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Straine-On-Success — Eye Candy? Scientists Debate the Value of Lutein Supplements

Published on September 16, 2015

The Claim: Lutein, a plant antioxidant, is critical for maintaining good vision and may even help keep brains healthy as they age. The Verdict: A large government study found that a daily cocktail of dietary supplements including lutein reduced the risk of a chronic eye disease progressing to an advanced stage. Other studies suggest that lutein can improve vision in healthy adults and improve cognition with age, but scientists say more research is needed.

Lutein and its close cousin zeaxanthin (pronounced zee-ah-zan-thin) are nutrients found in a variety of foods, including spinach, kale, collard greens and egg yolks. Lutein naturally found in marigolds is extracted to make dietary supplements, often sold in capsule form, says Richard L. Roberts, technical services manager at Kemin Industries Inc., of Des Moines, Iowa. Kemin partners with Royal DSM NV of the Netherlands to supply lutein and zeaxanthin to dietary-supplement companies.

When consumed, the two nutrients, which are yellow-orange colored, are deposited in the center of the retina, where they protect sensitive eye cells from incoming light, says Emily Y. Chew, deputy clinical director at the federal National Eye Institute. The nutrients also are believed to serve as antioxidants in the eye, protecting cells from being damaged by a chemical reaction called oxidation, she adds. Some scientists believe lutein may also provide similar protection to brain cells.

The two pigments were tested in a federally funded 4,203-person study, published earlier this year in the Journal of the American Medical Association. When taken along with vitamins C and E, zinc and copper, the nutrients helped prevent progression of an eye disease called macular degeneration in people who already have it, says Dr. Chew, co-author of the study. As a result, the NEI added lutein and zeaxanthin to its recommendation for daily supplements for macular-degeneration patients, which it calls AREDS2. The nutrients replace beta-carotene, which has been linked to lung cancer in smokers and former smokers, Dr. Chew says.

Some scientists think Americans aren’t getting enough lutein. A 2010 study, based on a large database of Americans and published in the Journal of the American Dietetic Association, estimated the average daily consumption of less than a milligram a day of lutein. That’s far below the six to 10 milligrams a day that a growing body of scientific research on vision and cognition suggests adults should consume, says Elizabeth J. Johnson, a scientist at the Jean Mayer U.S. Department of Agriculture Human Nutrition Research Center on Aging at Tufts University in Boston.

A 2013 study of nearly 300 centenarians and octogenarians, conducted by Dr. Johnson and colleagues and appearing in the Journal of Aging Research, found that the higher blood levels of lutein were linked to better performance on a series of brain-function tests, such as word association.

“If you have more lutein in the brain, it’s likely that you have better cognition,” says Dr. Johnson, adding that it’s not clear the nutrients are causing the better cognition. Part of the federal AREDS2 study, also published in JAMA, found no positive effect of nutritional supplements—including lutein, fish oil, zinc and beta-carotene, on cognitive function in elderly subjects.

Other research, some funded by the supplement industry, is finding benefits of lutein and zeaxanthin to people with healthy eyes and no known vision problems. For example, a 2014 study, published in Investigative Ophthalmology & Visual Science and co-funded by DSM and Kemin, found that one year of supplementation with the companies’ Floraglo brand lutein and Optisharp zeaxanthin reduced the time it took for subjects’ vision to recover after exposure to a blinding light, compared with controls taking a placebo, or sugar pill.

Other research has showed faster processing of images, improving reaction times—which can help with sports, such as baseball. “If you have higher lutein levels in your eye, you just see better,” says Billy R. Hammond, co-author of the Ophthalmology & Visual Science study and a neuroscientist at the University of Georgia, Athens. Dr. Chew says there is no proof that lutein supplementation improves vision appreciably in people without eye disease.

By Laura Johannes

 

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