People whose diet includes a lot of red meat are more likely to develop the early stages of an eye condition known as age-related macular degeneration (AMD), which is the leading cause of vision loss in older adults, according to an Australian study.

AMD arises from gradual damage to the macula, a structure on the retina of the eye that allows for seeing fine detail.

Dr. Elaine W.-T. Chong at the University of Melbourne and fellow researchers explain in the American Journal of Epidemiology that red meat contains compounds that “could result in oxidative damage and could be toxic to the retina.”

To clarify the role of meat consumption in the development of AMD, Chong’s group studied data on 5600 people who were aged 58-69 years in 1990-1994, when they completed food frequency questionnaires covering the previous year.

The presence of AMD was determined by retinal photography between 2003 and 2006, when the participants were 66-85 years old, and uncovered 1680 cases of early AMD.

The likelihood of developing AMD was 47 percent higher among people who ate red meat at least 10 times weekly, compared to those who ate it less than 4.5 times per week - even after accounting for factors that can increase the risk, such as smoking and obesity.

“A high level of red meat consumption may be a novel risk factor for early AMD or may act as a marker for a group of persons with an increased risk from other lifestyle factors,” Chong and her team conclude. “Confirmatory data from other cohort studies are needed.”

SOURCE: American Journal of Epidemiology, April 1, 2009.