Maybe you’ve heard the saying: “A coffee a day keeps the doctor away?” While not quite an adage, more and more research has come out citing coffee for its great health benefits. Increased coffee intake is correlated with a lower risk of developing or worsening the effects of diseases such as Alzheimer’s, Parkinson’s, multiple sclerosis, cardiovascular disease, and certain types of cancer. In particular, these health benefits are often enhanced by caffeine, the psychoactive stimulant that typically gives coffee its “kick” by blocking the inhibitory neurotransmitter adenosine. Controlled studies in humans have shown that caffeine consumption can improve various brain functions such as memory, energy levels, and mood. Additionally, a variety of studies have found a significant connection between coffee drinkers and having a greatly decreased risk in developing type-2 diabetes. Now, scientists are looking for potential ways to harness the caffeine content in coffee in order to help patients already suffering from diabetes.
Diabetes mellitus, more commonly known as diabetes, is a group of diseases that interfere with the body’s ability to produce insulin — a hormone released by the pancreas that signals other cells to take up the glucose in the bloodstream and use it for energy. In type-2 diabetes, the body cells develop a resistance against insulin and the pancreas is unable to compensate for this. As a result, the body is unable to absorb the excess sugar in the blood, leading to symptoms such as fatigue, extreme hunger or thirst, blurry vision, frequent urination, and cuts or sores that do not heal properly. As of yet, diabetes still has no cure and affects over 400 million people worldwide.
In a 2018 research study published in Nature Communications, the Swiss Federal Institute of Technology in Zurich looked to harness caffeine consumption to combat the insulin-production challenges faced by patients with type-2 diabetes. Researchers have genetically engineered human embryonic kidney cells that promote the production of insulin when exposed to caffeine, providing a promising therapeutic approach for those already suffering from type-2 diabetes.
In order to do this, the researchers created a receptor in the kidney cells that becomes activated when it senses caffeine coursing through the bloodstream, which they referred to as caffeine-stimulated advanced regulators, or C-STAR. When these receptors turn on, the cell responds by producing a synthetic version of human glucagon-like peptide 1 (GLP-1), a protein that promotes the production and release of insulin. To test out the efficacy of C-STAR, the researchers injected implants containing hundreds of these “designer” cells into two mouse models with type-2 diabetes. Then, they exposed the mice to drinks that had varying levels of caffeine, ranging from chocolate milk and herbal tea to Red Bull, cola, and Starbucks coffee.
The results were much more fine-tuned than expected. While drinks with little to no caffeine content such as chocolate milk and herbal tea had no effect, all of the caffeinated drinks led to an increase in GLP-1 levels. Not only that, but the increase was dependent on the amount of caffeine in each drink, showing that C-STAR doesn’t simply act as an on-and-off switch for insulin expression, but can rather adjust the levels according to the concentration of caffeine detected in the bloodstream. In other words, the blood–sugar levels in these animals could be regulated simply by the type of beverage that was added to their meals.
While the results of this study may sound promising for those with diabetes, this technology is still in its early stages of development and will be unlikely to undergo human trials for another decade or so. However, if proven to be safe and effective, these C-STAR implants could possibly replace the regular insulin injections required by diabetics. As Martin Fussenegger, principle investigator of the research, told The Guardian, “You could have your normal life back. The implant could last for six months to a year before it would need to be replaced.”
So, while taking shots of caffeine might not be a reasonable option for everyone with diabetes, this type of research could one day give some control back to those who are able to integrate the treatment into their everyday lives, allowing them to adjust their own blood–sugar levels merely by having a coffee or tea along with their meal. A coffee a day to keep the doctor away could actually be a reality someday!