Zeaxanthin and astaxanthin are carotenoids, which are pigment compounds responsible for the bright color of some fruits, vegetables and seafood. According to the NYU Langone Medical Center, carotenoids act as antioxidants, and a high intake of them may lower the risk of a variety of medical conditions, such as cancer and heart disease. If you're interested in taking supplements, make sure you check with your doc first.
Function in the Body
In the body, zeaxanthin is concentrated in the macula, an area in the center of the eye's retina. Along with another carotenoid known as lutein, zeaxanthin protects the macula from wavelengths of blue light that may damage the eye. Its function as an antioxidant may keep the eye's lens clear by preventing oxidation. Astaxanthin does not appear to accumulate in any one part of the body. It inhibits the ability of free radicals to damage genetic material and cellular tissue, though, unlike zeaxanthin, it is not thought to protect a specific organ or area.
Possible Health Benefits
The presence of zeaxanthin in the retina may help protect against age-related macular degeneration, concluded a 2002 review article published in The Journal of Nutrition. A study published in 2008 in the Archives of Ophthalmology demonstrated that a high dietary intake of zeaxanthin, lutein and vitamin E was linked to a significantly decreased risk of cataracts. A number of studies, including one in Molecules and Cells in 2003, show that astaxanthin inhibits cellular inflammation. However, these studies were conducted in the laboratory; there isn't enough evidence to prove astaxanthin can prevent inflammation in humans.
The Institute of Medicine's Food and Nutrition Board has not set a recommended daily allowance for carotenoid compounds like zeaxanthin and astaxanthin. Based on the amount of zeaxanthin used in research studies, the American Optometric Association says healthy adults may benefit from consuming approximately 2 milligrams of the carotenoid each day. Scientists focusing on astaxanthin have used doses ranging from 4 to 16 milligrams in their studies, but there isn't enough research to indicate the optimal amount.
Best Food Sources
Zeaxanthin is richest in dark green, leafy vegetables and produce with a yellow or orange color. Examples include corn, green beans, broccoli, spinach, carrots, oranges and orange juice, tangerines, leaf lettuce, collard greens, peaches and peas, where it is typically found along with lutein. A 1-cup serving of cooked kale contains nearly 24 milligrams of combined zeaxanthin and lutein, and 1 cup of cooked spinach contains 20 milligrams of the two. Astaxanthin gives shrimp, salmon and other seafood their pink hue. Pacific salmon may contain as much as 5 milligrams of astaxanthin in every 3 ounces, while a serving of Atlantic salmon supplies about 1 milligram.