We’ve all heard that getting adequate sleep is good for us. Ensuring sufficient rest means we are alert, perform efficiently, have normal reaction times, and can consolidate learned information well. Health problems including heart disease, elevated stress hormones, and decreased immune function have links to the inability to sleep when desired (insomnia). However, setting aside serious sleep conditions such as insomnia, many people suffer from occasional lack of sleep or inadequate sleep. Over time, a “sleep debt” can develop which may lead to increased memory lapses, accidents and injuries, as well as behavioural and mood problems.1
Exactly how much sleep do you need? How can the quality and duration of your sleep affect your digestive health and, conversely, how is your sleep affected by a gastrointestinal (GI) condition? Data suggest that there are very specific consequences for gastrointestinal functioning related to several GI disorders, including inflammatory bowel disease, gastroesophageal reflux disease (GERD), irritable bowel syndrome, and functional dyspepsia.
In humans, sleep is a reversible period of restfulness marked by significant changes in motor, sensory, and physiological criteria.2 We cycle through five distinct sleeping stages 3 to 5 times each night.3 During the first four stages, heart rate and temperature drop, muscles relax, and brain waves slow down, as we sink deeper and deeper into sleep. The fifth phase of sleep is rapid eye movement, or REM, which is a shallow sleep stage when brain waves speed up to waking levels, eyes dart back and forth beneath the eyelids, and most of our dreams occur. Although a sleeping person may appear inactive, some functions of the brain and body are actually more active during sleep than while awake.
People need all stages of sleep to ensure a good night’s rest. For most people, the average amount of sleep decreases with age: newborns get about 16 hours of sleep per day, by age two this drops to 9-12 hours, adults require anywhere from 6-9 hours of sleep nightly (with 7½ hours about normal), and the elderly get about 6 hours.5
There is evidence to suggest that sleep abnormalities can influence the course of some chronic inflammatory conditions including inflammatory bowel disease (IBD).6 According to a 2007 review published in the journal, Inflammation Research, IBD patients display increased rates of the following sleep disturbances when compared to healthy controls:
- significantly prolonged sleep latency,
- more frequent sleep fragmentation,
- higher rates of sleeping pill use,
- decreased day-time energy,
- increased tiredness, and
- overall poor sleep quality.
Moreover, poorer self-reported sleep quality was associated with more disease severity.
Another study found that the association between poorer sleep and IBD held true even when the disease was inactive.7
Sleep deprivation activates immune function, thereby increasing levels of some pro-inflammatory cytokines, which generate an immune response. Researchers postulate that further research into this phenomenon may lead to discoveries of a specific causal link between sleep disorders and IBD.8 Both studies recommend further exploration to find whether improved sleep could positively affect disease course and how this could lead to new IBD treatment modalities.
Troubles with sleeping also affect gastroesophageal reflux disease (GERD), irritable bowel syndrome (IBS), and functional dyspepsia (FD). IBS patients have more difficulties with sleep, including taking longer to fall asleep, repeated night-time waking, and excessive day-time sleepiness.9 Some studies suggest that these patients may have altered sleep patterns with a larger portion of their night spent in REM sleep, possibly leading to a less restful sleep.10 Research has also documented an increase in IBS symptom severity and lower health related quality of life scores linked to the previous night’s sleep.11,12 A large study from the United Kingdom, looking at health concerns co-morbid with sleep disorders, showed a significant link between GERD, IBS, FD and sleep disorders, although in the case of FD this result has been disputed.13,14
It’s clear that gastrointestinal complaints are associated with sleep abnormalities. Those with insomnia report more GI problems than do those without (33.6% versus 9.2%) and, conversely, people with gastrointestinal complaints report more chronic insomnia than do those with healthy sleep patterns (55.4% versus 20%).15 However, in spite of the significant overlap in these disorders, research has yet to uncover which came first, poor sleep or GI disorders. Further exploration into this research frontier may enable clinicians to develop therapies that develop this association and possibly lead to new treatments for digestive complaints and poor sleep.
The following are some tips to help improve both the quality and quantity of your sleep:16,17,18
Stick to a routine. Go to bed and get up at the same time each day regardless of how much you slept the night before.
Teach your body that bed is for sleeping. Don’t use the bed for any activities other than sleep (or sex). Do not read, watch television, or eat in bed. If you don’t fall asleep in about 15-20 minutes, then leave the bedroom and return to bed when you are sleepy.
Make the bedroom a haven. Maintain a comfortable temperature, minimize light and noise at bedtime, and let light in when you need to wake up.
Avoid sleeping-in. You may need to catch up on sleep, but don’t sleep in for too long on weekends, you might confuse your body’s internal clock. Instead, try a 30-40 minute nap during the day.
Avoid big meals at night. Stop eating at least 2 hours before bedtime. If you’re still hungry, a light snack at bedtime may promote sleep.
Avoid caffeine after noon. Caffeine can linger for many hours, even though blood levels spike 30 to 60 minutes after ingestion.
Avoid drinking alcohol near bedtime. Although it seems to help you fall asleep, alcohol actually disturbs sleep and, because it’s also a diuretic, you may have more nightly visits to the bathroom.
Get outside. Exposure to light influences a person’s daily sleep and wakefulness patterns (circadian rhythms), and sunlight is several times stronger than even the brightest indoor light.
Get active. According to the Harvard Health News, exercise is the only proven way for adults to prolong deep sleep. However, don’t exercise vigorously within 3 to 4 hours of bedtime, since this may actually lead to difficulty falling asleep.
Interesting Sleep Facts
- During sleep, recent memories consolidate and at the same time, by changing their representational structure, could initiate insight and allow for extraction of explicit knowledge.22
- The bottlenose dolphin must stay swimming in order to surface and breathe, so it sleeps with one brain hemisphere at a time, alternating sides about every hour.19
- Only 13% of us take naps, but this can be the best way to reduce sleep debt. Of those that nap, the average nap lasts 1.7 hours and is most likely among those who are at home during the day, such as seniors, “those keeping house”, and individuals looking for paid work.23
- A 45-minute nap in the afternoon can increase alertness and improve performance for up to 6 hours!
- The honeybee ‘sleeps’ for about 6 hours at night, by rolling on its side, letting its antennae droop, and becoming generally unresponsive.20
- According to Statistics Canada, Canadians sleep 48 minutes more on Friday and Saturday nights for a total of about 8½ hours per night.23
- The brain continues to hum away as we sleep; consolidating memories, but sleep’s great benefit to memory may be the way it allows most synaptic connections to weaken by paring down their receptors. As the day goes on, these junctions between neurons become saturated. Sleep helps wipe the slate so you’re ready to take on new things.21
- Too little sleep results in 40% increase in blood levels of cortisol, a stress hormone that slows metabolism and triggers a 33% increase in hunger pangs and cravings.