2014 Volume 23 Issue 1 Pages 17-21
In this review, we described two clinical trials that verified new nutritional functions of n-3 fatty acids in the ophthalmologic field. Firstly, we evaluated the efficacy of fish oil supplementation for subjects with dry eye in a randomized controlled trial. Fish oil group subjects (n = 15) ingested fish oil capsules containing eicosapentaenoic acid (EPA, 1245 mg/day) and docosahexaenoic acid (DHA, 540 mg/day) for 12 weeks. Placebo group subjects (n = 12) ingested placebo capsules. The subjective symptoms of "eye pain", the index of tear stability, and the deficits of mucin layer in the fish oil group were significantly improved, compared to those of the placebo group. These results suggest that fish oil supplementation may be effective in the treatment of dry eye. Secondly, we examined the effects of dietary supplementation with a combination of fish oil, bilberry extract, and lutein on subjective symptoms of asthenopia in humans in a randomized controlled trial. Active group subjects (n = 11) ingested a supplement containing n-3 fatty acid-rich fish oil (DHA 783 mg/day, EPA 162 mg/day), bilberry extract (anthocyanidin 59 mg/day), and lutein (17.5 mg/day) for 4 weeks. Placebo group subjects (n = 9) ingested placebo capsules. Asthenopia symptoms such as "stiff shoulder, low back pain", "frustration", "dry-eye", and "stuffy head" and a score of mental fatigue were improved in the Active group. These results suggest that dietary supplementation with the combination of n-3 fatty acid-rich fish oil, bilberry extract, and lutein improves subjective symptoms of asthenopia and mental fatigue in humans.
