Study: Lutein (1995) and Zeaxanthin - Cataracts & Cancer

(a) Xanthophylls Lutein and zeaxanthin) are the only carotenoids detected inhuman lens. Elevated plasma or nutrient intake levels of antioxidant vitamins, such as carotenoids, ... are associated with diminished risk for cataract... Elevated intake of spinach, which is high in lutein and zeaxanthin ..... was most consistently associated with a lower risk for cataract extraction. Elevations in lipid antioxidant status is associated with prolonged lens function.
(b) Xanthophylls are likely to eliminate the phototoxic blue light selectively. (c) There is a strong inverse association between elevated consumption of dark green vegetables, which are rich in lutein and zeaxanthin, and a decreased risk for oxidative stress related diseases such as cataract and cancer.
(d) Lutein and zeaxanthin are the only carotenoids that have been reported to be present in several sites of the human eye, such as the retina and the macula. Lutein and zeaxanthin are also the only carotenoids present inhuman lens. Consumption of spinach, which is rich in lutein and zeaxanthin showed a consistent inverse relationship with risk of cataract. Carotenoid intake is related to the risk for cataract. KJ Yeum etal, "Measurement of Carotenoids, Retinoids, and Tocopherols in Human Lenses," Investigative Ophthalmology and Visual Science, December, 1995, Vol. 36. No. 13, pp. 2756-2761.