In one of our earliest EduFacts briefings ("Macular Pigment Density, Dietary Carotenoids and Age-Related Macular Degeneration") we reviewed a study which documented a near-twenty percent increase in macular pigment (MP) density in subjects fed a diet vigorously enriched with spinach and corn
. The high levels of dietary spinach and corn effectively boosted lutein intake approximately 4-fold and zeaxanthin intake 3-fold. In the same article we reviewed 2 other studies relating increased serum and dietary intake of these dietary carotenoids with reduced risk of age related macular degeneration (AMD). While the value of adequate dietary levels of lutein and zeaxanthin is generally recognized, the value of using lutein/zeaxanthin supplements is disputed.However, a recent (1997) experimental study demonstrates that the use of a lutein supplement can directly generate an increase in the density of the protective macular pigment
. Landrum, Bone, and colleagues serially measured macular pigment optical density for a year in 2 test subjects who were given lutein supplements daily for 140 days. The subjects consumed lutein esters equivalent to 30-mg free lutein per day. MP optical density was measured before, during, and after the supplementation period using heterochromatic flicker photometry. The basic finding was that in all 4 test eyes, MP increased steadily during lutein supplementation (140 days) and continued at the same rate for another 40-50 days before leveling off. MP density then remained steady throughout the remainder of the observation period (through 350-400 days). Rate of increase ranged from 1.14 to 1.21 mAU per day. Supplementation caused a 10-fold increase in serum levels of lutein in both subjects within 10-20 days of treatment. After discontinuation of the supplement, serum levels fell to baseline levels after about 60 days.References