by Annie Derry
Prioritising sleep is much more important than you think
A really good 7- or 8-hour sleep seems elusive for many people in the working world. A lack of sleep is sometimes even bragged about as if being ‘too busy’ to sleep equates to success. In our fast-paced environment with constant work, endless Netflix series to binge-watch, and phones that we never put down – it is easy to see why it’s harder than ever to get some shut-eye… or any peace for that matter.
In his recent TED Talk, “Sleep is your superpower” and his popular science book “Why We Sleep”, Professor Matthew Walker from University of California, Berkley, hones in on the benefits of having good ‘sleep hygiene’, and the sometimes-detrimental effects of lacking it.
Throughout the day our bodies work tirelessly at a molecular level to keep us moving, working, thinking, breathing – living. There is a constant stream of reactions going on that allow us to do this. A lot of these reactions produce chemical by-products along the way, which can be harmful if they are not removed. During the time that we sleep, one of the many activities going on in the brain is the removal of these waste products, in a sort of cleaning process that ‘washes’ the brain. Along with this, sleep is important for the consolidation of connections between neurons, allowing information from the previous day to be processed and stored.
What are the effects when these sleep tasks cannot be carried out?
Late nights; at your own risk:
1.Cognitive ability and memory function
It is fairly common knowledge that our higher cognitive processes are impeded on the day after a poor night’s sleep. Sleep deprivation has been found to impair attention and working memory, as well as long term memory and decision making. Prolonged wakefulness decreases alertness and ability to concentrate through the fact that it causes slowed responses and lapses – brief moments of inattentiveness. This is one of the reasons why driving a car or taking an exam with a severe lack of sleep is generally a very bad idea.
2. Long-term disease risk
In recent years there has been a growing link between a lack of sleep and the protein implicated in Alzheimer’s Disease, beta-amyloid. A build-up of this protein has been found in Alzheimer’s patients and, independently, in people reporting sleep disorders. It is thought that a lack of sleep contributes to a vicious cycle, where the brain is less able to wash out toxic proteins like beta-amyloid, as it usually does this during non-REM sleep. This could therefore contribute to the increased levels seen and lead to disease progression.
3. Higher risk of cardiovascular problems
There were some alarming results in a study which monitored the effects of losing an hour of sleep when the clocks go forward in the Spring (Daylight Saving Time, DST). Researchers found that the incidence of heart attacks reported by hospitals increased by 24% in the days following the time change. The opposite effect is seen when we gain one hour of sleep as the clocks go backwards in the Summer – the number of heart attacks reported decreases by 21%.
4. Immune function
Some of the most eye-catching statistics from Matthew Walker’s research were from his studies into the effect of sleep on our immune system. We have a number of cell types that all work together in order to fight off infection by recognising and killing foreign microorganisms like bacteria and viruses. Among the cells that are important in this, the natural killer cells (NK cells) are vital in the process eradicating threatening microbes. It was found that when sleep was reduced to 4 hours, even just for one night, there was a 75% reduction in NK cells in the blood of patients the next day. This indicates at least an association between our sleeping habits and how well we could fight off an infection, even a common cold, if exposed after a poor night of sleep.
Studies in to sleep do have alarming conclusions sometimes, but we cannot assume that sleep is the isolated causative variable contributing to the negative effects seen. As with almost all studies they must be taken as an indication, rather than a conclusive result. It also must be considered that some people may be genetically (or otherwise) predisposed to restless nights of sleep – we cannot assume that one person needs exactly the same number of hours to see out a healthy life.
That being said, it wouldn’t do any harm to try and pay more attention to the needs of our body and to allow ourselves to sleep as much as we really need to.
How to prioritise getting more/better quality sleep?
- Reducing screen time at night
- Reducing artificial lighting in the bedroom
- Using apps like Headspace in order to practice mindfulness (and as a useful tool to get back to sleep if you wake up in the night)
- Reading before bed to help to wind down
- Going to sleep and waking up at a similar time every day
FYI… Matthew Walker received his PhD in Neurophysiology at Newcastle University in 1999.
This blog post was based on:
“Why We Sleep” – Matthew Walker
“Sleep is your superpower” – TED Talk by Matthew Walker
Sleep deprivation: Impact on cognitive performance – https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2656292/