Serum analysis indicates strong protective effect of acids againstAMD

May 1, 2006

Serum analysis indicated that high levels of omega fatty acids,linoleic acid (LA), and alpha-linolenic acid (ALA) are inverselyassociated with age-related macular degeneration (AMD).

Serum analysis indicated that high levels of omega fatty acids, linoleic acid (LA), and alpha-linolenic acid (ALA) are inversely associated with age-related macular degeneration (AMD).

"In the last few years, there has been an explosion of interest in the potential protective association of omega fatty acids in an ever-growing number of health-related conditions," said Astrid Fletcher, PhD, at the annual meeting of the Association for Research in Vision and Ophthalmology.

"The epidemiologic evidence for the benefits of omega fatty acids in AMD is far from conclusive," said Dr. Fletcher, of the London School of Hygiene and Tropical Medicine.

To date, studies of dietary markers have reported conflicting results of the benefits of omega fatty acids in AMD, but none have evaluated the blood levels of the nutrients.

A total of 4,700 individuals aged 65 years and older participated in a nested case-control study (the population-based cross-sectional EUREYE study). Of these participants, 158 developed AMD and blood samples were available for 149. The samples were evaluated for the levels of LA, ALA, eicosapentaenoic acid (EPA), and docosahexanoic acid (DHA).

"When adjusted for age, ALA was associated with a strong decrease of the odds of developing AMD in the third tertile (p < 0.0001). LA also was associated with a strong decrease of the odds of developing AMD (p < 0.001) with increasing levels of LA," Dr. Fletcher said. "For EPA, there was no association with decreased odds of developing AMD. For DHA, there was a suggestion of a reduction in the highest quartile."

The investigators also found significant interactions for LA with ALA, EPA, and DHA and significant interactions for ALA and EPA.

"Our results support a possible protective role of the essential fatty acids LA and ALA for geography atrophy and neovascular AMD," Dr. Fletcher said. "We found no association with EPA and DHA alone, but this was only observed in interaction with LA and ALA. Caution is advised due to limitations of a cross-sectional study design."

Trials are ongoing to provide further information on EPA and DHA.