The macula or macula lutea (“yellow spot” in Latin) is an oval yellow area near the center of the retina of the human eye.
At the center of the macula is the fovea; with the highest concentration of cone cells (photo-receptor cells) in the retina and is responsible for our detailed central vision. Central vision can be defined as your vision when reading a book or when looking directly at an object or someone’s face. It allows you to discern fine details, contrast and color.
The macula is shielded by an important and naturally occurring protective substance known as the macular pigment (MP). MP comes entirely from dietary origin, and is made of three carotenoids called lutein, zeaxanthin and meso-zeaxanthin (L, Z & MZ). These three carotenoids are found in equal amounts at the macula, (shown below in the bulls-eye pattern below) with MZ being the dominant carotenoid at the epicenter of the macula (fovea) where our vision is sharpest.
The most potent of the three antioxidants. It is found at the very center of the macula, the fovea, which is the epicenter of our central vision. This part of the eye has the highest density of photoreceptors (cones) and the highest light exposure. Therefore, the tissue at the most risk is protected by the strongest of the three antioxidants. Studies have shown that supplementation with Meso-Zeaxanthin has resulted in increased levels of macular pigment optical density.
The protective role of lutein in the eye stems from its ability to filter short wavelengths of visible blue light, function as an antioxidant and stabilize membrane integrity. These functions are believed to play an important role in reducing light-induced oxidative damage which can lead to age-related degenerative disease such as age-related macular degeneration and cataract.
The role played by the powerful antioxidant zeaxanthin in the eye is to sharpen central vision (the clearness with which objects stand out from their surroundings), reduce the effects of glare (blue light) and maintain healthy visual acuity. Zeaxanthin is also found in the brain and other organs. Zeaxanthin along with Meso-Zeaxanthin protects retinal tissue by absorbing similar wavelengths of high energy light.
It is no accident that nature has taken the trouble to give humans the ability to accumulate these three dietary compounds at the very center of the retina, where vision is sharpest, where color vision is processed, and where oxidative stress is maximum. Macular pigment limits oxidative injury at the retina by limiting the amount of short wavelength (blue) visible light incident upon the photoreceptors (irradiation with short wavelength light is known to promote free radical production), and also because its constituent carotenoids are effective scavengers of free radicals (i.e. antioxidants, just like vitamin C). However, it is important to realize that the collective antioxidant effect of the macular carotenoids is maximized when they (L, Z and MZ) are taken together in a supplement.
Macular pigment cannot be taken for granted. Humans do not have the ability to manufacture carotenoids, only plants produce them. Macular pigment starts developing in utero and comes from the nutrients found in the mother’s diet. As we grow and develop, MP continues to replenish itself from the nutrients in our diets. However, our diets today tend to be devoid in these critical nutrients due to a significant increase in processed foods, over farming and shortened harvest cycles. Since the western diet, even a healthy diet, does not provide for enough of these critical nutrients to protect our vision from oxidation over our lifetime, we must consider supplementation with all three of the critical carotenoids found in MacuHealth with LMZ.