Smoking more than coffee affects sleep

A team of sci­en­tists from the Uni­ver­si­ties of Flori­da, Har­vard, Emory and Mis­sis­sip­pi Med­ical Cen­ter found that, con­trary to pop­u­lar belief, cof­fee does not cause insom­nia. But it does cig­a­rettes and alco­hol.

The study, which last­ed 14 years, involved 785 peo­ple, some of whom were African Amer­i­cans. Mem­bers of this race are more like­ly than oth­ers to suf­fer from insom­nia, sleep apnea, and oth­er sim­i­lar dis­or­ders. It should be added that there were no peo­ple with clin­i­cal sleep dis­or­ders among the project par­tic­i­pants.

Each sub­ject received a sen­sor that was worn on the wrist and record­ed all stages of a per­son­’s sleep. In par­al­lel, the project par­tic­i­pants kept a diary in which they not­ed how they slept, how they felt, what they ate, how much they smoked and drank.

Sci­en­tists were sur­prised to find that caf­feine had almost no effect on the sleep of the sub­jects. This con­clu­sion did not change even after adjust­ing for their age, gen­der, weight, and employ­ment.

Insom­nia was more like­ly to over­take peo­ple who took alco­hol — most often when a per­son con­sumed it before bed­time.

But the strongest fac­tor caus­ing sleep dis­tur­bances was smok­ing or vap­ing nico­tine-con­tain­ing mix­tures. Those who received a dose of nico­tine in the evening, on aver­age, slept 43 min­utes less than non-smok­ers.