Why lack of sleep shrinks your brain
In this case, size does matter. Discover the consequences of not enough sleep and why our brain shrinks
Text: Leila Louise Fritton
We all know what it feels like when we don’t get proper sleep. It can make us irritable and listless. It impacts our focus. It messes up our immune system. And just when you think that this is bad enough, research suggests that a lack of sleep can affect the size of our brain. And no amount of coffee can cure it.
The American Academy of Neurology examined the link between having trouble sleeping or staying asleep at night, and changes in brain structure and size — known in the scientific world as brain atrophy. They found that people who have trouble sleeping face a decrease in the size of their brain (particularly in the right superior frontal cortex region). This in turn destroys the connections that help the brain cells communicate, but research is yet to discover whether poor sleep quality is a cause or consequence of changes in brain structure. Low sleep quality and brain degeneration are closely intertwined, so it's tricky to determine which one comes first. Either way, it’s a bummer for our health.
While we sleep
Indeed, sleep is one of the most crucial things we can do for our wellbeing. While we’re sleeping a whole host of maintenance work and repairs are playing out. Proteins and other toxins that accumulate in our brains during the day are removed as we rest. The lymphatic system works like a ‘housekeeper’, removing the toxins which repair and restore the brain. And cells expand significantly, clearing a gunk known as the amyloid-β protein, which is a precursor to the plaques in Alzheimer’s disease.
Of course, there are constant neurological tests on sleep taking place. During AAN research, all of the participants underwent a sleep assessment and had two MRI brain scans, taken approximately three and a half years apart. In each assessment, sleep quality was measured using a sleep quality index to evaluate how quickly participants fell asleep, how long they slept, whether they used medication and other health factors. The results found that 35% met the criteria for poor sleep health.
Comparing the two scans, researchers could correlate the relationship between sleep problems such as insomnia with atrophy of various regions of the brain. The participants with sleep problems showed a more rapid decline in brain volume than those who slept well.
In particular, poor sleep quality was associated with reduced volume within the right superior frontal cortex region of the brain (the part that controls our cognitive skills such as emotional expression, problem solving, sexual behaviours). This is something Dr. Adam Spira of John Hopkins University concluded in a separate study three years later. Numerous other studies have shown that poor sleep patterns can contribute to brain disorders such as dementia.
Take ownership
It stands to reason that, if a lack of sleep can lead to memory loss, the size of the brain would also be affected. Having the gunk amyloid-β in our brain will reduce its size and affect its function of helping us to concentrate, remember, learn new things, and make decisions that affect everyday life. However, William Jagust says in Brain, A Journal of Neurology, that the evidence that amyloid-β contributes to brain atrophy is more obvious when there has been a brain injury.
Despite all of this, there’s no reason to sleep over it. Start taking ownership of your health by getting that recommended seven to nine hours sleep at night. Work power naps into your day. Listen to your body when it’s telling you it needs to unwind. As Dr Lim Li Ling, neurologist at Singapore Neurology & Sleep Centre Gleneagles Hospital says, “With a good night's rest, or when we pay off our sleep debt, we are better able to achieve optimal physical and emotional health and mental alertness."
It won't only help increase your productivity at work and in the gym, it'll also improve your relationships and social life. What’s more, it’ll help to keep your brain at optimum size and capacity.
