Under 6 or more than 9 hours of sleep per night can be bad for you

Too little or too much of a good thing can be bad for you, and that includes sleep. Getting less than six or over nine hours of sleep per night is bad news for your longevity. This is the verdict of a joint UK and Italian research project, which pools the results of 16 previous studies, based on a total of 1.5 million people from the UK, the US and various European and East Asian countries.


The joint study found that people who regularly sleep less than 6 hours a night have a 12% higher chance of dying over a 25-year period than those who slept regularly for 6 to 8 hours a night. At the same time, compared to that group of  'ideal' sleepers, the odds for a longer life are worse people who sleep often more than 9 hours a night. The latter may not be directly linked to premature death but merely be a marker of ill health, i.e. it may be a symptom of some other underlying health problem directly linked to premature death. The degree to which too little sleep and the decrease in longevity is causally linked is not clear either. It may be that sleep-starved people are more prone to accidents or habits that harm health.

Full article in the BBC.

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