The effect of consuming an anthocyanin-containing supplement derived from Bilberry (Vaccinium myrtillus) on eye function: A randomized, double-blind, placebo-controlled parallel study

Abstract

Objective: The purpose of this study was to determine the effects of 6-week consumption of anthocyanin-containing supplement on eye function. Methods: This was a randomized, placebo-controlled, double-blind, parallel-group comparison study involving 32 healthy Japanese adults with eye fatigue after using visual display terminals (VDTs). Subjects were randomly allocated into either the active group (bilberry-derived anthocyanin 43.2 mg per capsule) or placebo group using a random number generator. Subjects consumed either one active or placebo capsule once a day for 6 weeks. The primary outcome measured was the change in percentage of pupillary response pre- and post-VDT use, whereas the secondary outcomes were tear film break-up time, Schirmer's value, muscle hardness, and subjective symptoms. Experimental data was analyzed using Student's t-test, the two-way analysis of covariance, or Mann–Whitney U-test. Results: Each group included 15 subjects in the efficacy analysis. The active group showed a significant improvement in the logarithmic conversion values of the percentage of pupillary response (active group: 0.2 ± 0.4, placebo group: 0.0 ± 0.3; P = 0.043) and pupillary response/near point (active group: 0.1 ± 0.4, placebo group: -0.1 ± 0.3; P = 0.049) pre- and post-VDT use at 6 weeks compared with the placebo group in a subgroup analysis per eye. No adverse events were reported. Conclusions: The consumption of the supplement containing anthocyanins extracted from bilberry for 6 weeks inhibited the decrease in the accommodative function caused by oxidative stress due to VDT use.