By Eyecare NGOverview | Nutrients
Nutrition according to the World Health Organization is the “intake of food considered in relation to the body’s dietary needs”. Humans need food for energy, growth, development and reproduction. Good nutrition is essential for a healthy body and mind; hence, the saying “you are what you eat”.
Nutrients are substances in food that provides nourishment for the body. They are required for the maintenance of life and growth and should be taken in the right quantity and combination.
The eye is a part of the body; hence diets that keep the whole body healthy will also keep the eyes healthy. However, there are certain nutrients that play key roles in maintaining healthy eyes. Most of these nutrients are antioxidants.
Antioxidants are nutrients that protect the cells of the body from a series of chemical reactions (oxidation) that can damage them. They help keep the eyes healthy by preventing or slowing down the development of many diseases. They also protect the eyes from damage by sunlight, cigarette smoke and harmful radiations as they absorb radiations in the lens and retina. Most antioxidants are vitamins and minerals that can be acquired from food or taken as supplements (though food sources are preferred).
Nutrients essential for healthy eyes
The following are some of the nutrients that play key roles in maintaining healthy eyes:
Vitamin A (Retinol)
Vitamin A is a fat-soluble vitamin that plays a very important role in night vision. It provides the chemical component needed for the retinal photoreceptor cells (rods) responsible for night vision to function well. It also helps with lubrication of the front surface of the eye. Sources of vitamin A include carrots, milk, eggs, butter, sweet potatoes, liver and pumpkin. Yellow vegetables and oranges contain a substance known as beta-carotene which is converted to vitamin A in the body. Deficiency of Vitamin A in the body causes night blindness and dry eyes. Learn more about Vitamin A deficiency and the eye.
Vitamin C (Ascorbic acid)
Vitamin C is a powerful antioxidant which helps to keep body tissues healthy and strong. Vitamin C is seen in large quantity in the aqueous humour (the fluid in the anterior chamber of the eyes). Adequate intake of Vitamin C reduces the risk of developing glaucoma and helps in alleviating it. It also plays a role in the prevention of cataract. Vitamin C in combination with Vitamin E, zinc and beta-carotene reduces the progression of age-related macular degeneration (a disease that destroys the macula, the part of the retina that provides the clearest vision). Sources of vitamin C include: citrus fruits (like grapes, oranges and lemon), strawberries, pawpaw, broccoli, guava, yellow pepper and more.
Vitamin E (Tocopherols)
Vitamin E is a fat-soluble organic compound and is an antioxidant. It protects the cells of the body from a series of chemical reactions (oxidation) that can damage them, thereby keeping them healthy and strong. It plays a role in preventing or minimizing the risk of age-related macular degeneration (ARMD), especially when combined with other vitamins and minerals. Vitamin E may also reduce the risk of age-related cataract. Some sources of this vitamin E include almonds, spinach, avocado, vegetable oils and red bell peppers.
Vitamin D (Secosteroids)
Vitamin D is a fat-soluble vitamin produced in the human skin and stored in the liver following exposure to sunlight. Other sources of Vitamin D include fishes like salmon, sardines and mackerel. It plays a role in lowering the risk of age-related macular degeneration (ARMD).
Lutein and Zeaxanthin (Carotenoids)
Lutein and zeaxanthin are antioxidants. They are present in large amounts in the macula (the sharpest point of vision on the retina). They are referred to as macular pigments. They block sun rays and protects the eye from harmful components of the visible light especially the harmful blue light. Lutein and Zeaxanthin play a major role in maintaining the health of the macula. They prevent and slow the progression of age-related macular degeneration and also reduces the risk of developing cataract. Sources of lutein and zeaxanthin include eggs, kale, spinach and other green leafy vegetables.
Zinc is an essential trace mineral needed to maintain a healthy body. It helps with the movement of vitamin A from the liver to the retina where melanin (the protective pigment in the eyes) is produced. Zinc also helps in preventing and reducing the progression of age-related macular degeneration. Some of the sources of zinc include meat, eggs, peanuts, crab, oysters and whole grains.
This is a trace mineral which when combined with lutein, zeaxanthin, vitamin C and E reduces the risk of advanced age-related macular degeneration. Sources include shrimps, crabs, salmon and brown rice.
These are antioxidants with anti-inflammatory properties. They enhance the effect of vitamin C and support blood circulation. Bioflavonoids protect against cataracts and macular degeneration. Sources include tea, red wine, citrus fruits, cherries, soy and other legumes.
Omega-3 fatty acids
Omega-3 fatty acids are essential fatty acids that play key roles in maintaining the integrity of the nervous system, the immune system, circulatory system as well as the eyes and visual system. In the eyes, Omega-3 fatty acids is known to protect the eyes from dry eye syndrome and macular degeneration. Sources include fish (like salmon, sardines, tuna), nuts (like walnuts and flax seeds) and primrose oil.
In conclusion, maintaining healthy eyes requires a healthy diet (food comprised of nutrients in the right quantity and combination). Some eye conditions such as age-related macular degeneration, retinitis pigmentosa, dry eye syndrome, cataract and glaucoma can be prevented and managed better with the intake of adequate amount of these nutrients. To ensure that your eyes have adequate amounts of nutrients to carry out its function, your eye doctor may prescribe supplements. If you are already taking supplements, it is important you let your eye doctor know as taking high quantity of some supplements may damage the eyes.