(NaturalNews) Researchers from Ohio State University may have discovered a mechanism by which proteins known as xanthophylls help prevent against age-related vision loss, they reported in a study published in the Journal of Lipid Research.
"Our research to understand this mechanism might provide a greater appreciation for how one could intervene to possibly slow macular degeneration," said senior study author Earl Harrison.
Age-related macular degeneration is one of the most common causes of age-related vision loss and affects approximately 10 million people in the United States. The deterioration of the macula, a tissue located in the center of the retina, causes vision in the center of the eye to blur, which lead to functional blindness. The condition cannot be reversed once it develops; it can only be slowed.
Prior research has suggested that the xanthophyll proteins lutein and zeaxanthin may protect against the eight-related macular degeneration by filtering out potentially harmful light from the blue end of the spectrum and also protecting the eye against damage from oxidation. The two proteins have been observed to concentrate in the macula, forming a yellow spot.
In the current study, researchers tested the hypothesis that the xanthophylls are transported to the macula by proteins known as scavenger receptor class B, type 1 (SR-B1). They treated pigment cells from the lining of the human retina with lutein, zeaxanthin and the related compounds beta-carotene, finding that the cells absorbed more xanthophylls than they did beta-carotene.
The researchers then blocked the action of SR-B1 by one of two methods. Both of the methods led to a decrease in xanthophyll of distortion of 41 to 87 percent.
Lutein and zeaxanthin cannot be synthesized by the body, but must be consumed in foods such as green, leafy vegetables, peas, summer squash, or yellow and orange fruits and vegetables (including carrots, papaya and peaches).