Coffee or caffeinated tea consumed before bedtime has no effect on sleep quality.
The researchers came from Florida Atlantic University and Harvard Medical School, which monitored 785 people's caffeine, alcohol and nicotine levels over 5,164 days. The researchers also used sensors that tracked sleep duration, efficiency, and how quickly the subjects woke up after their sleep.
The study found that nicotine and alcohol had a negative effect on sleep quality - a cigarette before bedtime reduced by 42 minutes - while caffeine had no effect.
The researchers were surprised by this result, but in fact, it simply confirms the findings of other studies.
The idea that consuming coffee before bedtime doesn't allow you to sleep is just a myth. If you've been drinking coffee for 10 years and suddenly have trouble sleeping, you probably don't have the coffee. However, if you know you are sensitive to caffeine, avoid it.
Such situations are easy to manage. Be attentive to the signs your body gives you and respond appropriately.