A typical study published in the British Journal of Nutrition has shown that drinking black coffee after experiencing poor quality sleep reduces the body's glucose tolerance. This study shows that when participants drink coffee before breakfast, their post-meal blood sugar levels increase by about 50% compared to when they do not drink coffee. This shows that coffee can reduce insulin sensitivity - a hormone that helps the body use sugar effectively.
Caffeine, the main active ingredient in coffee, is known to stimulate the central nervous system. However, according to a report by the American Diabetes Association, caffeine can increase epinephrine levels, thereby inhibiting insulin activity and temporarily increasing blood sugar levels. This is especially noteworthy in the morning - the time when the body naturally has high cortisol levels (hormones related to stress and energy metabolism). The combination of cortisol and caffeine can increase blood sugar more strongly.
The World Health Organization does not ban coffee consumption, but recommends reasonable use, especially in people at high risk of metabolic disorders such as prediabetes or metabolic syndrome. Experts also recommend that instead of drinking coffee right after waking up, you should eat a light breakfast first, to reduce the negative impact on blood sugar.
Drinking coffee as soon as you wake up can increase blood sugar levels due to the impact of caffeine on insulin activity. To protect long-term metabolic health, especially blood sugar, it is necessary to consider the time and way of using coffee appropriately.
