Today's Health Tips

The Truth About Antioxidant Supplements

by Cindy Kuzma April 9, 2012, 03:41 am EDT

When does fighting off free radicals do more harm than good?

They were supposed to be wonder-drugs that prolonged your life. Now, there’s evidence that antioxidant supplements don’t help your health. In fact, they may actually be linked to an increased risk of dying while taking them.

For a new study in The Cochrane Library, researchers combined 78 clinical trials that involved close to 300,000 people. Over an average three-year study period, people taking supplements containing one or more of five common antioxidants were about 4 percent more likely to die. Beta-carotene, vitamin A, and vitamin E, seemed the most harmful, while vitamin C or selenium merely didn’t help.

Some of the participants were healthy, while others had heart disease, stomach conditions, or other health problems. The results suggest that, whether you’re healthy or coping with chronic illness, there’s no clear benefit to getting these nutrients in pill form, say the study authors. Antioxidants are still important—it’s just best to get them from food.

Too Much of a Good Thing?
 

Antioxidants work by fighting free radicals. “Free radicals are unstable molecules that, if left unchecked, can damage the cells and impair their function,” says Mary Hartley, R.D., M.P.H., a nutrition expert at AskMaryRD.com. Your body creates free radicals when you break down food, and they can also come from outside sources, such as pollution and smoking. The damage they cause has been linked to aging, as well as diseases like Alzheimer’s and cancer.

More from MensHealth.com: 5 Myths About Antioxidants

 

Antioxidants neutralize these free radicals. Which is a good thing—most of the time. For one thing, other recent research suggests zapping too many free radicals blocks the beneficial effects your workout. And though they’re harmful in excess, your body needs some free radicals to do things like fight infection.

Most people in the studies took doses of antioxidants that were higher than what you’d get by eating a healthy diet, and even larger than the government’s daily recommended amounts. This could help explain their negative effects, the study authors note.

Why were some more harmful than others? Studies suggest that at high doses:

•    Beta-carotene may actually make cancer-causing chemicals more dangerous
•    Vitamin A causes DNA damage
•    Vitamin E actually becomes a pro-oxidant, increasing cell damage

When to Take a Supplement
 

Scientists are still learning about all of the effects antioxidant supplements can have, alone or in combination. But based on these results, it’s a bad idea to take antioxidant supplements alone unless your doctor says you have a deficiency, Hartley says.

However, the threat from free radicals is greater if you’re under extreme physical or emotional stress: “Extreme is the key word,” Hartley says. If you’re getting divorced, training for an endurance event, or working long hours on a big project, consider taking a multivitamin supplement. “The supplement should contain 100-percent of the daily recommended intake for most, if not all, nutrients, and no nutrient should exceed the tolerable upper intake levels.” Here’s how to make sure you’re not going overboard:

Otherwise, stick to eating a healthy diet rich in fruits, vegetables, and other plant foods—getting antioxidants this way hasn’t been shown to cause harm. Plus, these foods contain other nutrients and thousands of other chemical compounds your body needs to function, Hartley says. Here’s what to stock up on for your antioxidant fix.

•    Vitamin A and beta-carotene: Sweet potatoes, carrots, and spinach
•    Vitamin C: Citrus fruits, red and green pepper, tomatoes
•    Vitamin E: Safflower oil, peanuts, and almonds
•    Selenium: Brazil nuts, sunflower seeds, brown rice