Vitamin E and prostate cancer: Where do we stand?
It seems like ancient history, but only about a decade has elapsed since the peak of the antioxidant vitamin boom. The enthusiasm was certainly understandable. It began with the observation that people who eat lots of fruits, vegetables, and whole grains — all rich in antioxidants — enjoy substantial protection from cancer and heart disease. Next, laboratory and animal experiments showed that antioxidants could protect DNA from damage by oxygen-free radicals, potentially reducing genetic errors that cause cancer. The animal research also showed that antioxidants could protect arteries by preventing the oxidative damage to LDL cholesterol that puts the "bad" into bad cholesterol.
Unfortunately, it didn't take long for the boom to go bust. A series of large randomized clinical trials found that antioxidant supplements do not reduce the risk of cardiovascular disease — and they may even interfere with some cholesterol-lowering medications. Similarly, supplements do not reduce overall deaths from cancer, and one antioxidant, beta carotene, actually increases the risk of lung cancer in male smokers.
After reviewing all the information, the U.S. Preventive Services Task Force recommended against routine vitamin use to prevent cancer and cardiovascular disease. It's a sound recommendation, but a study published just a few weeks later reminds us that the issue is not fully resolved, at least as far as vitamin E and prostate cancer is concerned.