A study that looked at the prevalence of diabetes type-2 in 50 countries has found that people who drink black tea regularly have a low risk of developing diabetes type-2.

Researchers used data on the level of black tea consumption in 50 countries. They obtained this data from an independent market research company. They also used information available on the prevalence of diabetes, cancer and other diseases in these countries from WHO.

Ireland topped the list for the highest consumption of black tea with an average tea consumption of 2 kilograms or 4.4 pounds of tea per person a year. Next in the list were UK and Turkey.

South Korea, Brazil, China, Morocco and Mexico had low levels of black tea consumption.

Researchers found that countries where black tea consumption was high also had lower prevalence of diabetes type-2.

"These original study results are consistent with previous biological, physiological, and ecological studies conducted on the potential of [black tea] on diabetes and obesity... and they provide valuable additional scientific information at the global level," the researchers wrote.

Researchers add that the study doesn't show a cause and effect relation between black tea and diabetes type-2 and that more studies are required to show an association.

"You certainly can't say that on the basis of this study alone, but the findings are consistent with previous studies that have also suggested a link," Ariel Beresniak, of the mathematical research group Data Mining International in Geneva, Switzerland, and an author of the study, told WebMD.

Not all experts agree saying that while there is no harm in drinking black tea, there is no substantial evidence linking tea to lower diabetes risk. "I am not convinced on the basis of this study that drinking black tea lowers diabetes risk," said Spyros Mezitis, MD, of Lenox Hill Hospital in New York City, to WebMD.

The study is published in BMJ Open.

Healthy diet, regular physical activity, maintaining normal weight and avoiding smoking can help people stay away from diabetes type-2, according to WHO.