Carotenoid-Enriched Eggs Improve Macular and Visual Function
Generally, xanthophyll carotenoids like lutein, zeaxanthin, and meso-zeaxanthin, which are not produced by the human body, depends on dietary intake. A new lead study by the scientists of Ireland and the United Kingdom have revealed that intake of eggs both in normal (control) and modified (lutein and meso-zeaxanthin) forms for 8 weeks enhanced the serum carotenoid levels of macular pigments.
The macula, which is a core tissue of retina, is mainly constituted by three carotenoid pigments; namely lutein (L), zeaxanthin (Z) and meso-zeaxanthin (MZ). Naturally, macular pigments (MP) play an important role in proper visual function by providing protection from oxidative stress that causes damage to retinal photoreceptors. Most commonly, MP components in dietary and medical supplementation forms not only enhance the visual function in the macula, but also protect the degeneration process advancing with aging. Especially in the developing world, any alterations in MP with aging leads to the onset of age-related macular degeneration (AMD).Most commonly, eggs in the dietary form are considered to be a rich source of carotenoid pigments such as lutein and zeaxanthin. Previous studies have reported that enrichment of MP following supplementation with a combination of L, Z and MZ have shown clinically-relevant improvements in visual function, downstream regulation of oxidative stress, and cognitive function. A collaborative study in this direction by Kelly and co-researchers was published in the British Journal of Nutrition, 2017.
The Egg Xanthophyll Intervention Clinical Trial (EXIT) was carried out for understanding the role of macular carotenoid-enriched eggs on serum carotenoid concentrations, visual performance, MP and serum cholesterol levels from September 2013 to November 2013. A total of fifty human subjects between the ages of 18 and 65 years with no history of cardiovascular disease, no ocular pathology, cholesterol levels of ≤6.5 mmol/l, and having no allergies to eggs were recruited as study subjects while those with recent history of macular carotenoids and/or statin intake were excluded from the study trial. Two groups were developed from fifty subjects, each constituting twenty-five participants: Group 1was given a standard (control) egg daily; whereas Group 2 was fed with a modified egg (macular carotenoid containing L:MZ in a 1:1 ratio) daily…….