Introduction
A balanced diet and good lifestyle habits help maintain overall health and prevent chronic diseases. Around 250 million people worldwide suffer from different degrees of vision loss. Some of the important causes are glaucoma, cataracts, diabetic retinopathy, and age-related macular degeneration (AMD). Research suggests that vitamins, antioxidants, and carotenoids can benefit ocular health. Consuming nutritious foods protects vision and keeps the eyes healthy. Therefore, various eye-friendly nutrients can be incorporated into the daily diet to reduce the risk of serious eye disorders.
How Does Nutrition Impact Eye Health?
Despite extensive research and awareness, some people often need to pay more attention to the potential impact of nutrition on eye health. This may be one of the reasons for the recent increase in the frequency of eye diseases globally. Vitamin A is a popular nutrient linked to a healthy vision. Studies have shown that a deficiency of vitamin A can lead to blindness, night blindness, or even visual impairment, particularly in children. Hence, vitamin A supplementation is undertaken especially in low-income countries, as a crucial strategy for ensuring healthy vision. Antioxidants such as vitamin E, retinoids, and carotenoids like beta-carotene, lutein, and zeaxanthin play a vital role in protecting the eyes from ultraviolet (UV) radiation and are also known to reduce the risk of AMD and cataracts. The age-related eye disease study (AREDS) has evaluated the requirement of essential nutrients and supplements to maintain eye health and to prevent or delay the onset of eye diseases.
What Are the Nutrients Essential for Maintaining Eye Health?
Some of the key nutrients essential for maintaining eye health include:
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Vitamin A: Vitamin A plays a vital role in ocular health and is required to produce certain pigments in the body to function the retina properly. Vitamin A is also required to nourish the cornea and other parts of the eyes. The deficiency of this vitamin can cause night blindness, one of the leading causes of blindness in children worldwide. If night blindness is left untreated, the deficiency of vitamin A can worsen and cause drying of the conjunctiva (a clear and thin membrane lining the inner surface of the eyelids and the eyeball) and corneal ulcers (open sores), resulting in complete vision loss. Vitamin A is abundant in orange vegetables like carrots, pumpkin, sweet potatoes, green leafy vegetables, dairy products, eggs, and cantaloupes.
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Lutein and Zeaxanthin: These are yellow carotenoids naturally found in the retina (tissue lining the back of the eye), function as a natural sunblock, and protect the eyes from harmful blue light. These pigments or antioxidants are usually found in spinach, kale, pistachios, parsley, green peas, broccoli, asparagus, etc. Eye-healthy carotenoids are also in mangoes, papaya, peaches, and raspberries. Boosting the diet with these colorful fruits and vegetables can benefit the eyes.
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Vitamin E: It is a natural anti-inflammatory agent and an antioxidant that protects the eye cells from free radicals (unstable molecules), thus preventing diseases such as cataracts and age-related macular degeneration. Various studies have demonstrated that vitamin E intake through diet or supplements can reduce the development of cataracts. Vegetable oils such as safflower, soybean, corn, wheat germ, and nuts like almonds, peanuts, and sunflower seeds are good sources of vitamin E.
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Vitamin C: It is a water-soluble vitamin also known as ascorbic acid. The recommended dietary allowance (RDA) of vitamin C is 75 mg/day (milligrams per day) for women and 90 mg/day for men. Eyes have an added requirement for antioxidant protection because of the high metabolic rate, and plasma concentration of vitamin C indicates intake based on its levels in the eye tissues. Scientific evidence shows that regular consumption of vitamin C slows the progression of AMD and visual acuity loss (sharpness of the vision). Fruits such as oranges, grapefruit, strawberries, blackberries, cantaloupe, tomatoes, and papaya can be incorporated into the daily diet as they are rich in vitamin C.
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Zinc: It is an essential constituent of many enzymes and plays an important role in the retina's health and immunity. The distribution of vitamin A is mediated by zinc from the liver to the retina, thus producing the eye-protective pigment melanin. The RDA for zinc is about 8 mg/day for women and 11 mg/day for men. A zinc deficiency is associated with impaired vision or poor vision at night and cloudy cataracts. Some dietary sources of zinc include red meat, shellfish, oysters, nuts like almonds, cashews, peanuts, and seeds.
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Essential Fatty Acids: Omega-3 fatty acids such as docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) are required for proper visual development and retinal function. It also reduces the risk of dry eyes and macular degeneration. Some of the rich sources include plant oils, nuts, seeds, and seafood like tuna, salmon, sardines, and shrimp.
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Water: Drinking adequate water and keeping the body hydrated is necessary for overall health, including the eyes. The tear film is mainly composed of water and is responsible for the lubrication of the eyes. Dehydration can cause blurred vision, dryness of the eyes, irritation, and the development of corneal ulcers. Thus, water is required to keep the eyes moist, flush out the bacteria and dust particles, and have good vision.
How Can These Nutrients Be Included in the Daily Diet?
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Nutritious smoothies or shakes can be prepared to start the day using carrots, berries, spinach, orange juice, kale, and the daily breakfast.
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Green leafy vegetables can be included in dishes such as rice, pasta, pizza, flatbreads, etc., which boosts the nutritional value and benefits the eyes.
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The salad plate can be decorated with different and colorful fruits and vegetables, which helps the eyes be vibrant and healthy.
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Healthy soups, raw vegetables, or fresh fruits can be consumed during snack time instead of sugary foods or fried savories such as sweets, chocolates, or chips. Vegetables such as carrots, asparagus, and broccoli, when paired with certain healthy dips, can make a crunchy, healthy option and satisfy the taste buds.
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Non-vegetarians can include fatty fish, such as tuna, sardines, or salmon, in the weekly meal plan or at least twice a week to benefit from omega-3 fatty acids.
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Nuts such as peanuts, almonds, cashews, sunflower seeds, chia seeds, flax seeds, etc., can be added to breakfast or consumed as a midday snack to get the optimal amount of essential fatty acids.
Conclusion
A proper nutritious diet can have protective mechanisms for good vision and overall health. However, there is always scope for future research to appreciate the role of nutrition in optimizing eye health. Eye care specialists and nutritionists can identify or diagnose nutrition-related eye problems. Therefore, a regular visit to an ophthalmologist and including healthy foods in the diet support eye health and reduce the risk of eye disorders.
