According to an abstract presented by Elizabeth Johnson, PhD, assistant professor and nutritional biochemist with the Jean Mayer USDA Human Nutrition Research Center on Aging, Carotenoids and Health Laboratory, at Tufts University, lutein esters and lutein are equal in bioavailability. Dr. Johnson led a study to determine differences in the body’s absorption of lutein from eggs, spinach and supplements. Her research found that lutein from eggs is more bioavailable than from spinach or supplements. Further analysis showed that both Cognis’ XANGOLD® natural lutein esters and a competing brand of “free” lutein were equally bioavailable. Ten healthy men comprising the study group consumed cooked spinach, eggs, lutein and lutein esters supplements in separate treatment phases. Dr. Johnson measured levels of lutein and triglyceride-rich lipoproteins in their blood serum before, during and after each phase. The study, which was supported by the Egg Nutrition Center, used eggs from chickens that had been fed marigold petals, which are high in lutein.