Make sleep your secret weapon
ALL this week in the Daily Mail DR MICHAEL MOSLEY explains how to stay one step ahead of coronavirus as lockdown eases in exclusive extracts from his new book Covid-19. Today, he reveals how sleep can help to bolster your immunity and shares his tips on breaking the bad bedtime habits formed during lockdown.
ANyoNe who has been struggling to get a good night’s sleep during lockdown will be well aware of the impact tiredness has on your memory, mood and concentration.
But you might not realise that insufficient or poor-quality sleep is also very bad news for your immune system — and this could put you at risk of complications if you do catch Covid-19.
the science is clear that sleep is crucially important to almost every aspect of our mental and physical health, but more than this, satisfying slumber can bolster your immunity, and insufficient or consistently poor rest will leave you vulnerable to coughs, colds — and even coronavirus.
all this week the daily Mail has been serialising my new book, CoVId-19 which brings together all the latest research on the virus, as well as the knowledge and experience I’ve acquired through my long career as a science journalist.
and today, I will reveal why sleep is one of your best secret weapons when it comes to bolstering your immunity.
whether your nights are often fitful or restful, or whether you’re one of the estimated third of the uk population who, like me, suffers from occasional insomnia, be reassured, there is much you can do to improve your sleep and, in so doing, shore up your defences.
these are strange and worrying times, and the lack of control we all feel right now, not to mention the financial concerns, and the curbs on our freedom and our ability to socialise, will all be affecting our ability to sleep.
If you haven’t been infected and fall into any of the higherrisk categories (being over 60, overweight or with raised blood sugar levels), then I would urge you to prioritise sleeping well.
this is because we know there is a very clear link between poor sleep and vulnerability to viral infections. one of the reasons why a good night’s rest is so important for the immune system is that it is while you are in deep sleep that your body makes cytokines, the proteins that start and co-ordinate your immune response to viral infections. lack of sleep also suppresses the production of infection-fighting antibodies. these antibodies are vital for combating viruses.
Poor sleep also reduces the effectiveness of your body’s killer t cells, whose job is to latch on to cells infected by viruses and destroy them. research suggests t cells are particularly important for combating Covid-19 so you really want them to be working as well as they can for you.
the importance of the sleep/ immunity connection was shown starkly in a recent u.s. study.
researchers recruited 160 healthy volunteers and brought them into a lab, where they had cold viruses squirted up their nose. they were then fitted with sleep monitors and asked to stay in a nearby hotel for a week.
It turned out that those who slept less than six hours a night were four times more likely to get a cold than those who got seven hours or more. Not getting enough sleep made them more vulnerable to the impact of the common cold virus, despite being exposed to the same level of infection.
you might think you are spending more time in bed than you
did before lockdown but time between the sheets is no use to your immune system if you’re not getting good quality sleep during the night.
In another study, researchers found that if your sleep efficiency (the percentage of time in bed when you are actually asleep) was less than 90 per cent, then you were nearly six times more likely to get a cold.
On top of its impact on your immune system, night after night of interrupted rest makes you likely to gain weight, and being obese is a serious risk factor for Covid-19 complications.
At the very least, poor sleep will make it very difficult for you to lose weight. A bad night’s rest not only affects your brain but also messes with your body — including its ability to control your blood sugar levels.
During my career I’ve spent many nights in sleep labs with electrodes attached to my head and body. I’ve taken drugs to put me to sleep and drugs to keep me awake.
In one experiment I discovered just two nights of sleep deprivation altered my hunger hormones, leaving me ravenously hungry, as well as causing an escalation of the stress hormone, cortisol. The result was my blood sugar levels rose to that of someone with full-blown diabetes.
It’s not just your blood sugar levels that soar and your hunger hormones go into overdrive when you’re tired; the areas of your brain associated with reward also become more active.
This means that you become much more motivated than normal to seek out unhealthy foods such as crisps and chocolate. In fact, a big study at King’s College london found that sleep-deprived people consume, on average, an extra 385 calories a day, which is equivalent to a large slice of cake.
lack of sleep also contributes to metabolic syndrome, the medical term for a cluster of conditions that includes too much body fat around the waist, raised blood pressure, blood sugar and cholesterol.
Metabolic syndrome affects a quarter of UK adults and has a major impact on future health. It encourages further build up of fat, particularly around your gut and it can lead to insulin resistance. In other words, your body has to pump out ever-increasing amounts of insulin to bring your blood sugars back to normal.
There is now a lot of evidence that people who sleep less than seven hours a night are more likely to become overweight or obese and develop type 2 diabetes than those who sleep well.
And we now know that puts you at risk of complications if you do get Covid-19.