Zeaxanthin is one of the most common carotenoid alcohols found in plants and some micro-organisms. It is the yellow pigment (xanthophyll) that gives paprika, corn and saffron and many other plants and microbes their characteristic colour. Orange pepper contains the most zeaxanthin among vegetables. Spirulina is also a rich source. Zeaxanthin is used as a food dye with E numberE161h.
Zeaxanthin supplements are commonly used to treat different disorders mainly affecting the eyes. Several observational studies have connected high dietary intake of foods providing zeaxanthin with lower incidence of age-related macular degeneration (AMD), most notably the Age-Related Eye Disease study (AREDS). Studies have found that food rich in lutein may play a role in preventing and improving the symptoms of AMD but it is less clear whether other supplements are effective, although some are being marketed as a treatment for loss of vision.
In one small study zeaxanthin supplements improved vision just as well as the supplement lutein in older men who had early signs of age-related macular degeneration (AMD). It is thought that any benefit of supplementation is more likely to be apparent in individuals exposed to high oxidative stress such as heavy smokers or those with poor nutrition. There is currently insufficient evidence supporting the use of a zeaxanthin-containing supplement in prevention and treatment of AMD or the formation or progression of cataracts.