It may surprise you to know that your eyeballs are connected to the rest of your body. Now that you know, it shouldn’t surprise you to know that how one takes care of his or her body has the potential to affect the eyes and vision. Good nutrition and a healthy lifestyle are beneficial for every part of the body, but in what ways can we use our knowledge of nutrition and lifestyle to improve eye health?
Vitamin C Can Reduce the Onset of Cataracts and the Progression of Macular Degeneration
Studies indicate that long-term intake of vitamin C, also known as ascorbic acid, has positive effects in reducing the risk of developing age-related cataracts. This applies to both males and females. Cataracts, a gradual cloudiness of the lens inside the eye, are commonly thought to develop due to oxidative damage to the lens over time. As a powerful antioxidant, vitamin C helps to prevent some of this oxidative damage. While even an optimal intake of vitamin C cannot entirely avoid the development of age-related cataract – the only way to prevent cataracts would be to stop aging altogether! – the scientific literature suggests that the onset of cataract may be delayed, and its progression slowed.
In combination with a number of other nutrients, vitamin C has also been shown to be beneficial for the macula. A series of studies known as AREDS (Age-Related Eye Disease Study) and the subsequent AREDS2 investigated the use of nutritional supplementation to arrest the progression of a disease known as dry age-related macular degeneration. Macular degeneration is a disease of an anatomical part of the retina known as the macula and damage to this part of the eye results in loss of central vision. The original AREDS formula found a combination of vitamins C and E, beta-carotene, zinc, and copper, and was found to reduce the risk of progressing to advanced macular degeneration by 25%. Five years later, when AREDS2 was conducted, beta-carotene was replaced with two other carotenoids, lutein and zeaxanthin, as intake of beta-carotene had been linked with an increase in lung cancer in former and current smokers. This new AREDS2 formulation was found to have similar macula protective effects to the original AREDS formula. Interestingly, researchers did not find that taking nutritional supplementation with either the AREDS or AREDS2 formula helped with reducing the development of cataracts, despite containing vitamin C and other antioxidants such as lutein and zeaxanthin.
Omega 3 Fatty Acids Can Also Help the Macula and Dry Eye Syndrome
The macula will also benefit from a healthy intake of omega-3 fatty acids, such as that from cold-water fish or flaxseeds. A study conducted amongst elderly twins in the US found that an increased intake of fish, especially two or more servings per week, reduced the risk of developing age-related macular degeneration. This reduction in risk was seen primarily in the study participants who also had a lower intake of omega-6 fatty acids, indicating the need for a healthy ratio between omega-3 and omega-6. The average American diet results in an omega-6 to omega-3 ratio of 10:1 to 50:1; the ideal ratio is 3:1 or 4:1. It is thought that omega-3 regulates inflammatory and immune processes in the retina, thereby decreasing the risk of macular degeneration. Conversely, omega-6 fatty acids are known to encourage inflammation, which is not what your poor aging cells need. As omega-3 is not produced in the body it is important to gain this from diet.
Omega-3 has been shown to also decrease the inflammation seen in dry eye syndrome, a potentially debilitating issue that affects over 16 million Americans. Over 80% of dry eye is caused by a subtype known as Meibomian gland dysfunction, which is – you guessed it – dysfunction of the Meibomian glands of the eyelids. The purpose of these glands is to produce an oily layer over the very top of the tear film on the eye to prevent this tear film from evaporating too quickly. Inflammation and alteration in the composition of the glands’ secretions results in a poor-quality lipid layer and subsequent dry eye, but omega-3 fatty acids have been shown to interrupt the inflammation and improve the oil secretions. One study found that quality of life was actually improved in dry eye patients who were treated with omega-3 supplements. For therapeutic effects, at least 1000mg a day of omega-3 must be either incorporated into the diet or taken as a supplement.
Exercise May Improve Blood Flow to the Optic Nerve and Reduce the Risk of Glaucoma
The mention of physical exercise may elicit various responses from different people. Some people enjoy being sweaty and out of breath, while the next person’s idea of exercise is reaching for a bag of crisps and the exertion of pulling open said bag of crisps. Regardless of whether exercise is a daily routine or something to be considered only in the few months leading up to your wedding, research is showing it can actually reduce the risk of glaucoma by 25% for every 10-minute increment of moderate to intense exercise per week. Glaucoma is the leading cause of irreversible blindness due to damage of the optic nerve from the pressure in the eyeball being too high. Scientific findings suggest exercise may improve blood flow to the optic nerve and also transiently reduces the pressure in the eye.
Unfortunately, in a healthcare article about lifestyle factors and eyes, cigarette smoking is destined to get a mention. In the previously cited twin study about the effects of omega-3 and macular degeneration, researchers also found that current smokers had almost double the risk of age-related macular degeneration whilst even ex-smokers who had quit entirely still had a 1.7 times increased risk. Other studies have found even higher risks in current and former smokers for macular degeneration. Cigarette smoking has been associated with increased oxidative stress on the body and lowering antioxidants in the blood, which damages the supportive tissues of the macula.
In a world of diseases so heavily influenced by genetics it is both important and comforting to know that our risk of eye disease can be modified by simple dietary and lifestyle factors. Needless to say, your entire body will thank you for it.
- Long-term intake of vitamins and carotenoids and odds of early age-related cortical and posterior subcapsular lens opacities. https://academic.oup.com/ajcn/article/75/3/540/4689348
- Vitamin See: foods rich in vitamin C help curb cataracts. https://www.aao.org/eye-health/news/vitamin-c-rich-foods-help-curb-cataracts
- Prospective study showing that dietary vitamin C reduced the risk of age-related cataracts in a middle-aged Japanese population. https://link.springer.com/article/10.1007/s00394-006-0641-8
- NIH study provides clarity on supplements for protection against blinding eye disease. https://nei.nih.gov/news/pressreleases/050513
Age-related eye disease study 2 (AREDS2). https://nei.nih.gov/areds2
- Lutein/zeaxanthin for the treatment of age-related cataract. https://jamanetwork.com/journals/jamaophthalmology/fullarticle/1685136?utm_source=dlvr.it&utm_medium=twitter
- Cigarette smoking, fish consumption, omega-3 fatty acid intake, and associations with age-related macular degeneration. https://jamanetwork.com/journals/jamaophthalmology/fullarticle/417784
- Benefits of omega-3 fatty acid dietary supplementation on health-related quality of life in patients with Meibomian gland dysfunction. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4010636/
- New research: exercise may reduce risk of glaucoma. http://www.mivision.com.au/new-research-exercise-may-reduce-risk-of-glaucoma/
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