blood pressure increases a susceptible person’s chances of getting a heart attack or stroke at that time.
You are at high risk for heart attacks, strokes and complications of diabetes if your systolic (heart contraction) blood pressure does not drop below 120 just before you go to bed. (It often drops below 100 in normal people).
Dear Dr. Mirkin: Will taking coenzyme Q10 help to prevent the muscle pain caused by taking statin pills to lower high cholesterol?
Probably not. Two of three recent placebo-controlled studies show that coenzyme Q10 it does not prevent muscle pains (Current Opinion in Lipidology, December 2008). We do not know how statin pills cause muscle pain. We do know that statins reduce coenzyme Q10 levels in the bloodstream and taking coenzyme Q10 pills increases Q10 blood levels. However, of five studies of people taking coenzyme Q10, one found an increase, one a decrease, and three found no difference in the muscle level of coenzyme Q10. I could find no studies that show that statins affect mitochondrial function, where Q10 is active.
Sports medicine doctor, fitness guru and long-time radio host Gabe Mirkin, M.D., and his wife, nutritionist Diana Mirkin bring you news and tips for your healthful lifestyle. A practicing physician for 50 years more
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