The Vitamin Myth

Paul Offit:

Nutrition experts contend that all we need is what’s typically found in a routine diet. Industry representatives, backed by a fascinating history, argue that foods don’t contain enough, and we need supplements. Fortunately, many excellent studies have now resolved the issue….

On October 10, 2011, researchers from the University of Minnesota found that women who took supplemental multivitamins died at rates higher than those who didn’t. Two days later, researchers from the Cleveland Clinic found that men who took vitamin E had an increased risk of prostate cancer. “It’s been a tough week for vitamins,” said Carrie Gann of ABC News.

These findings weren’t new. Seven previous studies had already shown that vitamins increased the risk of cancer and heart disease and shortened lives. Still, in 2012, more than half of all Americans took some form of vitamin supplements. What few people realize, however, is that their fascination with vitamins can be traced back to one man. A man who was so spectacularly right that he won two Nobel Prizes and so spectacularly wrong that he was arguably the world’s greatest quack….

How could this be? Given that free radicals clearly damage cells–and given that people who eat diets rich in substances that neutralize free radicals are healthier–why did studies of supplemental antioxidants show they were harmful? The most likely explanation is that free radicals aren’t as evil as advertised. Although it’s clear that free radicals can damage DNA and disrupt cell membranes, that’s not always a bad thing. People need free radicals to kill bacteria and eliminate new cancer cells. But when people take large doses of antioxidants, the balance between free radical production and destruction might tip too much in one direction, causing an unnatural state in which the immune system is less able to kill harmful invaders. Researchers have called this “the antioxidant paradox.” Whatever the reason, the data are clear: high doses of vitamins and supplements increase the risk of heart disease and cancer; for this reason, not a single national or international organization responsible for the public’s health recommends them.