I was at my desk drinking my morning cup of coffee when an article caught my attention. Entitled “Caffeine, Glucose Metabolism, and Type 2 Diabetes” in the Journal of Caffeine Research-yes, there is a research journal dedicated to caffeine-it seemed appropriate to check it out.
Caffeine plus carbs
For people with diabetes (and also of interest nondiabetic individuals), caffeine intake can cause an increase in glucose levels when carbohydrate is also consumed. The thinking is that caffeine produces a temporary reduction in insulin sensitivity, or in other words insulin resistance. As is often the case with new research, it is not entirely clear why this happens. One theory is that caffeine stimulates the release of the stress hormones epinephrine and cortisol. These hormones then increase production of glucose from the liver and inhibit the action of insulin.
Before you toss your coffee maker…
Just how much is caffeine reported to affect glucose levels? The article cited 3 studies that showed that caffeine intake increased after meal glucose levels by 18-26%. But before you toss your coffee maker, it's important to note that the conclusions from this study are contradicted by other studies. To confuse matters, previous studies demonstrated that daily coffee consumption was associated with a lower risk of developing type 2 diabetes. With research studies, it is always good keep in mind that there can be a number of factors that link to a specific outcome but it isn’t always a cause and effect relationship. For example, research may show a link between eating whole grains and preventing type 2 diabetes, but there are a lot of other factors involved.
Try your own personal research project
The article concluded that more research is needed before telling people with type 2 diabetes to avoid caffeine. So why not try your own research? Think about your coffee, tea, soda, or energy drink intake. If caffeine is in your daily diet write down in your glucose logbook when you drank caffeine. You will likely also need to keep track of your carbohydrate intake and physical activity being that those will also alter your after meal glucose levels. See if caffeine intake affects your after meal glucose levels. Try the experiment for at least one week so that you can rule out other causes of after meal high glucose levels. Then you can know if caffeine affects your glucose levels.