Regular exercise and a balanced diet are important for general wellbeing and protecting against many health conditions. Diet is thought to be important because certain nutrients protect the body against substances called “oxidants”. Many of the vitamins and minerals found in a healthy diet are called antioxidants.
Most research has focused on vitamins A, C and E. These are thought to maintain healthy cells and tissues in the eye. They are found in many fruits and vegetables, such as oranges, tomatoes and in green leafy vegetables. They can also be found in nuts, seeds, dairy products and other food types.
More recently, interest has grown in another antioxidant, lutein, and a similar substance, zeaxanthin. Both of these are yellow plant pigments, which give certain fruit and vegetables their colour, for example the yellow and orange in peppers, sweetcorn and saffron. Surprisingly perhaps, green leafy vegetables such as kale, spinach and broccoli also have high levels of lutein (you can actually see the lutein as the vegetables age and turn yellow).
The human body cannot make lutein or zeaxanthin; they have to be eaten. Several studies suggest that consuming at least 10mg of lutein per day has the most beneficial effects on macular pigment levels.
What should I eat?
It’s important to have a wide range of foods in your diet.
Eggs contain high levels of lutein and zeaxanthin, and they may be easily absorbed by the body because they are eaten with the fat contained in the egg. Zeaxanthin is also found in orange and yellow fruits and vegetables.
Some studies are looking at the effects of omega 3 on eye health, which is an essential fatty acid found in oily fish, as well as some nuts and seeds such as walnuts and flaxseed.
Kale is the best source of lutein and has good bioavailability, even when raw.
Lutein in vegetables milligrams (mg)/100g (fresh)
Kale 11.4 mg
Red pepper 8.5 mg
Spinach 7.9 mg
Lettuce 4.7 mg
Leek 3.6 mg
Broccoli 3.3 mg
Peas 1.7 mg
Eggs contain lutein and zeaxanthin, and these carotenoids may be more easily absorbed by the body because they are eaten with the fat contained in the egg.
There has been a lot of research into whether nutritional supplements can make up for the lack of lutein, zeaxanthin and other antioxidants in people’s diets.
Two large studies, Age-Related Eye Disease Study AREDS1 and AREDS2, suggested that certain nutritional supplements can slow down the progression of AMD by about 25%.
The AREDS 2 study tested a modified version of the AREDS1 formula.
The AREDS2 formula:
Vitamin C 500mg
Vitamin E 400 IU
Should I take a supplement?
Studies into the benefits of taking supplements for eye health are conflicting. It is widely agreed that if you eat a healthy diet, including at least five portions of fruit and vegetables a day, you should not need a supplement. In reality, most people do not eat the recommended amounts.
Talk to your GP before taking supplements or making major changes to your diet, especially if you take other medications.