When acting as antioxidants, carotenoids have been shown to reduce the damage caused by certain molecules called free radicals. A generous amount of these chemicals might prevent damage to cells and tissues as well as genetic damage. This means that they might increase a person's immunity to infection, reduce the risk of cancer and protect against heart disease.
The potential benefits of beta-carotene are believed to include preventing hardening of the arteries, which is associated with an increased risk of heart attack. Beta-carotene also preserves the health of the body's mucous membranes and lining of the lungs, which are among the body's first lines of defense against infection. Excessive amounts of beta-carotene, however, might bring a higher risk of osteoporosis or of lung cancer in smokers.