Lutein for Eye Health
Lutein is concentrated in the macula, a small area of the retina responsible for central vision. Lutein helps keep the eyes safe from oxidative stress and the high-energy photons of blue light. Several studies show that an increase in macula pigmentation decreases the risk for eye diseases such as Age-related Macular Degeneration (AMD). The only randomized clinical trial to demonstrate a benefit for lutein in Macular Degeneration was a small study, in which the authors concluded that visual function is improved with lutein alone or lutein together with other nutrients and also that more study was needed. Lutein may also play a role in Haidinger's brush, an entoptic phenomenon that allows humans to detect polarized light.
While no recommended daily allowance currently exists for lutein as for other nutrients, positive effects have been seen at dietary intake levels of 6–10 mg/day. The only definitive side effect of excess lutein consumption is bronzing of the skin (carotenodermia).
Some foods are considered good sources of the nutrients: