How do gut bacteria and smartphones influence eye health? Find out what the latest research could mean for your diet & lifestyle habits, along with tips on keeping your peepers in perfect health to continue enjoying the sights of life!
The Eyes are the Window to…the Gut? By now, well-informed health nuts are acquainted with the research on the gut-brain connection. But far less light has been shone on the novel gut-retina connection. A 2018 literature review examined the role of diet, micronutrients, and gut microbiota in an eye condition called age-related macular degeneration (AMD). The authors suggest that dysbiosis, which is an unhealthy balance of gut bacteria, allows a state of low-grade inflammation to take hold in the body. Low-grade inflammation has been shown to contribute to the development of AMD (Rinninella, 2018).
Addressing dysbiosis seems to be key for quelling inflammation in the gut, with favourable implications for the eyes. A good quality probiotic supplement may be helpful to add more “good bugs” to outweigh the “bad bugs” in the gut. If you suspect you may have an infection or a case of stubborn bad bacteria, consider pairing your probiotics with the short-term use of oregano oil or black seed oil, which has antibacterial, antifungal, antiviral, and anti-inflammatory properties. For heavy-hitting anti-inflammatory and anti-oxidant action, consider supplementing with N-acetylcysteine (NAC). NAC is the precursor to the master antioxidant glutathione, and it’s been found to inhibit the development of cataracts in an animal study (Aydin, 2009).
Vitamin D is another staple to incorporate into your eye-care routine; the authors of the 2018 review found that a low level of vitamin D in the blood is associated with age-related macular degeneration. The sunshine vitamin may play a role in the gut-retina connection, as it helps regulate gut permeability, as well as the composition of the microbiome (Rinninella, 2018).
No Screening for Eye Health Staring at smartphones, tablets, laptops and televisions now consumes a vast portion of the day, whether at work or home. An American report conducted in 2016 showed that the average adult spends a staggering 11 hours per day using media of some kind (Denver Post). Along with this increase in screen use is an increased prevalence of digital eye strain (Sheppard, 2018), with symptoms including eye fatigue and dryness. Even smartphone use for as little as 1 hour increases oxidative stress indices in the tears and ocular surface (Choi, 2018).
If you’re not willing to stop screen use cold turkey, it’s important to protect against eye damage when possible. Many people are opting for “blue light” blocking glasses for the purported benefits of reducing eye damage and insomnia caused by screen light.
More research supports using the antioxidant astaxanthin and anthocyanins from bilberry to protect against light-induced damage to the retina (Otsuka, et al., 2013 and Wang, 2015).
Feast for the Eyes To protect against light-induced retinal damage, stock up on astaxanthin-rich seafoods including algae, salmon, yeast, and shrimp. If seafood isn’t your cup of tea, astaxanthin can easily be found in supplement form. Bilberry is a berry native to Europe, so unless you make regular trips to the Continent, a supplement might be your best bet.
Astaxanthin, together with its carotenoid cousins lutein, zeaxanthin, and lycopene, have been shown to protect against the development and progression of diabetic microvascular complications in the retina (Murillo, 2016). Increased levels of lutein and zeaxanthin in the diet have also been associated with a reduced risk of advanced age-related macular degeneration (Rinninella, 2018). Look for lutein in broccoli, spinach, kale and asparagus, and you can find both lutein and zeaxanthin together in corn and eggs. Tomatoes are the star veggie when you’re looking for a whopping dose of lycopene. These compounds are fat-soluble, so be sure to eat these veggies with a healthy fat source, like EVOO, avocado, or salmon. All the possible culinary combinations of these eye-protecting foods are certainly a feast for the eyes!
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Originally published for Healthy Directions magazine.
References:
Aydin, B., Yagci, R., Yilmaz, F.M., et al. Prevention of selenite-induced catarctogenesis by N-acetylcysteine in rats. Curr Eye Res. 2009 Mar;34(3):196-201.
Choi, J.H., Li, Y., Kim, S.H., et al. The influences of smartphone use on the status of the tear film and ocular surface. PLoS One. 2018 Oct 31;13(10)e0206541.
Denver Post. Spend almost 11 hours a day using media? That’s OK: You’re average. https://www.denverpost.com/2016/06/29/media-use-america-11-hours/
Lawrenson, J.G., Hull, C.C., Downie, L.E. The effect of blue-light blocking spectacle lenses on visual performance, macular health and the sleep-wake cycle: a systematic review of the literature. Ophthalmic Physiol Opt. 2017 Nov;37(6):644-654.
Murillo, A.G., Fernandez, M.L. Potential of Dietary Non-Provitamin A Carotenoids in the Prevention and Treatment of Diabetic Microvascular Complications. Adv Nutr. 2016 Jan 15;7(1):14-24.
Otsuka, T., Shimazawa, M., Nakanishi, T., et al. Protective effects of a dietary carotenoid, astaxanthin, against light-induced retinal damage. J Pharmacy Sci. 2013;123(3):209-18.
Rinninella, E., Mele, M.C., Merendino, N., et al. The Role of Diet, Micronutrients and the Gut Microbiota in Age-Related Macular Degeneration: New Perspectives from the Gut-Retina Axis. Nutrients 2018 10(11), 1677.
Sheppard, A.L., and Wolffsohn, J.S. Digital eye strain: prevalence, measurement and amelioration. BMJ Open Ophthalmology 2018;3e000146.
Wang, Y., Zhao, L., Lu, F., et al. Retinoprotective Effects of Bilberry Anthocyanins via Antioxidant, Anti-Inflammatory, and anti-Apoptotic Mechanisms in a Visible Light-Induced Retinal Degeneration Model in Pigmented Rabbits. Molecules. 2015 Dec 14;20(12):22395-410.