Eye Health
In
the Retina:
In 1945, George Wald (1906–1997) observed that the macular
pigment in humans had the same absorption spectrum as crystalline
leaf xanthophyll. The pigment when extract from human maculas
yielded a yellow hydroxy-carotenoid that Wald believed was
lutein or leaf xanthophyll itself.
While a number of studies have identified significant levels
of Lutein and Zeaxanthin in different parts of the eye such
as the photo-receptory rod outer segments of the peripheral
retina, specific binding sites of the retinal microtubules,
in the iris, ciliary body, and retinal pigment epithelium
and choroid at high concentrations, the most significant presence
of Lutein and Zeaxanthin is in the macular region of the retina.
Almost 36% of the total carotenoid content of the eye is composed
of Lutein, while Zeaxanthin occurs in 2 isomeric forms- 3R,
3'R-zeaxanthin and meso-zeaxanthin-each of which reperents
app 18% of the total carotenoids.
In
Other Tissues:
Recently, a small amounts of Lutein esters
have been reported in human skin and serum.
The macular region of the retina is highly vulnerable to age
related macular degeneration (AMD) which may involve peroxidative
damage to the highly unsaturated lipids in the tissue. Lutein
acts as an antioxidant, protecting cells against damaging
effects of free radicals. Hence, lutein is used as a nutritional
supplement to aid the treatment of AMD.
Studies indicate that the individuals with AMD degeneration
have lower levels of lutein than those corresponding individuals
with out AMD. People with more lutein content in the macula
of the eye appear to focus more clearly and posses healthier
eyes. Lutein plays an important role as a selective filter
to protect the macula from potentially damaging forms of light
and consequently preventing the progression of AMD. Thus,
diet with adequate amounts of lutein would lower the risk
of AMD. In this direction, there are two approaches of nutritional
supplementation, either employing lutein in ester form or
in free form. After ingestion, the human body has the ability
of converting lutein esters to lutein. There is no known toxicity
data regarding lutein, occurrence of the same in the daily
consumed foods and increasing literature report of the potential
health benefits have created a sufficient atmosphere for the
consumers to make buying decisions and not wait for approval
from health and government agencies.
Disclaimer: These statements have not been evaluated by
the Food & Drugs Administration. These products are not
intended to diagnose, treat, cure or prevent any disease
