Written by Jessica Patella, ND. Study results conclude that supplementing with bilberry and fish oil saw improvements in both signs and symptoms of severe dry eye disease.
Dry eye disease is one of the most common eye disorders, affecting an estimated 16 million Americans 1. Dry eye results in itching, burning eyes, that can feel as if something is scratching them due to reduction in tears. Past research has shown decreased tear production can be associated with oxidative stress and inflammation 2,3. Bilberry is high in antioxidants to combat oxidative stress and was researched as a supplement option for those suffering with dry eyes 2.
Bilberry is what gives plants and fruits a bluish-purple color due to the anthocyanins in the plant 2. Previous studies have found bilberry to have subjective improvements in dry eyes after supplementation for 1-month4,5. Yet, this led researchers to want to investigate if bilberry would result in objective changes and if supplementation could occur for longer-term2.
The current research included 24 participants diagnosed with severe dry eye symptoms (>33 on the Ocular Surface Disease Index (OSDI)). The participants were randomly assigned to either an intervention group (n=12, bilberry & fish oil) or a control group (n=12). The intervention group consumed 6 capsules daily, which totaled 600 mg bilberry extract and 240mg fish oil (docosahexaenoic acid) before breakfast2.
The results after 3-months of supplementation were as follows:
- The OSDI score improved 11.21 points in the intervention group, compared to 0.95 points in the control group.
- The non-invasive tear break-up time (NITBUT) improved 1.42 points in the intervention group, compared to 0.12 points in the control group.
- The percentage of meibomian gland openings was 10.8% in the intervention group, compared to 4.8% in the control group (the more openings the more oil production which keeps tears from drying).
These results indicate supplementing bilberry and fish oil can improve both subjective and quantitative objective measures of severe dry eye disease2. This was the first study to look at both factors and indicates the possibility that bilberry may improve tear film stability in those with dry eye disease2.
In conclusion, supplementing bilberry and fish oil showed improvements in both signs and symptoms of severe dry eye disease. This pilot study should be repeated with a larger sample size and include a placebo group, instead of just a control group.
Source: Wing, Y. Yu, Lily YL Chan, Aden Chung, Paul H. Lee, and George C. Woo. “Bilberry-containing supplements on severe dry eye disease in young and middle-aged adults: A 3-month pilot analysis.” Frontiers in Nutrition 10 (2023).
© 2023 Yu, Chan, Chung, Lee and Woo. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY).
Posted April 17, 2023.
References:
- Health NIo. Dry Eye. Updated 4/8/22 Accessed 4/3/23, https://www.nei.nih.gov/learn-about-eye-health/eye-conditions-and-diseases/dry-eye
- Yu WY, Chan LYL, Chung A, Lee PH, Woo GC. Bilberry-containing supplements on severe dry eye disease in young and middle-aged adults: A 3-month pilot analysis. Front Nutr. 2023;10:1061818. doi:10.3389/fnut.2023.1061818
- Kojima T, Wakamatsu TH, Dogru M, et al. Age-related dysfunction of the lacrimal gland and oxidative stress: evidence from the Cu,Zn-superoxide dismutase-1 (Sod1) knockout mice. Am J Pathol. May 2012;180(5):1879-96. doi:10.1016/j.ajpath.2012.01.019
- Ozawa Y, Kawashima M, Inoue S, et al. Bilberry extract supplementation for preventing eye fatigue in video display terminal workers. The journal of nutrition, health & aging. 2015;19(5):548-554.
- Riva A, Togni S, Franceschi F, et al. The effect of a natural, standardized bilberry extract (Mirtoselect®) in dry eye: a randomized, double blinded, placebo-controlled trial. Eur Rev Med Pharmacol Sci. May 2017;21(10):2518-2525.
