Mediterranean diet reduces risk for AMD

The popular Mediterranean diet-rich in fresh fruits and vegetables, olive oil, fish, nuts, lean meat and whole grains—not only does your heart good, but also your eyes.

That's according to a poster presented May 1 at the 2018 annual meeting of the Association for Research in Vision and Ophthalmology. Researchers at the international consortium EYE-RISK reported that the nutritious diet reduced the risk for age-related macular degeneration (AMD) by 39%. The findings were based on questionnaires from about 5,000 participants in two previous studies, the Rotterdam and Alienor research projects, that looked at the links between aging, disease (including degenerative eye diseases) and nutrition.

AMD is the leading cause of severe vision loss among U.S. adults over age 50.

'Remarkable outcome'

Among AMD's initial symptoms:

• Gradual loss of ability to see objects clearly.
• Shape of objects appears distorted.
• Straight lines look wavy or crooked.
• Loss of clear color vision.
• Dark or empty area in the center of vision.

The diet has much working in its favor, says Susan Summerton, O.D., certified nutritionist specialist with the Ocular Nutrition and Wellness Society who practices optometry in Florida. AMD is linked to oxidative stress, autophagy decline and inflammation, Dr. Summerton says. Research has revealed that the polyphenol (a plant-based compound) abundant in the Mediterranean diet are responsible for lowering inflammation. Good fats—such as olive oil, fruits, vegetables and nuts—deliver potent antioxidants that reduce inflammation and lower free radical damage, she says.

Also, the high-fiber diet has a positive effect on the gut's microbiome, Dr. Summerton adds: "It is quite a remarkable outcome to find the Mediterranean diet reduced the risk of advanced AMD by 39%."

The benefits of diet and lifestyle changes

Dr. Summerton quickly notes that the diet doesn't work in isolation but reflects a lifestyle change that includes exercise. Among the points made in the new study are the benefits of drinking more water that can lead to greater hydration and increased metabolic rate and mitochondrial function, she says.

"We have known from previous studies that moderate aerobic exercise helps protect the structure and function of nerve cells in the retina after damage," she says. "Previouis studies have shown that the effects of exercise come partly from a growth factor called 'brain-derived neurotrophic factor' (BDNF). In another study, low BDNF levels were detected in an AMD group and may have been found to be insufficient to protect the photoreceptors, resulting in thinning of our nuclear layer.

"Previous studies focused on the food and exercise part but we know AMD is multifactorial and the Mediterranean diet is also a lifestyle," she adds. "Some other lifestyle factors such as getting out in nature, getting a good night sleep, coming together with family and friends over a home-cooked meal and lower levels of chronic stress are also potential preventative health payoffs."

Learn more about eye-friendly nutrients such as lutein and zeaxanthin that can reduce the risk of certain eye diseases, including AMD.