Recently you may have seen headlines like “Vitamin E slows decline in patients with mild Alzheimer’s” or “There’s still no cure for Alzheimer’s disease, but the latest hope for slowing its progression is already on drugstore shelves.” They were referring to an article in the January 1, 2014 issue of the Journal of the American Medical Association (JAMA) announcing the results of the TEAM-AD VA Cooperative Randomized Trial of vitamin E and memantine (Namenda) for Alzheimer’s disease (AD).
The study attracted a lot of media attention. Most of the news reports I have seen were accurate and cautious, explaining the nuances of the study rather than suggesting that everyone should run out and buy vitamin E; but I wouldn’t be surprised to learn that a lot of readers ignored the fine print and did just that. It would be interesting to track sales of vitamin E and see if there was a bump following the publicity.
We know of no treatment that will delay, prevent or cure Alzheimer’s disease, or that affects the underlying disease process. It’s a tragic, frustrating disease that takes away the very things that make us who we are: memory and personality. It is affecting more and more people as the numbers of elderly increase. Available prescription medications are only modestly effective in slowing functional decline and delaying the need for institutionalization. They are expensive, they don’t help everyone, and when they do help, they only help for a limited time. It is very exciting to think an inexpensive vitamin could help patients with mild to moderate AD, but we must resist the temptation to read too much into this study. (more…)
Multivitamin supplementation has been getting a rough ride in the literature, as evidence emerges that routine supplementation for most is, at best, unnecessary. Some individual vitamins are earning their own unattractive risk/benefit profiles: Products like folic acid, calcium, and beta-carotene all seem inadvisable for routine supplementation in the absence of deficiency or medical indication. Vitamin E, already on the watch list, looks increasingly problematic, with data recently published confirming the suspected association of supplementation with an elevated risk of prostate cancer.
Reading through the vitamin posts here at SBM, one issue comes through repeatedly: The danger of assuming therapeutic benefits in the absence of confirmatory evidence. Vitamin supplement have the patina of safety and of health, a feature that’s reinforced when you purchase them: You don’t need a prescription, you don’t get counseled on their use, and there isn’t a long list of frightening potential side effects to accompany the product. You can pull a bottle off the shelf, and take any dose you want. After all, how harmful can vitamins be when you can buy 5 pounds of vitamin C at a time, or vitamin E capsules in a 1000-pack? But the research signals seem to be getting stronger, and most are pointing in the same direction: what we though we knew about antioxidants was based on simplistic hypotheses about nutrition and health. And while we thought we were doing ourselves good with antioxidant supplements, we may have been doing harm. (more…)
One of the recurrent themes of science-based medicine is that any medical intervention that can plausibly cause physiological benefit can also plausibly cause physiological harm. There is no such thing as “it can’t hurt.” Sometimes the risk may be minuscule – but we should never assume that it is zero. Being “natural” or “holistic” or being blessed with some other alleged marketable virtue does not affect the risk vs benefit calculation of an intervention.
Vitamins are an excellent example. There is widespread sentiment that vitamins are harmless, and that supplementing with vitamins is therefore a no risk-possible benefit scenario. It is certainly reasonable to conclude from the evidence that vitamins (at usual supplemental levels) are low risk, compared to many other types of medical interventions. High doses, or megadoses, of vitamins, however, risk toxicity and this risk increases with the dose.
But even at sub-toxic doses vitamins should not be assumed to be risk free. This is especially true when we take a public health perspective – what is the net effect of large scale supplementation on the population? A new meta-analysis looking at the net effects of Vitamin E supplementation on stroke risk reinforces this caution.