Meet our expert panel
Dr Guy Meadows is a specialist in chronic insomnia and clinical director of The Sleep School, London
Derk-Jan Dijk is professor of sleep and physiology at Surrey’s Sleep Research Centre
Gillian Twigg is principal clinical scientist at the sleep centre at Imperial College Healthcare NHS Trust
Dr Guy Leschziner is a consultant neurologist at the sleep disorder centre, Guy’s and St Thomas’ hospitals, London
How does alcohol affect sleep?
Guy Meadows A lot of the symptoms associated with a hangover are a product of sleep deprivation. Alcohol affects our ability to get into what is known as rapid eye movement (REM) sleep, the bulk of which occurs in the last two-thirds of the night. As a rule of thumb, it takes about an hour to metabolise one unit of alcohol, so if you have a 250ml glass of wine at 7pm it will mostly be out of your system by 10.30pm.
Is it bad to eat before bed?
GM It is important to leave at least a couple of hours between eating and sleeping. There is a whole raft of so-called sleepy foods – anything containing tryptophan, serotonin, melatonin, magnesium, calcium, potassium – often eaten in the hope they will aid sleep. I’m not a fan of this as I come from the chronic insomnia world where people are so desperate to sleep that they are consuming vast quantities of bananas, almonds, turkey, lettuce, warm milk, and so on. I always say do it because it’s a nice ritual, not because you need it to sleep.
Is it OK to eat cheese before bed or does it give you nightmares?
Derk-Jan Dijk If you experience nightmares after eating cheese, then don’t eat cheese before bed.
How can you cure sleepwalking?
Gillian Twigg There isn’t a cure. We advise people who sleepwalk to keep their room safe by locking windows and doors, and to maintain what’s called good sleep hygiene: keep to a regular sleep routine, turn mobile phones off, avoid stimulants, and so on. Sleepwalking can often occur as a result of poor or disrupted sleep.
Is it possible to sleep too much?
Guy Leschziner There is some evidence that suggests that if you sleep excessively, your risk of mortality increases, but it remains controversial. There is a lot of interest now in the cardiovascular risk of sitting around, and it may be that lying horizontally for 12 hours or more a night isn’t good for your cardiovascular health. It is uncertain at the moment.
GM Some need more sleep than others: the range is anything from four to 12 hours. When people sleep excessively, it is often an indication of other conditions, such as depression. Teenagers naturally have a delay in their sleep phase because production of the hormone melatonin (which aids sleep) gets released later as a product of puberty. This means they naturally want to go to bed and get up later. Oxford University is doing a study in which the start time for some A-level students has been shifted to 10am. Research suggests this shift helps students to perform better.
Why do we say ‘sleep like a baby’ when babies cry all night?
GM I have two young children and this has crossed my mind, too. There is something wonderful about seeing a baby sleep, but the truth is the majority of children need to be taught how to do it.
DJD Babies’ sleep is much deeper than that of adults.
Does having a period affect sleep?
GM Yes, definitely. Around 65% of those with with insomnia are female. Women are more at risk of insomnia than men and one of the reasons for this is hormonal change.
DJD The problem is that the hormonal disruptions that affect sleep have been used as an excuse to exclude women from sleep studies. As a result, they have become under-represented, which is not good practice.
Is it OK to rely on earplugs for a good night’s sleep?
GL Yes, absolutely. It’s better than taking sleeping tablets, isn’t it?
GM The odd bit of earplug usage is not a problem, but most of the people who come to our insomnia workshops are reliant on them. I had a client who was going to Paris for a romantic weekend with his girlfriend. They got to the hotel at 11pm, realised they didn’t have his earplugs and eye mask and spent the night driving around Paris trying to find some. When earplugs are props you can’t do without, they can become part of the problem.
Should you have your phone charging next to you at night? Will it kill you?
DJD If it could kill you, quite a few of us would be dead by now.
GT The trouble with anything that emits blue light is that it can disrupt circadian rhythms and affect your ability to go to sleep. I wouldn’t recommend having your phone near you at night.
What are the best cures for insomnia?
GL If you don’t fall asleep within 20 minutes of going to bed, get up, go to another room and do a calming activity, then go back to bed. If you are lying in bed unable to sleep, your brain will soon start associating lying in bed with being awake.
GM For me, the defining moment was when I realised that if you ask someone who sleeps well what they do to get a good sleep, they will say “nothing”. If you ask an insomniac, they will give you a list as long as your arm. I now pioneer acceptance and commitment therapy – a form of cognitive behavioural therapy – that is about changing your relationship with the struggle that arises as a result of insomnia. A lot of my clients are lying in bed thinking … I haven’t drunk alcohol or caffeine, I’ve opened the window, done some breathing, had a warm bath, counted sheep … and I still can’t sleep. Insomnia cures can become part of the problem. The key is to recognise that sleep is a natural biological process that we cannot control.
What happens if you never sleep properly?
GM In the long term, sleep is important for the health of our hearts, lowers our blood pressure, reduces our risk of diabetes, and is vital for boosting our immune system. We now know that sleep plays a role in washing our brains at night, though the data currently comes only from mice. It remains a tenuous link, but poor sleep increases our risk of Alzheimer’s. Finally, sleep plays a vital role in weight management.
Why does sleep worsen with age?
GM Up to 50% of people in their 60s and over, may experience insomnia. The overwhelming reason is because of an increase in medical conditions: the need to go for a pee, a rise in pain and medication, and as we get older we tend to drink a bit more alcohol.
Are naps good for you?
GM Power-napping is very good for you. Ideally, you should nap for 10-20 minutes between 12 noon and 3pm. You don’t want to nap for more than 30 minutes because you risk going into deeper sleep and waking up in a brain fog. Also, if you sleep for too long you risk reducing your “sleep drive”, which potentially worsens sleep at night.
DJD Our approach to napping has been that it must be natural because so many cultures have siestas. But often the desire to nap in adults comes from insufficient sleep during the night. There are reports showing that excessive napping can be associated with negative health outcomes. The odd nap on a rainy Sunday afternoon is not a worry, but it’s not true that lots of napping is a good thing.
How do sleeping pills work?
GL They depress the central nervous system, so they feed into biochemical changes that occur in the brain, causing you to drop off to sleep. But unlike the brain circuitry, they wash the entire brain in these chemicals so there are other unwanted effects. They reduce the amount of time you spend in the deepest stages of sleep, and people get used to them and require increasing doses. It is better to look at the underlying cause of your sleep problem, which is often psychological.
What is sleep paralysis ?
GM We are paralysed during REM sleep, and we believe that this is so we don’t act out our dreams. A small percentage of the population wake up in REM sleep, but the brain forgets to wake the muscles so they get this scary state where they are paralysed but awake. It is completely harmless, although it can feel terrifying.
Why do people fall asleep on the sofa while watching TV, but then can’t sleep when they go to bed?
DJD During a nap, you dissipate some of your sleep pressure. The brain can only produce so much sleep over 24 hours. If you use some of it up on snoozing in front of the telly, there is less left for the night.
Was there an equivalent to jet lag before we had planes?
GL No, it’s purely related to travelling fast through multiple time zones. You can cope with up to one hour’s shift a day and it’s quite difficult to travel that fast by boat or train.
GM What’s interesting is social jet lag, a modern condition that occurs as a result of keeping such an erratic pattern that your body clock is constantly confused. You get all the symptoms – insomnia, nausea, fatigue, lethargy, headaches and confusion – but you haven’t gone anywhere. The rise of technology has played a massive role in how we sleep.
Do electric blankets give you testicular cancer?
GL There is no known link, but I suppose if you wrap them around your balls for 12 hours a day, maybe …
Is lying in bed and resting with your eyes closed almost as good as sleeping?
GL No. Lying awake in bed rests your body, but it doesn’t rest your brain.
GM Yes, it’s definitely the next best thing. That’s a huge part of what I teach people: to lie in bed, rest and be still. There is a big movement called stimulus control therapy, which is about getting people out of bed if they have been awake for more than 15 minutes. I’m not a fan. I teach people how to stay in bed.
Is it OK to use the snooze function on your morning alarm, or should you get up as soon as it goes off?
GM The optimal way to wake up is naturally. If someone is hitting the snooze button, it suggests they are not getting enough sleep or they are sleeping at the wrong time for them. If you are a habitual snooze button user, reset your alarm to the later time and get more consolidated sleep.
DJD If we were all to go to sleep one or two hours earlier, fewer of us would need an alarm clock.
Does sleeping regularly and well make you live longer?
GM The research suggests you will be healthier for longer if you sleep well.
Are there any living creatures that don’t need sleep?
GL As far as we are aware, every living thing has sleep or sleep-like behaviours. In a lot of animals, such as aquatic mammals and birds, only one half of their brain sleeps at a time.
