Doctor Perspectives on the Medical Headlines

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  • Fish oil and AD
  • Say "No" to aspirin / ibuprofen mix.
  • Battling AD - Step by Small Step.
  • Fish, the Ultimate Brainfood.
  • Breakthroughs on Arthritis Diseases.
  • Emphysema alternative
 

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antioxidants, juice, vegetables, fruits

The Antioxidant Controversy

The jury is still out, but food sources probably win over pills.

The controversy surrounding antioxidant supplements has soared to a new level. A review of studies published in a recent issue of the Journal of the American Medical Association says that taking certain anti­oxidants as supplements provides no health benefits and might even increase the risk of death. The report contradicted previous findings, angered the multi-billion-dollar supplement industry, and confused those who consume over-the-counter antioxidants every day. As many as 20 percent of Americans and Europeans take daily antioxidant supplements.

Major Study.

Now that a little time has passed since the study was published, it is time to take an objective look at the research, the fallout, and the practical implications for older adults. Researchers in Denmark conducted a “meta-analysis” of more than 60 previous studies involving 232,606 subjects on the effects of antioxidants. Antioxidants are thought to block the damaging effects of free radicals on arterial walls as well as damage to cells that could cause cancer, but the benefits have never been totally accepted by the medical community.

Connie W. Bales, PhD, RD

THE VIEW FROM DUKE

Connie W. Bales, PhD, RD, Associate Research Professor of Medicine, Division of Geriatric Medicine, DUMC; Associate Director, Geriatric Research, Education, and Clinical Center (GRECC), Durham VA Medical Center

“One strong conclusion emerges from the somewhat confusing published literature about nutritional supplements—it cannot be assumed that the benefits from a nutrient taken in supplement form will be equal to that observed when it is consumed from food sources. Yet another beta carotene study published in the March 2007 Archives of Ophthalmology has found that this nutrient, long known to benefit the eyes when consumed

The most alarming new finding was that beta-carotene, vitamin A, and vitamin E were associated with a seven percent, 16 percent, and four percent, respectively, increased risk of mortality. In the highest quality studies reviewed, antioxidant supplements overall were associated with a five percent higher risk of death. Furthermore, there was no evidence that any of the three antioxidants provided measurable health benefits. Vitamin C and selenium taken separately did not have a negative effect on mortality rates. The authors concluded that “prevention (of medical problems) by beta carotene, vitamin A, and vitamin E cannot be recommended.” But there is another side to this story.

Not So Fast.

While objections from the supplement industry were to be expected, there was an equally vigorous defense of antioxidants from physicians and nutritionists who do not have a vested interest in dietary supplements. UCLA Medical Center clinical dietitian, Dana Ellis, RD, says, “In the study, some people may have had a disease from which they were going to die anyway, whether or not they took a supplement. Also, a single vitamin supplement contains one compound. By eating a piece of fruit or vegetable that contains vitamin C, you may be getting additional compounds that have not yet been identified, all of which could have a protective effect on cells and tissues.” Many older adults take vitamins and minerals, including the ones considered in these studies, for reasons other than longevity. For example, vitamins A, E, and C, as well as selenium, are routinely recommended in hopes of preventing or delaying age-related macular degeneration.

Ellis warns about reading too much into this study. “Since the interpretation of the new study is still in question, it would be irresponsible to tell people not to take vitamin supplements. Vitamins and minerals are always better when taken in food rather than pills, but even this report hints that the evidence is at best unclear in terms of a detrimental effect.”

The Bottom Line.

If you are not taking antioxidant supplements and your physician gives you a clean bill of health, there is probably no reason to start. A well-balanced diet may be all you need, although older adults do tend to develop dietary deficiencies. Ask your doctor if you should take one or more supplements. Ellis and other experts say, however, that if you have been taking antioxidant supplements all along, continue to do so until there is more compelling evidence to stop. Stay tuned... DM

 

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