Regular consumption of lutein-enriched eggs could provide the body with protective levels of this antioxidant widely believed to help fight degenerative eye diseases, suggests a small study from the US.
Scientists at the Human Nutrition Research Center on Aging at Tufts University found that the bioavailability of the carotenoid lutein was superior in eggs compared to other sources such as lutein, lutein ester supplements, and spinach.
"This finding may have implications for dietary recommendations that may decrease the risk of certain diseases, for example, ARMD," report the researchers in the August issue of the American Society for Nutritional Sciences', Journal of Nutrition (134:1862-1866).
Age-related macular degeneration is the leading cause of blindness in the western world, affecting an estimated 30 million people worldwide. This number is expected to double by 2030.
In this small study on 10 healthy men, researchers Hae-Yun Chung, Helen M. Rasmussen and Elizabeth J. Johnson carried out an intervention study with a crossover design.
After a two week washout period during which time the participants consumed a low-carotenoid diet, the men were administered one of four lutein doses - lutein supplement, lutein ester supplement, spinach, and lutein-enriched eggs - for nine days.
"All lutein doses provided 6 mg lutein except for the lutein ester dose, which provided 5.5 mg lutein equivalents. Serum samples were collected from fasting subjects on day 14, and 1one (baseline), 2, 3, and 10 were analysed for changes in lutein concentration," write the researchers.
Subjects completed all four treatments of the study in random order.
"Results showed that the baseline and dose-adjusted lutein response in serum was significantly higher after egg consumption than after lutein, lutein ester, and spinach consumption on day 10," report the scientists, concluding that the lutein bioavailability 'from egg is higher than that from other sources such as lutein, lutein ester supplements, and spinach.'
The lutein-enriched eggs used in the study came from chickens that had been fed marigold petals, which are high in lutein. Cognis supplied its Xangold natural lutein esters for the trial. Other key suppliers in the lutein market are Kemin, which supplies purified lutein.
Food makers have 'under-utilised' the nutraceutical properties of carotenoids such as lutein and consumers are still unaware of their health benefits, finds a recent report on the $348.5 million (€291.4m) carotenoid market from Frost & Sullivan.
The market research firm claims that the low level of public awareness about the health benefits of carotenoids, still used primarily as a colouring agent for the food and feed industries, is expected to stifle market growth in the short term.
"Low consumer awareness of the health benefits of carotenoids particularly affects the newer, naturally-extracted carotenoids lycopene, lutein and natural beta-carotene," said food research manager Anna Ibbotson.
The European carotenoid market is forecast to accumulate $419.6 million in 2010. Revenue expansion is projected to be driven by an emphasis on personal health combined with the rising interest in preventative health measures by Europe's ageing population. Principal growth is likely to be experienced by beta-carotene with $23.0 million, lycopene with $26.0 million and lutein with $21.0 million.