What is lutein? Lutein (and zeaxanthin) are two well-known members of the carotenoid family. They belong in the the subcategory of the carotenoids named the xanthophylls (pronounced ZAN-tho-fils), along with the antioxidant astaxanthin. They are very close relatives and are often found in the same foods.
There are over seven hundred known carotenoids, but only about a dozen out of about fifty that are absorbed by your body have been studied close enough so that we know what they do.
The name lutein is derived from the Latin word luteus meaning golden yellow, its natural color. However, it's also found concentrated in foods of other colors too, notably leafy green vegetables.
Carotenoids are fat-soluble: they are much better absorbed when you eat them with fats, since they are transported through your bloodstream by your LDL-cholesterol.
Lutein and zeaxanthin are the only carotenoids found in the retina and lens of the eye. When combined with vitamin C and vitamin E, they protect your eyes from free radical damage and improve your vision by filtering out potentially-dangerous ultraviolet radiation from the sun. People with light colored eyes are more susceptible to damage from sunlight than those with dark eyes.
Prevent cataracts and macular degeneration. Studies suggest that diets rich in these antioxidants may help reduce your risk of developing age-related cataracts and macular degeneration, the leading cause of blindness in people over 50. The macula, located in the center of the retina, is responsible for producing the sharp, central vision needed to see fine detail (for reading, sewing, etc.). The fragile cells in the macula are highly susceptible to damage from free radicals.
The best sources of lutein and zeaxanthin are dark green leafy vegetables. Egg yolks have the highest concentration of lutein and zeaxanthin among all foods. See my page on foods high in lutein for a complete list.
For prevention of degenerative eye problems, you can find products that combine lutein with other antioxidants beneficial for eye health. Refer to my page on lutein supplements to learn more.