March 18, 2014

More Bad News for Multivitamins

I’ve written periodically about the increasing evidence that multivitamins waste money, don’t really make a difference, and might even cause harm.

Now, results of three more studies – published in a recent edition of the journal Annals of Internal Medicine -- reinforce those conclusions.

No Benefit to Cognitive Health
First, Dr. Francine Grodstein from the Harvard School of Public Health, with colleagues, examined data from the Physicians Health Study II. Nearly 6,000 male doctors – all 65 or older – took either a Centrum Silver multivitamin or a placebo every day for twelve years. At intervals, researchers tested their subjects’ memory and cognitive function.

At the end of this study, researchers concluded: “In male physicians 65 years or older, long-term use of a daily multivitamin did not provide cognitive benefits.”

On the positive side, the data showed that risk of cancer dropped by 8 percent, and cataracts by 9 percent, for the men who took the multivitamin.

The report’s authors also noted that this particular study involved men only, and men who were generally in good health and well-nourished to begin with. It might be useful, the report suggested, to conduct the same exercise on a population not as well fed: 
This is of particular interest in an aging population because older persons are often at risk for nutritional deficiencies due to reduced micronutrient intake, altered absorption, and the metabolic requirements of vitamins.

No Benefit Against Recurring Heart Attacks
In another study, researchers recruited 1,708 people—average age 65 -- who had suffered heart attacks at least six months before (average interval between heart attack and study commencement was 4.6 years). Participants were randomly assigned to receive either a high-dose multivitamin and multimineral mixture, or a placebo.

Like all studies, this one had its flaws. Subject were required to take lots of pills, and many of the subjects withdrew early from the study or acknowledged non-compliance with the pill regimen.

Nonetheless, after about four years, there was no significant difference between the two groups in recurring heart attacks, chest pain, hospitalization, stroke, or early death.

No Meaningful Benefit Against Cancer and Heart Disease
The third report reviewed existing data from 27 different studies – which involved over 450,000 people – on the efficacy of vitamin and mineral supplements.

Conducted for the U.S. Preventive Services Task Force, this study revealed no benefit from supplements against heart disease, minimal benefit against cancer, and no evidence that supplements delay death from any cause.

Dr. Eliseo Guallar, professor of epidemiology at the Johns Hopkins School of Public Health, wrote in the summary: 
We believe it’s clear that vitamins are not working…. The probability of a meaningful effect is so small that it’s not worth doing study after study and spending research dollars on these questions.

The Industry Reacts
As we might expect, response from the supplement industry to the editorial in the journal Annals of Internal Medicine has been swift and sharp. After all, gigantic profits are at stake in the multi-billion dollar industry.

Wrote Steve Mister, president and CEO of the Council for Responsible Nutrition – which represents the supplement industry:
The editorial demonstrates a close-minded, one-sided approach that attempts to dismiss even the proven benefits of vitamins and minerals. It’s a shame for consumers that the authors refuse to recognize the real-life need for vitamin and mineral supplementation, living in a fairy-tale world that makes the inaccurate assumption that we’re all eating healthy diets and getting everything we need from food alone.

And Still We Buy
Estimates suggest that 42 percent of all Americans used multivitamins or other dietary supplements between 1988 and 1994. That percent rose to 53 between 2003-2006, and indications suggests the number continues to rise in spite of scientific studies showing no meaningful health benefit.

“It would be great if all dietary problems could be solved with a pill,” wrote editorial co-author Guallar. “Unfortunately, that’s not the case.”

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Here's the editorial -- titled "Enough Is Enough: Stop Wasting Money on Vitamin and Mineral Supplements" -- from the journal Annals of Internal Medicine. This link also provides details of the three studies mentioned above.

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