A new study published today in JAMA (Journal of the American Medical Association) found that “taking a daily multivitamin did not reduce major cardiovascular events” in middle-aged and older, healthy, predominantly-white male physicians, a population which “may have limited generalizability” according to the study authors.
The multivitamin and cardiovascular disease arm of the Physicians’ Health Study (PHS) II, a large-scale, randomized, double-blind, placebo-controlled trial (RCT) to study the long-term effects of a multivitamin on the prevention of chronic disease, was conducted by researchers at Brigham and Women’s Hospital and Harvard Medical School and will be presented today at the American Heart Association’s Scientific Sessions 2012. PHS II studied nearly 15,000 male U.S. physicians aged 50 years and older for over a decade.
According to the Council for Responsible Nutrition (CRN), the leading trade association for the dietary supplement industry, the conclusion of this arm of the PHS II is not all together surprising. Consumers should not expect a multivitamin to do everything from filling nutrient gaps to preventing a whole host of diseases in otherwise healthy individuals. “We’re not surprised by these results, but they don’t discount the many other benefits that multivitamins provide, including filling nutrient gaps, helping prevent neural tube birth defects, and serving in combination with other healthy habits as a basic and affordable insurance policy for overall wellness,” said Duffy MacKay, N.D., vice president, scientific and regulatory affairs, CRN. “Even though two weeks ago this same study demonstrated a modest but significant reduction in total cancer risk in this same population, no one should expect the multivitamin to wipe out all diseases known to man.”
CRN also noted that while this is a well-designed, well-executed study, the authors make a valid point in acknowledging that it is not necessarily generalizable to the whole population. “This particular population was extremely healthy, with the physicians doing everything right to prevent heart disease. Their diets were healthy, their BMIs were low, they exercised, very few smoked, and the majority was on a daily aspirin regimen,” noted Dr. MacKay. “The floor in this population may have been too close to the ceiling for a simple multivitamin to have demonstrated additional benefit for preventing strokes and heart attacks. Unfortunately, this study population is not representative of your average American, and even the study authors note this study may have limited generalizability.”
Finally, CRN found it unfortunate that the accompanying editorial makes negative assumptions about the habits of vitamin users when research demonstrates supplement users are taking them in combination with other healthy lifestyle choices. The opinion that people take a multivitamin in lieu of other healthy habits that can lower heart disease risk is a recurring statement that lacks an evidentiary basis. “Government and other studies show that supplement users are more likely to be leaner and more physically active than non supplement users. Our own research shows similar kinds of results, with supplement users being more likely than non-users to try to eat a healthy diet, engage in regular physical activity, and see a doctor regularly. It’s the whole lifestyle package, including consistent, long-term use of vitamins, that helps lead to good health,” concluded Dr. MacKay.
CRN’s most recent annual consumer survey on dietary supplements found, consistent with years past, that the multivitamin is the most popular dietary supplement, with 52 percent of American adults taking multivitamins; 42 percent of American adults taking multivitamins regularly. Additionally, the Life…supplemented Healthcare Professionals Impact Study found that 72 percent of physicians personally use dietary supplements and the multivitamin is the most popular dietary supplement taken by this population.