July 13, 2004 -- To protect your eyesight, try broccoli. An antioxidant found in broccoli may be a powerful force in preventing blindness.
Researchers at Johns Hopkins University School of Medicine have discovered that sulforaphane, the naturally occurring antioxidant in broccoli and broccoli sprouts, protects the eye from damage caused by the sun's ultraviolet light.
Cells in the eye's retina are extremely sensitive to damage caused by oxidants, especially those generated by light. While several processes within the eye help cut that damage, the eye gradually loses that capability as we age.
This is believed to be the primary cause of age-related macular degeneration -- the leading cause of blindness, writes researcher Xiangqun Gao, a molecular scientist with the Johns Hopkins University School of Medicine. His report appears in the current issue of the Proceedings of the National Academy of Science of the USA.
To combat this damage, a simple long-term strategy is important, Gao notes. That's where sulforaphane comes in.
Previous studies from this group of researchers have shown that sulforaphane prevents tumor growth and kills stomach bacteria that lead to ulcers and stomach cancer. In one study, they showed that feeding broccoli sprouts to rats prevented high blood pressure, heart disease, and stroke.
In their latest laboratory experiment, the Johns Hopkins researchers exposed human retina cells, which protect against oxidative stress and free radicals, to various doses of sulforaphane. Then they exposed cells to ultraviolet light -- similar to sunlight -- to produce oxidative damage.
Sulforaphane protected eye cells from damage, reports Gao. In fact, the more sulforaphane exposure the cells got, the more protection they received.
"Much evidence points to the central role of oxidative damage in chronic degenerative diseases of the eye," writes Gao. A diet high in broccoli and broccoli sprouts is a safe, long-term approach to preventing age-related macular degeneration and blindness, he says.