SECRETS OF BETTER SLEEP

A good night’s rest is key to staying healthy — yet insomnia and waking in the small hours are so common. Now the latest part of our sleep series shows how you can fight back

HOW well we sleep — and when — is very much determined by our body clock. And the body clock, as I explained in yesterday’s Mail, is regulated by sunrise and sunset: our exposure to light and darkness ‘tells’ the clock in the brain when it is the best time for sleep and wake.

Problems with sleep, such as insomnia, are often down to problems with the body clock — typically as a result of the wrong light exposure linked to our 24/7 culture where we try to squeeze more into our days and nights.

But the body clock is not the only driver of sleep.

The second key driver is called ‘sleep pressure’. This builds from the moment we wake and rises throughout the day and reaches its highest level in the evening prior to sleep.

We fall asleep naturally when the body clock drive for us to be awake drops, and the sleep pressure is high.

Then, as we sleep, sleep pressure declines — and the body clock instructs the brain, and the rest of the body, that it is time to wake up.

THE PERILS OF COFFEE ON THE GO

SO WHAT drives sleep pressure? One theory is that it’s down to the build-up of chemicals in the brain. The most likely contender is a molecule called adenosine, which animal studies have shown increases during periods of wakefulness and is then broken down during sleep.

The brain seems to use adenosine levels as a minute- to- minute measure of how long you have been awake. The reason caffeine — in the form of coffee, tea or chocolate — keeps us awake and alert is that it blocks the mechanisms in the brain that detect adenosine.

This means the brain cannot detect how tired it is even when adenosine levels are raised.

But while the short-term use of caffeinated drinks can be useful in keeping us awake during long motorway journeys, for instance, you need to be careful, because as the effects of caffeine wear off we can experience a wave of profound and overwhelming tiredness that can cause us to fall asleep at the wheel.

This is why you need a steady infusion of caffeine if you are on a long trip. Either way the bottom line is, don’t drive if you are tired.

The body clock and sleep pressure do not act alone — additional factors, including our genes, our emotional state and our age (see panel), combine to deliver the sleep and wake pattern that we get.

And any of these can also alter that pattern, leading to sleep problems.

Today, I look at some of the most common sleep issues, in particular insomnia, and what you can do to tackle them.

YOU MAY NOT HAVE A PROBLEM

OnE of the main causes of sleep problems is a ‘faulty’ body clock and, typically, insomnia is the result. ‘Insomnia’ is the term we use medically to describe difficulties falling asleep or staying asleep as long as the individual would like.

But what many people might regard as insomnia may, in fact, be a natural way of sleeping.

Some humans and other animals do not sleep in a single consolidated block of sleep — they have two episodes of sleep ( known as biphasic sleep) or even multiple episodes (called polyphasic sleep), where the periods of sleep are separated by short periods of being awake.

People who sleep in this pattern are regarded as suffering from ‘insomnia’. Yet it may be that having a single period of sleep without waking (monophasic sleep) is not, in fact, the normal state of human sleep as many assume — it could be as a result of a shortened night and less opportunity to sleep.

Historical records and laboratory studies where individuals have been exposed to 12 hours of light and 12 hours of darkness support the idea that when we have the opportunity to sleep longer, we revert to polyphasic sleep, with several sleep episodes interrupted by short periods of wakefulness.

This raises the important point: if the natural state of human sleep is polyphasic, then we need to re- think our interpretation of disrupted sleep at night.

Reassuringly, new research suggests that if you wake up at night, most people will fall back to sleep within 30 to 40 minutes or so — as long as you don’t get involved in social media or other ‘alerting’ behaviours. The key point is that waking at night need not mean the end of sleep.

If you do happen to stir from your slumbers in the middle of the night, it is important not to feel anxious because this activates stress responses.

Don’t keep checking the clock or remain in bed getting increasingly frustrated by the failure to sleep. Some people find it useful to get up, keep the lights low and engage in a relaxing activity such as reading or listening to music, then returning to the bed when sleepy again.

Others watch TV or listen to the radio — but be careful and ensure it’s nothing too exciting.

I know people who have a favourite and comforting DVD that works for them.

You may want to try a very light snack such as a plain digestive biscuit or small warm drink, such as milk.

But don’t eat or drink too much — remember the digestive system is prepared for sleep.

What you must never do is check your emails or go on social media.

AVOID SLEEPING PILLS LONG-TERM

PREScRIPTIOn sleeping pills can be useful to try to correct a period

of poor sleep — taking a low dose (in consultation with your GP) for a few days or weeks does work for some. But medication will often not address the underlying cause of the sleep problem.

And long-term use of such drugs, known as hypnotics, just masks the issue and can cause problems with side-effects.

For example, benzodiazepines (such as diazepam and lorazepam), which are anti-anxiety medications, increase drowsiness, and are potentially addictive and can affect memory and your ability to concentrate the next day.

Meanwhile, the newer so- called Z- drugs (for example, zopiclone, zaleplon and zolpidem) — which are more commonly used — are faster acting and clear from the system more quickly, so reduce daytime sleepiness.

However, while they are less addictive, they can still cause similar side-effects to benzodiazepines in some people.

The bottom line is that all hypnotics should be used shortterm or intermittently and use should be reviewed regularly by your GP.

DON’T FALL INTO THE ALCOHOL TRAP

SOME people self-medicate with sedatives such as alcohol. But tolerance builds over time so that you need more and more to get the same sedative effect.

This can lead to multiple problems including impaired reaction times and performance the next day.

Long-term sedation with alcohol will damage the brain and nervous system, heart, liver and pancreas.

Some over-the-counter antihistamines (for example, diphenhydramine or doxylamine found in some over- the- counter night remedies) are also used by many as sedatives.

They’re not as bad as chronic alcohol use but side-effects include daytime sleepiness, dry mouth, blurred vision, constipation and altered bladder function.

Meanwhile, herbal ‘remedies’ such lavender or herbal teas are often recommended to promote sleep.

While these are essentially riskfree, there is no real evidence that they actually promote sleep beyond a placebo effect. However, if they work for you, use them.