Lutein – Keeping Your Eyes Healthy
Some researchers refer to lutein, lycopene and zeaxanthin as "non-nutritive bioactive constituents of plants". Others refer to them as "micronutrients".
Regardless of what you call them, there seem to be little doubt that they are important to human health.
One of the reasons that researchers can not agree on what to call lutein is that they are not sure if it is necessary for life, in small amounts, or simply beneficial for good health. There are no deficiency diseases associated with its absence in the diet, although it is one of the carotenoids.
Carotenoids are converted within the human body to vitamin A. Vitamin A is necessary for life. Dietary deficiency first presents with impaired vision, usually night blindness.
Occasionally, the cornea is destroyed and total blindness is a result. If the deficiency is not corrected, the lining of the upper respiratory passes and the bladder becomes hard. Death can be a result.
The blindness caused by vitamin A deficiency can not be corrected. But, if thought in the early stages, vision is restored. Even night blindness goes away.
There has always been worry associated with supplements that contain the animal form of vitamin A called retinol. Retinol is toxic at high dosages. The body can not get rid of it.
Carotenoids, on the other hand, are non-toxic.
Lutein, itself, is important to vision because it is a component of the retina, the area within the eye that transmits signals to the brain and allows you to see. Along with zeaxanthin, it is the primary pigment, within the retina.
Zeaxanthin ("Zee-a-ZAN-thin") concentration is highest in the macula, a tiny spot on the retina responsible for central vision. Lutein concentration is highest in the peripheral retina, where peripheral vision occurs.
There is a disease of the macula called Macular Degeneration, which often results in blindness. At one time, it was simply thought to be an age-related disease.
But, there is more and more evidence indicating that it is a "dietary disease".
There are many elements in the typical American diet that contribute to disease. Too much animal fat, not enough vegetables, low nutrient intake and high caloric intake are among them. Many people never get the micronutrients that are present in plants, because they cook them away.
But, today, even someone with the best diet would have trouble getting these micronutrients. Studies have shown that fresh fruits and vegetables are not as nutrient-rich as they once were, due primarily to over-farming.
Researchers continue to accumulate evidence of the importance of micronutrients by testing blood levels in people that have specific diseases.
For example, low blood levels of lutein are associated with macular degeneration, bladder cancer, osteoporosis, heart disease and ovarian cancer.
Low levels of lycopene and beta-carotene are associated with endometrial cancer.
Low levels of zeaxanthin are primarily associated with macular degeneration, although new studies come on a regular basis.
To insure that you get enough lutein and other micronutrients on a daily basis to reduce your risk of various diseases, take a good multi-nutritional supplement. Think of it as long-term health insurance.
Source by Joan Gosselin