Scientists are also studying how caffeine affects insulin and blood glucose levels. Currently, they believe the following mechanisms may exist.
- Caffeine can increase levels of certain stress hormones, such as epinephrine (also called noradrenaline). Adrenaline can prevent cells from processing sugar and may also prevent the body from producing normal amounts of insulin.
- Caffeine blocks a protein called adenosine. This molecule can significantly affect the amount of insulin the body produces and can also control the cells’ response to insulin. And caffeine blocks adenosine from working so that it can’t quickly remove sugar from the blood.
- Caffeine can interfere with sleep. Excessive caffeine can keep people from falling asleep. Lack of sleep may decrease insulin sensitivity.