Many of us try, but often fail, to get
eight hours' sleep each night. This is
widely assumed to be the ideal
amount - but some experts now say
it's too much, and may actually be
unhealthy.
We all know that getting too little sleep is
bad. You feel tired, you may be irritable,
and it can contribute to obesity, high blood
pressure, diabetes, and heart disease,
doctors say. But too much sleep? You
don't often hear people complaining about
it.
However, research carried out over the
past 10 years appears to show that adults
who usually sleep for less than six hours
or more than eight, are at risk of dying
earlier than those sleep for between six
and eight hours.
To put it more scientifically, there is a
gradual increase in mortality risk for those
who fall outside the six-to-eight-hour
band.
Prof Franco Cappuccio, professor of
cardiovascular medicine and epidemiology
at the University of Warwick, has analysed
16 studies, in which overall more than a
million people were asked about their
sleeping habits and then followed up over
time.
Cappuccio put the people involved into
three broad groups:
• those who said they slept less than six
hours a night
• those who said they slept for between
six and eight hours
• those who said they slept for more than
eight hours
His analysis showed that 12% more of the
short sleepers had died when they were
followed up, compared to the medium
sleepers.
However, 30% more of the long sleepers
had died, compared to the medium
sleepers.
That's a significant increase in mortality
risk, roughly equivalent to the risk of
drinking several units of alcohol per day,
though less than the mortality risk that
comes from smoking.
But can it really be true that getting nine
hours' sleep is worse for you than getting
five?
There are different ways of looking at this.
Cappuccio was aware of the possibility
that people sleeping too long might be
depressed, or might be using sleeping pills.
He corrected for this, though, and found
the association was still there.
His own theory is that people who sleep
for more than eight hours sometimes have
an underlying health problem that is not
yet showing in other symptoms.

Credit: www.bbc.com/news/magazine-31928434

Albert Einstein slept for far less than 6hours everyday, and do you know how long he lived?