There are many resources for sleep now available. We are not going to repeat the work of others here in an attempt to explain what has already been deeply investigated elsewhere (resources at the close of this section).
However, we do want to explain why sleep is foundational to health – beyond the food, nutrients, exercise and stress levels we live with. In doing so we hope to help you understand why the ‘Sleep’ piece is a fundamental part of a healthy ‘Paleo’ lifestyle.
Sleep is our primary source of potential restoration, rest and rejuvenation and, as such, it is actually more important than how we eat or live our lives. It provides the counterbalance to our daily choices and is the chief buffering mechanism through which we make living possible.
Without ‘recharging’ our batteries, humans would expire more quickly than you can imagine. A dizzying array of processing, detoxifying, restoring and healing happens whilst we sleep. More importantly, the quality (not just the duration) of your sleep will directly impact energy levels, the physiological state of either stress or wellbeing, our capacity to make ‘decent’ choices, and even the diversity and population of our microbiome.
We used not to really know why the human body needed sleep. Now, we know that so much happens during sleep that doesn’t happen at any other time.
Going without sleep for any significant length of time (days, not weeks or months) creates the very dysregulating impacts that a Paleo approach is attempting to ameliorate: inflammation, hormonal disruption, immune system regulation issues and nervous system dysregulation.
Acute sleep deprivation (i.e. longterm lack of sleep and/or entire missed nights of sleep) has been shown to increase circulating cytokines (inflammation chemicals) which stimulates the maturation of T cells, increase C-reactive protein levels (a blood marker of inflammation), promotes increases in white blood cells (neutrophils) and B cells, raises blood cholesterol levels and causes higher levels of low-density lipoprotein (conventionally called ‘bad cholesterol’, LDL can be used as a marker for inflammation because the LDL particles transport toxins around and out of the body – high levels can therefore indicate high toxin levels which come from high inflammation).
Low-level sleep deprivation (i.e. marginally reduced sleep for a relatively short period of time) can still have similar effects – particularly on cytokines and C-reactive protein levels. It has been shown that this mild lack of sleep is easily achieved by simply going through the working week under-sleeping. This marginal sleep loss cannot be repaired by simply ‘catching up’ on the weekend – the immune system won’t quite return to normal with just a few hours’ extra sleep on Saturday and Sunday.
Beyond the cascading effects of raised inflammatory markers, sleep has a direct impact on hormones.
Hormones play key roles in the regulation of almost every physiological process, including the immune system but also insulin, leptin and ghrelin (appetite and metabolism hormones), cortisol and adrenaline (adrenal hormones) and even oestrogen and progesterone (sex hormones) – basically hormones control every part of the human experience. Disrupted hormone levels have consequences throughout multiple systems of the body – affecting not only the systems that they directly control but altering functions, stress, inflammation and immune function system-wide through their signalling mechanisms and regulatory reach.
Sleep, or lack thereof, has been demonstrated to cause insulin resistance, cortisol irregularities, disruptions in the ghrelin and leptin signalling of hunger and fullness and altering blood sugar regulation.
The net effect of a lack of sleep is, to put it simply, that our body cannot accurately send or receive the messages it needs to run, control and gain feedback from any of its essential functions or systems.
It is perhaps not surprising, therefore, that sleep deprivation is associated with many health issues, including both autoimmunity and chronic inflammatory conditions. It is well-known among patients experiencing these conditions that sleep often becomes dysregulated, due to both pain and the blood sugar or cortisol/stress issues which go hand in hand with these illnesses. This becomes the typical catch-22 situation, where restful, restorative sleep is necessary to recover but impossible to come by due to the health crisis currently being experienced.
When we sleep restfully our immune system is regulated effectively. Studies have shown that the main regulatory T-cell activity (i.e. the ‘off-switch’ part of our immune function which keeps everything in check) actually happens overnight. Therefore sleep is an important part of healing and recovering from any chronic condition.
This is not about being in darkness and these health conditions being ameliorated after the sun has set. Instead it’s entirely to do with the biochemical reality of the fact that you are asleep. That time in which you’re actually unconscious is a rarefied space where the constant stimuli and juggling act of ‘life’ is no longer a demand on our nervous systems and our body finally has time to look inward and enact its ‘general maintenance’ protocols to clean up the messes made by the day.
All of the above should convince you that you need sleep. But how much you need is entirely unproven by research. This is because it is so individual and dependent on so many other factors.
As we at Paleo in the UK think of sleep as nature’s great ‘reset’ button, with the ability to detoxify, heal, repair, replenish and re-orient ourselves: how much time you need in bed will largely depend on how much of this ‘inner work’ your body has to do.
Babies need around 14 hours of sleep during the day, toddlers and children slightly less, teenagers slightly less but still around 8-10 hours with adults needing an average of roughly 7-9. The reason for an increased sleep need in children which lessens with age is obvious when the functions of sleep are looked at in the context given above. Children and teens are still growing, building and making themselves fully-fledged humans. Their sleep is ensuring all the metabolic processes of growth and building are being supported and the clean-up processes necessitated by this intensively metabolic process are completed.
Your sleep – whatever your age – should reflect your need for repair. If you are fairly sedentary and in good health, the likelihood is your sleep needs may be less. If you’re fairly healthy but active and athletic then you will need time in bed to repair any muscle damage. If you are sick, with autoimmune conditions or general health problems, your need for sleep may exceed even that of a growing child.
Whilst embarking on a Paleo lifestyle means you’re avoiding some of the modern stressors, you are by no means obviating all.
In short: think of sleep as a fourth macronutrient, as vital for wellness as nutrients. And, to be frank, breathing.
We recommend that you do all that you can to protect this precious resource.
We would like here to refer you to one of our faves: Dr Sarah Ballantyne, PhD and her epic e-book on sleep.
We would also recommend checking out Dave Asprey at Bulletproof and his technological sleep hacks, including Swannies/TrueDark glasses and lots about light (blackout blinds, blinking LEDs etc).
To read more about light levels and how they direct your circadian rhythm and influence your sleep see the website above and also our Light section on our Chemicals, Toxins, Pollution, Mould page.
A brilliant read for anyone interested in sleep is “Sleep Smarter: 21 Proven Tips to Sleep Your Way to a Better Body, Better Health and Bigger Success” by Shawn Stevenson of the Model Health Show (Podcast).