Carotenoids Support Eye Health in Computer Users

by Irfan Qureshi, ND

Lutein and zeaxanthin are the only two carotenoids present in the retina and lens of the eye. Results of epidemiological studies have found that dietary intake of lutein and zeaxanthin is associated with support for overall eye health as well as helping reduce the prevalence of age-related eye health concerns.

Both lutein and zeaxanthin are carotenoids that play an essential role in protecting the eye and retina from free radical damage and support healthy visual function with aging.

Lutein and zeaxanthin form the macular pigment—with the highest concentrations found in the macula (the center of the retina)—and are efficient absorbers of blue light. By absorbing blue light, lutein and zeaxanthin prevent it from reaching structures in the eye responsible for visual function, conferring a protective role. It’s likely that these carotenoids provide direct antioxidant benefits by quenching free radicals that form in the retina.

Recent clinical trials also support the findings from epidemiological studies for the important role of lutein and zeaxanthin in eye health. Researchers from Florida International University recently investigated the effects of different supplemental doses of lutein esters on macular pigment optical density, a marker associated with age-related eye concerns. In contrast to placebo, lutein ester supplementation in amounts of 5, 10 or 20 mg of lutein daily for 140 days were all found to increase macular pigment density, with benefits being dose-related.

A study published in the British Journal of Nutrition in 2009 investigated the impact of lutein supplementation in 37 healthy Chinese subjects with long-term computer-display light exposure. These subjects received 6 mg of lutein/day, 12 mg/day, or a placebo, for 12 weeks. Serum lutein concentrations, visual acuity, glare sensitivity, and contrast sensitivity were measured at baseline and after 12 weeks. A statistically significant increase in contrast sensitivity was found along with a trend towards improvement in visual acuity in the 12 mg/day group, indicating that higher intakes of lutein have greater benefits on visual function.

Furthermore, a Japanese study found that a lutein, zeaxanthin and black currant extract supplement reduced symptoms associated with visual fatigue. In this double-blind, placebo-controlled crossover trial, individuals took the supplement or placebo daily for two weeks, following which treatments were crossed over. Visual fatigue was induced by a two-hour proofreading task, and each participant underwent four such testing sessions. The results of various tests indicated that the lutein supplement significantly reduced visual fatigue compared to placebo.