Food as medicine: The role of nutrition in eye health
Creating a healthier population will require extended efforts by optometrists.
Image credit: AdobeStock/millefloreimages
The idea of using food as medicine dates back to ancient civilizations. Jumping forward to the present day, this concept has gained renewed interest as health care professionals, scientists, and policy makers recognize the critical role that nutrition plays in maintaining health and preventing disease. With chronic illnesses such as heart disease, diabetes, and obesity on the rise, particularly in the US,1 there is a growing understanding that food can either contribute to disease or serve as a powerful tool for healing.
Food and its therapeutic role in eye health
The concept of food as medicine emphasizes the idea that what we eat directly influences our health and well-being. Certain nutrients, vitamins, and minerals found in whole foods such as fruits, vegetables, nuts, seeds, and fatty fish have shown therapeutic properties for eye health. Fiber-rich foods such as legumes and whole grains can lower cholesterol levels and improve gut health as findings from more studies link the microbiome with brain and eye health. This also rings true for the powerhouse antioxidant properties from the carotenoids lutein and zeaxanthin, which we know combat oxidative stress. This stress can lead to chronic diseases such as cancer, dementia, macular degeneration, and heart disease.
In addition to these nutrients, the growing field of nutrigenomics is exploring how food interacts with our genes to influence health outcomes. The food we consume can either activate or deactivate genes related to inflammation, disease resistance, and metabolism. Thus, our diet can modify the expression of genes, potentially preventing or mitigating the effects of genetic predispositions to certain diseases. With the advancements in genetic testing, results can guide a personalized nutrition plan for conditions such as macular degeneration. Although studies are limited, their findings firmly demonstrate that genetic testing could influence the macular degeneration treatment selection. The variation at the CFH and ARMS2 genes, which predispose individuals to age-related macular degeneration, determines the effectiveness of nutritional prophylaxis.2
The status of nutrition in the US
Despite the wealth of knowledge on the benefits of proper nutrition, the status of nutrition in the US presents a troubling image. According to the Centers for Disease Control and Prevention (CDC), a significant portion of the American population falls short in consuming essential nutrients. Only approximately 1 in 10 Americans meets the daily recommendations for fruits and vegetables. This deficiency leads to the underconsumption of vital vitamins such as A, C, and K as well as minerals such as potassium and magnesium, which are crucial for overall health—not to mention eye health.3 In fact, the CDC reports that more than 40% of adults and children in the US have obesity, increasing the risk of chronic disease. These adults often visit their eye care professionals with dry eyes, generalized inflammation, vision fluctuations, diabetic retinopathy, and hypertensive complications—not to mention the adverse effects from prescription medications managing these diseases.
The American food density crisis refers to the growing problem of low nutritional quality in the US food supply, where highly processed and calorie-dense foods dominate diets, further contributing to obesity and chronic disease. Many processed foods are energy rich but nutrient poor, lacking essential vitamins, minerals, and fiber while being high in added sugars, unhealthy fats, and sodium. This crisis is driven by multiple factors, including:
• Economic accessibility: Ultraprocessed foods are often cheaper and more accessible than healthier options such as fresh produce.
• Food deserts: Many communities, particularly low-income and rural areas, lack access to affordable, nutritious food.
• Marketing and culture: Aggressive advertising promotes unhealthy eating habits, especially among children and vulnerable populations – including those in poor health or experiencing barriers to accessing healthcare.
• Policy issues: Agricultural subsidies often favor commodity crops such as corn and soy, leading to an abundance of processed foods.
The result is a paradox of food insecurity and overconsumption, where individuals may consume excessive calories while still experiencing malnutrition due to inadequate nutrient intake. Addressing this crisis requires systemic changes that would involve improving food policies, increasing access to healthy options, and implementing education on balanced eating.
Integrating food into eye care
In recent years, there has been a growing movement toward integrating nutrition into health care. Eye care professionals are increasingly prescribing dietary interventions alongside traditional treatments. Programs such as Food Is Medicine from the US Department of Health and Human Services Office of Disease Prevention and Health Promotion are advocating for policies that support access to healthy foods as part of medical treatment plans.4 Some health care systems are beginning to offer “produce prescriptions,” where physicians prescribe fruits and vegetables to patients, subsidized by health insurance. Organizations such as the Ocular Wellness & Nutrition Society are providing tools and education to integrate nutrition into daily practice.5
Additionally, public health initiatives are focusing on improving food literacy and nutrition education. Schools are implementing healthier lunch programs, and campaigns promoting the consumption of whole foods are aiming to shift public awareness.
Patient education for healthy eyes
There is so much confusion about nutrition today; therefore, sharing specifics about recommended eye-healthy food types and quantities could be a step in the right direction. For instance, detail the types of food to focus on, such as those rich in lutein, zeaxanthin, and ω-3. Then prescribe a daily recommended intake of each prescribed food (eg, greater than 1000 mg of docosahexaenoic acid/eicosapentaenoic acid and 5 cups of produce daily). This may be overwhelming to patients, but what if you then suggest to add 2 to 3 cups of spinach in a smoothie? You have now just created an easy way to tackle a challenging task. Keep goals simple and sensible, with repetition at each patient encounter.
The Mediterranean diet continues to take the lead in research, offering a well-rounded nutritional delivery focusing on healthy fats, carotenoids, and few processed foods. The Mediterranean diet consists of generally leafy vegetables, nuts, whole grains, fish, olive oil, and red meat (once weekly). It continues to show a strong correlation with the reduced prevalence of macular degeneration.6
Food avoidance is another great tool in determining which foods could be contributing to inflammation. Processed foods, fast food, seed oils, gluten, dairy, and simple sugars are several foods that have a higher incidence of developing intolerances. Many of these can wreak havoc on general health and can lead to inflammation and chronic disease. An elimination diet is one in which the major food offenders causing inflammation are eliminated from one’s diet and slowly integrated back over time. This is a simple way to determine which category of foods may be the cause of known symptoms.7
Conclusion
The potential of food as medicine is vast. However, to fully harness its power, there must be a cultural shift toward valuing nutrition as a critical component of health. In the US, this requires addressing the challenges of poor diet quality, food accessibility, and socioeconomic barriers. By promoting whole, nutrient-dense foods and educating patients on their benefits, the health care system can move toward a more holistic approach where food is not only fuel but also a powerful healing tool.
Aim to keep small and attainable lifestyle modifications, with repetition at each patient encounter. Here are a few of my favorite tips:
- Increase daily greens and produce (5-cup daily goal), which is good for fiber intake and eye health
- Increase water intake, which flushes out toxins and maintains hydration
- Reduce processed foods and eat whole foods, which help avoid toxins
- Avoid unnecessary sugar, which contributes to inflammation
- Use intermittent fasting as a powerful detoxification tool
References:
Verbrugge LM. Longer life but worsening heath? trends in health and mortality of middle‐aged and older persons. Milbank Mem Fund Q Health Soc. 1984;62(3):475-519.
Vavvas DG, Small KW, Awh CC, Zanke BW, Tibshirani RJ, Kustra R. CFH and ARMS2 genetic risk determines progression to neovascular age-related macular degeneration after antioxidant and zinc supplementation. Proc Natl Acad Sci U S A. 2018;115(4):E696-E704. doi:10.1073/pnas.1718059115
Bhardwaj RL, Parashar A, Parewa HP, Vyas L. An alarming decline in the nutritional quality of foods: the biggest challenge for future generations’ health. Foods. 2024;13(6):877. doi:10.3390/foods13060877
Food Is Medicine. US Department of Health and Human Services Office of Disease Prevention and Health Promotion. Accessed January 16, 2025. https://odphp.health.gov/foodismedicine
Wellness Essentials for Clinical Practice. 4th ed. Ocular Wellness & Nutrition Society. September 2024. Accessed January 16, 2025. https://cdn.coverstand.com/22431/830441/497d6ca761593897a9ad81a495e4698e863f78c9.pdf
Hogg RE, Woodside JV, McGrath A, et al. Mediterranean diet score and its association with age-related macular degeneration. Ophthalmology. 2017;124(1):82-89. doi:10.1016/j.ophtha.2016.09.019
Bora S, Rindfleisch JA. Chapter 86 - the elimination diet. In: Rakel D. Integrative Medicine. 4th ed. Elsevier Inc; 2018:849-862.e6. doi:10.1016/B978-0-323-35868-2.00086-4
