Published: Tuesday, June 24, 2014 at 6:01 a.m.
Last Modified: Monday, June 23, 2014 at 3:03 p.m.
Q: I'm confused. I thought that antioxidants were really good for you; now I hear that they may not be.
— Freddie G., Philadelphia
A: First of all, trying to get antioxidants by taking megadoses (two or more times the daily value) of vitamins C, A, E or beta carotene generally is ineffective or harmful. The really good guys are polyphenols, which you get from fruits and vegetables.
By fueling up on fruits and veggies, you increase antioxidant levels inside your cells. That trio helps prevent damage caused by proliferation of oxidized molecules called free radicals. Unchecked, free radicals affect your nuclear DNA, causing mutations that can lead to cancer and diabetes.
But you need some oxidized molecules. They help you breathe, help your heart beat more strongly when you're stressed and may help fight infections. The key to good health is a balance between anti- and pro-oxidants. Here are some examples.
One study found that smokers taking vitamin E supplements increased their lung cancer risk. But it didn't increase nonsmokers' lung cancer risk, and eating foods rich in E poses no threat for smokers or nonsmokers.
Too much vitamin A from supplements is associated with bone fractures and birth defects. But a diet rich in foods that contain beta carotene, the building block of vitamin A, poses no such risks and is associated with a reduced risk of heart disease and some cancers.
In one study of older adults, eating a diet loaded with polyphenols and other antioxidants was associated with a 30 percent reduction in mortality over a 12-year period.
Bottom line: For the right balance of polyphenols, eat nine servings of produce daily. We also believe in taking half a multivitamin twice daily for almost everyone. It's especially important for women during childbearing years (a daily multi prior to conception may decrease autism-spectrum disorders by about 40 percent) and men 50-plus (it decreases cancer and cancer recurrences). Also, more than 93 percent of you are deficient in vitamins such as E, D, K and B-12, and 70 percent of kids don't get enough vitamin E. So talk to your doc about getting a blood test to determine if you or your kids are deficient and, if you are, how to remedy the situation.
Email your health and wellness questions to Dr. Oz and Dr. Roizen at email@example.com.