why sleep is so important.
There’s an overwhelming focus on nutrition and movement when it comes to human health, but rest, recovery and most importantly sleep, can often be overlooked. Which seems a little strange as a lack of sleep can influence both nutrition and movement after just one night.
Glucose tolerance goes down
Insulin sensitivity goes down
Cortisol goes up
Ghrelin (the hunger hormone) goes up
Blood pressure goes up
Immune signalling is disrupted
In years gone by there was almost a badge of honour to be able to survive on little or no sleep. Working in an Industry that is based around other people’s leisure time means I’ve done my fair share of early starts and late finishes.
I now relish sleep and I’ll do everything I can to ensure a good nights sleep of around 7 hours. Research suggest that adults require between 6 & 8 hours sleep a night, and you’ll probably think that it’s all about rest and repair, and to some extent you’re right, However, there are many other reasons why sleep matters, so let’s look at a few others;
glymphatic system
A reduction in the glymphatic system, the brains clearance mechanism is closely linked to the onset of dementia
Emerging research highlights the importance of night time clearance of metabolic and protein waste from the brain through the glymphatic–lymphatic system. Melatonin, a primary hormone governing circadian rhythms, appears to modulate this process alongside other key regulators.
All major CVD risk factors were associated with signs of impaired glymphatic flow across multiple imaging markers.
The findings shed light on how CVD risk factors could contribute to dementia.
Conditions such as hypertension and diabetes can damage the brain’s small blood vessels, leading in turn to glymphatic dysfunction.
The glymphatic system is most active during sleep with a 90% increase in activity compared to being awake with deep sleep (NREM 3) showing the highest levels of glymphatic clearance.
What about food influencing sleep and sleep influencing food?
Studies have shown that consuming too much sugar and to much fat or not enough fibre are all linked to sleep patterns that aren’t as restorative as they should be. Similarly, lack of fat in the diet, has been linked to a reduction in sleep quality, as does caffeine and alcohol, particularly if this is within 2-3 hours of bedtime.
Whilst these studies provide data, much more research is required to create a firm link between what we eat and drink and how we sleep with better designed studies.
On the other hand, there is better quality data showing that sleeps patterns influence how a person eats and how the body responds to food.
Less than 7 hours sleep a night for adults can influence the feeling of hunger and increase the likelihood of choosing foods that are sugary, more rewarding which may lead to overconsumption. Falling short on sleep may also reduce the body’s ability to break down sugar, leading to an increased risk of obesity , type 2 diabetes and heart problems
What you can try:
- Set a hard stop: phone off 21:30, lights out 22:30.
- Do a 10‑minute shutdown: tomorrow’s top 3, desk cleared, tabs closed.
- No caffeine after 14:00; walk 20 minutes first thing in natural daylight and allow light to hit the backs of the eyes.
Sleeping well isn’t fluffy. It’s operational.
How do you protect your sleep?
