Coffee protects against diabetes

Your early morning coffee might be doing more than just waking you up say American researchers who believe the caffeine-rich brew might protect against type 2 diabetes.

Your early morning coffee might do more than wake you up

Women who drink four cups of caffeinated coffee each day had higher levels of SHBG – sex hormone-binding globulin –than non-drinkers say researchers at the University of California Los Angeles (UCLA). Around 56% of these women were also less likely to develop diabetes than non-drinkers.

Researchers have discovered a possible molecular mechanism behind coffee’s protective effects – it increases plasma levels of SHBG, which regulates the biological activities of testosterone and oestrogen which are thought to play a role in the development of type 2 diabetes.

“This protein, SHBG, is critical as an early target for assessing the risk and prevention of the onset of diabetes,” said Dr Simin Liu, professor of epidemiology and medicine.

The researchers identified 359 new diabetes cases matched by ages and race with 359 apparently healthy controls selected from nearly 40,000 women enrolled in the Women’s Health Study – a large cardiovascular trial.

Previous work by Liu and his colleagues found there were two mutations in the gene coding for SHBG: one which increases the risk of developing type 2 diabetes and one that decreases it, depending on the levels of SHBG in the blood. This research showed that those carrying the protective copy of the gene appeared to benefit the most from coffee consumption.

“That genetic evidence significantly advanced the field because it indicated that SHBG may indeed play a causal role in affecting risk for type 2 diabetes,” said first author Atsushi Goto, a doctoral student in epidemiology.

“It seems that SHBG in the blood does reflect a genetic susceptibility to developing type 2 diabetes,” Liu said. “But we now further show that this protein can be influenced by dietary factors such as coffee intake – the lower the levels of SHBG, the greater the risk beyond any known diabetes risk factors.”