Beta-Carotene and Carotenoids

Carotenoids such as beta-carotene are natural pigments synthesized by plants that are responsible for the yellow, orange, red, and dark-green colors of various fruits and vegetables. About 50 carotenoids -- many of which the body can convert into retinol, an active form of vitamin A -- are consumed in the human diet, although people most often consume only 12.

Carrots, sweet potatoes, cantaloupe, and apricots are sources of alpha- and beta-carotene; tomatoes, watermelon, and pink grapefruit contain lycopene; mango, peaches, squash, and oranges provide beta-cryptoxanthin, lutein, zeaxanthin, and alpha- and beta-carotene; and greens such as spinach, kale, and broccoli contain lutein, zeaxanthin, and alpha- and beta-carotene.

Carotenoids act as antioxidants, protecting cells from damage by free radicals, and in clinical trials, beta-carotene is the most researched of the antioxidant supplements. The evidence supporting the link between beta-carotene and a reduced risk of heart disease or heart attack is inconclusive at best.

In the Women's Health Study and the all-male Physicians' Health Study, 50 mg of beta-carotene supplementation every other day had no effect on the incidence of heart attack, other cardiovascular events, or death. In another study, male smokers who took 20 mg of beta-carotene supplements a day for five to eight years showed an 8 percent increase in the rate of death due to heart disease and lung cancer, and in a follow-up, those participants also seemed to be at a higher-risk for a first-time nonfatal heart attack.

Evidence suggests that carotenoids may protect LDL cholesterol from the damage caused by oxidation, but the results are inconclusive. Also, some studies have found that at high concentrations, carotenoids may actually have a damaging effect on cells. There is no good information supporting beta-carotene supplements to reduce the risk of heart attack.

Vitamin C has shown a little promise in heart studies, but the evidence is still inconclusive. Learn about Vitamin C research on the next page.

For more information on cholesterol, see:
  • Foods That Lower Cholesterol: The first and best way to attack a cholesterol problem is through your eating habits. Find out what to eat for a healthy heart.
  • Foods That Claim to Lower Cholesterol: Many foods and supplements claim that they can help lower cholesterol. But do they really work? Find the answers here.
  • Low Cholesterol Diet: Many cholesterol-conscious diet plans focus on reducing saturated fat. Learn how to cut it out of your diet.
  • How Cholesterol Works: Cholesterol is essential to the body. Find out why we need it and how much is too much.

This information is solely for informational purposes. IT IS NOT INTENDED TO PROVIDE MEDICAL ADVICE. Neither the Editors of Consumer Guide (R), Publications International, Ltd., the author nor publisher take responsibility for any possible consequences from any treatment, procedure, exercise, dietary modification, action or application of medication which results from reading or following the information contained in this information. The publication of this information does not constitute the practice of medicine, and this information does not replace the advice of your physician or other health care provider. Before undertaking any course of treatment, the reader must seek the advice of their physician or other health care provider.