Fitness Together Georgia

By Sylvia M. Geiger, M.S., R.D., for EatingWell

My friend once turned a yellowish tinge after being on a crazy diet where she ate loads of baby carrots. The culprit? Beta carotene, the compound that makes carrots and sweet potatoes orange. (Leafy greens, such as spinach, also contain healthy doses of beta carotene.) In the body, beta carotene is converted to vitamin A, a nutrient essential for healthy vision, immune function and cell growth. It also acts as an antioxidant that neutralizes free radicals.

More carrots, less cancer?

After early research linked diets rich in beta carotene with reduced risk for cancer, scientists supposed that beta-carotene supplements might also help prevent cancer. Unfortunately, two large clinical trials in the 1990s revealed that taking mega-dose beta-carotene supplements increased rates of lung cancer in smokers. Test-tube research shows that, in high doses, beta carotene can act as a pro-oxidant (boosting free-radical production and risk of disease) and this might happen in the body, too, says Robert Russell, M.D., director of the Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University. Skip supplements; eat your veggies, says Russell; “there doesn’t appear to be any health risk to getting plenty of beta carotene from foods.” (Yellow skin is temporary and harmless, say experts.)

Can beta carotene keep you sharp?

A study in the December 2006 Journal of Gerontology linked high blood levels of beta carotene with a lower risk of cognitive decline in people predisposed to Alzheimer’s. “Beta carotene may counter free radical damage involved in the development of Alzheimer’s in some people,” says Peifeng Hu, M.D., the study’s author and an assistant professor at UCLA School of Medicine.

How much?

There’s no RDA for beta carotene. Eat plenty of dark green vegetables and orange vegetables and fruits (papaya, mango) weekly to meet your vitamin A needs and reap beta carotene’s potential antioxidant benefits.