BOSTON–Research published in the June American Journal of Clinical Nutrition (www.ajcn.org) highlighted the benefits of carotenoid intake on heart health and blood sugar levels. In one study, researchers from Harvard researched the role of carotenoids in coronary artery disease (CAD) since previous studies had shown higher intakes or higher blood concentrations of carotenoids were associated with lower disease risk (77:1390-9, 2003).
Using food frequency questionnaires completed by approximately 73,000 female nurses, researchers assessed the nurses’ consumption of carotenoids and various other nutrients. During the 12-year follow-up, researchers identified 998 cases of CAD. After adjusting for age, smoking and other CAD risk factors, they observed a modest but significant inverse association between the highest quintiles of intake of beta-carotene. They noted, thought, that there was no significant heart benefit seen with intakes of lutein, zeaxanthin, lycopene or beta-cryptoxanthin.
In another study conducted, this time by researchers out of Finland, the role of carotenoids (beta-carotene, lycopene) and other antioxidants (vitamin E) were investigated for Type II diabetes (77:1434-41, 2003).
The study involved 81 male and 101 female first- and second-degree, nondiabetic relatives of patients with Type II diabetes. Subjects taking supplements containing beta-carotene or vitamin E were excluded.
In men, dietary carotenoid intake was inversely associated with fasting plasma glucose concentrations, plasma beta-carotene concentrations were inversely associated with insulin resistance and dietary lycopene was directly related to baseline serum concentrations of nonesterified fatty acids. In women, however, dietary vitamin E and plasma beta-carotene concentrations were inversely and directly associated, respectively, with fasting plasma glucose concentrations. The Finnish researchers concluded this data suggests carotenoids may be beneficial for glucose metabolism in men at high risk of Type II diabetes.