Is Too Much Sleep Bad for You?

Nothing says "it's the weekend" quite like hitting snooze on the alarm and enjoying a few extra hours of shuteye. While sleeping in is considered a luxury, new research from Keele University suggests that people who regularly sleep in could be at risk of developing serious health problems, including heart disease, high blood pressure, obesity and diabetes. In extreme cases, the researchers warn premature death could be a genuine risk.

Reported in the Journal of the American Heart Association, the team drew on data from over 70 different studies, involving roughly 3 million people in total. After analysing both sleep patterns and health issues, the researchers found that people who regularly sleep for over 10 hours a day are 30% more likely to die of health complications than those who sleep for just seven hours. The findings also indicated a 44% increase in the risk of developing coronary heart disease, as well as a 49% increased risk of mortality caused by cardiovascular disease and 56% by stroke.

The mysterious mechanism behind oversleeping and mortality

“This research began because we were interested to know if it was more harmful to sleep below or beyond the recommended sleep duration of seven to eight hours” comments Dr Chun Shing Kwok, lead researcher of the study and a Clinical Lecturer in Cardiology at Keele University. “We wanted to know how incremental deviation from recommended sleep duration altered risk of mortality and cardiovascular risk."

While the study suggests there is a link between oversleeping and developing health conditions, the exact mechanism behind the link remains unknown. Critics maintain the connection is interlinked with lifestyle factors, including the fact that people who regularly oversleep generally have other pre-existing health conditions that increase the risk of mortality.

The complexities of a good night's sleep

Regardless, Kwok and his colleagues were quick to point out that seven to eight hours remains the optimum sleep cycle goal, stressing that "sleep affects everyone" and that both the amount and quality of sleep can be complex, with significant variations from person to person.

“There are cultural, social, psychological, behavioural, pathophysiological and environmental influences on our sleep such as the need to care for children or family members, irregular working shift patterns, physical or mental illness, and the 24-hour availability of commodities in modern society,” adds Kwok.

From measuring neuron and brain activities to analysing rapid-eye-movement (REM), near-infrared spectroscopy (NIRS) plays an important role in sleep research. For a closer look at the latest developments don't miss 'Avoiding Pitfalls During NIR Spectroscopy Analytical Method Transfer'.