A recent study at Yeshiva University – Albert Einstein College of Medicine, involving thousands of postmenopausal women, suggests that women who develop breast cancer may greatly benefit from taking multivitamins/mineral supplements. This very promising research, published in Breast Cancer Research and Treatment, found the risk of dying from breast cancer was 30 percent lower among women who took the supplements, compared to women who did not.

Sylvia Wassertheil-Smoller, lead author of the study, remarked, “Our study offers tentative but intriguing evidence that multivitamin/mineral supplements may help older women who develop invasive breast cancer survive their disease.”

The current study focused on 7,728 postmenopausal women between the ages of 50 and 79, who were diagnosed with invasive breast cancer, and were followed for an average of seven years after their diagnosis. The women were enrolled at 40 clinical centers throughout the United States during the years 1993 to 1998 as part of the Women’s Health Initiative (WHI).

After enrolling in the WHI study and during repeated follow-up visits, all participants provided extensive information about their health, including whether or not they had taken a multivitamin/mineral supplement at least once a week during the prior two weeks. About 38 percent of the 7,728 women who developed invasive breast cancer during the study were using the supplements. The vast majority were taking the supplements before their breast-cancer diagnosis. A comparison of mortality rates revealed that women with invasive breast cancer who took multivitamin/mineral supplements were 30 percent less likely to die from their cancers than women with invasive breast cancer who hadn’t taken the supplements.

The researchers considered whether other differences between the multivitamin/mineral users and non-users might account for this finding. They looked at many possible overlapping factors including education, race/ethnicity, weight, depression, tobacco or alcohol use, physical activity, age at breast cancer diagnosis, diabetes and additional supplements the women took. The association between regular use of multivitamin/mineral supplements and reduced risk of death persisted even after these factors were taken into account.

Dr. Wassertheil-Smoller stated, “Controlling for these other factors strengthens our confidence that the association we observed – between taking multivitamin/mineral supplements and lowering breast-cancer mortality risk among postmenopausal women with invasive breast cancer – is a real one.” She continued, “But further studies are needed to confirm whether there truly is a cause-and-effect relationship here. And our findings certainly cannot be generalized to premenopausal women diagnosed with invasive cancer or to other populations of women.”

Multivitamin/mineral supplements are the most commonly used dietary supplements in the U.S. They usually contain 20-30 vitamins and minerals – often at levels of 100 percent of U.S. Recommended Dietary Allowances or less. The usual label recommendation is to take them daily.