Poor diet linked to age-related macular degeneration

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Individuals who ate a diet high in red and processed meat, fried food, refined grains, and high-fat dairy were three times more likely to develop age-related macular degeneration (AMD), an eye condition that damages the retina and affects a person's central vision, according to a new study by researchers from the University of Buffalo in New York and published in the British Journal of Ophthalmology.

For one of the two forms of AMD, late neovascular AMD, treatment is invasive and expensive. For the other form, geographic atrophy, there is no treatment. Therefore, the best course of action is to catch the condition early and prevent development, according to Shruti Dighe, lead researcher who conducted the study as part of her master's in epidemiology.

The authors studied the occurrence of early and late AMD over approximately 18 years of follow-up among participants of the Atherosclerosis Risk in Communities (ARIC) Study. Dighe and colleagues used data on 66 different foods that participants self-reported consuming between 1987 and 1995 and identified two diet patterns in this cohort, Western and what researchers commonly refer to as "prudent" or healthy, that best explained the greatest variation between diets.

A Western dietary pattern, one defined as high in consumption of red and processed meat, fried food, refined grains and high-fat dairy, may be a risk factor for developing late AMD. However, a Western diet was not associated with development of early AMD in the study.

Early AMD is asymptomatic, meaning that people often don't know that they have it. To catch it, a physician would have to review a photo of the person's retina, looking for pigmentary changes and development of drusen, or yellow deposits made up of lipids. With early AMD, there could be either atrophy or a buildup of new blood vessels in the part of the eye known as the macula. Not everyone who has early AMD progresses to the more debilitating late stage.

To date, most research has been conducted on specific nutrients, such as high-dose antioxidants, that seem to have a protective effect. Dighe explains that people consume a variety of foods and nutrients, not just one or two, and that's why looking at diet patterns helps tell more of the story.

"Our work provides additional evidence that that diet matters," Millen said in a statement. "From a public health standpoint, we can tell people that if you have early AMD, it is likely in your best interest to limit your intake of processed meat, fried food, refined grains, and high-fat dairy to preserve your vision over time."