heartbeat
© Telegraph
Endured sleepless nights in the aftermath of the Brexit vote? You weren't the only one. A study of 11,600 wearers of Nokia Health devices shows our biorhythms shift during and after monumental political moments, including the election of Donald Trump and the Brexit vote.

Stress can cause sleepless nights and increase heart rates, but little was known about how this links to big societal changes. "We wanted to add in the quantitative data," says Daniele Quercia of Nokia Bell Labs.

Quercia and his colleagues analysed data from people who wore health monitoring devices, such as smartwatches, in San Francisco and London between April 2016 and April 2017. They found that an entire population's sleeping habits and heart rates, and the collective distance walked, can swing out of sync after big societal events.

The proportion of people in San Francisco who diverged from the general population's norm increased by 30 per cent after the election of Donald Trump, while heart rates rose from an average of 66 beats per minute before his election to 70 beats per minute on election day. Four months later, they still hadn't returned to their pre-voting baseline.

In the aftermath of the Brexit vote, around one in eight people saw their sleep, movement and heart rate shunted away from the average, with overall sleep time dropping by 10 per cent. The changes were more significant than those observed around events such as Christmas and New Year's Eve (arxiv.org/abs/1804.06931).

Stress seems to be the likeliest reason for these changes."When we're stressed, our sleep is one of the first things that gets affected," says Jason Ellis at Northumbria University's Centre for Sleep Research, UK. "You've got more to think about, more to cope with, and so in the short term it's a normal biological reaction."