Many people's morning routine involves drinking a cup of coffee right after waking up. However, a sleep expert explained to the British newspaper "Mirror" that "this is not the best time of the day to get the most energy from your favorite drink." Dr. Deborah Lee states that "the best time to consume caffeine is 45 minutes after waking up, when cortisol levels start to decline."
The doctor pointed out that "cortisol follows a specific rhythm in your sleep cycle. High levels of cortisol can affect your immune system, and if they are at their peak when you wake up, drinking coffee right after opening your eyes may do more harm than good, potentially making you tolerant to caffeine over a longer period."
Cortisol is the main stress hormone in the body, produced by the adrenal glands and released into the bloodstream during times of stress. It impacts sleep levels, mood, and energy. Additionally, it fights inflammation, controls blood pressure, and regulates blood sugar levels.
Dr. Lee explained: "The best time to drink coffee is mid-morning to late morning, when your cortisol levels are much lower and you start to feel a dip in energy, but of course not late in the afternoon as that may affect your sleep at night."
According to a study conducted in 2010, cortisol levels reach their lowest around midnight before rising between 2 to 3 AM. It peaks around 8:30 AM and then declines throughout the day, completing a 24-hour cycle.
