Higher Intakes of Fish and DHA/EPA Associated with Protection against Age-Related Macular Degeneration
Reference:
Center for Vision Research, Department of Ophthalmology, Westmead Millennium Institute, Australia
Tan et al., Arch. Ophthamol., 127: 656-665, 2009.
Summary:
This study involved an elderly Australian group wherein 3654 participants were examined at baseline and 2454 were examined 5 and/or 10 years later so as to evaluate any relationships between baseline dietary intakes of various fatty acids and the 10- year incidence of age-related macular degeneration (AMD). The so-called Blue Mountains Eye study indicated that increasing intakes of long-chain omega-3 fatty acids as DPA/EPA consumed in the form of fish (were associated with a significant reduced risk of developing early AMD) with better proximate 50% lowered apparent risk of developing early AMD in those with above-average intakes of DHA/EPA. it is noted that these latter effects were only seen among participants with lower intakes of linoleic acid (omega-6) as commonly found in certain plant oils such as corn oil, safflower oil, sunflower oil, and other sources. The authors conclude that increased intakes of long-chain omega-3 fatty acids (DHA+EPA) and regular consumption of fish in the diet may protect against the development of early AMD.
Relatively modest intakes of fish (at least one serving of fish per week) was sufficient to support a beneficial effect in reducing the risk of early AMD as compared to those individuals consuming less than one serving of fish per week. It is noteworthy that the average fish intake amounts to approximately one serving every ten days in North America and approximately less than 50% of the population consumed fish over a 7-day period. The present study adds to the potential benefits of greater consumption of fish and DHA/EPA for overall health in the population (as well as disease prevention / measurement) over and above the improvement of cognitive functioning, cardiovascular care, and other disorders which have received more intense investigation to date. It is of interest to note that the apparent protective effects of increased consumption of fish and DHA/EPA with respect to AMD incidence were evident in those having a reduced ratio of omega-6 : omega-3 fatty acids in their diet. Such has not been found in other studies related to cardiovascular disease benefits where higher intakes of fish and DHA/EPA appear to be beneficial regardless of the omega-6 : omega-3 ratio in the diet. The mechanisms by which higher intakes of fish an DHA/EPA may be beneficial with respect to the risk of early AMD await further investigation.