Putting Life in Focus with Lutein and Zeaxanthin
If you wanted a simple explanation of why lutein and zeaxanthin are so important to eye health, consider this: Of the 40 to 50 carotenoids in our diet, lutein and the two zeaxanthin isomers – RR-zeaxanthin (3R,3’R-zeaxanthin) and RS- (or meso-) zeaxanthin (3R,3’S-zeaxanthin) are the only three found in the eye. These are called macular carotenoids.
The macular carotenoids act as potent antioxidants in the eye. They protect our bodies against a process called oxidation. One of the most commonly cited examples of oxidation is rusted metal – something we certainly don’t want to see happen inside our bodies. Oxidation can happen in the eye from the environment like light from the sun. In fact, just being alive causes oxidation – it is a natural process of aging.
Lutein and zeaxanthin isomers also play a direct role in vision. They are highly concentrated in a small area in the center of the retina called the macula. The macula is responsible for our central vision and the sharpness with which we see things (known as visual acuity). Because the macula is yellow, lutein and the zeaxanthin isomers are often referred to as macular pigment.
Macular pigment enhances healthy vision by filtering light and enhancing detail and contrast. Studies suggest that macular pigment may benefit activities such as driving at night and protect against harmful effects that might occur after staring at a computer for too long.1,2 Studies also suggest that macular pigment density has also been shown to increase the speed with which we process imagesand to help us see in dim light.3,4,5 Lutein and zeaxanthin may also help the nerves to the eye talk to one another — a process known as neuronal signaling.6,7,8
These effects happen throughout our lives: as infants, while our vision is developing; as we mature during childhood; and as our eyes become more vulnerable with age.9
Lutein and zeaxanthin are also found elsewhere in the eye: in the iris, the lens and photoreceptors.10
1 Br J Nutr. 2009 Jul;102(2):186–90
2 Appl Ergon. 2009 Nov;40(6):1047–54
3 Ophthalmic Physiol Opt 2005;25:315–9
4 Ophthalmic Physiol Opt 2010;30:351–7
5 Exp Eye Res 2010;91:896–900
6 Optom Vis Sci Off Publ Am Acad Optom. 2007 Sep;84(9):859–64
7 Optom Vis Sci Off Publ Am Acad Optom. 2008 Feb;85(2):82–8
8 Nutr Rev. 2005 Feb;63(2):59–64
9 Nutr Rev. 2008 Dec;66(12):695–702
10 Nutrition Rev 2008 Dec; 66(12):695–702