EPA and DHA Again Linked with AMD Risk

According to a meta-analysis (1) published in the June issue of Archives of Ophthalmology, a higher intake of the omega-3 fatty acids EPA and DHA reduced the risk of age-related macular degeneration (AMD). In analyzing 9 studies that included roughly 88,900 participants, the Australian authors report that higher intakes of EPA and DHA cut the risk of early AMD substantially and yielded a 38% risk reduction for advanced AMD.

Most recently, a study published in the August issue of the American Journal of Clinical Nutrition is the first in Europeans to show a beneficial association between neovascular AMD and the consumption of oily fish (e.g. mackerel, tuna, salmon, sardines, and herring) (2). The study, funded in part by the European Commission and the Macular Disease Society UK, is consistent with results from studies in the US and Australia.

Study Design and Methods

The EUREYE study is a cross-sectional population-based study in persons aged 65 years or older in 7 centers located from north to south Europe. Participants in the cross-sectional population-based EUREYE study underwent fundus photography and were interviewed by using a food-frequency questionnaire. Fundus images were graded by the International Classification System for Age Related Maculopathy.

Questionnaire data were converted to nutrient intakes with the use of food-composition tables. Survey logistic regression was used to calculate odds ratios (ORs) and 95% CIs of energy-adjusted quartiles of EPA or DHA with neovascular AMD, taking into account potential confounders.

Results

Dietary intake data and fundus images were available for 105 cases with neovascular AMD and for 2170 controls without any features of early or late AMD.

Eating oily fish at least once per week compared with less than once per week was associated with a halving of the odds of neovascular AMD (OR = 0.47; 95% CI: 0.33, 0.68; P = 0.002). Compared with the lowest quartile, there was a significant trend for decreased odds with increasing quartiles of either DHA or EPA. Odds ratios in the highest quartiles were 0.32 (95% CI: 0.12, 0.87; P = 0.03) for DHA and 0.29 (95% CI: 0.11, 0.73; P = 0.02) for EPA.

In short, habitual consumption of oily fish at least once a week was linked to a 50% reduction in the risk of developing wet AMD. Further, people who consumed at least 300 mg per day of DHA and EPA were 69% less likely to have wet AMD then those consuming less.

References

1. Chong EW-T, et al. Dietary n-3 fatty acids and fish intake in the primary prevention of AMD-A systematic review and meta-analysis. Arch of Ophthalmol 126:826-833, 2008.
2. Augood C, et al. Oily fish consumption, dietary docosahexaenoic acid and eicosapentaenoic acid intakes, and associations with neovascular age-related macular degeneration. Am J Clin Nutr 88:398-406, 2008.