Did you know that some foods can actually boost your eyesight? Certain nutrients are vital for eye health!
Free radical damage increases with age and contributes to certain eye conditions. The cornea does not have its own blood supply. It gets its nutrients from the Aqueous Humour (the fluid in the anterior chamber). It is therefore crucial for people undergoing cornea transplants to consume the correct foods and supplements to help repair the damaged tissue.
Another way in which the cornea gets its nutrients is through the atmospheric oxygen. Although we cannot do much about the quality of air around us, we can make an effort to avoid pollutants – one of them being cigarette smoke.
Smoking actually doubles your risk of sight loss – and if you have a family history of eye disease, the risk may increase eight-fold. The chemicals in tobacco smoke damage retinal blood vessels and contribute to the development of AMD – it's estimated that one in ten cases are are due to smoking. What's more, the risk of AMD doubles for people who live with smokers!
Nutrients and Vitamins that protect the Eyes
Many common foods contain powerful antioxidants that may help to protect against eye disese.
The following are good sources of eye-friendly anti-oxidants:
Vitamin A
This vitamin protects against night blindness, dry eyes and conjuctivitis. Food sources containing vitamin A are egg yolks, oily fish, cheese and beef.
RDA: 3,000 IU for men; 2,333 IU for women (2,567 IU during pregnancy and 4,333 IU when breast-feeding).
Beta-carotene
Beta Carotene, which is converted to Vitamin A in the intestine, has also been found to protect against night blindness and dry eyes and are found in apricots, carrots, green leafy vegetables, pumpkin, squash, yellow peppers and sweet potatoes.
RDA: None (Most supplements contain 5,000 to 25,000 IU).
Vitamin C
Reduces the risk of cataracts and macular degeneration. It is found in citrus fruits, green peppers, strawberries, potatoes and green leafy vegetables.
RDA: 90 mg for men; 70 mg for women (85 mg during pregnancy and 120 mg when breast-feeding).
Vitamin E
It is thought that when combined with carotenoids and vitamin C, it may reduce the risk of advanced macular degeneration and cataract formation.
Food sources containing Vitamin E include whole grains, nuts, seeds and vegetable oil.
RDA: 15 mg for teens and adults (15 mg for women during pregnancy and 19 mg when breast-feeding).
Selenium
The benefits of selenium are the same as for Vitamin E, i.e. when combined with carotenoids and vitamins C and Vitamin E, it may reduce risk of advanced macular degeneration.
Selenium can be found in Avocados, lentils, meat, seafood (prawns, crab, salmon, halibut) brown rice and Brazil nuts.
RDA: 55 mcg for teens and adults (60 mcg for women during pregnancy and 70 mcg when breast-feeding).
Zinc
Zinc assists vitamin A in reducing the risk of night blindness. Food sources include sunflower seeds, oysters; fish; beef, peanuts and the dark meat of turkey.
RDA: 11 mg for men; 8 mg for women (11 mg during pregnancy and 12 mg when breast-feeding).
Bioflavonoids (Flavonoids)
May protect against cataracts and macular degeneration. The food sources include tea, red wine, citrus fruits, bilberries, blueberries, cherries, legumes, soy products.
RDA: None.
Lutein and Zeaxanthin
The Macula (the area of the retina that provides the most detailed vision) is yellow (another word for the retina is the “yellow spot”). The reason for this is that it contains high levels of two natural plant pigments namely lutein and zeaxanthin. They belong to a group known as carotenoids which are powerful antioxidants which means that they assist in counteracting free radicals (highly reactive and damaging chemicals that form in the body as a result of pollutants, radiation and metabolic processes).
These nutrients are also found in the lens and seem to protect against cataracts. Good sources of lutein and zeaxanthin include dark green leafy vegetables such as spinach. broccoli, kale, brussel sprouts, cabbage together with the yellow vegetables the likes of butternut, pumpkin, gem squash, orange peppers and sweetcorn.
RDA: None.
Vitamin D
Vitamin D may reduce the risk of macular degeneration.
Foods containing this vitamin include salmon, sardines, mackerel and organic milk
RDA: None. The best source of vitamin D is exposure to sunlight. Ultraviolet radiation from the sun stimulates production of vitamin D in human skin, and just a few minutes of exposure to sunlight each day (without sunscreen and sunglasses) will insure your body is producing adequate amounts of vitamin D.
Grape Seed Extract
Grape Seeds are a rich source of anti-oxidants – beta carotene, vitamin E and flavonoids.
These help to combat free radical damage in the eye, strengthen the tiny blood vessels (capillaries) of the retina, boost night vision and may protect against cataracts.
Some research has suggested that grape seed extract can slow down macular degeneration and perhaps reduce eye strain in people doing a lot of close work.
RDA: None.
Rutin
Another free radical-busting flavanoid, rutin comes from buckwheat and may help to protect against eye problems such as cataracts and macular degeneration.
RDA: None
Gingko Biloba
Made from the leaves of a Chinese tree fern, gingko has long been used in Oriental herbal medicine. It has been reported to improve long-distance visual acuity (detailed vision) in people with AMD.
A small study from the University of Brescia in Italy found that 40mg Gingko three times daily for four weeks also improved the field of vision in some patients with glaucoma.
Fats that protect the Eyes
Some fats are positively good for your eyes, others can be disastrous! The bad fats – saturated and trans-fats – clog the arteries and are linked to heart disease. Limit your intake of high-fat products derived from an animal source as well as processed foods like cakes, chips, take-aways and fast foods.
Omega fats are also known as Essential Fatty Acids (EFA’s) because they are vital for many bodily functions. Our bodies cannot produce omega 3, so we need to get them from foods
Omega-3 fatty acids reduce inflammation and make the tear film oilier, thus preventing gritty, dry eyes. It may also help prevent macular degeneration
Eat plenty of Cold-water fish such as salmon, mackerel and herring as well as two to three portions of sardines and pilchards. Omega 3’s are also found in some vegetable oils like rape, soya and flaxseed oil, as well as fish oil, green leafy vegetables and walnuts.
The ideal ratio of omega 3 to omega 6 is about 1:1. However, the typical modern diet is closer to 1:12 so care must be taken to reduce the omega 6 consumption!
RDA: None.
The Recommended Daily Allowance (RDA) is meant to be a guideline for the amount of a particular vitamin/nutrient that we need to consume per day to prevent malnutrition and diseases relating to their absence. However it has not been updated in the last two decades, and as such needs to be adjusted. It also does not take into consideration farming conditions such as nutrient content of the soil or the negative aspects of intensive animal farming. Neither does it consider external stresses such as environmental pollution, radiation or health challenges.
We should therefore excercise common sense when it comes to supplementation and eating habits. We need to eat five portions of organic fruits and vegetables a day and make sure that our meats are derived from a source absent of antibiotics and hormones (for more information on this please visit www.allabouthealth.co.za) to stay healthy and lower our risk of eye disease.