Another week, another study - this time on the dangers of too little sleep. But before we all panic, Channel 4 News speaks to the experts about whether we should lose sleep over counting sheep.

Why you shouldn't be losing sleep over sleep (Getty)

We don't really need a study to tell us about the affects of poor sleep.

Unlike other factors important for our wellbeing like eating and exercise, where we can go for years without realising that our arteries are about to close over, the effect of a good or bad night's sleep is immediate.

As Farah told Channel 4 News on Twitter: "[I] make sure I get at least seven hours good sleep each night, prioritise it. Poor sleep = poor physical health = poor mental health."

But there is little understanding about what happens in the body to make us feel that way - and we are fascinated by how much we need, and whether we are getting enough.

Now a new study from Surrey University has set out to measure how lack of sleep affects not just how we feel, but how our body's chemistry and mechanical systems react. Published in the Proceedings of the National Academy of Sciences journal, the study found that a week of less than six hours sleep a night suppresses hundreds of genes, which control how our body regenerates and repairs.

Scientists studied the sleeping habits of 26 volunteers for one week - with the group either getting less than six or up to ten hours a night - and suggest that if their findings are projected to long-term sleep deprivation, it could stop the body from carrying out key repairs involved in inflammation, immunity, and cell response to stress.

The study has raised questions about whether long-term sleep restriction could contribute to heart disease or organ impairment.

But, the conclusion is not so simple - and may be disputed by Margaret Thatcher, Barack Obama and Martha Stewart, all of whom are said to survive (and appear to thrive) on less than six hours.

For a start, sleep studies are often based on enforcing specific amounts of sleep on those willing to take part, so it is already an unnatural and more stressful scenario - and this observation comes from Professor Kevin Morgan, director of the clinical sleep research unit at Loughborough University, who is a serial studier of sleep himself.

Sleep and mortality

"Making your sleep do things you don't normally do, has a physiological cost. And the likelihood is that those costs will amplify if those procedures amplify," he told Channel 4 News. "But it's not a fair assumption: if I'm a naturally short sleeper and you insist I spend nine hours in bed, I'll get wound up. And that's likely to be reflected in the study."

And while we are well versed with warnings of too little sleep, getting too much could be worse.

In fact one of the most consistent findings from demographic studies of sleep patterns over the last few decades, shows that those who report the longest sleeping times, often over 10 hours, have the highest levels of mortality - even more than short sleepers.

Sleep starved nation?

The problem is not this study - but in interpreting it to draw implications for public health, adds Professor Morgan.

Many research studies into the effect of sleep loss support the modern 21st century narrative that we are overloaded with digital information and starved of sleep.

This in turn has led to a medicalisation of sleep. In the UK alone, the NHS dishes out around 10 million prescriptions for sleeping tablets each year.

But research by Loughborough's clinical sleep team suggests that the average sleep for adults has been about seven and a quarter hours for the last 40 years, with no difference to account for our increased time at the coalface - or "screen face" - and that we have been functioning fine on that throughout.

The 'magic number'

People sleep as much as their lifestyle dictates, and as such, sleeping times vary hugely. The average is around seven hours - but will only be reported by around a third of the population. According to a (very unscientific) poll of Channel 4 News readers on social media, the average tends to be around seven to eight hours.

Albert Roberts said on Twitter: "I can't survive without a full 9hrs. However if I am cut short of sleep to 7hrs a 15 min nap sorts me out later in the day."

But Oliver Watson said: "I find I get on average five hours sleep. My own fault. Too many distractions around."

We also need less sleep as we get older, while those with young children will often survive on fragmented sleep, snatched whenever possible.

Lisa Artis of the Sleep Council says there is no "magic number" but between six and nine hours for adults helps us "feel refreshed and to function well both mentally and physically". She adds that lack of sleep impacts on "attention, concentration and memory in most people".

Sleep literacy

Perhaps the solution to getting the right amount of sleep is to become more "sleep literate". While we are aware of how it affects us immediately, few of us are able to differentiate between different kinds of sleep.

And although 25 per cent of the population say they suffer from some kind of sleep disorder, the details are vague, according to Loughborough's sleep centre - probably because it is something we do in secret, and can't compare ourselves to other people.

"That extends to medicine," Professor Morgan told Channel 4 News, allowing us to take some comfort in our ignorance. "Sleep plays almost no part in medical education - most doctors don't understand sleep or disorders of sleep."