Sleeping with a partner gets a bad rap lately because of how many people, mostly women, say they are fleeing their partners’ disruptive snoring and sleep apnea for a separate bed. Several years ago, researchers writing in the journal Sleep also found negatives from sleeping with a partner, sometimes called co-sleeping.1

They found it was correlated with more night awakenings, more body movements and generally poorer sleep, even if the sleepers did not realize their sleep was compromised.2

Disrupted sleep also has negative effects on your immune system, according to the Mayo Clinic.3 Recently, scientists wrote in the journal Science that disrupted or fragmented sleep is linked to atherosclerosis,4 a buildup of fatty plaque in the arteries correlated to heart disease.5

In June 2020, however, researchers writing in the journal Frontiers of Psychiatry reported a positive benefit to sleeping with a partner when it comes to the all-important rapid eye movement (REM) sleep. Co-sleeping, stated the researchers, yielded “10% more REM sleep, less fragmented REM sleep [and] longer undisturbed REM fragments.”6

New Sleep Technology Yields Better Information

The reason the REM sleep improvements with co-sleeping have not been fully explored until now, say the authors, is that the traditional instrument used in sleep studies is actigraphy, a wrist device that records movements, and it does not monitor sleep stages such as REM.7

There are four distinct phases of sleep. In stage one and two there is no REM sleep. Stages three and four, on the other hand, are the deepest stages of sleep that feature the highly restorative REM sleep.8 This study used instrumentation called dual simultaneous polysomnography that is different from actigraphy.9

According to lead author Dr. Henning Johannes Drews of the Center for Integrative Psychiatry, Christian-Albrechts-Universität in Kiel, Germany, the technology is a “very exact, detailed and comprehensive method to capture sleep on many levels — from brain waves to movements, respiration, muscle tension [to] movements, heart activity.”10

Twelve young and healthy heterosexual couples were studied for four nights in a sleep lab, wired to dual simultaneous polysomnography in the research study.

The Many Benefits of REM Sleep

REM sleep occurs during the first 90 minutes of sleep and often again later in the night.11 It is the sleep stage most correlated with dreaming and has a positive role in consolidation of memories, learning and mood. According to the Frontiers in Psychiatry researchers:12

“REM sleep is known to benefit memory formation particularly of emotionally salient and episodic memories.

The latter or both have been linked to sociality. Moreover, imaging studies show that REM sleep is associated with an activation of — among others — the amygdala and the medial prefrontal cortex, the latter of which is part of the theory-of-mind network and therefore highly important for social cognition.

Therefore, REM sleep might increase our preparedness and fitness to navigate the social world. Connecting this hypothesis to the findings of our study leads us to propose the existence of a positive feedback loop of REM-sleep-sociality interactions: social sleep enhances and stabilizes REM sleep which in turn enhances our ability to interact socially.”

In addition to the possible positive feedback loop, REM sleep may also play an important role in mental health, the authors stated. The REM sleep of people with “suboptimal social support” showed the biggest improvement from co-sleeping.13

“REM sleep is related to dissolving emotional stress and balancing fear- related amygdala reactiveness. Moreover, REM sleep fragmentation is related to insomnia, which in turn is a risk factor for developing a mental illness [e.g., insomnia doubles the risk for depression].

Therefore, REM-sleep stabilization due to co-sleep might mediate (or moderate) the established effect of partnerships on mental health.”

The Relationship With a Partner Affects Sleep

The quality of a relationship would seem to have an impact on the type of co-sleeping that occurs. What if the couple just had a fight? What if they are both worried about financial stress or one of their children? What if they just met and are madly in love?

The researchers studied the effect of such factors as “conflict, relationship depth, passionate love [and] relationship duration” on sleeping and found they did affect “individual and dyadic parameters.” However, the quality of a relationship had a bigger impact on sleeping arrangements than on REM sleep, they wrote.14

“Depending on the sleeping arrangement, couple’s sleep architecture and synchronization show alterations that are modified by relationship characteristics. We discuss that these alterations could be part of a self- enhancing feedback loop of REM sleep and sociality and a mechanism through which sociality prevents mental illness.

… Depth of relationship represented an additional significant main effect regarding synchronization, reflecting a positive association between the two. Neither REM sleep nor synchronization was influenced by gender, chronotype, or other relationship characteristic.”

The researchers also noted that romantic relationships affect mental health and co-sleeping “expands” such relationships.15

Co-Sleeping Can Provide Comfort

The debate over co-sleeping has also extended to pets. Sleeping with your pet has been discouraged by some experts in the past because it could lead to poor pet behavior, sleep disturbances and even transfer of a disease.16 But the website Bark says it is a source of comfort that improves sleep.17

“[S]leeping with your pup has many mental benefits such as an increased feeling of safety and comfort. People suffering from PTSD [post-traumatic stress disorder] found that sleeping with their pet helped diminish nightmares.

There are physical benefits as well, like the fact that sleeping with your dog releases oxytocin in the brain. This is the chemical that’s released when a person falls in love, or when they are around their baby. The chemical promotes theta brainwaves which are associated with REM sleep.

This means it’s likely that you’re sleeping deeper when sleeping with your pet. The chemical also mitigates anxiety and stress, which can help you sleep better. Petting and touching your dog can even help lower your blood pressure. This not only happens during the waking hours, but when you sleep with your dog too.”

The Frontiers in Psychiatry researchers agree that having a bed partner can relieve stress.

“Another potential mechanism to be considered in future studies is how a partner alters stress levels before and during sleep. Presence of a partner might facilitate perceiving a sleeping environment as ‘safe’, whereas sleep in isolation might represent a stressor.

Psychosocial stress has been reported to fragment REM sleep and might promote insomnia. Moreover, it has been shown in rats that sociality improves stress resilience by stabilizing REM sleep.”

Humans are not the only animals that co-sleep, wrote the authors, citing the example of the hyrax, a small, furry herbivore. One theory of the origins of co-sleeping is that it produces the biophysical phenomenon of “partner-driven stabilization of ambient temperature.”18

Light Also Affects Sleep Quality

In addition to the improved REM sleep that co-sleeping seems to cause, the light that people receive and don’t receive has a big impact on sleep quality.

Most people in Western societies spend the larger portion of each day indoors, which essentially puts you in a state of “light deficiency,” as the light indoors is about two orders of magnitude lower, in terms of light intensity, than outdoor light. Just 30 to 60 minutes of outdoor light exposure that you can receive during the morning or midday or your lunch break, creates about 80% of the light you need.

On the opposite end, you need to avoid bright artificial lighting after sunset, as that light will impair your melatonin production. Melatonin is a hormone secreted by the pineal gland, a small endocrine gland in the brain that helps regulate sleep and wake cycles. When light is between 50 lux and 1,000 lux it will begin to suppress melatonin production.

A 2011 study in the Journal of Clinical Endocrinology & Metabolism compared daily melatonin profiles in individuals living in room light (<200 lux) versus dim light (<3 lux).19 Results showed that, compared with dim light, exposure to room light before bedtime suppressed melatonin in 99% of individuals and shortened the time period when the body has an elevated melatonin level by about 90 minutes.20

Other Health Benefits of Optimal Sleep

Optimal sleep helps you avoid many negative health conditions. Sleep is arguably the biggest key to good health and it is free and available to everyone. Lack of quality sleep is associated with:

Impaired memory and reduced ability to learn new things.21

Reduced ability to perform tasks, resulting in reduced productivity at work and poor grades in school.

Reduced athletic performance.

Reduced creativity at work or in other activities.

Slowed reaction time and risk of accidents on the road and at work.

Increased risk of neurological problems, ranging from depression to dementia and Alzheimer’s disease.22

Increased risk of Type 2 diabetes and obesity.23

Increased risk of cancer, high blood pressure, heart attacks and cardiovascular disease.24

Increased risk of osteoporosis.

Increased risk of pain and pain-related conditions such as fibromyalgia.25

Increased susceptibility to stomach ulcers.

Impaired sexual function.26

Impaired regulation of emotions and emotional perception.

Increased risk of depression and anxiety (including PTSD), schizophrenia and suicide.27

Premature aging.

Increased risk of dying from any cause.28

Ways to Improve Your Sleep Besides Co-Sleeping

As I noted above, sleep is crucial for health and we now know that it benefits each and every organ in the human body because every cell in the body has its own biological clock. These cellular clocks, all of which work in tandem to control and maintain biological homeostasis, regulate everything from metabolism to psychological functioning. Here are 33 ways to improve your sleep:

1. Sleep in complete darkness, or as close to it as possible — Even the tiniest bit of light in the room, such as that from a clock radio LCD screen, can disrupt your internal clock.

2. Keep the temperature in your bedroom no higher than 70 degrees F — The optimal room temperature for sleep is 60 to 68 degrees F.

3. Eliminate electric and electromagnetic fields in your bedroom — EMFs can disrupt your pineal gland’s production of melatonin and serotonin and harm your mitochondria, producing excessive oxidative damage.

4. Move alarm clocks and other electrical devices away from your bed — Shut down your phone or move it far away from the bed.

5. Adopt a neutral sleeping position — Find your natural sleep position and stick to it.

6. Reserve your bed for sleeping — Avoid working or watching TV in bed.

7. Consider your sleeping arrangements — A bed partner can impair sleep if snoring is an issue, but in other cases co-sleeping can be beneficial.

8. Get to bed as early as possible — Your body (particularly your adrenal system) does a majority of its recharging between the hours of 11 p.m. and 1 a.m.

9. Maintain a consistent bedtime, even on the weekends.

10. Establish a relaxing bedtime routine — Meditation, deep breathing, aromatherapy or a massage from your partner are all helpful.

11. Avoid drinking fluids within two hours of going to bed — This will reduce needing to go to the bathroom during the night.

12. Go to the bathroom right before bed — This will reduce chances that you’ll wake up.

13. Avoid eating at least three hours before bedtime — Particularly avoid grains and sugars.

14. Minimize use of electronics, during day and night — The more time you spend on electronic devices, the longer it takes to fall asleep.

15. Try controlled breathing before sleep — Slow, deep and steady breathing activates your parasympathetic response.

16. Take a hot bath or shower before bed — A raised body temperature facilitates sleep.

17. Wear socks to bed — Feet have poor circulation and can be cold.

18. Wear an eye mask — Sleeping in complete darkness is important.

19. Put your work away at least one hour before bed — Give your mind a chance to unwind.

20. Avoid TV right before bed — Even better, get the TV out of the bedroom.

21. Listen to relaxation CDs — White noise and nature sounds are helpful.

22. Read something spiritual or uplifting — Avoid anything stimulating.

23. Journal — If you often lie in bed with your mind racing, it might be helpful to keep a journal and write down your thoughts before bed.

24. Reduce or avoid as many drugs as possible — Both prescription and over-the-counter drugs can affect sleep.

25. Avoid caffeine — This is a no-brainer.

26. Avoid alcohol — It disrupts deeper stages of sleep.

27. Exercise regularly, but not within three hours of bedtime — Exercising for at least 30 minutes per day can improve your sleep.

28. Lose excess weight — Being overweight can increase your risk of sleep apnea.

29. Avoid foods you may be sensitive to — This is particularly true for sugar, grains and pasteurized dairy. Sensitivity reactions can cause excess congestion, gastrointestinal upset, gas and both.

30. Have your adrenals checked by a good natural medicine clinician — Insomnia may be caused by adrenal stress.

31. If you are menopausal or perimenopausal, get checked out by a good natural medicine physician — The hormonal changes at this time may cause sleep problems if not properly addressed.

32. Try the Emotional Freedom Techniques (EFT) — EFT can help balance your body’s bioenergy system and is definitely worth a try.

33. Boost your melatonin — Ideally you should increase your levels naturally with exposure to bright sunlight in the daytime (along with full spectrum fluorescent bulbs in the winter) and complete darkness at night.

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