Slow the progression of age - related Macular degeneration (AMD) through diet
A randomized clinical trial observed that two caroitenoids called lutein and zeaxanthin can slow the progression of age - related Macular degeneration (AMD). It was observed that lutein and zeaxanthin are retinoprotective.
In this clinical trial, 56 participants consumed 60ml of Lutein complex (LC) derived from marigold (lutein) and wolfberry (zeaxanthin) for 5 months.
The results of supplementing diet with Lutein Complex were promising as it was observed that inflammatory markers, best-corrected visual acuity (BCVA), and intraocular pressure (IOP) were lowered in subjects when treated with LC for 5 months. As a result, long-term consumption of LC may suppress the oxidative stress by enhancing the antioxidant status and thereby preclude the incidence of AMD.
Lutein effects on AMD were observed in mice that were exposed to light (2000 lux, 3 h). The retinal pigment epithelium (RPE) showed disruption at 12h. The disruption remained 48 hours after light exposure. However, this was ameliorated in the mice treated with intraperitoneal lutein at 12 h, suggesting that lutein promoted tight junction repair.
The role of zeaxanthin in slowing the progression of age - related Macular degeneration (AMD) was established by a study that found people with lower plasma concentrations of zeaxathin had higher chances of developing AMD.
Where does Lutein and zeaxanthin accumulate in the eye?
Lutein belongs to the xanthophyll family of carotenoids, which are synthesized within dark green leafy plants.
There is evidence that carotenoids help to retard some of the destructive processes in the retina and the retinal pigment epithelium that lead to age-related degeneration of the macula.
A study that measured The carotenoid pigments in the whole human retina, and in the macular region found that
lutein and zeaxanthin, are deposited at an up to 5 fold higher content in the macular region of the retina, as compared to the peripheral retina. Zeaxanthin is preferentially accumulated in the foveal region, whereas lutein is abundant in the parafoveal region.
Lutein and zeaxathin slows the progression of age related macular degeneration in two ways:
Current studies suggest that lutein is predominantly restricted to its function of quenching harmful triplet chlorophyll ( light- absorbing pigment). Triplet excited chlorophyll is known to act as the photosensitizer in photosynthesis, passing excitation energy to oxygen, thus forming singlet oxygen, results in lipid peroxidation, a chain reaction that can result in tissue damage.
zeaxanthin on the other hand is the major player in the deactivation of excited singlet chlorophyll and thus in NPQ (non-photochemical quenching, which is a process that starts in Response to Excess Light Energy.