Two decades of follow-up of more than 100,000 participants in the Nurses’ Health Study and the Health Professionals Follow-up Study finds that higher intake of bio-available carotenoids, particularly lutein and zeaxanthin and alpha-carotene, is associated with a reduced risk of advanced age-related macular degeneration (AMD).
“Because other carotenoids may also have a protective role, a public health strategy of increasing the consumption of a wide variety of fruits and vegetables rich in carotenoids could be most beneficial and is compatible with current dietary guidelines,” writes Dr Juan Wu, of the Harvard TH Chan School of Public Health, Boston in a recent article in the Journal of the American Medical Association.
These findings add to the existing body of evidence that carotenoids play an important role in preventing AMD.
Broadly speaking, carotenoids are plant pigments responsible for bright red, yellow and orange hues in many fruits and vegetables. Foods that are high in carotenoids include carrots, squash, oranges, grapefruit and apricots.
Research has also shown that consuming cooked whole eggs with raw vegetables greatly increases absorption of a variety of carotenoids, including lutein, zeaxanthin and alpha-carotene.
A study assessing the effects of egg consumption on the absorption of carotenoids from a raw mixed vegetable salad found that when the salad was consumed with 3 whole cooked eggs, the absorption increased 3-9 fold.
A study involving 33 men and women consuming 1 egg per day for 5 weeks reported increased serum lutein (26%), and zeaxanthin (38%), but serum concentrations of total cholesterol, LDL (bad) cholesterol, HDL (good) cholesterol and triglycerides were not affected.
In another study it was reported that daily intake of 3 eggs for 12 weeks increased the lutein and zeaxanthin by 21% and 48%, respectively in 20 adults.
Thus, egg yolk could be an important dietary source to improve lutein and zeaxanthin status for the prevention of AMD in adults.
Increasing age is the dominating factor for the onset of AMD because of physiological and biochemical changes due to old age.
Eggs are an affordable source of these essential nutrients for the elderly and together with fruit and vegetables, may be an important strategy to help prevent and manage AMD.