Drinking coffee before bed does not affect sleep quality, study finds

Drinking coffee, tea before bed does not affect sleep quality, study finds. (File photo: KUTV)

SALT LAKE CITY (KUTV) - Coffee lovers rejoice; you can have that late-night cup of coffee and it won't affect the quality of your sleep, according to a new study which was reported in The Independent.

The same goes for caffeinated tea, according to the study published in Sleep.

Researchers from Harvard Medical School and Flordia Atlantic University arrived at their conclusions after studying 785 people for a total of 5,164 days and nights.

The researchers then recorded how much caffeine, alcohol, and nicotine people consumed.

Those results were compared with wrist sensors and sleep diaries which recorded sleep duration, sleep efficiency, and how quickly people awoke after falling asleep.

Researchers found that while alcohol and nicotine both disrupted sleep, caffeine seemed to have no effect, which was surprising to researchers.

Writing in the journal Sleep, Dr. Christine Spadola, of Florida Atlantic University said:

This study represents one of the largest longitudinal examinations of the associations of evening use of alcohol, caffeine, and nicotine with objectively measured sleep outcomes. A night with use of nicotine and/or alcohol within four hours of bedtime demonstrated worse sleep continuity than a night without. We did not observe an association between ingestion of caffeine within four hours of bed with any of the sleep parameters.

Nicotine was the biggest sleep disruptor, taking off a total of 42 minutes of sleep time on average.

Other doctors say it's a myth that drinking coffee before bed will keep you awake. It all depends on the person and how their body reacts to caffeine.

Sleep expert Dr, Neil Stanley told The Independent:

Some people are very sensitive to the effects of caffeine and for these people it’s important to avoid drinking beverages containing caffeine too close to bedtime – but there is no golden rule about this, just listen to your body. For some people the effects caused by caffeine are much lower and [it] may not have any effects at all. If you have been drinking two strong black cups of coffee every evening for the past 40 years and you have just developed a sleeping problem, then it is almost certainly not the coffee.

The conclusion to the study published in Sleep reads:

Nicotine and alcohol use within 4 hours of bedtime were associated with increased sleep fragmentation in the associated night, even after controlling for multiple potential confounders. These findings support the importance of sleep health recommendations that promote the restriction of evening alcohol and nicotine use to improve sleep continuity.