BOSTON, MASS. -- The human body can absorb lutein better from eggs than from other dietary sources, according to a study funded through the Agricultural Research Service and Egg Nutrition Center.
Lutein is a carotenoid known to be important for eye health, and low lutein intake has been implicated in age-related macular degeneration, the leading cause of vision loss among older people, according to biochemist Elizabeth Johnson, who did the work at the Carotenoids & Health Laboratory of the Jean Mayer U.S. Department of Agriculture Human Nutrition Research Center on Aging at Tufts University in Boston.
The macula is located in the eye in the retina behind the pupil and is responsible for central vision, she said, and lutein and zeaxanthin, another carotenoid present in eggs, accumulate in the macula and imbue a pigment that protects the macula.
In the research, Johnson arranged for 10 volunteers to consume eggs, spinach or one of two lutein supplements, according to an article on the research published in the August Journal of Nutrition.
She measured lutein concentrations in the volunteers' blood serum before and following each test and found that when the volunteers consumed eggs as their lutein source, lutein blood serum levels were about three times greater than when they took lutein from the other sources.
Johnson suggested that egg lutein is more readily absorbable into the bloodstream than lutein from other sources because of components in the egg's yolk, which contains the egg lutein. She added that egg lutein is 200-300% more bioavailable than plant sources and that eggs provide lutein in lipids, which are easier for the bloodstream to absorb.
