Waking up and smelling that freshly brewed coffee is great, isn’t it? However, according to a study from the University of Bath in the United Kingdom, drinking coffee on an empty stomach can be harmful to blood sugar control, especially after a poorly slept night. The study was published in the British Journal of Nutrition.
For the analysis, 29 healthy men and women were recruited and subjected to three nocturnal experiments in random order: in one, volunteers had a normal night’s sleep and ate breakfast upon waking; in another, people were awakened every hour for five minutes and had to drink some coffee with sugar, as well as when they got up in the morning; in the third scenario, participants also had their sleep interrupted during the night but ingested coffee without sugar, and upon getting out of bed the next day consumed the beverage 30 minutes before breakfast.
Blood samples from the participants were collected after each of these tests. The study showed that strong, unsweetened coffee consumed before breakfast increased blood glucose by about 50% during the morning meal.
“These results show that a night of interrupted sleep alone does not worsen the glucose and insulin response of participants to sweetened coffee compared to a normal night’s sleep. However, starting a day after a poor night’s sleep with a strong coffee had a negative effect on glucose metabolism by about 50%,” interprets Harry Smith, the main author of the investigation, in a statement.
The Best Way to Drink Coffee
Although population-level research indicates that coffee may be related to good health, some previous studies have shown that caffeine has the potential to cause insulin resistance, which can lead to diabetes.
“We know that almost half of us wake up in the morning and, before anything else, have a cup of coffee. And intuitively, the more tired we are, the stronger the coffee,” analyzes James Betts, coordinator of the Centre for Nutrition, Exercise and Metabolism at the University of Bath and supervisor of the work.
The good news is that you can work around the situation by eating first and drinking coffee afterwards. In any case, more studies like this are needed. “There’s also a lot more we need to learn about the effects of sleep on our metabolism, such as how much sleep disruption is necessary to impair metabolism and what are the long-term implications of this practice. It’s also important to know what exercises could help combat this,” adds Smith.