A recent article in the Miami Herald on the health benefits of lutein and zeaxanthin caught my eye (pun intended). Lutein and zeaxanthin are carotenoids that can impact, among other things, visual health by decreasing the risk of macular degeneration, an age-related eye condition. The article points out that green leafy vegetables, including spinach, kale, mustard greens, and broccoli, as well as eggs and oily fish are good sources of these nutrients. What the article fails to point out, however, is that a good amount of research exists indicating that the lutein and zeaxanthin in eggs are more bioavailable than they are when they come from plant sources. This is probably due to the lipid matrix of the egg yolk, which facilitates absorption of the fat soluble carotenoids. And nutrient bioavailability is an important consideration for human health. It doesn’t much matter if a food is high in a given nutrient if that nutrient is inaccessible to the body upon consumption.
The amount of lutein and zeathanthin in eggs is variable, and is largely dependent on the feed that the hen consumes. Some egg producers fortify the hens’ diet with marigold extract (an excellent source of these carotenoids) or purified lutein in an effort to raise the content of these vitamins in eggs. As a consumer you can get a rough idea of the lutein content of an egg by observing the color of the egg yolk. Lutein imparts an orange-yellow color to the yolk. Yolks from hens not supplemented with additional carotenoids tend to have a more yellow color.
For more information on lutein and zeaxanthin and their impact on eye health, the articles below are recommended. With an aging population comes a rise in age-related health conditions such as macular degeneration. So you’re likely to hear more and more about these carotenoids in the future.
- Vishwanathan R, Goodrow-Kotyla EF, Wooten BR, Wilson TA, Nicolosi RJ. Consumption of 2 and 4 egg yolks/d for 5 wk increases macular pigment concentrations in older adults with low macular pigment taking cholesterol-lowering statins. Am J Clin Nutr 2009;90:1272-9.
- Moeller SM, Jacques PF, Blumberg JB. The potential role of dietary xanthophylls in cataract and age-related macular degeneration. J Am Coll Nutr 2000;19:522S-527S.
