The retinal carotenoids, lutein and zeaxanthin are replenished through dietary intake. In previous EduFacts issues we have summarized several published studies demonstrating an inverse relationship between high dietary intake of these retinal pigments and the risk of Age Related Macular Degeneration (AMD). The effect of dietary carotenoids on the density of the protective macular pigment has also been studied. One study demonstrated a significant increase in macular pigment (MP) density in subjects fed a diet vigorously enriched with spinach and corn - good source of both carotenoids. Another study demonstrated increases in MP density during lutein supplementation.

A recent study in the British Journal of Ophthalmology undertook to document relative levels of lutein and zeaxanthin in various food sources. Homogenates of 33 food items were analyzed to measure the mole% amounts of these nutrients using high performance liquid chromatography.

Foods rich in both Lutein and Zeaxanthin*

*adapted from Sommerburg, et al (1).

The Table lists those food sources rich in both nutrients. Eighteen other fruits and vegetables studied had levels of lutein in the 15-55 mole% range. However, only orange peppers, oranges, and mangos supplied a serious level of zeaxanthin.

The question of whether to optimize intake of these important nutrients through diet alone or through supplementation remains unanswered. Certainly a restricted diet - without eggs, for example, would eliminate an important source of zeaxanthin. Orange peppers, honeydews and mangos may be unavailable to many elderly, depending on the season.

Clearly, patients at risk for macular degeneration should be thoroughly evaluated nutritionally. They may have reduced their dietary intake of important nutrients for ocular health.

References

• Sommerburg O, Keunen JEE, et. al. Fruits and vegetables that are sources for lutein and zeaxanthin: the macular pigment in human eyes. Br J Ophthalmol 1998;82:907-910.