Macular Pigment

Macular Pigment is composed of three xanthophyll carotenoid molecules – Lutein, Zeaxanthin and Meso-zeaxanthin.  The body selectively absorbs these carotenoids from the diet, and deposits them in the macula (forming the ‘Macula Lutea’ or ‘Yellow Spot’).

Metabolism & Oxidative Stress

The retina is the most metabolically active tissue in the human body, with an extremely high demand for oxygen.  Oxidative stress occurs when, during normal metabolic processes, the rate of production of free radicals and reactive oxygen species (molecules with extra, unpaired electrons) is higher than the retina’s antioxidant and repair systems can handle.  These oxidants steal electrons from other molecules they come into contact with, damaging them in the process.  In particular, proteins needed for cell health, lipids within cell membranes, and even DNA are damaged by the oxidants as they steal electrons.  This high level of stress on the retinal cells can affect their efficiency, resulting in mitochondrial dysfunction and a reduced level of function.

Macular Pigment = Antioxidant

Due to its chemical composition, macular pigment is a potent scavenger of a variety of reactive oxygen species, as it is able to donate electrons, thereby protecting against oxidative damage.  In addition, macular pigment attenuates high-energy visible light, reducing the photo-oxidative effects of this portion of the visible light spectrum.

Risk Factor

A depleted macular pigment is a high risk factor for Age-Related Macular Degeneration (AMD) and other retinal diseases.  The pathogenesis of AMD and other retinal diseases includes the effects of oxidative damage, and a robust Macular Pigment reduces these effects.

Macular Pigment Histology Images

From http://www.sbs.utexas.edu/SnodderlyLab/gallery.html

(Click image to view full size)