Though millions of women take multivitamins to help prevent cancer and heart disease, the results of the largest study of its kind suggest that the effort has little effect. The study found little effect on reducing risk or death from cancer or heart disease among post-menopausal women who took the vitamins. As the largest study on women's health and diet, the researchers say that it provides definitive evidence that multivitamins do not provide these health benefits to post-menopausal women.
"Dietary supplements are used by more than half of all Americans, who spend more than $20 billion on these products each year. However, scientific data are lacking on the long-term health benefits of supplements," said lead author Marian L. Neuhouser, PhD of the Fred Hutchinson Cancer Center, in a news release.
To determine whether multivitamins could reduce risk of or death from cancer or heart disease, Dr. Neuhouser and her colleagues followed he study assessed multivitamin use among nearly 162,000 women aged 50 to 79 for about eight years. The women were enrolled in the Women's Health Initiative, a large U.S. study examining the most common causes of death, disability and impaired quality of life in postmenopausal women.
According to the study results, over the eight-year period, 9,619 cases of breast, colorectal, endometrial, renal, bladder, stomach, lung or ovarian cancer were reported. Also, 8,751 cardiovascular events and 9,865 deaths occurred. However, the study found no significant differences in risk of cancer, heart disease or death between women who took multivitamins and those who did not.
"To our surprise, we found that multivitamins did not lower the risk of the most common cancers and also had no impact on heart disease," Dr. Neuhouser said. The results are consistent with prior studies, which have also shown little health benefits of multivitamins, the most commonly used vitamin supplement.
Instead of taking multivitamins, Dr. Neuhouser recommends that women obtain nutrients from healthy foods such as fruits, vegetables, and whole grains.
- The study, "Multivitamin Use and Risk of Cancer and Cardiovascular Disease in the Women's Health Initiative Cohorts", was published in the February 9, 2009, issue of the Archives of Internal Medicine.
- A February 9, 2009 Fred Hutchinson Cancer Research Center news release about the study results was published on the Center's website.
