Do multivitamins really protect us against cancer or heart disease?

The Introduction

Millions of post-menopausal women use multivitamins in the belief that these supplements prevent chronic diseases such as cancer and cardiovascular disease (CVD). The marketing and advertising industry has lead us to believe they will help prevent chronic disease. But what are the facts? A recent American study examined relationships between multivitamin use and risk of cancer, CVD, and mortality in 161,808 post-menopausal women.

The Research

vitamin bottlevitamin bottlevitamin bottleThe women were first studied between 1993 and 1998 and then followed-up after about 8 years. The American research team documented cancers of the breast, colon/rectum, endometrium, kidney, bladder, stomach, ovary, and lung; CVD (myocardial infarction, stroke, and venous thromboembolism); and total mortality (death).

The Results

41.5% of the women used multivitamins. After 8 years of follow-up, 9619 cases of breast, colorectal, endometrial, renal, bladder, stomach, lung, or ovarian cancer; 8751 CVD events; and 9865 deaths were reported. Statistical analyses revealed no association of multivitamin use with risk of cancer (breast cancer, colorectal, endometrial, lung cancer; or ovarian); CVD (heart attacks, strokes or venous thromboembolism); or death. However, the research team did identify a relationship between multivitamins that contain high doses of folic acid and B vitamins that fight stress and suggest a possible protective effect against heart attacks.

The So What?

This study provides convincing evidence that multivitamin use has little or no influence on the risk of common cancers, CVD, or death in postmenopausal women. Thus, we should be questioning the largely unregulated manufacturers and marketers who ply us with product health claims, testimonials from high profile celebrities and athletes, in a supplement industry that in America is worth $23 billion annually. All the nutritional research suggests eating a wide range of whole foods enables us to get the vitamins and minerals we need for good health.

However, from a masters athlete point of view, especially women (and men) training hard and often, the use of multivitamins and minerals might be suggested, especially for those older athletes who may not eat a well-balanced and/or nutritious diet. Using them acts as a form of ‘insurance’ to ensure we are getting the vitamins we need as athletes. When choosing from the shelf, choose multivitamins that emphasise vitamins B and C as they are water soluble and lost from the body easily compared to the fat soluble vitamins A, D, E and K.

Photo from: The Astrids

Neuhouser, M., Wassertheil-Smoller, S., Thomson, C.  and others.  (2009). Multivitamin use and risk of cancer and cardiovascular disease in the Women’s Health Initiative cohorts. Archives of Internal Medicine. 169(3):294-304.