Omega 3 supplement no more beneficial for dry eye than olive oil, study finds

16 Apr 2018 --- Omega 3 fatty acid supplements yield no more beneficial results for dry eye symptoms than a placebo – olive oil – a study funded by the National Eye Institute (NEI) has found.

“The trial provides the most reliable and generalizable evidence thus far on omega 3 supplementation for dry eye disease,” says Maryann Redford, D.D.S., M.P.H., program officer for clinical research at NEI.

The study utilized 535 participants with at least a six-month history of moderate to severe dry eye symptoms. Among them, 349 people were randomly assigned to receive three grams daily of fish-derived omega 3 fatty acids in five capsules. Each daily dose contained 2000 mg eicosapentaenoic acid (EPA) and 1000 mg docosahexaenoic acid (DHA). These are high doses, respectively.

Concerning the placebo, 186 people were randomly assigned to receive five grams daily of olive oil (about one teaspoon) in identical capsules. Study participants and the researchers did not know their group assignment.

Findings indicated no significant differences between groups in terms of improvement of dry eye symptoms.

Patient-reported symptoms were measured as change from the baseline in the "Ocular Surface Disease Index," a 100-point scale for assessing dry eye symptoms, with higher values representing greater severity. 

After 12 months, mean symptoms scores for people in both groups had improved substantially, but there was no significant difference in the degree of symptom improvement between the groups.

Symptom scores improved by a mean of 13.9 points in the omega 3 group and 12.5 points in the placebo group. A reduction of at least ten points on the index is considered significant enough for a person to notice an improvement. Overall, 61 percent of people in the omega 3 group and 54 percent of those in the control group achieved at least a ten point improvement in their symptom score, but the difference between the groups was not statistically significant.

“This well-controlled investigation conducted by the independently-led Dry Eye Assessment and Management (DREAM) Research Group shows that omega 3 supplements are no better than placebo for typical patients who suffer from dry eye,” adds Redford.

To replicate real-life settings, all participants were free to continue taking their previous medications for dry eye, such as artificial tears and prescription anti-inflammatory eye drops. This is due to omega 3’s status as an “add-on” therapy.

Therefore, “the study results are in the context of this real-world experience of treating symptomatic dry eye patients who request additional treatment,” says study chair for the trial, Penny A. Asbell, M.D., of the Department of Ophthalmology at the Icahn School of Medicine at Mount Sinai in New York City.

Dry eye disease occurs when the film that coats the eye no longer maintains a healthy ocular surface, which can lead to discomfort and visual impairment. The condition affects an estimated 14 percent of adults in the United States. 

Omega 3 fatty acids supplements are big business, representing a US$1 billion market in the United States, according to the Nutrition Business Journal. Despite omega-rich foods being available in the grocery aisles, consumer increasingly turn toward supplements for the various medical benefits such as cardiovascular health.