Is the time for eye health coming?
Back in 2010, I remember sitting at a conference listening to Dr. Jeffrey Anshel from the Ocular Nutrition Society talk about the benefits of omega-3s in eye health. The gist of the talk was that omega-3s are an important part of the eye, which is something most ophthalmologists have recognized for years. However, this position had been developed without any human clinical trials having been published to date. So why exactly is that?
It really boils down to two factors. First, omega-3s have been shown to help a variety of eye health maladies in multiple animal and in-vitro studies. Second, the mechanism of action is very plausible, since omega-3s are both a structural component in the eye and help regulate inflammation. Many eye problems like age-related macular degeneration (AMD) or dry eye disease are thought to be related to structural or inflammatory issues, so the theory fits neatly into that bucket.
However, there is actually suddenly an accumulating body of human clinical science in this area. So it begs the question, is the time for eye health coming?
- García-Layana et al (2013) - The combination of lutein and DHA (280mg daily) increased the macular pigment ocular density in AMD patients, which further supports a structural role for DHA.
- Pinazo-Durán et al (2013) – This study showed that three markers of inflammation (IL-1B, IL-6 and IL-8) were all improved in dry eye disease patients with a supplement containing fish oil and antioxidants, plus subjective symptoms improved as well. This was a small study and the researchers think data from larger trials are warranted.
- Souied et al (2012) – This study found that AMD patients with high EPA and DHA status had lower incidences of choroidal neovascularization, which is where the eye grows new blood vessels because it needs more oxygen. Interestingly, supplementation with fish oil (270mg EPA/840mg DHA) did not appear to help until you looked at their actual omega-3 status. Since people metabolize omega-3s differently, this may mean some people need higher doses.
- Stough et al (2012) – This study found that tuna oil (60mg EPA / 252mg DHA) improved vision in the right eye of elderly patients who wore glasses or contacts, after only 90 days of supplementation. The thought here is that some age-related vision loss may be related to structural issues in the eye.
- Kawabata, et al (2011) – This study looked at fish oil (162mg EPA/783mg DHA), bilberry and lutein on asthenopia, which is basically eye strain that results in people hunching over or squinting to read things (we have all had that, right?). The group receiving the supplement had less back pain, dry eyes, and frustration than the placebo group, but the study was fairly small.
- Brignole-Baudouin, et al (2011) – This study showed that an omega-3 and omega-6 supplement reduced levels of human leucocyte antigen-DR, a marker of inflammation in patients with dry eye disease. The dosages of EPA and DHA aren’t listed in the abstract, but the study was on 138 patients and supports the idea that omega-3s help resolve inflammatory eye diseases.
- Creuzot-Garcher, et al (2011) – This study also looked at a supplement with both omega-3 and omega-6 fatty acids in dry eye disease. However, this study found that adding an omega-3 to an existing pharmaceutical regimen for dry eye disease resulted in lower eye fatigue and breakup time scores, a measure of dry eye severity.
- Wojtowicz, et al (2011) – This study found that the Thera Tears supplement (450mg EPA / 300mg DHA) increased the average tear production and tear volume in patients with dry eye disease. In addition, 70% of the patients taking omega-3s saw their symptoms disappear, compared to 37% in the placebo group. This was only a pilot study, so we will have to wait for more evidence from the full trial.