An increasing body of evidence is revealing that our diet directly influences the health of our eyes. For National Eye Health Week we've put together some of the latest scientific evidence, and found five foods that should definitely be in your diet to keep your eyes as healthy as possible.
We’ve all heard the old wives tale that carrots make you see in the dark. While that’s partially true, there are many other benefits to the eyes from eating carrots. Carrots and other orange fruit and vegetables get their colour from Beta-carotene – a kind of vitamin A, which is great for keeping your retina (where the rod and cone cells that detect light and send nerve signals to the brain) healthy. Although it is pretty well known that carrots are good for your eyes, there are other foods that we shouldn’t forget when talking about eye health.
2. Leafy greens
Leafy green vegetables like cabbage and lettuce contain high levels of both lutein and zeaxanthin. These are two types of carotenoids that, in nature, help plants to absorb excess light energy to prevent damage from overexposure to the sun. They are particularly good at absorbing high energy blue light rays. Lutein and zeaxanthin are found in really high concentrations in the human retina, and even give it its yellowish orange colour when looked at with a bright light. Keeping the retina stocked up with these compounds prevents damaging blue light from reaching the nerves and other tissues under the retina, and having a diet with plenty of them has been shown to reduce the risk of age related macula degeneration (AMD) – a condition that can lead to blindness.
Eggs are another great source of lutein and zeaxanthin, but also are a good source of zinc. Zinc is essential for eye health, as well as the immune system, brain and other body systems. High levels of zinc are found in the macula – a part of the retina. Zinc helps over a hundred different enzymes in the eyes, skin and muscles to work effectively. One of these enzymes is a powerful antioxidant called superoxide dismutase which, with the help of zinc, prevents damaging free radicals from causing harm to cells in the eyes.
4. Citrus fruits and berries
Citrus fruits and berries are a great source of vitamin C and bioflavenoids, which are important antioxidants. They work together to promote healthy bones, skin, immune function, liver function and blood vessels – including the tiny delicate capillaries found in the eye. They also reduce the risk of heart disease, have anti-aging properties, decrease cholesterol and even reduce the risk of some cancers. Humans can’t make their own vitamin C, so we need it in our diets. Other really good sources of vitamin C are red peppers, broccoli and orange juice.
Nuts and seeds are great snacks, and are a much healthier alternative to chocolate and crisps. Almonds and other nuts are excellent sources of vitamin E, and other minerals that keep your eyes healthy. Vitamin E is an excellent antioxidant that protects cell membranes from damage caused by free radicals. These occur naturally during metabolism, but can also result from exposure to environmental pollutants such as cigarette smoke. Vitamin E is actually a group of eight different compounds called tocopherols and tocotrienlols. In a huge 5000 patient study with AMD, researchers found a 25% lower risk of developing the advanced condition when vitamin E, vitamin A, vitamin C and zinc were given.