7th April 2018
Most people don't immediately associate what they eat with their eye health (unless it's "carrots help me see in the dark"), but the food we eat contains nutrients that impact our vision, the condition of our eyes, and our overall physiological state on almost every level. Many eye diseases such as diabetic retinopathy, age related macular degeneration, and dry eye disease can be prevented, slowed, or treated through better diet.
Lutein & zeaxanthin
It turns out we are told over and over again to eat vegetables for a reason! Foods like broccoli and kale contain carotenoids called lutein and zeaxanthin. In nature, these are found in plants to help absorb excess powerful blue light that would otherwise cause damage. Aside from being beneficial to plants, lutein and zeaxanthin are also useful to humans, as they are present in the human macula in high concentrations. Both work to essentially block harmful high-energy blue light from your macula, preventing sun damage that could lead to macular degeneration.1
We hear a lot about omega-3 these days. It's an 'essential nutrient' – an organic product you have to consume because the body cannot make it by itself. It has been hailed as a 'superfood' and it has been recognised as improving almost all aspects of health, including cardiac and mental health. Research is now showing that omega-3 benefits our eyes in the same way, and is particularly significant for patients with dry eye disease, macular degeneration and glaucoma. The Age-Related Eye Disease Study (AREDS) revealed that people who consumed high amounts of omega-3 significant decreased their risk of macular degeneration by at least 30%.2 Omega-3 can be found in fish, soybeans, walnuts and canola oil.
As our bodies metabolise organic materials for energy, certain unstable byproducts (known as "free radicals") are formed that can be detrimental to our cells. The tissue in our eyes is no exception, but it has been found that vitamin E may work to reduce the damage caused by free radicals and thereby reduce the risk of macular degeneration. One well-known study found that an intake of 400IU a day decreased the risk of macular degeneration by 25% in high-risk groups.3 Some studies have also found that vitamin E prevents the development of cataracts. Vitamin E is present vegetable oil, nuts and seeds.
Several regenerative benefits are associated with vitamin C. As with omega-3, vitamin C is another 'essential nutrient' that we are unable to synthesise ourselves. It has been found that vitamin C has a crucial role in the assembly and preservation of connective tissue, including collagen in the cornea and the fine vascular capillaries that carry blood in the back of our eyes.4 It therefore follows that a higher intake of vitamin C helps to prevent the degeneration of those tissues, which can be the cause of diseases like macular degeneration and cataract. The most well-known source of vitamin C is oranges, but high levels of it can also be found in broccoli, capsicum, potatoes and tomatoes.
CAPTION: If you are considering changing your diet in any way, this should be in accordance with your doctor's advice. Please consult your general practitioner before altering your dietary intake.
1 Landrum, J. and Bone, R. (2001). Lutein, Zeaxanthin, and the Macular Pigment. Archives of Biochemistry and Biophysics, 385(1), pp.28-40.
2 Lutein + Zeaxanthin and Omega-3 Fatty Acids for Age-Related Macular Degeneration. (2013). Journal of the American Medical Association, 309(19), p.2005.
3 Chew, E. (2009). Summary Results and Recommendations From the Age-Related Eye Disease Study. Archives of Ophthalmology, 127(12), p.1678.
4 Chew, E., Clemons, T., Agrón, E., Sperduto, R., SanGiovanni, J., Kurinij, N. and Davis, M. (2013). Long-Term Effects of Vitamins C and E, β-Carotene, and Zinc on Age-related Macular Degeneration. Ophthalmology, 120(8), pp.1604-1611.e4.