Does Decaf Coffee Reduce the Risk of Diabetes?

The release of a new study about coffee and diabetes has raised questions again about whether decaffeinated coffee is a healther choice for coffee lovers than regular coffee. A number of earlier studies on coffee and diabetes have shown that people who drink four or more cups of coffee a day reduce their risk of developing type 2 diabetes by 50 percent or more. The new study, published in the Dec 2011 issue of “Journal of Agricultural and Food Chemistry”, found that three compounds found in coffee may be the agents of that risk reduction.

Kun Huang of Huazhong University of Science and Technology led a team of researchers who examined the effect of several compounds in coffee on the toxic build up of hIAPP (human islet amyloid polypeptide), a protein chain that has been implicated in the development of type 2 diabetes. They found that three of those substances — caffeine, caffeic acid and chlorogenic acid — appear to block the build up of hIAPP. More importantly, they found that the two acids have a significantly stronger effect against the toxic buildup than the caffeine.

The team speculates that this inhibitory effect on the buildup of hIAPP may be the reason that coffee has a beneficial effect on preventing diabetes. If that’s the case, their research may provide a starting point for new, more effective treatments for type 2 diabetes and pre-diabetes.

When asked about the effects of decaffeinated coffee, Huang states that he believes decaf coffee may be even more beneficial than regular coffee because the concentration of caffeic acid and chlorogenic acid is higher than it is in regular coffee, while the level of caffeine, which has uncomfortable side effects for many people, is greatly reduced.


Huang’s team did not use actual coffee in their experiments, though. They used the concentrated extracts from coffee on human cells in petri dishes, and the concentrations of coffee compounds used by the Chinese researchers are much higher than you’d get in a cup of coffee. The results in the study are suggestive, but they are just a starting point for further research using animals and humans — and maybe, real coffee! — to further understand the link between coffee and diabetes.

Many medical professionals recommend decaffeinated coffee for diabetics because caffeine is known to impair glucose metabolism. A 2004 study carried out at Duke University found that when subjects with diabetes took 250 mg of caffeine — a little more than the average amount in a cup of coffee — with their meals, they had higher blood glucose spikes after eating, and blood sugar readings an average of 8 percent higher. This suggests that diabetics who are attempting to control their blood sugar levels should avoid caffeinated beverages, including coffee.

However, a 2010 study published in “Diabetes Care” found that decaffeinated coffee also has an acute effect on glucose metabolism. The researchers found that young men who drank decaffeinated coffee before an oral glucose tolerance test showed significantly higher levels of glucose at every point during the test than those who drank a placebo, and lower levels than those who drank regular, caffeinated coffee.

The conflicting results and advice can be confusing, but most medical professionals agree on one point. Like just about anything else, the key to enjoying coffee is moderation. Keep your coffee consumption within reasonable limits, and follow the advice given you by your own doctor or medical professional.