Morning coffee on poor sleep causes more harm than good

A cup of coffee in the morning is a must for some to start the day off properly. It helps us get in a positive and energized mood. Besides this mood-boosting effect, new research shows that coffee can lower your risk of developing Type II diabetes. 

Diabetes is a metabolic disease that causes blood sugar levels to be high, which the body cannot adequately regulate. Type II diabetes can develop through a combination of one’s genes and unhealthily conditions, such as being overweight. 

A 2014 study by Shilpa Bhupathiraju and colleagues from Harvard School of Public Health and Yong Loo Lin School of Medicine concluded that people who decreased their regular coffee intake by more than one cup per day had a 17 per cent increased risk of developing Type II diabetes. Those that increased the amount of coffee they consumed saw their chances of developing Type II diabetes decrease by 11 per cent. 

A more recent study by Harry Smith and his team, published in the British Journal of Nutrition, looked at how morning coffee affects our blood glucose levels. Glucose, as in blood sugar, is what your body uses for energy. This study also looked at how disrupted sleep at night might also affect our blood glucose levels. 

Sleep disruption can include sleep deprivation, broken sleep (i.e., interruptions or a pause between two sleep periods), or non-specific sleep fragmentation (i.e., random interruptions throughout the night). Sleep disruption of any type is known to cause problems with blood sugar levels. This is due to sleep disruption’s effect on our ability to use glucose and sensitivity to insulin, the hormone that regulates glucose. Various studies have either only looked at the impact of morning coffee on blood glucose levels or the effects of disrupted sleep on blood glucose levels, but not both, until now. 

For this study, 29 healthy men and women in their early twenties were recruited. The participants were divided into two groups: disrupted sleep and non-disrupted sleep. The researchers woke the disrupted sleep group every hour for five minutes with text messages. The disrupted sleep group was further divided into two groups: caffeinated and not caffeinated. The Oral Glucose Tolerance Test (OGTT) was given to participants after they’d woken up and had their coffee. The OGTT checks the body’s sensitivity to insulin and how fast and to what extent glucose is cleared from the bloodstream. This was done to look at the effects caffeine might have after eating breakfast in the morning. 

The study found that one night of sleep disruption did not affect how insulin regulates blood sugar, provided that no coffee is had upon waking. Thus, our body’s ability to use and regulate blood is not affected by fragmented sleep alone. However, drinking coffee in the morning after a night of disrupted sleep did have a negative effect on the body’s ability to tolerate high levels of glucose in the blood. Having your usual morning coffee following a night of inadequate sleep can reduce your body’s ability to regulate its blood sugar levels. 

As a result of this thorough study, while a cup of coffee in the morning can lower your risk of developing Type II diabetes, caffeine and low quality of sleep can cause other significant health issues.