Dec. 22, 2009 -- Carrots may be good for the eyes, but so are leafy green vegetables and colored fruits, University of Georgia scientists report.
Green leafy vegetables and colored fruits may affect visual performance and may prevent age-related eye diseases, according to a new study in the Journal of Food Science.
These foods contain the carotenoids such as lutein and zeaxanthin, which play an important role in vision and have a positive impact on the retina, scientists led by Billy R. Hammond, PhD, a professor of neuroscience and experimental psychology at the University of Georgia, say in a review of previous research.
Lutein and zeaxanthin may help reduce disability and discomfort from glare, enhance contrast, and reduce photostress recovery times, the researchers say, and also may increase visual range.
The researchers write that their review on the effects of lutein and zeaxanthin is important because "it is clear that they could potentially improve vision through biological means."
They cite a 2008 study that suggests the pigments protect the retina and lens, and may "even help prevent age-related eye diseases such as macular degeneration and cataract."
Hammond and colleagues reached their conclusions after reviewing multiple studies of the effects of lutein and zeaxanthin on visual performance. The researchers say about 600 carotenoids can be identified in nature, but only a fraction is absorbed by people.
Lutein and zeaxanthin are found in kale and spinach, among other vegetables.
Of about 20 carotenoids found in human blood, only lutein and zeaxanthin are found in the visual system, the researchers write, suggesting these pigments play a "special role" in human vision.
Lead author James M. Stringham, PhD, formerly a colleague of Hammond's, is now with the Northrop Grumman Corp. in Texas.