BOSTON—The relative intake of the xanthophyll carotenoids varies in the U.S. adult population and may be important in assessing risk for degenerative eye conditions, according to a new study (J Am Diet Assoc. 2010 Sep;110(9):1357-1362. DOI: 10.1016/j.jada.2010.06.009). Lutein and zeaxanthin are selectively taken up into the eye to form the macular pigment, which protects the eyes from oxidative damage and conditions including age-related macular degeneration (AMD). However, there is a lack of information about dietary intake of the carotenoids to make appropriate recommendations on appropriate consumption levels.
Researchers from the Jean Mayer USDA Human Nutrition Center on Aging at Tufts University sought to determine intakes of lutein and zeaxanthin separately in the National Health and Nutrition Examination Survey (NHANES) 2003-2004. Major food sources for the carotenoids were analyzed by HPLC in 2006 and results applied to dietary data from 8,525 participants from the NHANES 2003-2004 study.
Among all age groups, both sexes and all ethnicities, lutein intake was greater than zeaxanthin intake. Relative intake of zeaxanthin to lutein decreased with age, with zeaxanthin to lutein ratios lower in females. Further, lower zeaxanthin to lutein ratios were seen in groups at greater risk for AMD—older participants and women. Of note, zeaxanthin to lutein ratios were significantly greater in Mexican Americans compared to all other ethnicities, including other Hispanics. The researchers concluded the relative intake of these carotenoids may be an important factor in AMD risk.
