Coffee and Diabetes
The effect of coffee on diabetes, when presented in the media can often be confusing.
News stories can in the same week tout the benefits coffee can have on diabetes and shoot down coffee as being unhelpful for blood sugar levels.
This doesn’t mean the articles are contradictory though.
Put slightly more simply, coffee contains different chemicals, some of which have beneficial effects whereas others can have a less beneficial effect, such as caffeine which can impair insulin in the short term.
Caffeine and blood sugar levels
Caffeine has been shown to impair insulin sensitivity in people with type 2 diabetes, indicating that coffee may see higher blood glucose levels.
Benefits of coffee
Coffee has been shown to offer the following health benefits:
- Lowering risk of developing type 2 diabetes
- Lower risk of developing cancers
- Reduction of cardiovascular disease
- Reduction of strokes
Coffee contains polyphenols, which are a molecule that anti-oxidant properties which are widely believed to help prevent inflammatory illnesses, such as type 2 diabetes, and anticarcinogenic (anti-cancer) properties.
As well as polyphenols, coffee contains the mineral magnesium and chromium.
The blend of these nutrients can be helpful for improving insulin sensitivity.
Coffee and prevention of diabetes
Coffee and its effect on risks of developing type 2 diabetes have been studied a number of times and has indicated a notably lower risk of type 2 diabetes being associated with coffee drinkers.
A 2009 study of 40,000 participants noted that consumption of 3 cups of tea or coffee a day lead to a 40% lower risk of type 2 diabetes developing. 
Decaffeinated coffee and blood glucose
So whilst caffeine may hamper insulin sensitivity, other properties in coffee have the opposite effect.
It is therefore believed that decaffeinated coffee may present the best option for people with diabetes as researchers find it includes the benefits of coffee with some of negative effects that are associated with caffeine.