Vitamin C and Bioflavonoids Help Prevent Cataracts (2006)
Two studies show significant reductions in cataracts for those in the highest percentage of vitamin C intake.
In the first study, Japanese researchers followed 35,000 people. They evaluated the participants for their vitamin C intake and cataract formation. They found that those in the highest 20% of vitamin C intake had a 40% reduced risk of getting cataracts.
The second study followed 177 (116 women, 61 men) participants over the age of 60. In this study, the researchers found that if you are in the top 5% of vitamin C intake, your risk is reduced some 20% compared to the lowest 5%.
But that's not all this study found. If you ingest more than 3,290 mcg daily of lutein, your risk drops 14% compared to ingesting less than 256 mcg daily. Zeaxanthin had a smaller risk reduction, but mostly in men.
Interestingly, the study also found that sunlight exposure is also a major risk factor. If you were out in the sun a lot in your early years, your risk triples compared to being closeted indoors.
Ref: International Journal for Vitamin and Nutrition Research, 2006; 76(6); Nutr, 2007 January 30.
Read more about cataracts.