Research suggests that decaffeinated coffee can prevent Type 2 Diabetes

The American Heart Association Journal has published research, which suggests that decaf coffee drinkers lower the risk of type 2 diabetes. The study looked at the coffee drinking habits of a large sample of American adults and found that those who drank moderate amounts of coffee, that’s less than 5 cups per day, had a lower risk of death from cardiovascular disease, neurological diseases, type 2 diabetes and even suicide. Now, in this month’s landmark study by the American Chemical Society’s Journal of Natural Products suggests that certain components in coffee – both caffeinated and decaf - protects against type 2 diabetes. 

In the latest study, researchers identified two compounds in coffee that are thought to help lower the risk of type 2 diabetes. In the new study, researchers from Aarhus University Hospital in Denmark tested several components of coffee in rat cells. They found two components that appeared to combat symptoms of diabetes in the cells: Cafestol and caffeic acid, which are found in both caffeinated and decaf coffee.

When a person has diabetes, he or she becomes insulin resistant. Unregulated blood sugar levels also characterize the disease. The researchers found that cafestol increased blood sugar intake in the cells and that both cafestol and caffeic acid increased insulin secretion. The fact that the two components targeted systems and actions related to diabetes suggests they could be the components that give coffee its protective benefit. The dual benefit of cafestol was especially noteworthy to the study authors. This is true for both caffeinated and decaf coffee. 

Now, this knowledge is not brand new. The link between drinking coffee and a lower risk of type 2 diabetes onset has been previously discovered. However, scientists were unsure why the connection was there. While there was some speculation that the caffeine in coffee might have a role, other data has suggested that people benefit even if they’re drinking decaf.   

A disclaimer on the study is that it was on rat cells – not humans. Since the study was done in rat cells, it remains unconfirmed whether they indeed are responsible, and the researchers argue that it’s likely other components play a part too. After all, coffee is a highly complex beverage with hundreds of different compounds. In any case, the findings could contribute to the development of better medications for the disease.

2018 Update: 

From the following study:

Caffeinated and Decaffeinated Coffee Consumption and Risk of Type 2 Diabetes: A Systematic Review and a Dose-Response Meta-analysis

The main conclusion of the Study stated that:

"In conclusion, this meta-analysis provides strong evidence that higher consumption of coffee is associated with a significantly lower risk of diabetes. Both caffeinated coffee and decaffeinated coffee are associated with reduced diabetes risk. Longer-term randomized controlled trials are needed to establish causality and to elucidate the underlying mechanisms."

Regular Coffee, Decaffeinated Coffee and Insulin Sensitivity in Type 2 Diabetes

Regular coffee, which contains caffeine, is shown to impair insulin sensitivity in people with Type 2 Diabetes.  Caffeine has been shown to affect the body’s response to insulin, which is called insulin sensitivity. People with type 2 diabetes develop an inability either to secrete insulin or to respond to higher blood sugars; the latter situation is known as insulin resistance, and that’s where coffee’s effects need to be considered.

Research published in Diabetes Care in 2002 announced that caffeine decreased insulin sensitivity in healthy male volunteers by 15 percent when compared to placebo. Then, the American Journal of Clinical Nutrition in 2008 published a study, which found that coffee with caffeine significantly impaired insulin sensitivity in healthy men, while decaffeinated coffee did not have the same effect.

Regular high caffeine consumption, over a 4 week period, has been shown to impair insulin sensitivity in people with type 2 diabetes.

In addition, the study also wanted to look specifically at whether caffeine and caffeinated coffee had the same effect when it came to insulin resistance, citing other research that shows moderate coffee intake protects people against type 2 diabetes.

The researchers found that while pure caffeine and caffeinated coffee caused an increase in blood sugar, the effect was less for the coffee. This suggests, they say, that the protective effect of coffee when it comes to type 2 diabetes must be due to other compounds in the coffee.

Having said that, though the researchers found a relationship between higher coffee consumption and lower sensitivity to insulin, they recognised that the rapid transition to having more coffee may have produced an atypical or emphasised response by the body.

So, does regular caffeinated coffee cause insulin resistance?

It would seem to be that the jury’s out, but it is clear that caffeine alone definitely decreases insulin sensitivity. In short, further research is required.

So whilst the caffeine in coffee 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 without some of negative effects that are associated with caffeine. Like regular coffee, decaf coffee contains polyphenols, which are a molecule that anti-oxidant properties which are widely believed to help prevent inflammatory illnesses  and anticarcinogenic properties.

Decaffeinated Coffee & Memory Loss Prevention in Diabetics

In an article published in 2012, the Diabetes UK Charity wrote that “decaffeinated coffee could prevent memory loss and associated problems for patients with type 2 diabetes”.

According to research published in the Nutritional Neuroscience Journal in 2012, researchers at Mount Sinai School of Medicine showed that decaffeinated coffee could help to improve the brain energy metabolism linked with type 2 diabetes, as well as being a risk factor for dementia and Alzheimers disease .

In the research article, the scientists explained that they focused on whether dietary supplementation with a regular decaffeinated coffee prior to diabetes onset would improve insulin resistance and glucose control in laboratory mice that had diet-induced type 2 diabetes. For the Study, they gave mice the supplement for a five-month period, assessing the genetic response in brain of the mice, revealing that the brain was able to more effectively metabolise glucose and then utilise it for cellular energy.

The Lead Researcher, Giulio Maria Pasinetti, stated "This is the first evidence showing the potential benefits of decaffeinated coffee preparations for both preventing and treating cognitive decline caused by type 2 diabetes, aging, and/or neurodegenerative disorders."

Of course, as with many such studies, more research is needed to have a comprehensive answer, but it does intriguingly point to decaffeinated coffee being helpful in preventing memory loss for people with type 2 diabetes.