A varied and balanced diet should supply us with sufficient quantities of all the vitamins and trace elements needed to keep us in good health, but if you are particularly concerned about protecting your eyes and vision, there are several specific nutrients that can be easily incorporated into everyday eating. Of course, the shelves of health food shops are stacked with a wide range of supplements that can aid eye health, but the fact that the three main vitamin groups that protect eyes are found in so many everyday foods makes this the best place to start.
Eating carrots to help see in the dark is not just an old wives’ tale – the Vitamin A present in carrots as carotenoids is vital to eye health. The powerful antioxidants known as lutein, zeaxanthin and lycopene in carotenoids protect healthy tissue against damage from free radicals which are produced by cell metabolism. Insufficient vitamin A leads to reduced night vision, susceptibility to infection and conjunctival corneal drying. Carotenoids are also found in other brightly coloured red and yellow fruit and vegetables and dark green leafy vegetables.
Another easily consumed supplement is the Vitamin B complex. Vitamin B2 (riboflavin) plays an important role in maintaining optic nerve health and is an antioxidant that may help ward off cataracts. It is found in many foods, especially Marmite which has 11 milligrams per 100g, the highest of any foods. Offal, wheat germ, milk, hard cheese and – believe it or not – faggots are also at the top of the list. Deficiency of Vitamin B in a normal diet is rare but absorption by the digestive system of B1 and B12 in particular is easily reduced by alcohol.
Vitamin E is the third musketeer in the store cupboard of eye health. Vitamin E is a generic term for a group of substances of which the most important is tocopherol. This is connected with the protection of cell membranes and helps protect vitamin A from oxidation in the retina. Vitamin E is present in many foods and deficiency in a normal diet is rare but may arise in people with digestive problems who are unable to absorb dietary fats. Lack of vitamin E causes neurological problems due to poor nerve conduction.
Store cupboard foods high in vitamin E include sunflower and vegetable oil, peanut butter, eggs and cereals containing wheat germ.
Trace elements are less understood than vitamins but it is believed that they are minerals required in small quantities to help vitamins to work. Selenium and zinc are important in the preservation of ocular health.
Selenium works with vitamin E to have an antioxidant effect. A lack of selenium is linked to the development of cataracts and age-related macula degeneration (AMD). Foods high in selenium include mushrooms, salmon, tuna and Brazil nuts.
Zinc is a critical trace element and is involved in antioxidant activity. It has a vital function in the metabolism of vitamin A and is found in the choroid and retinal receptors and may help to maintain the health of the crystalline lens. Zinc deficiency causes poor wound healing and night blindness and has been linked to disease of the optic nerve. Shellfish and red meat are high in zinc but for vegetarians eggs and dried fruit are the next best source.
Many studies have taken place on understanding the function of nutrition and dietary supplements and their effect on vision. Some show that dietary supplements can be beneficial while others show no benefit at all. Most experts agree that a healthy diet is by far the most valuable way to obtain nutrients from food but sensible use of supplements provides a good back up for those whose lifestyle and dislikes – such as Marmite – means they are missing out.
What’s next?
Do you protect your eyes from the harmful UV radiation of our sun? Most of us cover up our skin to protect ourselves from sunburn but what about your eyes? Tomorrow we will visit the dangers of ultraviolet radiation to our eyes, see you then…
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