Black Tea May Lower Diabetes Risk
November 8, 2012

Countries Who Drink Black Tea Have Lower Diabetes Rate

Lee Rannals for — Your Universe Online

Drinking black tea each day could keep diabetes away, according to new research published in the online journal BMJ Open.

Researchers found that the prevalence of type 2 diabetes is lower in countries where consumption of black tea is high.

The team performed a mathematical analysis of data from 50 countries and found that global prevalence of type 2 diabetes has increased six-fold over the past few decades.

The International Diabetes Federation calculates that the number of those with the disease will soar from 285 million in 2010 to 438 million in 2030.

Authors of the study systematically mined information on black tea consumption in countries across every continent. They used 2009 sales data collected by an independent market research company for the study.

They analyzed World Health Organization data for those same countries on the prevalence of respiratory, infectious and cardiovascular disease, as well as cancer and diabetes.

The team found that Ireland was the top country for black tea drinkers, consuming more than 4.5 pounds per person a year. The U.K. and Turkey followed behind.

The bottom of the list for black tea drinkers was South Korea, Brazil, China, Morocco and Mexico.

Using a statistical approach known as principal component analysis (PCA), the team teased out the key contribution of black tea on each of the health indicators selected at the population level.

Their analysis showed an impact for black tea on rates of diabetes, but not on any of the other health indicators studied.

They confirmed the link with further statistical analysis, which pointed to a strong linear association between low rates of diabetes in countries where black tea consumption is high.

However, even though the findings suggest black tea could help ward off diabetes, the authors admitted to several caveats in their findings.

They said the quality and consistency of data among all 50 countries are likely to vary, as well as the criteria to use to diagnose diabetes.

They also point out that various factors could contribute to the dramatic rise in diabetes prevalence, and that a link between black tea consumption and the prevalence of the disease does not imply an association.

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

They said in recent years, a great deal of interest has focused on the health benefits of green tea, which is thought to have anti-inflammatory properties. However, the fermentation process of green tea to turn the leaves black creates several potential health benefits.