Oral Omega-3 Supplementation Lowers Eye Pressure

Oral Omega-3 Supplementation Lowers Intraocular Pressure in Normotensive Adults

Elevated intraocular pressure (abbreviated IOP, and also called eye pressure) is the only medically treatable risk factor for the sight-threatening eye disease, glaucoma. In this study, researchers investigated whether oral omega-3 fish oil supplements affect intraocular pressure in normotensive adults.

The conclusion of the study states, "Oral omega-3 supplementation for 3 months significantly reduced IOP in normotensive adults."

Full Text paper attached. See link below.

Introduction section from the paper:

Increasing scientific evidence supports an association between dietary factors and long-term health outcomes. Of particular interest has been whether dietary omega-3 essential fatty acids (EFAs) can prevent and/or provide therapeutic management in a range of general health conditions, including cardiovascular disease, hyperlipidemia, and systemic inflammatory disease. Humans cannot form EFAs in vivo and must ingest them from dietary sources.

Omega-3 fatty acids exist as short- (α-linolenic acid [ALA]) and long-chain (eicosapentaenoic acid [EPA] and docosahexaenoic acid [DHA]) subtypes. The omega-6 fatty acids are the other major class, which derive from the diet in the form of linolenic acid. As omega-3 and omega-6 fatty acids compete in vivo for enzymes regulating their metabolism, the ratio of consumed omega-3 to omega-6 EFAs determines the inflammatory status of the body, with omega-3s biasing prostaglandin metabolism towards the production of anti-inflammatory eicosanoids.

Diets rich in omega-3 EFAs are associated with a reduced risk of coronary heart disease mortality, attenuated age-related cognitive decline, and a decreased risk of late-stage age-related macular degeneration. In addition, significant literature has considered the association between omega-3 fatty acid intake and eye health. Omega-3 EFA deprivation may predispose individuals to ocular disease in later life. It follows that the potential benefit of omega-3 fatty acid supplementation has undergone evaluation in clinical trials in eye diseases that show an increased prevalence with age, particularly age-related macular degeneration and dry eye disease.

Another significant eye disease that shows an age-dependent increase in prevalence is glaucoma, the second major cause of blindness worldwide. Currently, the major modifiable risk factor for glaucoma is elevated intraocular pressure (IOP). Reducing IOP is the mainstay of glaucoma treatment, and is achieved typically by medical management using topical IOP-lowering agents as first-line therapy. Identification of other targetable risk factors has the potential to enhance intervention options for managing the disease.

It is noteworthy that IOP tends to increase with age in Western populations, but the opposite trend occurs in traditional Japanese populations, who have higher dietary intakes of polyunsaturated fats. A large prospective cohort study, undertaken in Europe and involving >17,000 participants, showed an association between the ratio of consumed omega-3 to omega-6 fatty acids and incident glaucoma, especially among older individuals. Most recently, data from the National Health and Nutrition Examination Survey (NHANES, 2005–2008), a cross-sectional survey involving 3865 participants from the United States, showed that increased daily consumption of the long-chain, polyunsaturated omega-3 fatty acids, EPA, and DHA, was associated with a lower likelihood of glaucomatous optic neuropathy. In that study, the odds of an individual having glaucoma were nearly three times as high in participants whose daily dietary total long-chain omega-3 consumption level was in the second and third quartiles, compared to those in the first quartile. Furthermore, evidence from animal studies indicates the potential to modify IOP by up to 23% through omega-3 dietary manipulation. Taken together, these findings suggest that omega-3 intake may modulate IOP in humans. However, to our knowledge the effect of omega-3 supplementation on IOP in normotensive adults has not been investigated previously.

We analyzed pooled data from two double-masked, randomized, placebo-controlled trials (RCTs) to investigate whether a 3-month period of oral omega-3 supplementation significantly alters IOP in a population of normotensive adults consuming a typical Western diet.

Full Text paper attached. See link below.