Coffee can reduce the blood glucose levels of people with type 2 diabetes by improving insulin sensitivity. This is the conclusion of a study just published in the International Journal of Pharmacy and Pharmaceutical Sciences.
This cross-sectional study compared four groups of people:
- 48 people who have type 2 diabetes and do drink coffee
- 42 people who have type 2 diabetes and don’t drink coffee or any caffeinated beverage
- 143 people who don’t have diabetes and do drink coffee
- 57 people who don’t have diabetes and don’t drink coffee or any caffeinated beverage
All of the coffee drinkers in the study had drunk 3 to 4 cups of filtered coffee daily for at least 16 years. And all of the people with diabetes in the study took oral diabetes drugs and were free of diabetes complications.
Fasting blood tests showed that 22 percent of the people who have diabetes in the study and drink coffee had lower blood glucose levels than the matched group of people with diabetes in the study who don’t drink coffee. The coffee drinkers who don’t have diabetes had a 5 percent lower level that the matched group who don’t drink it. It seems that drinking coffee helps those of us who have diabetes more than it helps people who don’t have this condition.
Pros and cons
Researchers have been going back and forth for years about whether coffee is good or bad for us. One earlier review in the French publication La Revue du praticien found, for example, that the more cups of coffee, caffeinated or decaffeinated, the greater the risk of type 2 diabetes. But most studies over the years, including the other reviews, have been positive for people with pre-diabetes and diabetes to drink coffee.
When I searched the U.S. National Library of Medicine for studies that have the words “diabetes” and “coffee,” in the titles, it showed links to 123 other studies going back to 1967. One of these studies, a mini-review that the European Journal of Nutrition put online last month ahead of print, concluded that “there are mounting evidences of the reduced risk of developing type 2 diabetes by regular coffee drinkers of 3-4 cups a day.”
Reports emphasize that what you add to your coffee is “a potential confounding factor.” Sugar and cream are, of course, the usual suspects. This is at least a partial explanation why some of the earlier studies may have mistakenly warned us about drinking coffee.
Is it the caffeine?
But maybe the difference is whether you drink caffeinated coffee. Three of the earlier studies of coffee and diabetes concluded that the caffeine in coffee increase our blood glucose levels. Yet six of these earlier studies found that whether we drink our coffee caffeinated or decaffeinated makes little difference in the risk of people getting diabetes.
As a person who has long enjoyed my caffeinated coffee (as well as my caffeinated tea), I’ve read many of these conflicting studies as they came out over the years. But the weight of the evidence, including the latest study, encouraged me as I prepared this report to enjoy an extra cup.
This article is based on an earlier version of my article published by HealthCentral.
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