Maintaining a sharp and healthy brain is crucial for your overall health and well-being. But one of your poor habits could be sabotaging your brain health. This habit is making your brain age faster and even causing dementia.A new study from Karolinska Institutet has linked a common habit in modern society to rapid brain ageing. The findings of the study are published in the journal eBioMedicine.
A common habit accelerates brain ageing
The researchers found that people who sleep poorly are more likely than others to have brains that appear older than they actually are. Poor sleep was also linked with increased inflammation in the body, which may partly explain the association.Previous research has shown that poor sleep is linked to dementia, but it was unclear whether unhealthy sleep habits contribute to the development of dementia or whether they are rather early symptoms of the disease. In this study, the researchers investigated the link between sleep characteristics and how old the brain appears in relation to its chronological age.
The study
To understand the link between sleep and brain ageing, the researchers studied 27,500 middle-aged and older people from the UK Biobank data who underwent magnetic resonance imaging (MRI) of the brain. They estimated the biological age of the brain based on over a thousand brain MRI phenotypes, using machine learning. The participants’ sleep quality was ranked based on five self-reported factors: chronotype (being a morning/evening person), sleep duration, insomnia, snoring, and daytime sleepiness. They were then divided into three groups: healthy (≥4 points), intermediate (2-3 points), or poor (≤1 point) sleep.“The gap between brain age and chronological age widened by about six months for every 1-point decrease in healthy sleep score. People with poor sleep had brains that appeared on average one year older than their actual age,” Abigail Dove, researcher at the Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, who led the study, said in a statement.
How inflammation affects the brain
The researchers also examined the levels of low-grade inflammation in the body to understand how poor sleep can affect the brain. They found that inflammation could explain just over 10% of the link between poor sleep and older brain age.“Our findings provide evidence that poor sleep may contribute to accelerated brain ageing and point to inflammation as one of the underlying mechanisms. Since sleep is modifiable, it may be possible to prevent accelerated brain ageing and perhaps even cognitive decline through healthier sleep,” Dove added.
One other possible mechanism that could explain the association is negative effects on the brain’s waste clearance system, which is active mainly during sleep, or that poor sleep affects cardiovascular health, which in turn can hurt the brain.
