Eating fish helps prevent eye disease

Sunday May 17, 2009 (foodconsumer.org) -- A diet of fish, nuts and olive oil, and devoid of trans fats like pies and donuts, could help stave off the eye disease called age-related macular degeneration (AMD).

Two Australian studies in the May issue of Archives of Ophthalmology have found that simple diet changes can prevent the disease, which is the leading cause of severe vision loss among individuals over the age of 65.

AMD attacks the macula of the eye, near the center of the retina, where our sharpest vision occurs, according to the Macular Degeneration Partnership. While AMD never causes complete blindness, it robs the individual of all but the peripheral vision, leaving only dim images or holes at the center of vision.

By the year 2020, according to the Archives article, as many as three million Americans are expected to have late stage AMD. The National Institutes of Health (NIH) says an estimated 8 million elderly Americans are at high risk to develop advanced AMD.

“With baby boomers poised to reach retirement age,” says the NIH website, “AMD is increasingly being viewed as an oncoming epidemic that would affect millions of Americans.”

In one of the research reports, Dr. Jennifer S.L. Tan of the University of Sydney and colleagues studied 2,454 participants from 1992 to 1994. The participants completed a food questionnaire which was analyzed to show their intake of fatty acids. Digital photographs of the retina were taken to assess the development of the disease.

Eating just one serving of fish per week was associated with a 31 percent lower risk of developing AMD, said researchers, after adjusting for risk factors such as age, smoking and gender. Women are more at risk for AMD.

“In conclusion,” wrote researchers, “our findings support the hypothesis that increased intake of omega-three polyunsaturated fatty acids and regular consumption of fish and or nuts in the diet may protect against the development of early AMD.” Further studies are needed, they added, to determine whether changing an individual’s diet or adding supplementation could prevent or delay the disease.

The second study examined 6,734 individuals ages 58 to 60 and was conducted at the Centre for Eye Research Australia by Dr. Elaine W.T. Chong and others. Between 1990 and 1994, participants’ diets were assessed and they were tracked for the development of AMD between 2003 and 2006. In the follow-up period, researchers found that 2,872 cases of early AMD and 88 cases of late-stage AMD developed.

People who ate higher levels of trans fats, including cakes, pies and processed foods, were more likely to have late AMD, said researchers. Those who consumed the most omega-three fatty acids, such as olive oil, were less likely to have AMD.

Omega-three fatty acids are believed to protect against damage to the retina, said researchers, the part of the eye that AMD attacks. People who follow a diet low in processed foods and high in omega-three fatty acids and olive oil “might enjoy some protection from developing AMD,” wrote the authors.

(By Sheilah Downey, and edited by Heather Kelley)