The secret to good eyesight as we age may not be a secret after all. The adage that eating your carrots will ensure good eyesight has some truth. Mom may have been right all along! Even though conventional therapies for improving eyesight like eyeglasses, contact lenses, and surgery may be preferred by some, it is evident that proper nutrition and lifestyle modifications may be equally or more effective for the treatment and prevention of vision impairment and loss.
Traditional medical and eye doctors are taught to treat conditions in a disease model. A doctor visit for a health condition will result in a treatment, pharmaceuticals, or other therapy that can be expensive, to alleviate the symptoms a patient is experiencing. A trip to the eye doctor for impaired vision will most likely result in eyeglasses, contact lenses, or possibly LASIK laser surgery. Though these strategies for improving eyesight may be effective, they are neither preventative, nor will they remedy any underlying nutritional deficiencies or other factors that may have caused the vision impairment. Knowing the underlying causes of vision impairment can give us the tools we need to prevent vision loss.
Modern medicine is amazing. If a medical condition requires medical attention, then an appointment with a doctor is in order. Despite all our medical and technological advances, the basics of human nutrition are often forgotten. We are humans and are not machines. We need proper nutrition to keep us healthy and strong instead of costly pills and procedures. Even though proper nutrition is the key to good health, medical professionals are inadequately prepared to offer nutrition advice. Medical students receive on average only 23.9 hours of nutrition education in medical school (Adams, 2006), hence nutrition as a preventative measure or a remedy for a health condition or vision impairment is not usually considered. More emphasis is currently being placed on preventative lifestyle medicine and nutrition education (Macaninch, 2020), nevertheless medical school curriculum has not yet been developed to the point of prevention being the standard care, and the amount of nutrition education for medical students continues to be inadequate (Adams, 2010).
Losing the ability to see clearly is frustrating. We live in a visually oriented world that assumes that most everyone can see clearly, and as a result, a person that cannot see well may be at a disadvantage. Difficulty reading a book, label, computer screen, mobile phone text, or road signs can cause feelings of irritation and lower the quality of life. Additionally, the thought of dealing with uncomfortable contact lenses, unattractive eyeglasses, or potentially risky surgery may also cause feelings of frustration. On the other hand, these frustrations may be able to be avoided completely with proper nutrition and lifestyle modifications.
Proper nutrition for ocular health has indeed been studied extensively. A 2019 article, ‘Nutrients and Eye Health’ was published in the peer reviewed international scientific journal Nutrients states that “Diet is a key lifestyle factor that can have long-term effects on ocular health.” (Lawrenson, 2019). The article is an overview of twelve articles published in the Special Edition of Nutrients on ocular health along with a review of the randomized control trials (RCT) conducted that utilized vitamin supplements to improve vision. Of note in the review of the RCT’s is one large study that showed an 8% reduction in progression of age-related macular degeneration. The supplements used were vitamin C, Vitamin E, beta-carotene, zinc, and copper. If we can improve the risk of further decline of age-related macular degeneration with supplements, then it is plausible that a nutrient rich diet can facilitate long term ocular health.
The specific nutrients for ocular health have been determined though scientific research. The Journal of Food Science reviewed the medical literature concerning the dietary nutrients lutein and zeaxanthin on visual performance. They conclude that the yellow macular pigment that accumulates near the center of the retina in the eye does dramatically influence visual performance, and that the specific carotenoids lutein and zeaxanthin from food could potentially improve vision (Stringham, 2010). One study wanted to find out if dietary lutein and zeaxanthin from spinach and sweet corn would have any influence on blood serum or macular pigmentation. They found that blood serum levels of these nutrients rose 33% and macular pigment levels rose 19% on average in the study participants in only a few weeks (Zaripheh, 2001). These results show that diet most certainly is a major factor in determining long term eye health.
Lutein and zeaxanthin from our dietary food sources are present in dark leafy greens, green peas, pumpkin, squash, carrots, broccoli, and asparagus. Eating carrots certainly helps increase the macular pigment, along with other green, yellow, and orange vegetables that are rich in lutein and zeaxanthin. These carotenoids also play a role in decreasing: inflammation, oxidative stress, and endothelial dysfunction. They are important to ocular health, but equally important for general health and reduce the risk of developing coronary artery disease (Hozawa, 2006). In the process of improving vision with nutrition, it is reasonable to assume that overall health would also improve.
Deteriorating vision is often thought of as an age-related condition, or a condition resulting from genetic heredity. It is true that some oxidative damage can be a result of aging, nonetheless much of that may be preventable by consuming enough antioxidant rich foods. Just because two parents have good vision, does not mean that their child will not have a visual impairment. What may have been inherited from our parents is their eating habits. For example, growing up eating fried chicken, mash potatoes and mac n’ cheese, will most likely lead to continuing these eating habits. Likewise, growing up eating plant-rich Mediterranean style meals will be the eating style a person is accustomed to. Studies show that chronic lifestyle health conditions like obesity, type two diabetes, and cardiovascular disease rates are similar in parents and their children (Nielsen, 2015). Children that have overweight parents are almost twice as likely of being overweight compared to their peers (Thibault, 2010). Conceivably lifestyle, and not genetics is the cause of deteriorating vision.
Given that low macular pigment is a predictor of age-related macular degeneration and visual performance, protecting our eyes from damage to the pigment is important. There are key components to retinal health with nutrition being the most important. Smoking tobacco products and exposure to blue light can cause damage to the pigments so not smoking and limiting exposure to blue light will help prevent vision loss. High energy visible light, which is also known as blue light, is emitted by the sun and through our electronic devices such as televisions, computer monitors, and cell phones. Blue light can cause cell death in retinal pigment epithelial cells. (Moon, 2017). Some of our electronic devices have the technology included as a feature that will block blue light, and blue light blocking computer glasses and sunglasses are inexpensive and readily available.
For long term visual excellence, and to improve eyesight, protecting your macular pigment by not smoking, limiting screen time, and wearing protective eyewear will help. Moreover, avoiding the frustration of corrective lenses and expensive procedures can only be achieved with superior nutrition. Carrots are not a superfood for our eyes, but mom was right to encourage us to eat our nutrient rich vegetables with antioxidant carotenoids lutein and zeaxanthin.
Adams, K. M., Lindell, K. C., Kohlmeier, M., & Zeisel, S. H. (2006). Status of nutrition education in medical schools. The American journal of clinical nutrition, 83(4), 941S–944S. https://doi.org/10.1093/ajcn/83.4.941S
Adams, K. M., Kohlmeier, M., & Zeisel, S. H. (2010). Nutrition education in U.S. medical schools: latest update of a national survey. Academic medicine : journal of the Association of American Medical Colleges, 85(9), 1537–1542. https://doi.org/10.1097/ACM.0b013e3181eab71b
Hozawa, A., Jacobs, D. R., Jr, Steffes, M. W., Gross, M. D., Steffen, L. M., & Lee, D. H. (2007). Relationships of circulating carotenoid concentrations with several markers of inflammation, oxidative stress, and endothelial dysfunction: the Coronary Artery Risk Development in Young Adults (CARDIA)/Young Adult Longitudinal Trends in Antioxidants (YALTA) study. Clinical chemistry, 53(3), 447–455. https://doi.org/10.1373/clinchem.2006.074930
Lawrenson, J. G., & Downie, L. E. (2019). Nutrition and Eye Health. Nutrients, 11(9), 2123. MDPI AG. Retrieved from http://dx.doi.org/10.3390/nu11092123
Moon, J., Yun, J., Yoon, Y. D., Park, S. I., Seo, Y. J., Park, W. S., Chu, H. Y., Park, K. H., Lee, M. Y., Lee, C. W., Oh, S. J., Kwak, Y. S., Jang, Y. P., & Kang, J. S. (2017). Blue light effect on retinal pigment epithelial cells by display devices. Integrative biology : quantitative biosciences from nano to macro, 9(5), 436–443. https://doi.org/10.1039/c7ib00032d
Macaninch, E., Buckner, L., Amin, P., Broadley, I., Crocombe, D., Herath, D., Jaffee, A., Carter, H., Golubic, R., Rajput-Ray, M., Martyn, K., & Ray, S. (2020). Time for nutrition in medical education. BMJ nutrition, prevention & health, 3(1), 40–48. https://doi.org/10.1136/bmjnph-2019-000049
Nielsen, L. A., Nielsen, T. R., & Holm, J. C. (2015). The Impact of Familial Predisposition to Obesity and Cardiovascular Disease on Childhood Obesity. Obesity facts, 8(5), 319–328. https://doi.org/10.1159/000441375
Stringham, J.M, Bovier, E.R., Wong, J.C. & Hammond, B.R. Jr. (2010, January 11). The influence of dietary lutein and zeaxanthin on visual performance. Journal of Food Science. https://onlinelibrary.wiley.com/doi/full/10.1111/j.1750-3841.2009.01447.x
Thibault, H., Contrand, B., Saubusse, E., Baine, M., & Maurice-Tison, S. (2010). Risk factors for overweight and obesity in French adolescents: physical activity, sedentary behavior and parental characteristics. Nutrition (Burbank, Los Angeles County, Calif.), 26(2), 192–200. https://doi.org/10.1016/j.nut.2009.03.015
Zaripheh, S., & Erdman, J. W., Jr (2002). Factors that influence the bioavailablity of xanthophylls. The Journal of nutrition, 132(3), 531S–534S. https://doi.org/10.1093/jn/132.3.531S Retrieved from https://www.researchgate.net/publication/11481612_Factors_That_Influence_the_Bioavailablity_of_Xanthophylls