The report in the American Chemical Society's Journal of Agricultural and Food Chemistry supposes that drinking tea may be a simple and inexpensive means of preventing diabetes and the complications that may ensue, including cataracts.
Researchers from the University of Scranton, Pennsylvania, fed green and black tea to diabetic rats for a period of three months before monitoring the chemical composition of the rats' blood and eye lenses.
The amount of tea was, according to the scientists, equivalent to less than five cups of tea per day for a human. They claimed that this volume of both teas significantly inhibited cataract formation compared to a control group that was not given any tea. The researchers found that both teas decreased glucose levels, which in turn affects other biochemical pathways that accelerate diabetic complications such as cataracts.
However, as Joe Vinson, lead author of the paper, said: "Most people, scientists included, believe that green tea has more health benefits than black tea".
Researchers worldwide think that all efforts to prevent diabetes are welcome in health and cost benefit terms, as an estimated 41 million Americans have 'pre-diabetes', or impaired glucose tolerance, in which blood sugar levels are higher than normal and lead to high risk of developing type 2 diabetes.
Around 25 per cent of UK adults are also thought to have this condition and the number of people with diabetes, now 3 per cent of the population, will continue to rise as the population ages and becomes more overweight.
This most recent report is scheduled to appear in 4 May print issue of the journal and was published in 31 March editon of ACS's website.