Back to the Blogosphere

Hi folks–haven’t posted since late 2009, its been a busy couple of years. I’ve been involved in a lot of projects, speaking, writing, and consulting for other physicians about their patients.  I’ve been involved in some new areas of study, one of which is telomere science (subject of the Nobel Prize for Medicine in 2009), and which I think is potentially  one of the most significant biological discoveries, with very immediate applications for human health, and especially for healthy aging–something of great personal interest to me as I find myself in my mid 60s.

The length of our telomeres–the little caps that protect the end of our chromosomes, is what allows our stem cells to continue to populate the 50-100 trillion cells that make up each of our bodies. How we live, in terms of our nutrition, our environment, our physical activity levels, how much stress we’re under, and how we manage it, and to a minor extent, our genetic heritage, all influence how rapidly our telomere’s shorten. Ground breaking research by Maria Blasco in Spain, and many others, have indicated that the % of our cells with critically short telomeres is an excellent indicator of our risk for cancer and other degenerative diseases, as well as our likely health span and lifespan. I’ll have a lot more to say about this emerging field over the next few months and years.  Its good to be back!

Vitamin D may be the MOST important vitamin

Evidence that vitamin D may be the MOST important vitamin continues to mount. Although epidemiological studies such as this one (link) don’t prove cause and effect, the sheer number of such associations are suggesting that one of the most important things you can do for your health is make sure that you have a 25-hydroxy vitamin D level in the neighborhood of 50 ng/ml.

A new study in the Journal of Nutrition research showed:

Higher vitamin D levels associated with increased survival among older women over a 6 year period

Vitamin D deficiency is associated with osteoporosis, poor muscle strength, falls, and fractures. The relationship between serum vitamin D concentrations and mortality in older community-dwelling women has not been well characterized. We hypothesized that women with lower 25-hydroxyvitamin D (25[OH]D) concentrations were at higher risk of mortality. We examined the association between serum 25[OH]D concentrations and all-cause mortality in a prospective, population-based study of 714 community-dwelling women, aged 70 to 79 years, the Women’s Health and Aging Studies I and II in Baltimore, Md. The studies were originally designed to evaluate the causes and course of physical disability in older women living in the community. Vital status was determined through follow-up interviews and matching with the National Death Index. During a median of 72 months of follow-up, 100 (14%) of 714 women died. Women in the lowest quartile of 25(OH)D (<15.3 ng/mL or 38.2 nmol/L) were at higher risk of death (hazards ratio, 2.45; 95% confidence interval, 1.12-5.36; P = .02) compared to women in the highest quartile (>27.0 ng/mL or 67.4 nmol/L) of 25(OH)D in a multivariate Cox proportional hazards model adjusting for demographics, season, and conventional risk factors. Older community-dwelling women with low 25(OH)D levels are at an increased risk of death.

Mercury not a problem in fish oil products

News reports are routinely talking about the problem of mercury in fish.

WASHINGTON – Mercury contamination was found in every fish tested at nearly 300 streams across the country in the most comprehensive look at the spread of the toxic element in streams and rivers.

All fish had traces of contamination, and about a quarter had mercury levels exceeding what the Environmental Protection Agency says is safe for people eating average amounts of fish.

Why do “they” never advise people to take fish oil (DHA and EPA) supplements? Seems like a no brainer to me….. Even without the extra purification step of molecular distillation (which should be used to remove PCBs, dioxins, and other fat soluble environmental contaminants to produce a high quality fish oil), the mercury stays in the fish protein. There is essentially no mercury in any (even low quality) fish oil products. Seems like this ought to be better known…..

All fish had traces of contamination, and about a quarter had mercury levels exceeding what the Environmental Protection Agency says is safe for people eating average amounts of fish.

Vitamin E, C and Exercise

A question of balance… and prejudice?  Recent publication of a research article from Germany has created lots more controversy around antioxidant supplements, though vitamin C and vitamin E were the only compounds studied, and there are a great many more antioxidants both in foods and in supplements that have not been looked at in this context.

The article, published in the on-line version of Proceedings of the National Academy of Sciences (PNAS) http://www.pnas.org/content/early/2009/05/11/0903485106 showed that 500 mg of vitamin C twice daily and 400 IU of d-alpha tocopherol (1 of the 8 forms of the vitamin E complex) taken once daily by 20 young healthy men who performed supervised exercise for 85 minutes Monday thru Friday for 4 weeks, decreased the beneficial effects that this exercise program had on insulin sensitivity in the 20 unsupplemented men (control group). What this study appears to have discovered is that the oxygen free radicals produced by exercise produce beneficial effects on glucose metabolism, and may help decrease development of diabetes. However, the title of the article “Antioxidants prevent health-promoting effects of physical exercise in humans” overstates the case quite a bit, since their findings related ONLY to insulin sensitivity, and did not at all investigate the other known benefits of exercise, such as improving cardiovascular function, immune response, stress handling, mood, cognitive function, etc. etc. There was also no detriment shown in the supplemented group

Antioxidant vitamins such as vitamin C and E are different from many of the other antioxidants found in foods, herbs, spices, and teas, in that they can become free radicals themselves, if the diet is low in antioxidants and the individuals are under high oxidative stress. The “burst” of oxygen free radicals associated with an hour of exercise are quite different from the continuous barrage of free radicals associated with smoking for instance. So this study tells us only about the effect of 2 specific vitamin antioxidants, in a group of healthy young men, in terms of markers of insulin sensitivity, 1 of many known positive benefits of exercise.

 

This is not to minimize the importance of these findings, but simply to put them in context. Unfortunately, a controversy loving and science undereducated press will generalize and draw unwarranted conclusions, and the anti-supplement folks will point and say, see we told you so—supplements are no good….

 

It is important to document that at least in this context, the oxygen free radicals generated by an hour of intensive exercise have some beneficial effects that we would be better off not to block. We don’t know if other antioxidants such as co-q-10, alpha lipoic acid, OPCs, and other polyphenolic compounds would have similar effects or not. We also don’t know if a high antioxidant diet vs a low antioxidant diet has impact on the system they studied (diet is a major confounding influence on any studies of antioxidant supplements, and notoriously difficult to control for). But its probably the case that if you’re a young healthy man who exercises, or someone with risk factors for metabolic syndrome or diabetes who exercises, its probably best not to take vitamins C and E along with your exercise.

 

In biology there is always a question of balance. Its almost always possible to have too much of a good thing, whether that be oxygen free radicals or antioxidants—having the RIGHT AMOUNT is key, which probably varies with age, sex, state of health, environment, diet, level of physical activity, etc. I would predict that if the investigators studied antioxidants (optimally a much larger number in much smaller amounts, because that is how nutrients work) in people training for marathons and triathlons, where the oxidative stress is much greater, they would find a net BENEFIT for antioxidants supplements. My rule of thumb in 35 years of experience prescribing and formulating nutritional supplements has been to use many nutrients together, and avoid megadoses of any one, as that is most likely to create imbalances. My hope is that before too many more decades scientists will develop a model to study nutritional supplements in humans as networks of many interacting compounds that support and supplement the diet to support health, rather than as a few compounds in large doses and in isolation.

 

Below are some quotes from other experts that illustrate the points I’m making (borrowed from www.nutraingredients.com)

The design of randomized clinical trials to study isolated nutrient factors, following the drug- or evidence-based model in general has received much criticism.

Andrew Shao, PhD, vice president of scientific & regulatory affairs for the Council for Responsible Nutrition (CRN), a trade association, said: “The current drug-based approach used in randomized clinical trials may not be the best approach to assess the health benefits of antioxidants, or other nutrients for that matter, and that researchers need to rethink how to design and execute such trials.”

“I do think more clinical trials are needed for antioxidants, but it is critical that they are designed and conducted to truly test the question(s) of interest, with the results interpreted and communicated appropriately,” added Dr Shao.

Jeff Blumberg, professor of nutrition science and policy at Tufts University said: “I think that when we look at  the idea of a single gold standard, like the randomized clinical trial, for evaluating nutrients, foods and diets, it  just doesn’t work.

“Sometimes it’s useful for answering for some very specific questions, but I think at other times we must go and use the approach that we have been using for the last generation or two, of looking at all of the research strategies and the information they can give us, from basic research using cell cultures and animal models, from clinical experience looking at how patients respond in the clinic, to observational studies of large populations followed for long times consuming different types of diets, as well as the intervention clinical trials.”

Understanding antioxidants

The criticisms of the drug-model for testing nutrients highlight fundamental issues with the understanding of antioxidants, and nutrients in general. Professor Blumberg added that it was important to understand how nutrients work.

“When we look at nutrients, nutrients are distributed throughout the body. Essential nutrients like vitamins and minerals have to be in every cell in every tissue in our body,” he said. “But in fact the body concentrates those nutrients in higher amounts in some tissues and in lower amounts in other tissues, it uses them in combination with other nutrients. They are designed in a system of synergies and networks.”