Three cups of coffee a day could help keep diabetes away, scientists say

Drinking more coffee may slightly reduce your risk of diabetes, and people who drink three or more cups appear to be at the lowest risk of all, an American study has suggested.

The study
Researchers at Harvard University’s School of Public Health analysed data on more than 120,000 people’s coffee consumption over several years. For the study, the scientists analysed the results of three large US diet and lifestyle surveys involving health professionals. The diets of participants were assessed every four years by questionnaire and those developing Type 2 diabetes identified. In total, 7,269 cases were recorded.

Researchers found that those who increased their intake by more than a cup a day over a four-year period had an 11% lower chance of developing diabetes in the following years. Those who had consistently higher coffee consumption – of three or more cups a day – had a risk which was 37% lower than people who consistently drank one or fewer cups a day.

The findings
The American researchers, led by Professor of Nutrition Frank Hu, said: “Our findings demonstrate that change in coffee consumption is associated with both immediate and long-term diabetes risk. It appears to affect risk in a relatively short amount of time.”

The report said: “We observed that increasing coffee but not tea intake over a four-year period was associated with a lower Type 2 diabetes risk in the next four years. Decreasing coffee intake was associated with a higher Type 2 diabetes risk. These changes in risk were observed for caffeinated but not decaffeinated coffee and were independent of initial coffee consumption and changes in other diet and lifestyle factors.”

There was no evidence that tea consumption had an effect on diabetes risk but the researchers said this may have been because there were fewer people drinking tea or who altered their tea consumption.

Co-author Dr Shilpa Bhupathiraju said: “Our findings confirm those of previous studies that showed that higher coffee consumption was associated with lower Type 2 diabetes risk. Most importantly, they provide new evidence that changes in coffee consumption habit can affect Type 2 diabetes risk in a relatively short period of time.” She said that while exercise and maintaining a healthy diet were by far the best ways to cut the risk of type 2 diabetes, there were also “biologically plausible” theories as to why coffee might also help.
“Coffee has a lot of bio-active compounds, including chlorogenic acid, which we know improves glucose metabolism when tested in animals,” she said. “Coffee is also a rich source of magnesium, which is known to be associated with a  lower risk of type 2 diabetes. The biological plausibility is actually very strong.”

Current health advice suggests that around 400mg – roughly four mugs of instant coffee – is the safe limit for caffeine consumption, although pregnant women are advised to consume half that amount. The cups of coffee referred to in the study had roughly 100mg of caffeine.

Sources: http://www.sciencedaily.com/, http://www.newswise.com/, http://www.express.co.uk/, http://www.independent.co.uk/, http://www.thecrimson.com/