Even if you are reading this without glasses, it's not too early to start taking your eye vitamins. Some nutrients can stave off the burdensome vision loss and eye disease that occur as we age, mounting research suggests.
But claims by supplement manufacturers about the powers of eye-friendly antioxidants are frequently overblown. And though carrots have long been touted as a magical sight-booster, other foods, including dark, green leafy vegetables, may have a stronger impact on your peepers.
More than 150 million Americans use glasses or contacts to correct refractive errors such as nearsightedness or farsightedness, according to a report from the eye health organization Prevent Blindness America. And the prevalence of blindness and sight problems increases with age. In people older than 40, the most common diseases include age-related macular degeneration, cataracts, diabetic retinopathy and glaucoma.
Some 7.6 percent of adults older than 40 have either advanced or intermediate age-related macular degeneration, according to the National Eye Institute.
Studies over the last few decades suggest that people whose diets are high in specific antioxidants such as vitamin C, E, zinc, or carotenoid plant pigments such as beta-carotene or lutein are less likely to develop common age-related eye diseases, said Julie Mares, a professor of ophthalmology and visual sciences at the University of Wisconsin at Madison.
But Mares cautions that it's better to get these nutrients through whole foods, rather than supplements, which usually provide only single nutrients and may be lacking other critical compounds. Researchers are finding that those who eat a wide range of healthy foods "have much lower odds for having age-related diseases," said Mares an expert in nutrition and vision.
A study published in the journal Ophthalmology showing that vitamins E and C did nothing to help protect aging eyes from macular degeneration -- the longest-running study to test vitamin E for eyesight in men, and the first to try out vitamin C alone -- further confirms the lack of benefits of single antioxidants, said Mares.
Nutritious diets may yield a higher density of macular pigment, according to a study co-written by Mares. This important yellow pigment contains the lutein and its sister compound zeaxanthin, which are thought to protect the back of the eye. Other protective nutrients and plant chemicals contained in fruits, vegetables and whole grains may help by reducing the breakdown of lutein and zeaxanthin, Mares said.
Still, sales of vision supplements in the U.S. reached $370 million in 2010, a 6 percent increase over the previous year, according to estimates by Nutrition Business Journal. Lutein, multivitamins and fish oil are the most popular eye-related products, NBJ said.