Study Finds Higher Blood Caffeine Levels Can Help Prevent Type 2 Diabetes

If you've ever vowed to give up coffee only to find yourself — just a few days later — shouting romantic movie lines like "I wish I knew how to quit you" into your to-go cup of cold brew, we're certain you're not alone. Many avid coffee, tea, and soda drinkers have entertained the idea of giving up the juice at one time or another. Some of them are in search of better sleep, while others are hoping less caffeine equals less anxiety. Others still may be hoping to achieve an altogether healthier lifestyle without depending on a substance like caffeine. And while all of that is well and good, a new study published in BMJ Medicine on Tuesday suggests that perhaps your morning cup of coffee is contributing to your good health.

We've all heard about — and likely experienced — some of the negative effects too much caffeine can have on the body. And while side effects like insomnia, restlessness, anxiety, shaking hands, increased heart rate, dehydration, dizziness, and dependency are all common, the new study is painting caffeine in a different light: as a deterrent for type 2 diabetes.

Previous studies, including a 2018 meta-analysis published in Nutrition Reviews and another 2020 study published in The American Journal of Clinical Nutrition, have linked increased caffeine consumption with a decreased risk of type 2 diabetes. However, according to The Guardian, the observational nature of the studies made it difficult to decipher whether caffeine specifically was the reason for the decreased risk.

In order to combat this, researchers working on the new study used a method called Mendelian randomization, which examines how different variations of a gene react when exposed to the same elements. In this case, their focus was on two variations of genes that deal with metabolism of caffeine (per Healthline).

People with the variant of the gene that allow them to metabolize caffeine more slowly were more likely to have an increased level of caffeine in their blood than those with the gene that causes caffeine to metabolize at a faster rate. What researchers discovered by examining the data of almost 10,000 people was that a higher blood caffeine level (slower metabolization of caffeine) was associated with a lower body mass index (BMI) and less body fat compared to a lower blood caffeine level (faster metabolization of caffeine). What's more, because excess weight contributes to the incidence of type 2 diabetes, people who metabolize caffeine more slowly were also found to be less likely to develop type 2 diabetes.

Authors of the study note that more research is needed to determine whether calorie-free beverages containing caffeine could be a viable option for reducing the incidence of obesity and type 2 diabetes.