In our aging population, more and more older adults will find their independence prematurely ended as eye disease removes their ability to drive, read and pursue favorite hobbies. Two new studies offer hope that healthy eating patterns that lower our risk for cancer and heart disease may also protect our eyes. Experts say that while high-dose nutrients in supplement form might help those diagnosed with one type of eye disease, evidence does not support high-dose supplements as a preventive tool.
Cataracts are the main cause of mild to moderate visual impairment associated with aging. A cataract is a clouding of the lens in the eye that causes blurred vision. Scientists believe that damage from ultraviolet rays of the sun can lead to cataracts. Experts urge people to protect their eyes from sunlight by wearing sunglasses that block both UVA and UVB rays, and a hat with a brim. Avoiding tobacco also decreases risk.
Earlier, researchers thought that getting enough antioxidant nutrients might protect eyes from developing cataracts. Then a major study called the Age-Related Eye Disease Study (AREDS) found that supplements of vitamins C and E, beta-carotene, zinc and copper had no effect on development of cataracts. But a new study links greater consumption of healthful foods, including fruits, vegetables and whole grains, with lower risk of cataracts. Similarly, in studies of cancer risk, individual nutrient supplements may show no effect while an overall plant-based diet supplying a variety of antioxidant phytochemicals is linked with lower cancer risk.
Age-related macular degeneration (AMD) is the leading cause of vision loss in older Americans. It occurs when the cells break down in the macula � part of the retina of the eye.
The macula is responsible for distinguishing fine detail, so it's vital for reading, driving, watching television and recognizing faces. In the AREDS study, the supplement of antioxidants with zinc and copper reduced development of advanced AMD by 25 percent among people in early stages of the disease. A study using supplements of beta-carotene alone had no effect.
Another study found that lutein (a related carotenoid) in a supplement alone or with other antioxidants could decrease symptoms in people with AMD and increase pigment in the macula by 50 percent. All of these studies deal with supplements to slow the progress of AMD to its advanced stage. Experts caution that not all "optical supplements" are the same formula found effective in AREDS, and people should not use them without first consulting with their physician. And none of these studies provide any evidence that these supplements can prevent development of AMD.
A new study of more than 110,000 men and women found that people who ate three or more servings of fruit per day reduced their risk of getting AMD by about 36 percent compared to those who ate fewer than 1.5 servings daily. For now, experts say people who don't have AMD should wear UV protection and work toward diets that supply a wide variety of carotenoids and other antioxidants.
Lutein and another carotenoid called zeaxanthin are found in many vegetables, especially dark green leafy vegetables such as spinach, kale, collard greens, and chard. By focusing on fruits and vegetables instead of supplements, you don't need to worry about excesses and imbalances that can occur when bolstering isolated nutrients.
Some scientists believe that lifestyle habits, such as exercise, that promote heart health and blood flow to the eyes may also help protect against AMD. Initial evidence links fish (and the omega-3 fats it contains) and nuts with protection from AMD, and high fat consumption and obesity with greater progression of early AMD to more severe forms.
AICR
