WASHINGTON • Social pressures are forcing people to cut back on their sleep, contributing to a "global sleep crisis", according to a new study based on research collected through a smartphone app that also shows people in Singapore having the lowest average amount of sleep.
The app enabled scientists from the University of Michigan to track sleep patterns around the world and better understand how cultural pressures can override biological rhythms. It gathered data about how age, gender and the amount of natural light which people are exposed to affect sleep patterns in 100 countries.
The study found that people in Singapore and Japan had the least amount of sleep on average - seven hours and 24 minutes.
In contrast, it was eight hours and 12 minutes in the Netherlands.
"The effects of society on sleep remain largely unquantified," says the study published last Friday in the journal Science Advances.
"We find that social pressures weaken and/or conceal biological drives in the evening, leading individuals to delay their bedtime and shorten their sleep."
Lack of sleep is mostly affected by the time people go to bed, the study found.
Middle-aged men get the least amount of sleep, less than the recommended seven to eight hours.
And age is the main factor determining amount of sleep.
The research is based on data collected through the free smartphone app Entrain, launched in 2014 to help users fight jetlag.
Scientists asked some 6,000 people 15 years or older to send anonymous data about sleep, wake-up and lighting environment, enabling the scientists to obtain a large amount of data about sleep patterns worldwide.
The app also asks users to input information about their ages, gender, countries and time zones.
People who need sleep suffer a reduction in their cognitive abilities without really being conscious of it, according to the new study.
"Impaired sleep presents an immediate and pressing threat to human health," it says.
Chronic lack of sleep increases the risk of obesity, diabetes, hypertension and cardiovascular disease, according to the Centers for Disease Control and Prevention in the United States.