Lack of sleep wrecks your body clock and your health
MODERN living has made us ‘supremely arrogant’ in the way we ignore the importance of sleep, leading scientists warn. The demands of today’s 24hour society mean many people push themselves too far, or ‘override the clock’, in the words of one expert.
Far too many of us bury our heads in the sand over the issue and ignore the health risks of neglecting our sleep, he added.
Lack of sleep puts the body clock out of sync and can cause severe health problems, such as cancer, heart disease, Type 2 diabetes and obesity.
A project involving scientists from Oxford, Cambridge, Harvard, Manchester and Surrey universities concluded that the public and governments are failing to take the problem seriously.
The experts, who collaborated for the BBC’s Day of the Body Clock programme, found that on average, people get two hours’ less sleep a night than 60 years ago. They warned that modern life – and particularly our attachment to computers and hand-held gadgets such as tablets and smartphones – means many are ‘living against’ their natural body clocks, which are biologically geared to rest at night.
Professor Russell Foster, a neuroscientist at the University of Oxford, said: ‘We are the supremely arrogant species; we feel we can abandon four billion years of evolution and ignore the fact that we have evolved under a light- dark cycle. What we do as a species, perhaps uniquely, is override the clock. Long-term acting against the clock can lead to serious health problems.’
It is an issue that affects the whole of society, but is particularly acute among teenagers, he said.
Nearly all living things have an internal mechanism known as the circadian rhythm, or body clock, which synchronises bodily functions to the 24-hour pattern of the Earth’s rotation.
In humans and other mammals, it is regulated by the senses – most importantly the way the eye perceives light and dark and the way skin feels temperature changes.
The mechanism rules our daily rhythms, including our sleep and waking patterns and metabolism.
But the pressures of modern living mean we are now increasingly working against our clocks and risking long term health problems from metabolic disease.
Professor Charles Czeisler of Har-
‘It’s a big concern’
vard University, said smartphones, tablets and computers had high levels of light at the blue end of the spectrum, which hits us ‘in the sweet spot’ for disrupting the human body clock.
‘Light is the most powerful synchroniser of your internal biological clock,’ he said.
‘Light exposure, especially short wavelength blue-ish light in the evening, will reset our circadian rhythms to a later hour, postponing the release of the sleep-promoting hormone melatonin and making it more difficult for us to get up in the morning.
‘It’s a big concern that we’re being exposed to much more light, sleeping less and, as a consequence, may suffer from many chronic diseases,’ Professor Czeisler said.
Separate research published today in the Journal of the Royal Society Interface, suggests forcing the body to work overnight may also cause damage to the brain similar to Alzheimer’s disease.
US scientists at Brigham and Women’s Hospital, Boston, found that rats kept awake at night suffered disturbances in the electrical activity of neurons that are typically seen in dementia. The authors believe the findings may also apply to humans.
Another study, in Sleep Medicine, found women who get less than six hours a night were 65 per cent more likely to have high total cholesterol and 71 per cent more likely to have raised levels of LDL – the so-called ‘bad’ cholesterol which clogs up arteries around the heart.