Trial uncovers protective effect for multinutrient supplementation against cancer

Tuesday, October 23, 2012. The Journal of the American Medical Association published an article on October 17 that reports a reduction in the risk of cancer among male physicians who consumed multinutrient supplements.

The trial included 14,641 men aged 50 or older upon enrollment in the Physician's Health Study II (PHS II). One thousand three hundred twelve men reported a history of cancer at the beginning of the study. Participants received a daily multivitamin or a placebo over a period of 10.7 to 13.3 years, during which 2,669 cases of cancer (excluding nonmelanoma skin cancers) occurred.

Among those who received the multinutrient supplement, the risk of developing any cancer was 8 percent lower than those who received a placebo. While multinutrient supplementation had no effect on the risk of prostate cancer (which comprised approximately one half of the cancers that occurred), total epithelial cell cancers were reduced by 8 percent. The protective effect of supplementation did not differ significantly between those with or without a history of the disease.

"We are unaware of other long-term clinical trials testing a common multivitamin in the prevention of cancer and chronic disease," lead author J. Michael Gaziano, MD, MPH and his associates announce.

"The reduction in total cancer risk in PHS II argues that the broader combination of low-dose vitamins and minerals contained in the PHS II multivitamin, rather than an emphasis on previously tested high-dose vitamins and mineral trials, may be paramount for cancer prevention," they write. "The role of a food-focused cancer prevention strategy such as targeted fruit and vegetable intake remains promising but unproven given the inconsistent epidemiologic evidence and lack of definitive trial data."

"Although the main reason to take multivitamins is to prevent nutritional deficiency, these data provide support for the potential use of multivitamin supplements in the prevention of cancer in middle-aged and older men," they conclude.