The presence of the long chromophore of conjugated double bonds (polyene chain) provides the distinctive light-absorbing properties.

The polyene chain is susceptible to oxidative degradation by light or heat and is chemically unstable in acids.

Lutein is present in plants as fatty-acid esters, with one or two fatty acids bound to the two hydroxyl-groups.

[10] There is preliminary epidemiological evidence that increasing lutein and zeaxanthin intake lowers the risk of cataract development.

[3][17][18] Consumption of more than 2.4 mg of lutein/zeaxanthin daily from foods and supplements was significantly correlated with reduced incidence of nuclear lens opacities, as revealed from data collected during a 13- to 15-year period in one study.

The authors speculated that there may be a cataract prevention benefit for people with low dietary intake of lutein and zeaxanthin, but recommended more research.

According to the NHANES 2013-2014 survey, adults in the United States consume on average 1.7 mg/day of lutein and zeaxanthin combined.

[34] Although much higher levels have been tested without adverse effects and may also be safe, the data for intakes above the OSL are not sufficient for a confident conclusion of long-term safety.

[35] In the dietary supplement industry, the major market for lutein is for products with claims of helping maintain eye health.

Skin health via orally consumed supplements is one of the fastest growing areas of the US$2 billion carotenoid market.