Omega-3 ALA counteracts dry eye symptoms
Omega 3 ALA: an aid against dry eye syndrome
Omega-3 AL A (alpha-linolenic acid) reduces the symptoms of dry eye inflammation (also known as dry eye syndrome or hypolacrimia). The potential of this fatty acid in treating this condition was suggested by a study conducted in mice published in the Archives of Ophthalmology1. For the authors of the research, led by Reza Dana of the Schepens Eye Research Institute in Boston (United States), the findings pave the way for a new topical therapy to reduce the inflammatory phenomena associated with this problem.
Dry eye or Hypolacrimia: when the eye does not cry enough
Dry eye syndrome is a more frequent disorder after the age of 40 that particularly afflicts:
- Contact lens wearers;
- Who spends a lot of time on the computer;
- Those who are frequently exposed to the sun and wind.
The perception of having a foreign body in the eye is one of the symptoms of dry eye. The problem underlying this sensation is reduced tear production or an alteration in tear composition. In fact, if tears fail to keep the ocular surface sufficiently moist, the most superficial layer of the eye (the cornea) becomes dehydrated and consequently irritated.
Symptoms of dry eye
The symptoms of dry eye are different:
- feeling similar to having sand in your eyes;
- redness;
- pain;
- burning;
- discomfort during exposure to light;
- Wound formation (in severe cases).
Staining the surface of the eye with fluoriscein is one way to visualize the presence of these lesions. The number of certain cells of the immune system (the CD11b+ cells) as well as the expression of genes involved in immunity increase in the eye affected by the disorder. Another marker of dry eye syndrome is the expression of several molecules involved in inflammatory processes:
- TNF-alpha;
- interferon gamma;
- IL-1 alpha, IL-2, IL-6 and IL-10 interleukins.
The effect of Omega-3s
Through an experiment on mice, Dana and colleagues showed that direct application to the cornea of a product with Omega-3 ALA reduces the ability of fluoriscein to stain the eye as well as the number of CD11b+ cells. Treatment with ALA also reduces:
- IL-1 alpha expression in the cornea;
- TNF-alpha expression in the cornea and conjunctiva, the membrane lining the inside of the eyelids.
This effect appears to be exclusive to Omega-3s. In fact, the application of linoleic acid (LA), a fat belonging to the Omega-6 grouping, does not achieve the same results observable with ALA. Nor does the combined use of ALA and LA achieve the same benefits as the application of the product containing only Omega-3.
Omega-3 against inflammation
These findings confirm theanti-inflammatory action of Omega-3s on the body. In particular, the usefulness of this function toward dry eye syndrome is also confirmed by research that has shown that a diet rich in these nutrients prevents symptoms of the disorder.
Source:
1. Rashid S, Jin Y, Ecoiffier T, Barabino S, Schaumberg DA, Dana MR, "Topical omega-3 and omega-6 fatty acids for treatment of dry eye," Arch Ophthalmol. 2008 Feb;126(2):219-25.
