Article by Dr S P Pradhan, MBBS, MD on 5th May,2023
Dietary nutrients rich in carotenes and vitamin A with micronutrients are essential for eye health. Some trace elements also aid in vision and protect our eye.
Role of Vitamin A in vision
Vision is a physiological process. It requires different forms of vitamin A like retinol retinal and retinoic acid. Beta carotene or carotenoids are the plant sources of vitamin A. Foods rich carotenoids and vitamin A are the primary requisites for our eye health and prevention of degenerative eye disorders.
Other nutrients for eye health
Apart from vitamin A, other nutrients required for eye are vitamin C, omega 3 fatty acids, zinc, lutein, zeaxanthin,. These micronutrients in combination prevent our eyes from inflammatory and degenerative disorders like cataract and age related macular degeneration.
Foods rich in Vitamin A
Carotenes are the natural plant source of vitamin A. The foods rich in carotenes are mango, papaya, sweet potato, carrots. Carrots as the name suggest are rich in beta carotenes. Other plant sources are pumpkin, winter squash, tomatoes, spinach, amaranth. The plant source vitamin A is the inactive form of vitamin A that are digested into our body to the active form retinol. The carotene pigments give colour to the green vegetables and fruits.
Animal sources of vitamin A are meat, fish, milk, egg yolk, cheese, butter. Animal source vitamin contain the active form of vitamin known as retinol. In fish liver oil like Cod liver oil is very rich in vitamin A along with vitamin D. The contain beyond the recommended dietary allowance.
Foods rich in C
Vitamin C are the antioxidant vitamins required for prevention of inflammatory and degenerative disorders. The citrus fruits are very rich in vitamin C. Vitamin C rich foods are orange, sweet lemon, black currants, strawberries, broccoli, brussels sprout and amla. This is one of the vitamin if taken in large quantities doesn’t cause any harm. It helps in eye disorders like cataract, age related macular degeneration.
The daily requirement of of vitamin C is around 90mg in men and 70mg in women.
Zinc rich foods for Retinal function
Zinc is an essential trace element required for melanin synthesis. It protects from night blindness, cataract and age related macular degeneration. The physiological functions of zinc is seen in retina where it interacts with vitamin A and taurine. Suboptimal status of zinc also involved in many chronic disorders of eye. Zinc supplementation trials have seen positive result in age related macular degeneration.
Foods rich in zinc are sea foods, meat, fish. Plant sources are beans, nuts and cereals. But the bioavailability plant source zinc is very less due to presence of phytates which interact to decrease the absorption of zinc.
The RDA(Recommended dietary allowance) of zinc is 11mg in adults.
Foods rich lutein and zeaxanthin to support eye health
Lutein and zeaxanthin belong to the xanthophyll family of carotenoids which are plant sources of vitamin A. They accumulate in macula hence known as macular pigments. They are not produced inside our body and need to be supplied through our diet.
Diet containing these elements are usually the green leafy vegetables like spinach, kale, broccoli, lettuce, brussels sprout. Fruits like blackberries, raspberries, kiwi fruits also contain good amount of these pigments. Among all these kale has the highest amount of these pigments per gram.
The main role of these pigments is to protect from the oxidative stress mainly in age related macular degeneration(ARMD).
Diet rich in Omega-3 fatty acids
Fish oils and nuts, seeds like flax seeds are rich in omega 3 fatty acids. They are potent free radical scavengers preventing in oxidative stress. They are helpful in cataract, age related macular degeneration and glaucoma.
