Sleep – Your #1 Health Priority
By John Fell
Seven to nine hours per night. If you are consistently getting this much sleep, congratulations! You are supporting your health at the most fundamental level. Reading the rest of this blog is optional for you.
If you are regularly getting less than seven hours sleep, this may be the most important thing you read all year. Sleep needs to become your number one health priority. Why? Because your brain and body depend on it. Not getting enough of it can lead to weight gain, cardiovascular disease, cancer and Alzheimers disease, just to name a few. Sleep is the foundation upon which we grow, heal and thrive.
To appreciate it’s importance, consider how sleep has been naturally selected through the countless generations of evolution even though it renders us unconscious for a third of our existence, leaving us vulnerable to predators, using up valuable time for hunting, food gathering, making shelters and procreating. It is a basic need of all animals and studies show that not enough of it can lead to an early death.
Why We Sleep
There are two factors that cause us to fall sleep. The first is our circadian rhythm which is like an internal clock that helps us feel alert during the day and sleepy at night. It is affected by the regular timing of light and darkness as the earth rotates and constantly adjusts it’s internal timer to match the twenty four hour cycle of a day. In most healthy adults, the alerting energy signal of this rhythm starts a few hours before waking, continues to rise throughout the morning, peaks in the early afternoon, before waning again in the late afternoon and evening.
The second factor that causes us to sleep is a chemical called adenosine which starts building up in our brain from the moment we wake. The longer we are awake, the more adenosine levels rise, increasing the desire to sleep. This is known as ‘sleep pressure’. After approximately eight hours of healthy sleep (in an adult) adenosine has been purged and the sleep pressure has been removed. When we are in a healthy pattern of sleep, this happens about the same time that our circadian rhythm is telling us to get up and get going which results in the wonderful feeling of being wide awake.
How do we know if we’ve had enough sleep?
Here’s a simple test. If you could fall asleep again at 11am (when the alertness from your circadian rhythm is high and still rising) it indicates the adenosine hasn’t been fully cleared from the night before which is why the sleep pressure is still there, out of sync of the circadian rhythm. If you drink coffee (or tea) in the morning, this test won’t work since caffeine artificially mutes the sleep affect of adenosine to make us feel more alert and awake.
A daytime nap can be a very effective supplement after a disrupted night of sleep if you can find time to squeeze it in. Just try not to have it after 3pm. Anything later than mid afternoon will most likely make it harder for you to fall asleep that night since adenosine levels will be lower upon waking and the sleep pressure may not have built up enough by your regular bed time.
Lack of Sleep and Weight Gain
A series of studies by Dr Eve Van Cauter at the University of Chicago identified the detrimental hormonal effects of inadequate sleep on eating behaviour. People who sleep only five hours per night have reduced levels of leptin (our ‘stop eating’ hormone) and increased levels of ghrelin (our ‘keep eating’ hormone). There are also increased levels of endocannabinoids which are chemicals that give us the munchies.
In addition, the decision making areas of our brain are adversely effected. Supervisory regions in the pre frontal cortex required for thoughtful judgements and controlled decisions are silenced by inadequate sleep while the primal, deep brain structures that drive motivations and desire are amplified.
As if an altered hormonal balance and lack of impulse control aren’t enough, the lethargy we feel after a poor night of sleep makes it harder to get ourselves to exercise, compounding the problem.
The Benefits of Sleep and Harmful Effects of Not Getting Enough
The body of science on sleep is abundant with motivating and alarming discoveries. I encourage you to check out the work of Matthew Walker, a Professor of Neuroscience and Psychology at the University of California, Berkley who is an expert in this field and very good a simplifying the science. You can watch his 20min TED Talk here: https://www.ted.com/talks/
His book ‘Why We Sleep’ is an international best seller and adds a lot more depth to the main points he covers in the presentation. He says he wants to help the reader “fall in love with sleep” and it certainly did that for me.
How to Get More Sleep
So if somewhere between seven to nine hours per night is the target, how do we achieve that?
1. Stick to a routine. Try your best to get up and go to bed at the same time every day, even on weekends. Our brain and body respond to regular patterns. In addition to the light and darkness of day and night affecting our circadian rhythms, external cues like meal and exercise times, temperature fluctuations and regularly timed social interactions can also help to reset our biological clock. Consistency and regularity are the key points here. (In regard to exercise type and timing for optimal sleep, vigorous workouts are best in the morning and relaxing ‘work ins’ like yoga or stretching are best in the afternoon or evening)
2. Set an alarm clock for bed time and label it with a phrase describing how you want to feel in the morning. “Wake up feeling great tomorrow” or something like that. Give yourself the opportunity to obtain adequate sleep by insisting on eight hours of darkness. Make sure it’s ‘lights out’ eight hours before your alarm will go off. If this is very different to your normal routine, you may not fall asleep straight away. This would be an ideal time to follow a guided meditation or listen to some relaxing music while focusing on slowing and deepening your breath. As you develop a habit of this, your body and brain will become more ‘primed for sleep’ as the soothing side of your nervous system (parasympathetic) is emphasised. 10-20min of deep, slow breathing or meditation on a regular basis just before you fall asleep and just after you wake up will develop a ‘routine of relaxation’ that will manifest into longer, deeper sleep. If eight hours seems unattainable compared to your current routine, then start by adding half an hour to your sleep for the first month and gradually build towards the seven to nine hour range over a realistic timeframe for you.
3. Reduce light after sunset. Dim all lights in your home or use lamps at least two hours before bed time. The less light entering your eyes after sunset the better. This will assist the hormonal balance of your circadian rhythm decreasing the stress hormone cortisol and increasing the sleepy hormone melatonin. Set your phone for ‘night time use’ which will remove the blue light (which has an extra wakey effect) from the screen. Install the program ‘F.lux’ on your laptop which will similarly adjust your screen lighting to match the time of day. If possible, avoid screens of any kind one or two hours before sleep time. Ensure your bedroom is as dark as possible with block out curtains or wear an eye mask to bed.
4. Cool down. A lowering of your body temperature increases the production of melatonin and helps to initiate the onset of sleep. Maintain a cool bedroom (15-19 degrees) and have a shower 30-60min before bed. The relative drop in core body temperature after you get out of the shower will help you fall sleep. New technology for linking lights and air conditioning systems in ‘smart homes’ will continue to improve night time lighting and temperature control for optimising sleep in the near future.
5. Don’t try too hard. If you focus too much on ‘having to get more sleep’ it can create anxiety and become counter productive. Depending on your personality, you may find the sleep tracking apps on your phone, smart watch or Fitbit to be enlightening and a helpful way to monitor any changes in your habits. The information you can gather can be really interesting if you like that sort of thing. But good sleep doesn’t depend on apps or gadgets. If that all seems too intense, just relax about it, get yourself a good book and remember that you’ll be sleeping every night for the rest of your life, so a few bad nights are no big deal. Small, consistent changes to your routine over time will achieve great results.
I hope this helps. Until next time, sleep well…