When we talk of healthy eyes, the term zeaxanthin almost always pops up. Zeaxanthin is one of the more popular carotenoids found in the eye, specifically in the retina. The macula, which is the center of the retina, is where a high abundance of zeaxanthin can be found.
Together with a related compound known as lutein, zexanthin is said to protect the eyes against damage from ultraviolet rays, hence preventing the development of certain diseases, such as age-related macular degeneration, glaucoma, diabetic retinopathy, and cataracts. Zeaxanthin is visible in the macula as a dark yellow spot known as the macular pigment.
|Zeaxanthin is a yellow pigment which accumulates at the back of the eye, where it improves eyesight and protects the eye against light damage.|
Aside from eye protection, other merits of zeaxanthin include protection from oxidation and free radical damage, which becomes more difficult for your body as you age. Zeaxanthin also improves blood circulation in the eye, which helps improve vision and prevent the development of eye infections.
Zeaxanthin’s role in eye protection is supported by a number of different studies. One of them is the study conducted by the Schepens Eye Research Institute and Department of Ophthalmology of Harvard Medical School, which became the pioneering study on the effects of zeaxanthin on the eyes. In this study, the researchers made use of Japanese quails as subjects, since their retinas resemble human retinas in that they have more photoreceptive ‘cones’ that absorb carotenoids like zeaxanthin.
The researchers divided the carotenoid-deficient quails into two groups, with one group being fed with a zexanthin-supplemented diet. They were then subjected to light damage after a week. The result of their study showed that quails supplemented with zeaxanthin incurred minimal eye damage, while those with low levels of zeaxanthin incurred severe light damage.
This study became the start-off point for the famous Age-Related Eye Disease Study or AREDS, a highly-publicized study sponsored by the National Eye Institute of the National Institutes of Health. In this study, the researchers concluded that daily consumption of dietary antioxidants can slow the progression of age-related macular degeneration. At that time, both zeaxanthin and lutein were not yet included in the study, which only included Vitamins C and E, beta-carotene, zinc, and copper. The same institution is also in the middle of another study known as AREDS2, which will evaluate the effect of lutein and zeaxanthin versus a placebo for subjects between 50 and 80 years of age. It is expected to be completed at the end of 2012.
A lot of other studies have been published in various medical journals all supporting the fact that zeaxanthin increases the macular pigment in the retina, thus not only leading to healthy eyes and improved vision, but also protecting the eye against the development of macular degeneration.
Zeaxanthin Sources - Where Do You Get Zeaxanthin?
Both zeaxanthin and lutein can be found in large concentrations in dark green and leafy vegetables, like kale and spinach, two vegetables which are said to have the highest zeaxanthin content, making them ideal for maintaining good eye health. Likewise, these compounds can also be found in yellow vegetables and fruits, and even egg yolks. Other good zeaxanthin foods include collards, turnip greens, green peas, corn, broccoli, romaine lettuce, carrots, paprika, saffron, and green beans.
Zeaxanthin being a yellow/orange pigment, is found in highest concentrations in yellow/orange fruits and vegetables. Plenty can also be found in dark greens
There are also a lot of lutein and zeaxanthin supplements that are already out in the market as eye vitamins. Examples are EyePromise Zeaxanthin and Macula Complete, just to name a couple.
Zeaxanthin Dosage – How Much Should You Take?
As of this moment, there is no recommended dietary allowance or recommended daily intake for zeaxanthin, although experts agree that you need at least 6 milligrams of zeaxanthin daily to maintain good eye health. Most zeaxanthin supplements contain 1 to 10 milligrams of the said compound. There are also supplements that contain a combination of lutein and zeaxanthin, although lutein is more dominant in these supplements.
Zeaxanthin Side Effects – Any Dangers/Toxicity?
With regard to toxicity, there are no known toxic effects for large intakes of zeaxanthin. People who eat a lot of yellow and green fruits and vegetables may develop a condition known as carotenemia, which is characterized by a yellow discoloration of the skin. However, this condition is pretty harmless, although it can be confused with jaundice.
Extra Tips & Advice
Since zeaxanthin is fat-soluble, it is best absorbed when taken with fatty acid supplements like linoleic acid and fish oil. People that have low-fat diets are at risk for developing carotenoid deficiency since they cannot properly absorb zeaxanthin and lutein. Absorption of zeaxanthin can also be enhanced by Vitamin C, so taking Vitamin C supplements together with dietary and supplemental zeaxanthin can greatly enhance the beneficial effects that can be derived from these compounds.
There have also been studies conducted that show the adverse effect of smoking on carotenoid supplements. Smoking interferes with the body’s absorption of carotenoids, which is why it is important for smokers to include yellow and green fruits and vegetables in their diet. However, carotenoid supplements should be avoided by smokers since, for some unknown reason, this can increase the risk of acquiring lung cancer. This emphasizes the importance of making dietary changes rather than taking supplements wherever possible, and of course, let us not forget – the dangers of smoking.
Where To Learn More
To find out more about natural methods – including diet and exercise – for improving your eyesight, click the link to visit How To Improve Eyesight Naturally.