Fish oils may protect against vision loss
Consuming docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), two omega-3 fatty acids found in fish, could help prevent age-related macular degeneration (AMD), study results published online first in the Archives of Opthamology indicate.
Women with the highest DHA intake had a 38% lower risk for developing AMD compared with women with the lowest DHA intake (95% CI 0.45 to 0.86, P=0.004), according to William G. Christen, ScD, of Brigham and Women's Hospital and Harvard Medical School in Boston, and colleagues.
“These data appear to be the strongest evidence to date to support a role for omega-3 long-chain fatty acids in the primary prevention of AMD, and perhaps a reduction in the number of persons who ultimately have advanced AMD,” the researchers wrote.
They administered food frequency questionnaires to 38,022 Women's Health Study participants who did not have a previous AMD diagnosis to analyze the effect of DHA, EPA and fish intake on AMD incidence. During an average 10-year follow-up period, 235 confirmed AMD cases occurred, in which best-corrected visual acuity was 20/30 or worse.
The researchers found that women in the highest tertile for DHA intake had a 38% lower risk of developing AMD compared with women in the lowest tertile (95% CI 0.45 to 0.86, P=0.004). Similarly, women who consumed more EPA had a 34% lower AMD risk (95% CI: 0.48-0.92).
In general, women who consumed one or more servings of fish per week had a 42% lower risk compared with those who ate fewer than one serving per month (95% CI 0.38 to 0.87, P=0.001)
“This lower risk appeared to be due primarily to consumption of canned tuna fish and dark-meat fish,” the researchers wrote.
The findings remained significant after adjusting confounders including intake of saturated, monounsaturated and trans unsaturated fat.
Study limitations include potential for recall bias due to questionnaire use and a lack of generalizability beyond the study population of female healthcare professionals, according to the researchers. They added that more randomized trials are necessary to confirm the findings.