Many people try to treat dry eye symptoms by consuming fish oil, either as a supplement or by consuming oily fish. Fish oil contains omega-3 fatty acids, which research has shown to have overall health benefits. However, more research is needed to determine whether omega-3 fatty acids can specifically help treat dry eyes.
There is some evidence that fish oil may be beneficial in treating dry eyes. People can take fish oil as a supplement, either in capsule form or in liquid form. People can also get fish oil from eating oily fish like salmon, trout, and tuna.
In this article, we look at whether fish oil is an effective and safe treatment for dry eyes, as well as dosage recommendations.
Fish oil contains the omega-3 fatty acids docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA).
According to the National Center for Complementary and Integrative Health, DHA is important for the proper functioning of the brain and eyes. Researchers are still investigating whether omega-3 fatty acids can help treat diseases of the brain and eyes.
According to the American Academy of Ophthalmology (AAO), omega-3 oils can improve the function of the meibomian glands. The meibomian glands produce the oily layer in tears.
Problems with the oily tear layer can lead to dry eyes as the oily layer prevents the water layer of the tears from evaporating and provides moisture to the eyes.
The AAO also states that the omega-3 fatty acids found in fish oil can reduce inflammation. Inflammation of the eyelids or the front of the eye can make dry eye worse, so fish oil can improve symptoms.
People can take fish oil as a supplement, either as a capsule or in liquid form.
People can also consume fish oil by eating fish high in omega-3 fatty acids, such as:
- White tuna
- Lake trout
Flaxseed oil also contains an omega-3 called alpha-linolenic acid (ALA). Flaxseed oil only contains ALA, not EPA or DHA. The liver converts ALA into EPA and DHA.
According to the National Institutes of Health (NIH), the body is only able to convert ALA into about 15% of EPA and DHA. The NIH recommends that consuming EPA and DHA from food sources or supplements is the only way to increase fatty acid levels in the body.
If people don’t want to consume fish products, they can opt for an omega-3 supplement made from seaweed. According to the NIH, algae oil provides around 100-300 milligrams (mg) of DHA and can also contain some EPA. Algae oil can provide the body with a similar amount of DHA as eating cooked salmon.
A 2016 study looked at the effects of EPA and DHA on dry eyes in 105 people over a period of 12 weeks. The study found that supplementation with EPA and DHA resulted in a significant improvement in dry eye symptoms compared to placebo with linoleic acid.
Other research mentioned in the study also suggests that omega-3s in fish may help relieve dry eyes. In a study of 32,470 women, the researchers found that women who ate 5-6 servings of tuna every week had a 66 percent reduction in dry eye than women who ate 2 servings a week or less.
According to the AAO, omega-3 fatty acids can also help reduce the risk of abnormal blood vessel growth that occurs in retinal diseases such as age-related macular degeneration.
However, a 2018 NIH study found that omega-3 supplements were no more effective than a placebo at treating chronic dry eye symptoms. The study included 535 participants who had had moderate to severe dry eye for at least 6 months.
In the omega-3 group, 349 participants received 2000 mg EPA and 1000 mg DHA. According to the study, this dosage was the highest that researchers used in a test to treat dry eye. In the placebo group, 186 people received olive oil in capsules identical to the omega-3 fatty acids.
The study found no significant differences in the improvement in dry eye symptoms between the two groups.
Fish oil can pose some risk to certain people. If patients are taking warfarin or any other blood-thinning drug, they should see a doctor before taking omega-3 supplements. This is because fish oil can interact with these drugs and affect blood clotting.
Children and anyone who is pregnant, breastfeeding, or breastfeeding may also need to consult a doctor before ingesting fish oil or eating certain types of fish. This is because certain fish have high levels of mercury.
According to the American Heart Association (AHA), fish high in mercury include:
- King mackerel
- Tile fish
Low mercury fish and shellfish include:
- Canned tuna
The AHA recommends eating at least 2 servings of oily fish every week. One serving consists of 3.5 ounces of cooked fish or ¾ cup of fish flakes.
According to the NIH, long-term ingestion of up to 5 grams (g) per day of combined EPA and DHA seems safe. The U.S. Food and Drug Administration (FDA) recommends consuming no more than 3 grams of combined EPA and DHA per day and up to 2 grams from dietary supplements.
If people take high doses like 900 mg EPA and 600 mg DHA per day for several weeks, it can suppress inflammatory reactions in the body and impair the function of the immune system.
So far, research is inconclusive as to whether fish oil can help treat or prevent dry eye symptoms.
Some research suggests that increasing your omega-3 intake may improve dry eye symptoms. Other research found no significant difference between fish oil and a placebo in improving dry eye symptoms.
Researchers still need to conduct more studies to find consistent evidence on whether fish oil can help treat dry eyes.
Fish oil contains the omega-3 fatty acids EPA and DHA. Some research suggests that increasing your intake of these omega-3 fatty acids might help relieve dry eyes. However, there is currently insufficient evidence to support this.
People can make sure they get adequate EPA and DHA from food sources, or talk to a doctor about taking a dietary supplement.