Multivitamins Do Not Reduce Cancer, Cardiovascular Risk
If you are taking multivitamins because you think they can reduce your risk of cancer, cardiovascular disease, or dying, then think again. According to results of a large epidemiological study, use of multivitamins has no clear impact on these risks.
Don’t give up on multivitamins entirely
In the new study, led by Song-Yi Park, assistant professor of epidemiology at the University of Hawaii Cancer Center, and his team, 182,099 individuals who participated in the Multiethnic Cohort Study in Hawaii and California were evaluated. The study looked at the relationship between use of multivitamins and mortality and cancer.
During an average 11 years of follow-up, the researchers identified 28,851 deaths. Analysis of the data revealed no significant association between use of multivitamins and overall death rates, as well as no relationship between supplement use and death from cardiovascular disease or cancer. Neither the length of supplement use nor frequency of use had a significant impact on the findings.
When the researchers allowed for factors such as age, body mass index, smoking, use of hormone replacement therapy among postmenopausal women, presence of preexisting conditions, and single supplement use, they still did not find an association between multivitamin use and death. They also did not find any difference between the risk of dying overall or of major cancers (e.g., lung, prostate, breast, colorectal) between people who took multivitamins and those who did not.
Although many people take multivitamin and multimineral supplements in the hopes they will improve their health, the authors of this study noted that the ability of these supplements to prevent premature death or chronic disease “is not proven, and the National Institutes of Health do not recommend multivitamin/mineral supplements for this purpose.”
In 2006, the National Institutes of Health released a report entitled the “NIH State of the Science Conference Statement on Multivitamin/Mineral Supplements and Chronic Disease Prevention." Among its findings was that more than half of Americans take nutritional supplements, and that multivitamin/ multimineral use is widespread.
The report also stated that generally, people who take multivitamins and multiminerals follow a healthier lifestyle than those who do not supplement, which can make it difficult to interpret the relationship between supplement use and overall health. It concluded that currently there is insufficient evidence to either recommend or not recommend use of multivitamins and multiminerals to prevent chronic disease. They may, however, help supplement the diet.
Some previous clinical trials have indicated that multivitamins may reduce the risk of some conditions such as cardiovascular disease and cancer. However, Park and his team noted that “these trials tested specific combinations of vitamins with or without minerals rather than commonly used multivitamin products.”
National Institutes of Health State of the Sciences Conference Statement
Park SY et al. American Journal of Epidemiology 2011; doi: 10.1093/aje/kwq447