We’ve all heard that getting eight hours of sleep is essential for good health. But what if that number is just an arbitrary benchmark? Exciting new research suggests that healthy sleep duration isn’t one-size-fits-all; it varies across cultures!
Researchers compared sleep and health across different countries, and what they found challenges previous ideas. It turns out that people in countries with shorter average sleep times don’t necessarily have worse health outcomes. In fact, the “ideal” amount of sleep seems to depend on where you live.
Previous studies show significant differences in sleep duration across countries, sometimes by as much as 1.5 hours. East Asian countries, like Japan, tend to sleep less, while people in Oceania and Western Europe sleep more. This raises some questions. Is it genetics? Lifestyle? Or something else?
Does less sleep equal worse health? Past studies link insufficient sleep to health problems. So, researchers wondered if countries where people sleep less suffer more. A study comparing university students in Japan and Canada revealed that Japanese students slept about an hour less but rated their health better. This suggests cultural factors play a big part.
Two Studies, Surprising Results
To dig deeper, researchers conducted two major studies: Study 1: They looked at data from 71 countries and compared average sleep duration with national health indicators like heart disease, obesity, diabetes, and life expectancy. Study 2: They surveyed nearly 5,000 people in 20 countries about their sleep habits and health.
The results turned some assumptions upside down: Different countries showed substantial differences in average sleep duration (up to 1.57 hours!). The link between sleep duration and health wasn’t the same across all countries. People who slept closer to their country’s “ideal” sleep duration reported better health.
In other words, if you’re in a culture that values shorter sleep, you might thrive on less sleep than someone in a culture that prioritizes long sleep. It’s all about cultural fit!
“Optimal” Sleep: It’s Not Universal
The latitude of a country does correlate with sleep duration. But the study suggests cultures cultivate norms for sleep and lifestyle. For example, Japanese culture is known for promoting less sleep, while French culture favors longer sleep.
The study revealed that the turning points for sleep duration (the amount of sleep linked to best health) varied across countries. For instance, individuals in Japan averaged six hours and 18 minutes of sleep, whereas those in France averaged seven hours and 52 minutes. In Canada, the average sleep time was recorded at seven hours and 27 minutes.
In all 20 countries studied, people slept less than this optimal duration, hinting that most could benefit from a little more shut-eye. But what’s “optimal” differs from place to place.
Limitations to Keep in Mind
It’s important to acknowledge the limitations. The studies relied on self-reported data, which can be subjective. Also, the researchers note, there are countless cultural differences that could impact health. The sample sizes for each country were relatively small.
Nonetheless, the study helped to shed light on the important concept of sleep and the long held believe that as far as sleep is concerned, one cap fits it all!