At 91, Judi Dench swears by one simple trick to fall asleep – and the science stacks up

Extolling the gifts of growing older, Dame Judi Dench recently said she wouldn’t change a thing for the smooth face and flat stomach of her youth. ‘Who cares if I choose to read or play on the computer until 4 in the morning and then sleep until who knows how much?’

Sometimes, though, you really do just want to fall asleep – yet it stubbornly evades you. What then? ‘I listen to Classic FM,’ she told broadcaster Zeb Soanes. ‘Especially at night sometimes, if I can’t sleep. Classic FM is my friend, neighbour, lover... anything you like. I’m right there with my ear at the radio.’

It sounds charming. But it also turns out to be remarkably well supported by science.

Why women struggle to sleep

For many women, particularly after menopause, falling asleep becomes much harder than it once was.

As levels of oestrogen and progesterone decline, sleep often becomes lighter and more fragmented. Night sweats, hot flushes and more frequent waking all play their part, while our body clocks naturally shift as we age.

The long-running Study of Women’s Health Across the Nation (SWAN), which has followed almost 3,000 women for more than two decades, found that sleep quality and duration decline significantly during the menopausal transition. More than half of postmenopausal women experience sleep problems, making insomnia one of the most common complaints during this stage of life.

If you’re lying awake at 3am wondering whether anyone else is counting the minutes until morning, you’re very much not alone.

Can listening to music really help you sleep?

Last year, a review of scientific research concluded that: ‘Across studies, listening to music consistently reduced sleep-onset latency, improved sleep efficiency and increased total sleep time.’

In other words, it cut down the tossing and turning time before you drift off and boosted the the percentage of time you spend actually sleeping while in bed. Sleep efficiency is calculated by dividing your total time asleep by your total time in bed, then multiplying by 100. Experts consider 85% to 90% optimal, while scores below 75% often signal insomnia or other sleep disorders.

Pause before you queue up Metallica, however. There were some important provisos.

The kind of music that works best

Not all music has the same effect.

Researchers found the greatest benefits came from music that was:

• Slow, at around 60 to 80 beats per minute
• Soft and gentle in tone
• Simple rather than highly complex
• Instrumental, particularly classical or ambient music

Nature sounds and familiar music also appeared to help many people relax enough to fall asleep.

In other words, Dame Judi’s nightly date with Classic FM makes rather more sense than you might think.

Why music helps us switch off

Of course, if your neighbhourhood is noisy, music will help mask that noise pollution. But there’s more. Our brains also respond physically.

According to the Sleep Foundation, listening to calming music lowers levels of the stress hormone cortisol while increasing dopamine – the neurotransmitter associated with pleasure and reward. It also calms the autonomic nervous system, slowing breathing, lowering heart rate and reducing blood pressure: exactly the physiological state your body needs to drift into sleep.

Four ways to make Judi’s bedtime trick work for you

If you’d like to give it a try tonight, sleep experts recommend keeping a few simple rules in mind:

• Choose slow music. Aim for around 60 to 80 beats per minute.
• Keep it simple. Instrumental music or gentle classical pieces tend to outperform complex, high-energy tracks.
• Pick something familiar. Music with happy memories attached can feel especially soothing.
• Let someone else choose. Classic FM has several bedtime playlists, including its calming Baby Bedtime collection, if you’d rather not spend half an hour scrolling before bed.

Dame Judi herself has long loved Vaughan Williams’ The Lark Ascending, which was her late husband Michael Williams’ favourite piece.

‘I remember once being at Nottingham Playhouse and going out one day with friends and stopping and lying in a cornfield and looking up and hearing the larks,’ she told Zeb Soames. There’s something to dream about.