Encyclopedia - Lutein

What are antioxidants?
How does lutein protect the eye?
What about diet?

Lutein is an antioxidant found in several areas of the body including the skin and eyes. In recent years, researchers have discovered that age-related eye diseases such as cataracts and macular degeneration might benefit from the antioxidant effects found in vitamins and minerals from fruits or vegetables.

Lutein belongs to a chemical class of compounds called carotenoids and is found in the central area of the retina called the macula. The macula is responsible for acute central vision, and damage to this portion of the retina severely limits a patient's ability to read, recognize faces, and perform any other task that requires straight-ahead vision. Some research suggests that lutein may protect the macula from potentially damaging forms of light.

What are antioxidants?

Antioxidants act as scavengers, preventing the formation of and neutralizing the damage from free radicals - substances thought to be responsible for acceleration of the aging process and causing damage such as lowered immune system responses, heart attacks, arthritis, eye diseases, cancers, and other disorders. Free radicals are produced by the body in response to environmental pollutants such as cigarette smoke, pesticides, smog, radiation, and many drugs. Although free radicals do have certain beneficial effects, there is extensive evidence to indicate that they can damage both the structure and function of cell membranes, causing degenerative diseases and conditions.

How does lutein protect the eye?

Lutein deposited in the retina and lens of the eye is thought to protect the macula from damaging oxidation by filtering blue light. The substance apparently absorbs and dissipates dangerous ultraviolet light rays that are associated with age-related macular degeneration, the leading cause of irreversible blindness among those 65 years of age and beyond.

What about diet?

The body does not make its own lutein and must depend on dietary sources to get an adequate supply. Nutritionists suggest 6 milligrams per day, which would be two salad bowls of spinach, for instance. Generally, a diet rich in yellow and orange fruits and leafy green vegetables will provide an adequate supply, although most people do not get enough to reach the 6 milligram level. The foods richest in lutein are spinach, collards, kale, mustard greens, and turnip greens. Other fruits and vegetables that contain lutein are:

Romaine lettuce
Leeks
Pears
Broccoli
Brussels sprouts
Butternut squash
Cabbage
Carrots
Celery
Corn
Cornmeal
Cucumbers
Green beans
Honeydew
Kiwi
Mango
Okra
Oranges and orange juice
Peppers, green and orange bell
Persimmons
Pumpkins
Red grapes
Yellow squash
Zucchini squash

Cooked vegetables appear to be a better source of lutein because cooking unlocks the cell walls and releases the substance making it more available. Lutein also appears to be more easily absorbed when vegetables are served with a source of fat, such as cooking oil or butter.

Lutein has been the subject of much interest over the past few years, with the general conclusion being that a diet rich in lutein may reduce the risk of developing macular degeneration. In any event, lutein-rich foods should be a part of any balanced diet.