By Emily Stearn, Health Reporter For Mailonline
15:56 09 Apr 2024, updated 16:14 09 Apr 2024
Women really do sleep worse than men, a study shows.
And scientists reckon it’s because their body clock runs about six minutes quicker.
This means they’re out of sync with their environment, which plays havoc on their internal wiring that tells their brain when they should feel sleepy.
An all-female team of experts stationed at the universities of Harvard, Stanford and Southampton reviewed dozens of academic papers published in the last decade on the poorly-understood ‘sleep gap’ that exists between men and women.
Many used actigraphs, digital wrist-worn devices similar to Apple watches or Fitbits, which monitor heart rate and sleeping patterns.
Results showed that women were almost 60 per cent more likely to experience insomnia.
They rate their sleep quality lower than men and complain about getting more bad nights.
Men, meanwhile, get less restorative, deep sleep than women and are more likely to be night owls. Additionally, they were more likely to have sleep apnoea.
Deeper experiments also revealed there were differences between the sexes in terms of the speed of their body’s in-built clock, or circadian rhythm, which sets the rhythm of our lives.
When it comes to sleep, the body reacts to environmental cues to drop our core temperature in the hours before getting some shut-eye to get our body ready to sleep.
Internally, the body also secretes more melatonin, a hormone that helps send us to sleep.
Research in the new analysis found melatonin is secreted earlier in women than men.
Core body temperature seemingly followed the same pattern, peaking earlier among women.
Researchers stated their findings, published in the journal Sleep Medicine Reviews, illustrate the ‘crucial role sex plays’ in sleep and health.
Study author Dr Renske Lok, an expert in psychiatry based at Stanford, said: ‘While this (six-minute) difference may be small, it is significant.
‘The misalignment between the central body clock and the sleep/wake cycle is about five times larger in women than in men.
‘Imagine if someone’s watch was consistently running six minutes faster or slower.
‘Over the course of days, weeks, and months, this difference can lead to a noticeable misalignment between the internal clock and external cues, such as light and darkness.’
Dr Lok added: ‘Disruptions in circadian rhythms have been linked to various health problems, including sleep disorders, mood disorders and impaired cognitive function.
‘Even minor differences in circadian periods can have significant implications for overall health and well-being.’
Fellow author Dr Sarah Chellappa, a neuroscientist at Southampton, added: ‘Lower sleep quality is associated with anxiety and depressive disorders, which are twice as common in women as in men.
‘Women are also more likely than men to be diagnosed with insomnia, although the reasons are not entirely clear.’
One study assessed showed women were up to four times more likely to develop a sleep-related eating disorder, where people eat repeatedly during the night.
Another found they had a 25 to 50 per cent higher chance of getting restless legs syndrome.
Linked to iron deficiency, the condition creates a creepy-crawly feeling in the legs and an irresistible urge to move them, which can keep sufferers awake at night.
Women tended to sleep longer than men, spending around eight minutes more in non-rapid eye movement (non-REM) sleep.
Around 80 per cent of adults’ sleep is non-REM sleep, although only 20 per cent of this is deep sleep — the other type is known as rapid eye movement sleep and it is when vivid dreams occur.
During the deepest stage of deep sleep, the brainwaves are much slower and this is when growth hormone is released. The body uses this to repair and regrow tissues, build bones and muscle, and strengthen the immune system.
While the time spent in non-REM declines with age, researchers noted, this decline is more substantial in older men.
Men also tended to overeat more than women in response to sleep loss, researchers said.
Writing in the journal, Sleep Medicine Reviews, researchers said understanding sex differences during sleep was ‘essential for tailoring approaches to sleep medicine’ and combatting sleep disorders.
Many of the studies, however, failed to assess how biological differences such as during the menstrual cycle and menopause, affected sleeping patterns, they noted.
Previous research has suggested a link between lack of sleep and increased risk of obesity and type 2 diabetes.
The most common causes of insomnia are thought to be anxiety, depression, alcohol, caffeine, recreational drugs and working shifts.
While adults need between seven and nine hours of sleep, children are advised to have between nine and 13, the NHS recommends.
The health service estimates it takes most people 14 minutes on average to nod off.
Studies suggest that at least 30 per cent of the issues GPs face are directly or indirectly related to sleep.
Yet just one Briton in ten talks to their doctor about insomnia, despite 30 per cent taking medication to try to deal with it.
Sarah Carter is a health and wellness expert residing in the UK. With a background in healthcare, she offers evidence-based advice on fitness, nutrition, and mental well-being, promoting healthier living for readers.