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NIH-Funded Clinical Trial Finds Omega-3 Fatty Acid Supplements Not Helpful for Treating Dry Eyes

Worst Pills, Best Pills Newsletter article August, 2018

Countless companies heavily promote dietary supplements containing omega-3 fatty acids as the solution to many health problems. Among the many alleged benefits attributed to these supplements is improvement of dry eyes.

For example, one online company peddles a product called “Lipotriad Dry Eye,” which is sold in capsules containing 1,400 milligrams (mg) of omega-3 fatty acids from fish oil and flaxseed.[1] The company’s ad claims that the product is recommended for “dry eye support”...

Countless companies heavily promote dietary supplements containing omega-3 fatty acids as the solution to many health problems. Among the many alleged benefits attributed to these supplements is improvement of dry eyes.

For example, one online company peddles a product called “Lipotriad Dry Eye,” which is sold in capsules containing 1,400 milligrams (mg) of omega-3 fatty acids from fish oil and flaxseed.[1] The company’s ad claims that the product is recommended for “dry eye support” and that it is formulated “to achieve maximum tear production.” Another company hawks “HydroEye” with the claim that its proprietary blend of omega-3 fatty acids supports “a healthy tear film and soothe[s] the ocular surface.”[2]

Dietary supplement companies rarely conduct the type of large, well-designed clinical trials needed to prove such health claims because the FDA does not require such trials. Fortunately, the National Institutes of Health (NIH) sometimes does fund such trials. The most recent of these, published on May 3, 2018, in the New England Journal of Medicine (NEJM), provides strong evidence that dietary supplements containing omega-3 fatty acids are not beneficial for treating dry eye disease.

What are omega-3 fatty acids?

Omega-3 fatty acids, a type of polyunsaturated fat, are essential for life. Several different omega-3 fatty acids exist, but most scientific research has focused on three: alphalinolenic acid (ALA), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA).[3]

ALA is not made in the body and must come from the diet.[4] Good sources of this critical nutrient include certain vegetable oils, such as canola, soy and flaxseed oil; chia seeds, flaxseed, and English and black walnuts; and mayonnaise.[5]

Although ALA from the diet can be converted by the liver to EPA and then to DHA, such conversions occur on a very limited basis.[6] Thus, dietary intake of EPA and DHA often is needed to increase the level of these fatty acids in the body. The richest food sources of EPA and DHA are certain fish, including Atlantic salmon, Atlantic herring, sardines, Atlantic mackerel and rainbow trout.[7]

Overview of dry eyes

Dry eye disease is a common, chronic condition that affects millions of adults in the U.S. The condition occurs when the quantity or quality of tears fails to keep the surface of the eyes adequately lubricated.[8] It is more common in women than in men and is more likely to occur as people get older.[9] Some of the factors that can contribute to dry eyes are listed in the box below.

Factors That Can Cause or Contribute to Dry Eyes*
  • Medications such as antihistamines; decongestants; antidepressants; birth control pills; hormone replacement therapy to relieve symptoms of menopause; and medications for anxiety, Parkinson’s disease and high blood pressure
  • Rosacea (an inflammatory skin disease) and blepharitis (an inflammatory eyelid disease), which can damage glands in the eyelids that produce oils that prevent tear evaporation
  • Autoimmune disorders such as Sjögren’s syndrome, lupus and rheumatoid arthritis and other disorders such as diabetes, thyroid disorders and vitamin A deficiency, which are associated with dry eye disease
  • Hormonal changes that occur during pregnancy and after menopause
  • Windy, smoky or dry environments, which increase tear evaporation
  • Seasonal allergies
  • Prolonged periods of computer or cell phone screen time, which encourage insufficient blinking
  • Laser eye surgery, which may cause temporary dry eye symptoms

*Source: National Eye Institute, Facts About Dry Eye

Symptoms of dry eye include a scratchy sensation or the feeling that something is in the eye; stinging or burning; episodes of excess tearing that follow periods of dryness; and discharge, pain and redness in the eye.[10] Dry eye disease also may cause blurred vision.

Guidelines from the American Academy of Ophthalmology that were issued in 2013 state that omega-3 fatty acids may be beneficial for this condition but “the evidence is insufficient to establish [their] effectiveness.”[11]

The NEJM clinical trial is the largest and most rigorous randomized clinical trial to date to assess the effectiveness of omega-3 fatty acid supplementation in patients suffering from dry eye disease.

The new NEJM clinical trial[12]

The trial, which was funded by the NIH’s National Eye Institute, was called the Dry Eye Assessment and Management (DREAM) trial. From October 2014 to July 2016, researchers at 27 clinical centers in the U.S. enrolled 535 adult subjects who had had moderate-to-severe symptoms of dry eye disease, as measured by a standardized rating scale, for at least six months. The subjects also had abnormalities on eye tests used to assess the adequacy of tear production. Patients who were already regular users of treatments for dry eyes, medications known to cause dry eyes, oral or injected glucocorticoids, or other immunosuppressive drugs were eligible to enroll in the trial, provided that they committed to continuing to use these drugs for 12 months.

The subjects were randomly assigned to receive either five capsules containing a total of 3,000 mg of omega-3 fatty acids (two-thirds of subjects) or five placebo capsules containing olive oil (one-third of subjects) daily for one year. The researchers then measured changes in dry eye symptoms using a standardized rating scale at six and 12 months after enrollment. They repeated the eye tests used to assess the adequacy of tear production at these same time points.

The average dry eye symptom scores were significantly improved in both groups at six and 12 months, but there was no significant difference between the groups in the level of improvement. Likewise, there were no significant differences between the two subject groups at six and 12 months on the tests that assessed the adequacy of tear production.

In contrasting their results to prior clinical trials, most of which did show improvements in the signs or symptoms of dry eye disease with use of omega-3 fatty acids, the DREAM trial researchers noted the inadequacies of many of these prior trials, such as enrolling far fewer subjects and excluding many types of patients with typical dry eye disease symptoms. The DREAM trial also was longer than all but two of the prior trials. The DREAM trial findings thus likely have greater validity and generalizability than results from most of the prior trials.

What You Can Do

Don’t waste money on dietary supplements that promise to improve your dry eyes. Instead, eat a balanced diet that includes natural sources of omega-3 fatty acids and a wide variety of other nutrients.

If you are taking medications associated with dry eyes, consult with your doctor about switching to alternative drugs. If your dry eye symptoms are mild, consider overthe- counter products such as artificial tears.

Cutting back on computer and cell phone screen time and taking periodic eye breaks also may improve your symptoms. Periodically closing your eyes for a few minutes, or blinking repeatedly for a few seconds, may replenish the tears and spread them more evenly across your eyes. Also, sunglasses that wrap around the face and have side shields that block wind can reduce symptoms in windy conditions.

For more severe dry eye symptoms, you should consult your doctor about other treatment options.


References

[1]Lipotriad Vitamins for Healthy Eyes. Lipotriad Dry Eye - 1400mg Omega 3 Supplement - 60ct. https://lipotriadvitamins.com/collections/where-to-buy/products/lipotriad-dry-eye-60ct. Accessed May 31, 2018.

[2]Science Based Health. HydroEye. http://www.sciencebasedhealth.com/HydroEye-Powerful-Dry-Eye-Relief-P43.aspx. Accessed May 31, 2018.

[3] National Institutes of Health, Office of Dietary Supplements. Omega-3 fatty acids: Fact sheet for health professionals. March 2, 2018. https://ods.od.nih.gov/factsheets/Omega3FattyAcidsandHealth-HealthProfessional/. Accessed May 31, 2018.

[4]Ibid.

[5]Ibid.

[6]Ibid.

[7]Ibid.

[8]National Institutes of Health, National Eye Institute. Facts about dry eye. July 2017. https://nei.nih.gov/health/dryeye/dryeye. Accessed May 31, 2018.

[9]Ibid.

[10]Ibid.

[11]American Academy of Ophthalmology. Dry eye syndrome PPP – 2013. October 2013. https://www.aao.org/preferred-practice-pattern/dry-eye-syndrome-ppp--2013. Accessed May 31, 2018.

[12]Dry Eye Assessment and Management Study Research Group, Asbell PA, Maguire MG, Pistilli M, et al. n-3 Fatty Acid Supplementation for the Treatment of Dry Eye Disease. N Engl J Med. 2018;378(18):1681-1690.