In a study published in 2006 Archives of Opthalmology, 2335 elderly patients were screened for dry (early) and wet (late) age-related macular degeneration (AMD) (maculopathy) at baseline and after five years using pictures of their retinas. Their diets were assessed using a standardized questionnaire which was validated by physically measuring the daily food intake in 70 patients.
The screening showed that low fat diets (less than 27% calories from fat) including low unsaturated fat, increased the likelihood of early ARM by 50-70%. A low omega-3 unsaturated fat diet also slightly increased the likelihood of both dry and wet ARM. Diets high in omega-3 unsaturated fats decreased the incidence of wet ARM by 60%. The possible reasons for this discrepancy were discussed in detail in the article.
When the food origin of fat intake was compared, the researchers found that one fish meal a week could reduce the incidence of dry ARM by 40%. Three or more fish meals per week could reduce the incidence of wet ARM by 75%. Fish oil contains omega-3 fatty acids DHA and EPA.
Loss of vision in the elderly is often the result of macular degeneration or a breakdown in central vision - the macula being the retinal area in the center of the eye. In 85 – 90% of cases it is known as the “dry” form caused by the buildup of fatty tissue called drusen. In 10-15% of cases it is the “wet” form which usually follows the dry form, where blood vessels grow extensively behind the retina and then hemorrhage.
Some common risk factors for macular degeneration include hypertension, cardiovascular disease, high (omega-6) fat diets, oxidative stress and exposure to intense sunlight. Wet macular degeneration can be treated with laser cauterization, but few treatments are available for the dry form.
Researchers concluded that consuming three or more fish meals per week [or taking omega-3 fish oil supplements] may help keep elderly eyes healthy. There are a number of good fish oils on the market, but one of the best new ways to get omega-3 polyunsaturated fats is from krill oil.
Chua B, Flood V, Rochtchina E, Wang JJ, Smith W, Mitchell P. Dietary Fatty Acids and the 5-Year Incidence of Age-Related Maculopathy. Arch Ophthalmol. 2006;124:981-986.