Seniors whose diets are rich in omega 3 fatty acids have a significantly lower risk of developing AMD (age-related macular degeneration) compared to other people of the same age, scientists revealed in the journal Ophthalmology. Good sources of Omega 3s are cold water oily fish, such as sardines, anchovies, mackerel, herring and salmon, as well as several types of shellfish.

Sheila K. West, PhD., of the Wilmer Eye Institute, Johns Hopkins School of Medicine and team set out to determine whether a diet rich in omega-3 fatty acids among seniors might be linked to a lower risk of developing AMD, compared to other seniors whose diets were not rich in omega-3s. They focused mainly on elderly individuals “for whom fish and shellfish were a normal part of the diet”.

Some previous studies, including AREDS (Age-Related Eye Disease Study) found that omega-3 intake could protect against advanced AMD, a leading cause of vision loss in the USA.

The retina of the human eye has high concentrations of omega-3s.

The team gathered information on the fish and shellfish consumption over a 12-month period of 2,391 individuals aged 65 to 84 years. They were all from Maryland’s Eastern Shore, USA. They were asked to complete a validated questionnaire.

They were all evaluated for AMD and placed in four groups: 1. A control group – people with no AMD (1,942 participants). 2. Those with early AMD (227 participants). 3. Those with intermediate-stage AMD (153 participants). 4. Those with advanced AMD (68 people). In this fourth group participants had either abnormal blood vessel growth and bleeding in the eye (neovascularization) or geographic atrophy in the macular area of the retina – both these conditions can lead to either severe vision loss or total blindness.

Dr. West said:

    “While participants in all groups, including controls, averaged at least one serving of fish or shellfish per week, those who had advanced AMD were significantly less likely to consume high omega-3 fish and seafood. Our study corroborates earlier findings that eating omega-3-rich fish and shellfish may protect against advanced AMD.”

No association was found between dietary zinc consumption and lower advanced AMD risk. Crab and oysters are rich in zinc. However, the researchers stress that supplements have much higher zinc levels than crab or oysters. Many experts say zinc protects against AMD. The AREDS recommended zinc supplements.

The scientist say they selected participants whose diets rich in omega-3s were part of their normal lifestyles, rather than a deliberate choice to please the investigators.

“The Impact of Fish and Shellfish Consumption on Age-Related Macular Degeneration”
Bonnielin K. Swenor, Susan Bressler, Laura Caulfield, Sheila K. West
Ophthalmology – December 2010 (Vol. 117, Issue 12, Pages 2395-2401, DOI: 10.1016/j.ophtha.2010.03.058)

Written by Christian Nordqvist