You’ve probably heard that lutein and zeaxanthin are good for the eyes. These two major carotenoids found in the macula and retina are sometimes called xanthophylls or macular pigment. They function as antioxidants and also help protect tissues from phototoxic damage by filtering out some of the blue light.
The eye, and particularly the macula and retina, are almost constantly subjected to free radical generation and oxidative damage. Just as exposure to too much sunlight can damage the skin, so too can light damage the eyes. It is, thus, critical that you maintain your basic nutrients and especially antioxidants in the eye.
A study of macaque monkeys (with eyes similar to humans) showed that there was more zeaxanthin than lutein in the central fovea where vision is most clear. But, the concentration of zeaxanthin is reduced the further you get from the fovea and lutein dominates.
The macula has a yellow tint due to the presence of lutein, zeaxanthin and another xanthophyll called meso-zeaxanthin. It’s these pigments that help filter out or absorb some of the more damaging blue light to help protect the eye.
What the Studies Show
Carotenoids are especially important because they seem to help prevent age related macular degeneration. A study indicated that getting high levels of carotenoids (especially in dark green leafy vegetables) in the diet results in a 43% lower risk of age related macular degeneration, the leading cause of blindness.
The original Age-Related Eye Disease Study showed that antioxidants (vitamin C, vitamin E, beta carotene, and zinc) reduced the risk of age related macular degeneration by 25%.
The second Age-Related Eye Disease Study showed beneficial effects of adding lutein and zeaxanthin to the mix for preventing late stage age related macular degeneration.
Another study showed that lower levels of the antioxidant lycopene in the blood was associated with age related macular degeneration.
A study of monkeys who were feed a diet with no plant pigments for several years found that these pigments dissppear in the macula. And retinal abnormalities resembling age relate macular degeneration appeared.
Overall, there is an inverse relationship between the amount of macular pigment and age related macular degeneration. The more pigment the less macular degeneration. The less pigment, the more macular degeneration.
The Third National Health and Nutrition Examination Survey (NHANES III) examined the contents of lutein and zeaxanthin in the blood and found a wide variation. The quarter of the people with the lowest concentration averaged 0.19 μMole/L while the average concentration for the upper quarter of the people was 0.79 μMole/L. This is a difference of greater than 4 to 1.
How to Get Natural Antioxidants
Lutein and zeaxanthin cannot be synthesized or made within the body. They must come from external sources. If not in a supplement, they come almost entirely from plant sources.They may also come indirectly from plants through animals that eat plants.
The most important source of carotenoids are fruits and vegetables.
The best natural sources of both lutein and zeaxanthin are egg yokes and corn, both of which are yellow.
Most other fruits seem to supply more lutein or more zeaxanthin. For example, orange pepper has close to 5.6 time more zeaxanthin than lutein. But green pepper has 13 times more lutein than zeaxanthin.
Overall, most vegetables supply more lutein than zeaxanthin. Topping the list are egg yoke and corn. Other good sources for lutein and zeaxanthin include:
- Red seedless grapes
- Zucchini squash
- Orange pepper
- Yellow squash
- Green pepper
- Red grapes
- butternut squash
- Orange juice
- Celery stalks and leaves
- Green grapes
Conclusions You Can Use
Lutein and zeaxanthin are important components of eye health. These and other antioxidants are important to help reduce the likelihood of a number of eye problems including macular degeneration, cataracts and retinitis pigmentosa.
- Fruits and vegetables that are sources for lutein and zeaxanthin: the macular pigment in human eyes as published in the British Medical Journal
- BIOLOGIC MECHANISMS OF THE PROTECTIVE ROLE OF LUTEIN AND ZEAXANTHIN IN THE EYE as published in the Annual review of nutrition
- Secondary Analyses of the Effects of Lutein/Zeaxanthin on Age-Related Macular Degeneration Progression AREDS2 Report No. 3 as published in the Journal of the American Medical Association: Ophthalmology
- The Body of Evidence to Support a Protective Role for Lutein and Zeaxanthin in Delaying Chronic Disease. Overview as published in the American Society for Nutritional Sciences
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