Headlines claiming that “vitamins lower cancer risk” don’t truly reflect trial results
The media’s search for a ‘magic pill’ to reduce cancer risk continues. Yesterday saw several stories about multivitamins “lowering the risk of cancer”. Some of the headlines would have you believe the magic pill has been found – but unfortunately it’s not that simple.
The headlines were based on the results of a study published in the Journal of the American Medical Association, which looked at the effects of taking multivitamins on cancer in middle-aged or older men.
Over 11 years, about 15,000 male health professionals took either a general multivitamin, or either vitamin E, vitamin C, beta carotene (a precursor of vitamin A) or a dummy pill (placebo). This was a ‘blind’ trial, so neither the researchers nor the men on the study knew which pill they were taking. The study included men with a history of cancer as well as healthy individuals.
Daily multivitamin use was shown to slightly reduce the overall risk of developing cancer – by 8 per cent. To put that in perspective, about 18 cancers per 1,000 people per year were diagnosed in the placebo group, compared with 17 cancers per 1,000 people per year in the multivitamin group.
But we don’t recommend you rush out to your local vitamin emporium based on this research. Let’s take a look at why…