Science Update – Sept-Nov, 2008, including Thinking about Sex
I usually just review nutrition research in the two top nutrition research journals, the American Journal of Clinical Nutrition and the Journal of Nutrition. Since being elected to the top nutrition research organization in the world, the American Society of Nutrition, the legitimate nutrition researchers are aware that we do an awful job of informing the public about legitimate research news about nutrition, and Nutrition Investigator is my contribution to trying to inform concerned people around the world, like you, who I hope will inform others that there is legitimate research information.
The progress in nutrition research is so great that even the top research journals on earth, Science and Nature, now often publish nutrition research articles. I recently sent a note about the No Fours Diet, because of a recent theory explains why eating four legged animal meat may slowly cause chronic disease like cancer and heart attacks. Below are four more articles worth noting.
1) Why thinking about sex may extend your life! – On sabbatical in 2005, I was fortunate to work on the National Institute of Aging research on caloric restriction. Rhesus monkeys have a daily value of vitamin C equivalent to 3,000 mg per day for a human, while the human daily value is only 90 mg, and I wanted to learn why. Tragically, the reason appears to be that monkeys receive better care than humans. Thus I continue to draw attention to my own research that shows 500 mg of vitamin C twice a day is optimal for human health. While conducting that research, I also encountered research trying to identify biomarkers for human longevity – factors that indicate how much longer one will live, rather than how old a person at present. Two factors were identified. The tentative one was the level of vitamin C and E you maintain in your body. But there was one that was clearly established – how much you think about sex! Note it is not necessary to actually have a physical experience, just to think about it. This research is described more thoroughly on the research poster I presented at the Linus Pauling Conference in May, 2005.
But until November of this year, no one knew why that was the case. In Science 322: 865 (7 Nov 2008), the mechanism is starting to appear. Here are a few quotations if you cannot access the journal at your local library: “Genetic factors and reproductive and nutritional status influence aging…These studies have revealed important roles for reproduction, dietary (caloric) restriction, stress, and the hormone insulin in regulating aging (1-4). Recently, germline stem cells—those in the gonad that can renew and also differentiate into gametes—in the worm and fly have been shown to produce a signal that enhances aging, whereas somatic cells of the gonad produce a signal that retards aging…This coupling of reproduction and aging may have maximized the use of natural resources for reproduction during evolution.” The diagram in the figure illustrates how the gonads secrete three signaling molecules that affect the cells of our intestines. One inhibits the insulin receptor, one activates lipase which decreases fat storage increasing longevity, and one activates a receptor DAF-12 that enhances longevity.
So for a change, instead of worrying about what to eat, for good nutrition and healthy longevity, try thinking about sex!
2) AGING: Searching for the Secrets of the Super Old, Mitch Leslie, Science 26 September 2008 321: 1764-1765
“Supercentenarians, or people who’ve survived to at least age 110, are longevity champions…Although almost half of the supers had osteoporosis and almost 90% had cataracts, 41% of them either lived on their own or required only minimal help with tasks such as preparing food, dressing, and bathing. Cardiovascular disease, the leading killer in developed countries, was rare among supercentenarians–only 6% had suffered heart attacks and 13% reported strokes. Diabetes and Parkinson’s disease were also uncommon in the group, striking only 3% of the subjects each. Like centenarians, supercentenarians seem to be good at putting off the day when they become disabled, says Perls…A family connection doesn’t mean that only genes are responsible for supercentenarians’ great age, Perls cautions. Everything from diet to exercise habits can also run in families–the analysis can’t distinguish between genetic and environmental factors.”
3) Cholesterol Veers Off Script, Jennifer Couzin, Science 10 October 2008 322: 220-223
“Recent drug trials have produced surprising results; along with genetics research, these findings have put in question some long-held beliefs…
Cholesterol numbers are a mantra of medicine, and millions of us regularly supply a vial of blood to measure this waxy substance that circulates in the bloodstream. All cells need it to survive. But it also feeds plaques in the arteries that can break open, causing a heart attack. Controlling cholesterol is gospel in cardiovascular medicine; it guides treatment and sells billions of dollars’ worth of drugs. It has also been reinforced by a Hollywood-like story line: A villainous “bad” cholesterol clogs arteries, and a valiant “good” cholesterol clears them.
The cholesterol hypothesis “is like religion for some people,” says Harlan Krumholz, a cardiologist at Yale University. “They’ve been taught it in medical school. They’ve been taught it forever.”
But Krumholz and some others say that after many decades, the cholesterol story is turning out to be messier and more nuanced than previously believed…FDA was so confident of the link that, in approving lovastatin and five other statins that followed, it made an unusual departure: Instead of judging efficacy based on the drug’s ability to improve health or increase survival, it relied on the therapy’s ability to lower LDL…in rural China, LDL levels hover around 60 or 70, and heart disease is about 15 times lower than in the United States…The big shock, however, was that Vytorin’s middling artery protection was at odds with its superior LDL-lowering performance. The drug pulled LDL down from 210 or more without treatment to a respectable average of 141, substantially better than 192 for the statin alone. But that didn’t translate to healthier arteries…Vytorin was hammered in a second study called SEAS, which found that even though the drug lowered LDL, it did not help aortic stenosis, a disease that obstructs blood flow from the heart and can lead to heart failure. Results suggested it might also raise the risk of cancer.”
4) Genes and Weight Gain, Science 17 October 2008:Vol. 322. no. 5900, p. 341 “What are the factors that increase an individual’s risk of future weight gain? It has been hypothesized that obese individuals may have an underactive reward circuitry, which leads them to overeat in an effort to boost a sluggish dopamine reward system. Using brain imaging, Stice et al. (p. 449; cover) discovered a relationship between activation of the striatum and ingestion of a tasty calorific liquid compared with a neutral liquid that could differentiate between obese and non-obese individuals. This differential activation was accentuated in individuals bearing the A1 allele of the dopamine D2 receptor gene, which is associated with reduced dopamine transmission in the striatum. This relationship predicted an individual’s weight gain when measured a year later.”
5) And a final note from the Journal Cell, brought to my attention by Matt Watson who is doing research on Telomerase, the enzyme that controls telomeres, the ribbons on the end of our chromosomes that may control our physiological aging proess. This new research indicates that once we can extend our telomeres, a process possible using technology presently being developed, we may able to reduce the risk of many chronic diseases now associated with aging.
Telomerase delays aging, Cell, Vol 135, 14 November 2008, Pages 609-622 “Telomerase confers limitless proliferative potential to most human cells through its ability to elongate telomeres, the natural ends of chromosomes, which otherwise would undergo progressive attrition and eventually compromise cell viability. However, the role of telomerase in organismal aging has remained unaddressed,…These results demonstrate that constitutive expression of Tert provides antiaging activity in the context of a mammalian organism.”
