Tea or coffee before bed has 'no impact' on sleep so says science

If you want to nod off easily you know that chugging caffeine before bed isn’t the best idea, right?

Well, new research has revealed that drinking coffee or tea within four hours of hitting the hay doesn’t actually affect your slumber.

Counting sheep

In fact, it’s smoking and drinking alcohol pre-lights out that are the biggest sleep thieves according to a recent study by researchers at Florida Atlantic University and Harvard Medical School.

In the study titled Evening intake of alcohol, caffeine, and nicotine and published in the journal Sleep, researchers used sensors and daily sleep diaries to track the sleep of 785 participants across 5,164 days and nights.

As well as recording the hours of sleep each person clocked up, they also analysed the quality of their sleep, plus how much alcohol, caffeine, or nicotine they consumed within four hours before going to bed.

Surprising results

The study found that while nicotine and alcohol disrupted sleep - characterised by lower quality rest and feeling groggy in the morning - caffeine seemed to have no effect.

Smoking was the substance most strongly associated with sleep disruption, with nightly nicotine use linked to an average 42-minute reduction in sleep duration.

But researchers found that consuming caffeine within four hours of bedtime had no impact on sleep.

"We did not observe an association between ingestion of caffeine within four hours of bed with any of the sleep parameters,” explained Dr Christine Spadola in the study.

"This was a surprise to us but is not unprecedented. The previous evidence is mixed when it comes to the effect of caffeine on sleep," Dr Spadola added.

Cuppa, anyone?

Before you pop the kettle on for a pre-bed cuppa, it’s worth noting that the study authors do warn that dosing, sensitivity, and tolerance weren’t measured and “can play an important role in the association between caffeine use and sleep.”

In other words you could be more sensitive to the effects of caffeine than others, which means just one little latte before bed could actually have a big impact on your sleep disruption.

Night, night.

Additional reporting by Marie Claire Dorking.

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