What has nutrition got to do with eye health?

Globally, approximately 250 million people suffer from varying degrees of vision loss*. Diet is thought to be an important factor because certain nutrients are able to help reduce the harmful effects of oxidants. Many of the vitamins and minerals found in a healthy diet are antioxidants, examples include Vitamins A, C and E.

Additionally, carotenoids are also effective against antioxidants. Lutein and zeaxanthin are important carotenoids and many of these substances can only be obtained from the food you eat. They are yellow plant pigments which give certain foods their colour, which is why we are always told that colourful vegetables are good for us.

Lutein and zeaxanthin are found in high concentrations in the macula, which is part of the retina at the back of the eye. Another carotenoid called meso-zeaxanthin is formed in the body from lutein. It is these three carotenoids, lutein, zeaxanthin and meso-zeaxanthin that are known as macular pigment and are thought to play an important role in absorbing damaging blue wavelengths of light. It works by acting as a natural sunblock for the macula which can then counteract the effect of free-radicals.

The issue is that the average western person’s diet is thought to contain no more than 3mg of lutein or zeaxanthin and the body cannot make either lutein or zeaxanthin.

What foods contain lutein?

Food which contains lutein: include: kale, red pepper, spinach, lettuce, leek, broccoli, peas, sweetcorn and egg yolk.

Kale is thought to have the best source of lutein and it has good bioavailability, even when raw. Look at our video below to find out how you can make a tasty kale pesto!

Egg yolk contains lutein, zeaxanthin and these carotenoids may be more easily absorbed by the body because they are eaten with fat contained in the egg.

Zeaxanthin is also found in orange and yellow fruits and vegetables such as sweetcorn, orange and peppers. Many of these foods also contain vitamins C and E.

What is the best way to eat the veggies?

It seems as though researchers are on the fence about this as light boiling or steaming may increase the bioavailability of lutein so the body can absorb it easier, but some people say cooking it too much may destroy it – research is ongoing with this.

What about supplements?

Due to these findings, it comes to no surprise that there has been considerable research into the potential therapeutic benefits of antioxidant vitamin and mineral supplements as a simple and cost-effective strategy for disease prevention/control. However, it is widely agreed that if you eat a healthy diet including at least five portions of fruit a day you should not need a supplement. This shows that supplements shouldn’t be a substitute for a healthy diet. It is also important to note that as lutein and zeaxanthin are fat-soluble, they are more easily absorbed as an oil capsule rather than tablets.

Take a look at Anne in her carrot costume giving out healthy eye “shots” to our patients which are rich in anti-oxidants.

Ask your GP before taking any supplements

 

Nutrition and Eye Health: John G Lawrenson and Laura E Downie