Sleep & Mental Illness

Sleep - far from inactive, it's your body and mind's busy time for growth and repair:

"Circadian rhythms are innate and hard-wired into the genomes of just about every living thing on the planet. In humans, our physiology is organised around the daily cycle of activity and sleep. In the active phase, when energy expenditure is high and food and water are consumed, organs need to be prepared for the intake, processing and uptake of nutrients."

https://theconversation.com/why-sleep-could-be-the-key-to-tackling-mental-illness-50102

Natural Sleep and Its Seasonal Variations

Some interesting research picked up by the BBC and presented in Current Biology on sleep.  Biphasic sleep may not my innate nor optimal (although there is conflicting evidence).  The highlights are:

• •Preindustrial societies in Tanzania, Namibia, and Bolivia show similar sleep parameters
• •They do not sleep more than “modern” humans, with average durations of 5.7–7.1 hr
• •They go to sleep several hours after sunset and typically awaken before sunrise
• •Temperature appears to be a major regulator of human sleep duration and timing

Clearly season, light and temperature themselves are all linked by sunlight and day-length.  Sleep quality moves up a gear and the basics of sleep hygiene remain the same.

Disruption of the Circadian Clock

Another interesting aspect to sleep:

• The researchers used mice whose body clocks run at about 24 hours - much like our own - and housed them in a shorter 20-hour day. This forced their biological clocks out of sync with the light-dark cycle. After four weeks, the researchers injected the mice with lipopolysaccharide, a molecule found in bacteria that can make an animal sick without being contagious.
  
  The researchers saw that the disrupted animals had blunted immune responses in some cases or an overactive response in others, suggesting the altered circadian cycle made them potentially less able to fight illness and more likely to get sick.
  
  "This represents a very clear dysregulation of the system," said Karatsoreos. "The system is not responding in the optimal manner." Over time, he said, this could have serious consequences for an organism's health.

Night Shift

Long time no post, but there isn't much more to add apart from 'live life close to the ground'.  Some of the themes covered on this blog continue to gain traction - including issues around our circadian rhythm.

The latest news item to capture my attention was this podcast on Radio4 (The Night Shift):

Sleep Arrogance

Sleep, a tenet of the paleo model - a something covered several times over the years at Natural Messiah, now goes increasingly mainstream. The artcile notes that cancer, heart disease, type-2 diabetes, infections and obesity have all been linked to reduced sleep - which kind of ties in to a paleo viewpoint that many of our modern ailments are different manifestations of the same underlying problem; we're trying to force genes selected for a lifestyle some 40,000 years ago to adapt to a modern lifestyle that is devoid of the necessary cues that allow our genes to express themselves in a healthful way.

These cues include periodicity of:

• Light/dark,
• Hunger/feeding,
• Activity/rest,
• Temperature

From the article,

• "...scientists have warned that modern life and 24-hour society mean many people are now "living against" their body clocks with damaging consequences for health and wellbeing.
  
  ...
  
  We are the supremely arrogant species; we feel we can abandon four billion years of evolution and ignore the fact that we have evolved under a light-dark cycle. "

Why limit that interpretation to our body-clock?

When it comes to our survival, our body works over longer periods than 24 hours - it has to prepare for periods of days weeks and months.  It has to make sense of the world from energy flows, hormonal flows, and, other signals that pulse, ebb and flow in response to external forces.  These signals hold information.

If the signal isn't clear then our body will be confused by noise - the noise of persistent grazing, persistent indolence, persistent temperature exposure, and yes, persistent light of an eternal summer - trapped in a state where it prepares for a lean times that never come. 

Lean times signal repair, renewal and regeneration.

Time to Pay Attention to Sleep

It’s Time to Pay Attention to Sleep, the New Health Frontier from Time:

• Your doctor could soon be prescribing crucial shuteye as treatment for everything from obesity to ADHD to mental health as experts say carving out time for sleep is just as important as diet and exercise.

Interesting and something that has long been championed on this site.  Remember, as well as the fact that you are probably not getting enough sleep, you may well need different amounts depending on season.  Furthermore, contrary to modern advice, sleep does not have to be a contiguous event.

Divided Sleep

My recent brush with hypertension is pretty much under control now.  I still get spikes but when I go to bed or get up, the numbers are in the normal zone.  On awakening the other day I managed three readings taken five minutes apart as follows:

• 114/64
• 116/67
• 115/65

Not bad for someone that a year ago was considered hypertensive.  The link above gives some background on both my diagnosis and what I have done to address the issue.

A LOT of caffeine through the day seems to have had an impact on my sleep.  I tried to get lots of sleep but dragging oneself off to bed before 2200hrs is difficult.  I only have one coffee a day now (if at all), and moderate my tea drinking (no more than four cups a day, and seldom after 1600hrs).  The big change though, has been with sleep.

I work hard at getting to bed shortly after 2100hrs to read and then meditate.  I am strongly aware of the importance of sleep for several years and divided sleep in particular.  Sleep is doctor, counsellor, psychiatrist, physiotherapist, massively anabolic, and generally restorative at every level.  I hit the gym hard three times a week and know that this must be mirrored in terms of quality and quantity of sleep.

All this stuff was thrown back in to perspective again today by the re-trending today of this story on the BBC site from 2012, The Myth of the Eight Hour Sleep.

I typically awaken at 0230hrs each morning and will be awake for 30-60 minutes, but then sleep pretty solidly until around 0600 - 0630hrs.  As a coarse indicator of sleep hygiene, I'd say that this is spot on!

More and Better Sleep

Sleep is high on my agenda at the moment.  The NYT seem to be running with a similar theme.  HO on the heels of this article, they've posted up Steps for More, and Better, Sleep:

• EXERCISE Physical activity leaves you tired, but if you do your workout within two or three hours of bedtime, you may be too revved up to fall asleep easily.
  
  MEDICATION Many drugs, both prescription and over-the-counter, contain stimulating chemicals like pseudoephedrine and caffeine, commonly found in decongestants and painkillers. Beta-blockers, used to treat certain heart conditions and high blood pressure, may be disruptive as well. Ask your doctor if you can use an alternative drug.
  
  FOOD AND DRINK Eating a big meal close to bedtime can be a problem, especially if you are prone to indigestion. Drinking a caffeinated beverage late in the day can disturb the sleep of anyone who has not developed a tolerance to caffeine by drinking too much of it. Caffeine’s stimulating effects can last for six to eight hours and make it hard to fall asleep or cause middle-of-the-night wakefulness.
  
  Alcohol may help you fall asleep, but when its effects wear off hours later, you may wake up and be unable to get back to sleep. (I and others I know find wine especially problematic and avoid drinking it with dinner.)
  
  STRESS Anxiety, excessive stress and difficulty shutting out worries trigger the release of body chemicals that act as stimulants. Try a relaxing bedtime ritual like a hot bath, meditation or progressive muscle relaxation, starting at the toes and working up to your head. Or, odd though it may seem, try reading something dull.
  
  If things you must remember or do the next day keep popping into your head, put a pad and pen next to the bed, write them down and then do your best to forget about them until morning.

Good advice!

Remember, sleep is not 'the daily event where you black out', it is time for your mind and body to service itself - time to repair and rebuild.  It is right up there with nutrition and exercise, and you wouldn't scrimp on those now would you?

Don't stress about sleeping solidly for 8 hours either (it is natural to awaken a couple of times during the night).  Just ensure you avoid electric light for the sleep window (which for me is 2130hrs to 0700hrs), and focus on relaxing and resting during that time.  With practice comes habituation and the process of initiating sleep - QUALITY SLEEP - may become easier for you as it has done for me.

Sleep Architecture

We fixate on diet and exercise, but in the West, of at least equal importance is sleep.  I've ruminated on the importance and nature of sleep a few times in the past. Only a day or two ago there was broad media coverage of the health implications of blue light from modern media and its impact on our circadian rhythm.  Sleep and our circadian rhythm are every bit as important as the 'diet and exercise' tenets of health and worthy of greater understanding.

The diagram above was appropriated from a site which has a good breakdown of the sleep and shows that idea of a 'solid eight hours' is indicative of sleep debt.

Lights Out Goes Mainstream

Mainstream are playing catch up!  Peering at bright screens after dark could harm health, doctor claims. None of this is news to those of us who have looked at our health and fitness from an evolutionary perspective for any lingth of time.

UPDATE: Nature has more detailed coverage of Charles Czeisler's work - including a couple of pithy observations:

• Paradoxically, the daily peak of waking energy driven by the brain's master circadian clock in the suprachiasmatic nucleus (SCN) of the hypothalamus occurs not at the start but near the end of our usual waking day, providing us with a 'second wind' that keeps us going as the day wears on. Before the widespread use of electric light, people probably experienced that second wind in the mid-afternoon, keeping them going until night fell. But light exposure after sunset signals 'daytime' to the SCN, shifting the clock later, postponing the second wind and delaying the onset of melatonin secretion. As a result, many people are still checking e-mail, doing homework or watching TV at midnight, with hardly a clue that it is the middle of the solar night. Technology has effectively decoupled us from the natural 24-hour day to which our bodies evolved, driving us to go to bed later. And we use caffeine in the morning to rise as early as we ever did, putting the squeeze on sleep.

This brings to mind Wiley and Formby's observation that our bodies are stuck in a perpetual summer, preparing for a winter that never comes.

5 Lux = Circadian Friendly

Another bit on the relationship between light exposure and melatonin:

• The research team established that duration of exposure and the distance between the eye and the display, which determines the amount of light reaching the back of the eye, affects melatonin levels. Melatonin suppression after a one-hour exposure to the tablet was not significantly affected. However, after a two-hour exposure there was significant suppression.
  
  The type of task being performed on the tablets also determines how much light is delivered to the cornea and, therefore, the impact on evening melatonin levels. As shown by the team’s Dimesimeter measurements, the range of photopic illuminance levels at the cornea from the tablets alone varied from 5 lux, which is not likely to affect melatonin, to over 50 lux, which would result in measurable melatonin suppression after a two-hour exposure. Therefore, before any generalizations can be made, it is important to measure how much light one is receiving from these self-luminous devices.

Best to limit exposure to modern electronic devices in the evening.

Sleep Fat Boy Sleep

The myth of 8 hours sleep has now been spun in to 'The Sleep Diet'. 

• A “sleep diet” may be the best way to slim for someone with an inherited tendency to put on weight, research suggests.
  
  Sleeping more than nine hours a night appears to suppress genetic factors that lead to weight gain, a study has found.
  
  In contrast, getting too little sleep seems to have the opposite effect.
  
  Previous research has shown an association between poor sleep and obesity, but the new findings reveal a complex interaction between sleep and genetic factors linked to body weight.

Like most things in biology, things are a bit more nuanced.  The problem here seems to be a combination of sleep deprivation/debt (total sleep) and the hormonal impact of light signalling. 

Somewhere in Night Time

We often think of a good night's sleep as something along the lines of eight hours of uninterrupted snoozing.  Kind of like 'lights out' when your head hits the pillow, not stirring until the next morning.  I disagree.

In an exchange with Methuselah some time ago, we ruminated on actually how 'normal' it is to be 'zonked out' for eight hours solid.  From a hunter's perspective what could be more appealing than your prey snoozing away in a deep sleep?  Hunting would become tame to say the least, and your prey's appearance on the tree of life would be likely VERY short.