It's the same advice that mothers everywhere have been giving for years, but now there's science to back it up: Eating veggies is good for the eyes. A new study from the University of Wisconsin confirmed that women who have a healthy diet, exercised regularly and didn't smoke were less likely to suffer macular degeneration as they got older. Macular degeneration is the leading cause of vision problems in older people in the United States, researchers said.
The study of 1,313 women from Oregon, Iowa and Wisconsin is the first to look at several lifestyle factors that influenced age-related macular degeneration (AMD), according to a release from the university. These findings show a healthy lifestyle can improve the chances of good eyesight for those who inherit the condition, according to Dr. Julie Mares of the UW School of Medicine and Public Health.
According to the study, 18 percent of women deemed to have unhealthy lifestyles developed early AMD while just 6 percent of women in the healthy-lifestyle group developed the condition. Researchers found that the association of healthy eyes and healthy overall diets was stronger than what they observed for any single nutrient. Women whose diet score was the in top 20 percent had a 50 percent lower prevalence of early stages of macular degeneration than woman with the lowest percent for healthy diet scores. Higher scores were given to those with more leafy green and orange vegetables, fruits, dairy, grains and legumes, according to the release.
Mares said this was the first study where researchers found higher levels of physical activity lowered the likelihood of early macular degeneration. However, this study didn't show obesity was related to AMD, but obese women were more likely to have more macular degeneration. That trend was explained by a poor diet and low physical activity, according to the university. The study also confirmed other studies that smoking played a role in eye disease.
The university said the study is being published online in the Archives of Ophthalmology, a journal of the American Medical Association. The research was funded by the National Institutes of Health, National Eye Institute. It was also supported by the Research to Prevent Blindness and the Retina Research Foundation.
This month the federal Department of Agriculture and Health and Human Services will release the 2010 dietary guidelines. These guidelines directly impact the eating habits of one in every four Americans whose meals are subsidized by federal programs. The precise timing of the release this month is unknown, according to John Webster, a spokesman for the USDA.
The major question here is whether or not the new guidelines will impact the obesity epidemic that is increasing ever so quickly in our country. Decisions about what to eat are generally made at the supermarket, not while reading federal guidelines. “What we need to do is put more effort into figuring out how to engage people who don’t use nutrition as a major deciding point when buying food,” says Alice H. Lichtenstein, a professor at the Friedman School of Nutrition Science and Policy at Tufts University. “We really need to learn more about consumer behavior.’’ Some experts wonder if more nutrition information helps or confuses shoppers.
It is arguable that the guidance needs to be much clearer, more like the wildly popular “Eat This, Not That!,’’ a magazine column, which was then reworked into a book and an iPhone app, that made its mark by telling readers which fast food was nutritionally better than others. Dr. David L. Katz, director of Yale University’s Prevention Research Center and an associate professor at the university’s School of Medicine, is an advocate for more specific guidance. For example, 45 to 65 percent of daily calories should come from foods that contain carbohydrates. But “lollipops and lentils are both carbs,’’ Katz says. And while the current federal recommendations do stress eating carbohydrates from whole grains, fruits, and vegetables, he adds, “We need to do a better job of specifically defining highly recommended foods.’’
While no one is talking about the final 2010 recommendations before their release, a June advisory report, open for public comment, gives some clues. Cohen of UMass Amherst expects the final guidelines to place even greater emphasis on physical activity and continue to recommend that people include more fruits, vegetables, nuts, seeds, foods with Omega-3 fatty acids, and a suggestion to eat three servings of low-calorie dairy products a day (some argue that calcium supplements should be used in place of the third serving).
Eating a diet rich in omega-3 fatty acids appears to protect seniors against the onset of a serious eye disease known as age-related macular degeneration (AMD), a new analysis indicates.”Our study corroborates earlier findings that eating omega-3-rich fish and shellfish may protect against advanced AMD,” study lead author Sheila K. West, of the Wilmer Eye Institute at Johns Hopkins School of Medicine in Baltimore, said in a news release from the American Academy of Ophthalmology.
“While participants in all groups, including controls, averaged at least one serving of fish or shellfish per week, those who had advanced AMD were significantly less likely to consume high omega-3 fish and seafood,” she added.
The observations are published in the December issue of Ophthalmology.
West and her colleagues based their findings on a fresh analysis of a one-year dietary survey conducted in the early 1990s. The poll involved nearly 2,400 seniors between the ages of 65 and 84 living in Maryland's Eastern Shore region, where fish and shellfish are eaten routinely. After their food intake was assessed, participants underwent eye exams. About 450 had AMD, including 68 who had an advanced stage of the disease, which can lead to severe vision impairment or blindness. In the United States, AMD is the major cause of blindness in whites, according to background information in the news release.
Prior evidence suggested that dietary zinc is similarly protective against AMD, so the researchers looked to see if zinc consumption from a diet of oysters and crabs reduced risk of AMD, but no such association was seen. However, the study authors theorized that the low dietary zinc levels relative to zinc supplements could account for the absence of such a link.
Anand Swaroop, chief of the neurobiology, neuro-degeneration, and repair laboratory at the U.S. National Eye Institute, interpreted the findings with caution. “It does make huge sense theoretically,” he said. “Photoreceptors have a very high concentration of a specific type of fatty acids and lipids, relative to many other cell types. So it would make sense that omega-3 consumption would be beneficial. The theory is sound.”
“However, I wouldn't want people to start taking grams of omega-3 to protect against AMD based on this finding because I'm not really sure that this study has sufficient power to draw any conclusions,” Swaroop added. “This is just a one-year analysis and AMD is a long-term disease. The correlation is important, and it should be explored further. But we need larger studies with longer term follow-up before being able to properly assess the impact.”
SOURCE: Anand Swaroop, Ph.D senior investigator and chief of neurobiology, neurodegneration, and repair laboratory, U.S. National Eye Institute, Bethesda, Md.; American Academy of Ophthalmology, news release, Dec. 1, 2010