Coffee's Secret: How Your Daily Brew Shapes Your Dreams and Sleep Cycles

• Caffeine blocks adenosine, a chemical signaling fatigue, keeping the brain alert even when the body needs rest.
• With a half-life of 3-6 hours, afternoon coffee can disrupt sleep onset and alter sleep cycles, including REM sleep.
• Caffeine reduces total sleep time, fragments sleep, and interferes with the balance between deep sleep and REM sleep.
• Disrupted REM sleep makes dreams harder to recall, as recall is best when waking during or immediately after REM.
• Cutting back on caffeine can lead to a 'REM rebound,' where increased REM sleep results in clearer, more vivid dreams.

Why It Matters: Coffee not only keeps you awake but also significantly alters sleep architecture and dream vividness.