The “Eyes” Have It: Fish Oil for Eye Health

These days, you can’t pick up a health magazine or nutrition book and not find someone singing the praises of fish oil. From supporting cardiovascular health and a normal inflammatory response, to supporting healthy brain function and keeping the skin supple and hydrated, there’s certainly no shortage of feathers in fish oil’s cap. Eating oily fish as a whole food is a great option, since it comes with complete protein and other helpful nutrients, but many of the benefits that come from eating fish are primarily due to the omega-3 fatty acids found in the fat – specifically, eicosapentaenoic acid and docosahexaenoic acid, EPA and DHA for short.

Fish oil is well known for helping conditions associated with the body’s natural inflammatory process. (Think of good quality fats as oil being added to rusty machine parts to help them work more smoothly.) One of the lesser-known properties of fish oil is that it may be good for eye health. Occasional inflammation in the eyes may interfere with the production of tears and other eye lubricants, both in quantity and chemical composition. Tears aren’t just water and salt; they contain an oily layer, which prevents them from evaporating too quickly and leaving someone with excessively dry eyes.

Dry eye syndrome, or “dry eyes,” has been the unfortunate victim of somewhat comical ads for prescription and over-the-counter eye drops and artificial tear products. To people living with the condition, however, it’s no laughing matter. It can cause mild to moderate discomfort, and more severe cases may interfere with work and reduce overall quality of life. Studies support a role for EPA and DHA in aiding this condition.

The incidence of dry eyes is lower in populations consuming large amounts of omega-3 fats, and is higher in populations with a high omega-6 to omega-3 ratio. In one trial that investigated the effects of fish oil supplementation in individuals with dry eyes, compared to placebo, subjects taking fish oil (1245mg EPA and 540mg DHA per day) for 12 weeks experienced small but notable improvements in subjective eye pain and dry sensation. Aside from dietary supplementation, topical application of omega-3 fatty acids via eye drops may be another way to introduce these helpful compounds into the eyes. Experiments employing mouse models of dry eye indicate that eye drops containing a mixture of omega-3s and hyaluronic acid improved corneal function and decreased inflammation and oxidative stress markers on the surface of the eyes.

Another eye health concern for which fatty fish consumption or fish oil supplementation may be beneficial is age-related macular degeneration (AMD). Compared to healthy controls without AMD, AMD patients consume significantly lower amounts of oily fish. Amounts of EPA and DHA measured in blood and the cell membranes of red blood cells (a good way to assess body levels of these fats) showed that higher amounts of these fats in the blood and cell membranes were associated with significantly lower risk for AMD, independent of potentially confounding factors, such as high triglycerides, hypertension, and family history of AMD.

Okay, sounds great! But what if you don’t like fish? Are you doomed to the adult equivalent of when you were forced to choke down soggy, overcooked Brussels sprouts at the dinner table as a kid? Do you have to eat fish to get these benefits? No: fish oil capsules to the rescue! But what about those “fishy burps” that scare people away from taking fish oil supplements? Fortunately, many high-quality fish oils are now available that are designed to reduce the risk of the fishy flavor “repeating” on you.

For vegetarians and vegans, who may find it difficult to get adequate EPA and DHA from the selection of foods available to them, the omega-3 fat, alpha-linolenic acid (ALA, found in flax, chia, and walnuts) has also been shown to be beneficial in animal models of dry eye. However, because many people do not efficiently convert ALA into the more potent EPA and DHA, it may be best to prefer eating fish or taking fish oil, but if those are not options, plant-based omega-3s are still a good choice.

Sources

1. Liu A, Ji J. Omega-3 Essential Fatty Acids Therapy for Dry Eye Syndrome: A Meta-Analysis of Randomized Controlled Studies. Medical Science Monitor: International Medical Journal of Experimental and Clinical Research. 2014;20:1583-1589.
2. Miljanović B, Trivedi KA, Reza Dana M, Gilbard JP, Buring JE, Schaumberg DA. The relationship between dietary n-3 and n-6 fatty acids and clinically diagnosed dry eye syndrome in women. The American journal of clinical nutrition. 2005;82(4):887-893.
3. Kawakita T, Kawabata F, Tsuji T, et al. Effects of dietary supplementation with fish oil on dry eye syndrome subjects: randomized controlled trial. Biomed Res. 2013;34(5):215-20.
4. Merle BM, Benlian P, Puche N, et al. Circulating omega-3 Fatty acids and neovascular age-related macular degeneration. Invest Ophthalmol Vis Sci. 2014 Mar 28;55(3):2010-9.