Mrs. Greeley is nearly 80 and she does not eat fresh fruits and vegetables as much as she once did. Her daughter is concerned that she may develop vitamin deficiencies, so she has asked the dietitian if giving her mother a carotenoid supplement will help ensure her health and decrease her risk for macular degeneration. What should the dietitian tell her?

Answer 1

It is true that higher circulating levels of lutein and zeaxanthin, nonprovitamin A caroentoids, have been related to decreased risk of age-related deterioration of the retina—a disease called macular degeneration. (Macular degeneration affects the macula, the highly sensitive portion of the retina needed for central vision.) Many studies suggest that carotenoids exert their effects on the macula by positively influencing the immune system. However, though research shows that consuming high amounts of carotenoid-containing fruits and vegetables is associated with a reduction in many chronic diseases, it does not show the same effect for carotenoid supplements. In fact, dietary intervention trials often suggest a negative effect of carotenoid supplements on health. Some studies have shown that carotenoid supplements increase the risk for lung cancer in some individuals. Scientists believe that the health-promoting effects of fruits and vegetables may be due to carotenoids working in synergy with each other and/or with other nutrients found in foods.
If consuming fresh fruits and vegetables is problematic, perhaps Mrs. Greeley's daughter could explore with her various ways that Mrs. Greeley could increase her consumption of canned and cooked fruits and vegetables—such as in casseroles, soups, and salads. ?-carotene may be more bioavailable as a result of processing and heating.