What is Lutein ?
Lutein and zeaxanthin are xanthophylls, which belong to carotenoid pigments consisting of more than 600 members. Lutein is a yellowish pigment found in kale, spinach, and broccoli, and gives yellow colors to corn and egg yolk, and various fruits, vegetables, and flowers. Zeaxanthin is chemically very close to lutein, and occurs in most lutein preparations (extracts) as a minor constituent. Zeaxanthin shares health benefits with lutein, and can be either taken from food or produced in our body from lutein by biochemical conversion.
"contaminant", which, in this case, is a desirable one.
Carotenes and xanthophylls, the brilliant yellow pigments, were isolated in 1831 from carrot root by Heinrich Wilhelm Ferdinand Wackenroder (1789-1854), and from yellow autumn leaves in 1837 by Berzelius, respectively. In Greek, xantho" means yellow, and "phylls" stands for leaves, which is comparable to "chlorophylls" (green leaves). Many scientific studies ensued, and by 1902, there were over 800 publications in the field of carotene research. Xanthophylls were found in algae, and lutein, a component of xanthophylls was found in egg yolks. Later researches confirmed that carotenes and xanthophylls are close related in molecular structure, and Harold Strain coined the word "carotenoids " to refer to the entire group of diverse, and yet closely related substances. Major known functions of these phytochemicals are photoreception and photoprotection. Zeaxanthin and antheraxanthin, other members in the family, are also found to be involved in heat (energy) dissipation by converting themselves to violaxanthin, thus adding additional measures for the protection of photosynthsis systems.
In addition to being an integral part of photosynthesis systems as photoreceptors and protectors, carotenoids are strong anti-oxidants and protects plant tissues from damages caused by free radicals formed by UV-irradiation, etc. When we eat carotenoids such as beta-carotene, lutein, and pycopene through food, they protect our body against oxdiative and free radical damages as well.
In addition to anti-oxidant actions, beta-carotene converts in our body to Vitamin A, which is an essential for our body functions including vision. Like beta-carotene, lutein is a carotenoid found commonly in diets. Studies indicate lutein and zeaxanthin essential nutritions for healthy eyes and vision.
More recently, lutein and zeaxanthin are found to accumulate specifically in the small area called macula in the retina of our eyes, raising the possibility that lutein also may protect our eyes and optic nerves, like they do for plant tissues from UV damages. As light enters the eye through the lens and passed focused to the back of the eye, an area known as retina (which is like a movie screen onto which images are projected) captures the light and converts the information to electrical impulses of optic nerves, which are sent to the brain. A small area at the center of the retina, called macula, is important for detailed vision. Macula contains pigments whose main constituents are lutein and zeaxanthin, which are both anti-oxidants and photoprotectors.
Every 11 minutes, a person goes blind in the US. As we age, our eyes, thus our vision deteriorate inevitably. Unlike skin or other tissues, eye systems, especially optic nerves will not regenerate, and once they are damages, it won't recover and the damages are there to stay. Accumulation of the damages will result in the functional loss of the eye - blindness. What is life without vision? (Please don't say this to blind people!) Macular degeneration is a leading cause of blindness among old people in the US, causing 300,000 complete blindness annually, and affecting the vision of 13 million people. It doesn't take a genius to see that we need to protect this important part of our eyes. Once the lutein pigment runs out and become thin in the protective pigment layer of macula, the eye and the optic nerves become vulnerable to damages by UV or any harmful irradiation, and free radicals.
Recent studies also indicates that lutin is likely to be preventive of eyes from other dieases such as cataracts and glaucoma, and other body parts from lung cancer, breast cancer, and cardiovascular problems.
LUTEIN ,(loo teen) n [LATIN luteum = egg yolk, from luteus = yellow]- a yellow pigment in the chemical family of carotenoids and found in egg yolks, vegetables, marigold flowers, alfalfa and to a lesser degree in many other plants. The original medical association of LUTEIN was as an isolate from the corpus luteum, a part of the ovaries, and hence its name, but important medical aspects are its presence in the macula of the eye where it is strongly implicated in maintaining eye health, and as a protective agent from heart disease. Humans do not synthesize lutein and depend entirely on dietary sources such as vegetables (and eggs) or supplement lutein pills.
CHEMICAL-Organic, carotenoid, biological anti-oxidant,
PHYSICAL (in purified form)-yellow colored slightly hydroscopic crystalline solid
FORMULA C40 H52 O2
STRUCTURE- see graphic above
MOLECULAR WEIGHT 644
Lutein has in the past several years been the subject of many studies (see reference link below) associating it with risk reduction for failing eyesight due to Age-related Macular Degeneration or AMD, and therefore has generated significant interest. While the National Eye Institute adopts a "guarded evaluation" (see NEI link at bottom) of a Lutein/AMD risk association, a general conclusion from the studies available is that increased dietary intake of Lutein reduces the risk for macular degeneration. Note that risk reduction does not imply a cure once macular degeneration has started but reduction of risk implies prevention for some people, and slowing or halting the progression of macular degeneration once it starts could be realistic expectations as more studies are indicating.
See also ZEAXANTHIN
A recent study relating lutein to macular degeneration by Stuart Richer, O.D. presented at the Southern Council of Optometrists 1999 annual meeting, indicated "improvements in visual function in as little as three months. Often striking improvements in vision were detected through follow-up tests, even when the patient did not report subjective vision changes" in study subjects with the dry form of macular degeneration after a diet supplemented with lutein rich foods. Since the study group apparently did not include subjects with wet form macular degeneration it would not be scientifically prudent to assume that both forms would have the same results. Yet assuming that the wet form would not benefit may not be a prudent approach either, considering the relative ease and inexpense of supplementing a diet with lutein rich foods or lutein pills.
Sufficient lutein of the quantity indicated for macular degeneration risk reduction can be obtained from a proper diet, but considering that this requires daily attention to the lutein content of specific food items not usually present in a diet and the disciplinary persistence to maintain that attention, many people may not obtain the lutein required for macular degeneration risk reduction solely from diet. Often people in the over 75 high risk group reside in senior housing complexes where meals are supplied and the option to select a lutein rich diet is not available.
Considering this failing, for some people in a high risk group or those with macular degeneration hoping to slow or halt its progression, taking lutein pills can be a reliable way to assure sufficient lutein intake that results in increases in blood serum levels equivalent to dietary consumption of high lutein foods. A study sponsored by the USDA (see USDA link at bottom) indicates "the amount of lutein that gets into the body from supplements is similar to that contained in spinach when eaten as part of a fat containing diet." It is important to note that in either case the presence of some fat (or oils) in the diet acts to aid the absorption of lutein.
NEI page position on Lutein
This evaluation has changed from not encouraging the use of Lutein and even loosely insinuating by association a possibility of harm, to acknowledging studies that indicate "a link between lutein and decreased risk of eye disease." Also they have published results of their nutritional study (AREDS) and fully endorse the concept that a combination of those nutrients included in the study (Lutein was not included) as "effective treatment to slow the progression of AMD." Thankfully they have announced further studies which specifically address the roll of Lutein.
USDA sponsored study SERUM RESPONSE OF LUTEIN IN HUMANS AFTER INGESTION OF A LUTEIN SUPPLEMENT OR SPINACH
The Foundation Fighting Blindness has coverage of many conditions causing blindness including AMD. However their literature, (like the NEI page used to) seems to discount lutein, only passivly refferring to it in green leafy vegetables, while promoting the more medically orthadox treatments, some of which they fund studies for. Which brings us to the the reason for providing a link - from time to time they enroll patients for clinical trials involving treatment for AMD. If you have AMD this web site should provide up-to-date information for enrollment.