The health benefits of coffee are attributed to the antioxidants found in the coffee bean, not caffeine.
However, consuming more than three or four cups of coffee a day can negatively impact health and sleep.
Different stages of sleep do different things for your brain and your body at different times of the night. So when people come to me and they’ll say, ‘Look, how do I get more REM sleep or how do I get more deep sleep?’ I’ll ask them, ‘Why do you want more of that deep sleep?’ and they’ll say, ‘Well, isn’t that the good stuff?’ or they say the same thing about REM sleep, and it’s actually not true. It’s just that they all perform some different functions. – Matthew Walker