What are lutein and zeaxanthin?
Lutein is an antioxidant nutrient that belongs to a sub-category of the carotenoid family: the xanthophylls.
Xanthophylls are a group of plant pigments responsible for many of the bright coloured fruits and vegetables. It is also the pigment that gives salmon its colour. Closely related to lutein is another carotenoid xanthophyll called zeaxanthin.
In the body, lutein is stored in the eyes, brain, blood and skin. The highest concentration is found in the macular area of the retina in the eyes. Of the 30 to 50 carotenoids found in the diet, lutein and zeaxanthin are the only two that are found in the retina.
Why do we need them?
At the centre of the retina sits the macula lutea which is seen as a yellow spot. Lutein and zeaxanthin are the pigments responsible for giving the macula its yellow colouring.
It is believed that lutein and zeaxanthin act in two ways to help support the health of the eyes:
- They are antioxidants and therefore help to protect against free radical damage.
- As the pigments of the macula, they are involved in blue-light filtration effects, including glare reduction, contrast enhancement and cellular health maintenance.
Through these protective mechanisms it is thought that lutein and zeaxanthin may help support our eye health, particularly as we get older and are at a greater risk of developing age related eye conditions.
Where do we get it?
Lutein and zeaxanthin are found in green vegetables (especially spinach), egg yolk, kiwi fruit, grapes, orange juice, zucchini, squash and corn. In supplements, lutein and zeaxanthin are commonly derived from marigold flowers.
How much do we need?
There are currently no recommended daily intakes (RDI) for lutein and zeaxanthin. The amount of lutein that is generally found in supplements for eye health is 6-10 mg.
It seems the level of lutein and zeaxanthin found in our blood is related to our dietary intake. For example, a 10% increase in our dietary intake of lutein and zeaxanthin leads to a 2.4% increase in blood levels.
References available on request