Vitamin pills don't do anything and may be harmful

[Undertoad]

http://www.nytimes.com/2009/02/17/health/17well.html?em

But are vitamins worth it? In the past few years, several high-quality studies have failed to show that extra vitamins, at least in pill form, help prevent chronic disease or prolong life.

The latest news came last week after researchers in the Women’s Health Initiative study tracked eight years of multivitamin use among more than 161,000 older women. Despite earlier findings suggesting that multivitamins might lower the risk for heart disease and certain cancers, the study, published in The Archives of Internal Medicine, found no such benefit.

Last year, a study that tracked almost 15,000 male physicians for a decade reported no differences in cancer or heart disease rates among those using vitamins E and C compared with those taking a placebo. And in October, a study of 35,000 men dashed hopes that high doses of vitamin E and selenium could lower the risk of prostate cancer.

The story goes on to point out that vitamin-takers may be fortifying their tumors:

Vitamins given in high doses may also have effects that science is only beginning to understand. In a test tube, cancer cells gobble up vitamin C, and studies have shown far higher levels of vitamin C in tumor cells than are found in normal tissue.

The selling point of antioxidant vitamins is that they mop up free radicals, the damaging molecular fragments linked to aging and disease. But some free radicals are essential to proper immune function, and wiping them out may inadvertently cause harm.

In a study at the University of North Carolina, mice with brain cancer were given both normal and vitamin-depleted diets. The ones who were deprived of antioxidants had smaller tumors, and 20 percent of the tumor cells were undergoing a type of cell death called apoptosis, which is fueled by free radicals. In the fully nourished mice, only 3 percent of tumor cells were dying.

“Most antioxidants are also pro-oxidants,” said Dr. Peter H. Gann, professor and director of research in the department of pathology at the University of Illinois at Chicago. “In the right context and the right dose, they may be able to cause problems rather than prevent them.”

Eat well, and don't take vitamin pills.