Studies on Dietary Supplements Show Mixed Results

Dorian Martin Health Guide November 06, 2012
  • Are multi-vitamins and supplements worth it? It depends.


    For instance, you can look at a new study presented at the American Heart Association conference and come to conclusion that these supplements aren’t worth it. This study looked at data from 14,641 American men who were physicians and who were 50 years of age and older. Of these, 745 participants had prevalent cardiovascular disease. The participants were randomly assigned to one of two groups. The first group took a specific multivitamin that is widely available while the second took a placebo. The participants were followed for an average of 11.2 years.


    The researchers found that there were 1,732 major cardiovascular disease events such as myocardial infarction, nonfatal strokes and cardiovascular disease deaths during the time study’s span. However, there was no statistical significance of these events happening among participants who took the multivitamin versus those who took the placebo.  


    “Multivitamins are the most common supplement taken by at least one-third of all U.S. adults,” said Howard D. Sesso, Sc.D., M.P.H., lead researcher and Associate Professor of Medicine in the Division of Preventive Medicine at Brigham & Women’s Hospital in Boston, Mass. “While multivitamins are typically used to prevent vitamin and mineral deficiency, there is an unproven belief that they may have benefits on other chronic diseases, including heart attack, stroke or cardiovascular death.”


    However, the participants in this study were all physicians who, for the most part, led a healthy lifestyle. “The majority of men in our trial appeared to have, on average, good dietary habits.” Dr. Sesso said. “The question remains about how the long-term cardiovascular effects of daily multivitamin use might change among people with a wider range of nutritional status. Other healthy habits, such as smoking cessation and increased physical activity, remain effective tools in preventing cardiovascular disease and other outcomes.”


    Another study published earlier this year looked at whether omega-3 supplements lowered the risk of major cardiovascular events. The researchers did a meta-analysis of 20 previously published studies that had evaluated the effect of omega-3 supplements on cardiac death, myocardial infarction, stroke, sudden death and all-cause mortality. Their analysis found that there was no association between taking omega-3 supplements and a lower risk of cardiac events.


    However, other studies have actually found beneficial results from taking supplements. For instance, a study that used the same physicians as the first study I described above learned that multivitamins may actually help decrease the risk of cancer. The researchers found that those taking a daily multivitamin “modestly, but significantly reduced the risk of total cancer,” according to the summary on the Journal of the American Medical Association (JAMA).


  • So what should you do? First of all, I think that the mixed news about supplements should be a reminder that you need to focus on eating a healthy diet that includes a variety of fruits and vegetables, lean meats, fish, grains and low-fat dairy in order to get most of your nutritional needs through whole food. Don’t depend on supplements as your primary source of vitamins, minerals and nutrients.


    Secondly, if you have a specific health condition, check with your physician to see what type of diet is recommended. For instance, physicians often recommend the Dietary Approaches to Stop Hypertension (DASH) eating plan for people who have high blood pressure. And again, while following whatever diet is recommended for your specific condition, make sure that you eat a variety of foods (such as different colored vegetables and fruits) in order to benefit from their respective nutrients and vitamins.


    Finally, I’d suggest that you initially talk to your physician about the findings from these and other studies and how they may influence your own need for supplements. Talk to the doctor about tailoring any supplements to your own individual case based on your current health, heredity and lifestyle.


    Primary Sources for This Sharepost:


    American Heart Association. (2012). A multivitamin a day doesn’t prevent cardiovascular disease in men. Press release.


    JAMA. (2012). Association between omega-3 fatty acid supplementation and risk of major cardiovascular disease events: A systematic review and meta-analysis.


    JAMA. (2012). Multivitamins in the prevention of cancer in men; The Physicians’ Health Study II randomized controlled trial.