Study: Daily Multivitamin Use Does Not Reduce Cardiovascular Disease Risk in Men

Researchers enrolled nearly 15,000 men over the age of 50 in the study and followed them for more than 10 years. The men were randomly assigned to take either a multivitamin or a placebo every day which ensured that both treatment groups were identical with respect to risk factors for cardiovascular disease.

6 Nov 2012 --- Approximately one-third of Americans take a daily multivitamin, but little is known about a multivitamin's long-term affect on chronic diseases. Now, new research from Brigham and Women's Hospital (BWH) finds that daily multivitamin use does not reduce the risk of cardiovascular disease in men. A similar BWH study, announced last month, found daily multivitamin use can reduce a man's risk of cancer by 8 percent. The cardiovascular disease findings will be presented Nov. 5 at the American Heart Association's Scientific Sessions 2012 and published simultaneously in the Journal of the American Medical Association.

"The findings from our large clinical trial do not support the use of a common daily multivitamin supplement for the sole purpose of preventing cardiovascular disease in men," said Howard D. Sesso, ScD, lead author and an associate epidemiologist in the Division of Preventive Medicine at BWH. "The decision to take a daily multivitamin should be made in consultation with one's doctor and consideration given to an individual's nutritional status and other potential effects of multivitamins, including the previously reported modest reduction in cancer risk."
 
Researchers enrolled nearly 15,000 men over the age of 50 in the study and followed them for more than 10 years. The men were randomly assigned to take either a multivitamin or a placebo every day which ensured that both treatment groups were identical with respect to risk factors for cardiovascular disease. The men self-reported episodes of heart attacks, strokes and cardiovascular disease, and a panel of physicians reviewed and confirmed their events with medical records. Researchers then compared the group that took the multivitamin with the group that took the placebo and found no significant impact on risk of heart attack, stroke, or cardiovascular mortality. Additionally, the effect of a daily multivitamin on major cardiovascular events did not differ on participants with a baseline history of cardiovascular disease and those who were initially free of cardiovascular disease.
 
J. Michael Gaziano, MD, chief of the Division of Aging at BWH, investigator at VA Boston and senior author of the study, said, "Since so many Americans take daily multivitamins, studies like this are key to providing us with valuable information about what specific benefits multivitamins do or do not provide in terms of their long-term impact on chronic diseases. For cardiovascular disease, we must continue to emphasize a heart-healthy diet, physical activity, smoking cessation and regular screening for cardiovascular risk factors."
 
This research was supported by grants CA 097193, CA 34944, CA 40360, HL 26490 and HL 34595 from the National Institutes of Health and an investigator-initiated grant from BASF Corporation. Study agents and packaging were provided by BASF Corporation and Pfizer (formerly Wyeth, American Home Products and Lederle) and study packaging was provided by DSM Nutritional Products, Inc. (formerly Roche Vitamins).

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 [see references below]. 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.