Fish Oil and Eye Health

by | Aug 26, 2008 | 2006, Eye Health, Fish Oil Supplements, Macular Degeneration

Written by Susan Sweeny Johnson, PhD, Biochem.
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. (1)

Some common risk factors for macular degeneration include hypertension, cardiovascular disease, high 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 early dry form. (1)

In a recent study, 2335 elderly patients were screened for early (dry) and late (wet) age-related maculopathy (ARM) (macular degeneration) at baseline and after five years using pictures of their retinas. Their diets were assessed using a standardized questionnaire which was corroborated by physically measuring the daily food intake in 70 patients.

After correcting for smoking, age, sex, and vitamin C intake, 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 n-3 unsaturated fat diet also slightly increased the likelihood of early and ARM. Contrary to previous studies, (2-4) high unsaturated fat intake did not correlate with increased incidence of early or late ARM.  In fact, diets high in n-3 unsaturated fats decreased the incidence of late 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 early ARM by 40%. Three or more fish meals per week could reduce the incidence of late ARM by 75%. Fish oil contains essential n-3 fatty acids and is known to promote cardiovascular health.

As indicated by the known risk factors for ARM and the known benefits of n-3 fatty acid intake, consuming three or more fish meals per week may help keep elderly eyes healthy. Alternatively, fish oil supplements are available.

Source: Chua, Brian, Victoria Flood, Elena Rochtchina, Jie Jin Wang, Wayne Smith, and Paul Mitchell. “Dietary fatty acids and the 5-year incidence of age-related maculopathy.” Archives of ophthalmology 124, no. 7 (2006): 981-986.

© 2006 American Medical Association. All rights reserved.

Posted August 26, 2008.

References:

  1. Age-related Maculopathy, posted on Wikipedia.
  2. Seddon JM, Rosner B, Sperduto RD, et al. Dietary fat and risk for advanced agerelated macular degeneration. Arch Ophthalmol. 2001;119:1191-1199.
  3. Seddon JM, Cote J, Rosner B. Progression of age-related macular degeneration: association with dietary fat, transunsaturated fat, nuts, and fish intake. Arch Ophthalmol. 2003;121:1728-1737.
  4. Cho E, Hung S, Willett WC, et al. Prospective study of dietary fat and the risk of ge-related macular degeneration. Am J Clin Nutr. 2001;73:209-218.