Seven hours sleep a night could be the optimum
’Sleeping your life away’ could be more than a saying.
Excessive sleeping may increase your risk of an early death by up to 15%. So hints a new analysis of data collected on one million people by the American Cancer Society. The figures cast doubt on the reputed benefits of eight hours’ sleep a night.
People with the longest lives get only seven hours of sleep each night, find psychiatrists at the University of California, San Diego1. Why seven is the magic number is not clear. And sleeping more appears to be riskier than sleeping less. On the short side, increased mortality kicks in only when you get below four hours.
"If people don’t sleep eight hours, they have nothing to worry about," says Daniel Kripke, a member of the team.
Insomniacs, the data suggest, have no greater risk of premature death. Sleeping pills, in contrast, might just shave some days off your life. Kripke’s group plans to conduct experiments to determine whether setting the alarm clock can lengthen survival.
But critics of the study hope it will not be over-interpreted. They point out that the enormous data set - part of a cancer prevention study in the 1980s - was not specifically designed to analyse sleep. Insomnia was not defined, sleeping pills were not identified, and those surveyed reported their own sleep behaviour in one-hour increments, leaving little room for fine detail.
"I do not think there is a specific survival advantage to short-changing ourselves from sleep," says Daniel Buysse, a sleep specialist at the University of Pittsburgh. More targeted studies are needed to explore the implications of excess sleep, he adds.
And there are trade-offs to consider. Cranky moods, heightened susceptibility to disease, and glucose intolerance are just some of the side-effects of sleep deprivation that diminish quality of life, even if they don’t cause early death.
VIRGINIA GEWIN | © Nature News Service
Dengue takes low and slow approach to replication
12.01.2018 | Duke University
Fast food makes the immune system more aggressive in the long term
12.01.2018 | Rheinische Friedrich-Wilhelms-Universität Bonn
For the first time, scientists have precisely measured the effective electrical charge of a single molecule in solution. This fundamental insight of an SNSF Professor could also pave the way for future medical diagnostics.
Electrical charge is one of the key properties that allows molecules to interact. Life itself depends on this phenomenon: many biological processes involve...
At the JEC World Composite Show in Paris in March 2018, the Fraunhofer Institute for Laser Technology ILT will be focusing on the latest trends and innovations in laser machining of composites. Among other things, researchers at the booth shared with the Aachen Center for Integrative Lightweight Production (AZL) will demonstrate how lasers can be used for joining, structuring, cutting and drilling composite materials.
No other industry has attracted as much public attention to composite materials as the automotive industry, which along with the aerospace industry is a driver...
Scientists at Tokyo Institute of Technology (Tokyo Tech) and Tohoku University have developed high-quality GFO epitaxial films and systematically investigated their ferroelectric and ferromagnetic properties. They also demonstrated the room-temperature magnetocapacitance effects of these GFO thin films.
Multiferroic materials show magnetically driven ferroelectricity. They are attracting increasing attention because of their fascinating properties such as...
The oceans are the largest global heat reservoir. As a result of man-made global warming, the temperature in the global climate system increases; around 90% of...
Scientists at Helmholtz Zentrum München have discovered a mechanism that amplifies the autoimmune reaction in an early stage of pancreatic islet autoimmunity prior to the progression to clinical type 1 diabetes. If the researchers blocked the corresponding molecules, the immune system was significantly less active. The study was conducted under the auspices of the German Center for Diabetes Research (DZD) and was published in the journal ‘Science Translational Medicine’.
Type 1 diabetes is the most common metabolic disease in childhood and adolescence. In this disease, the body's own immune system attacks and destroys the...
15.01.2018 | Event News
08.01.2018 | Event News
11.12.2017 | Event News
15.01.2018 | Physics and Astronomy
15.01.2018 | Life Sciences
15.01.2018 | Life Sciences