Had a bad night? It could disrupt your brain’s cleaning system and therefore increase the risk of dementia.
This is evident from a large-scale study by the University of Cambridge. For the study, they used the data of around 40,000 adults from the Netherlands UK Biobank used. The researchers saw that small disruptions in the flow of cerebrospinal fluid are associated with a greater risk of dementia years later. The research can be found in Alzheimer’s & Dementia: The Journal of the Alzheimer’s Association.
Clean brain
In a healthy brain, the so-called glymphatic system ensures that waste products are flushed away. The system works like a nightly cleaning crew: cerebrospinal fluid travels through tiny channels around blood vessels, collects the waste there and then removes it.
The team wanted to know whether a disrupted cleaning system can increase the risk of dementia. During her studies, team member Yutong Chen developed an algorithm that can extract such disruptive signals from MRI scans on a large scale. Applied to the images of the UK Biobankparticipants, this provided three important clues that can predict the later risk of dementia.
They are all directly related to the brain’s cleaning system. For example, the size of the place where the ‘cleaning agent’ is produced appears to be important and also how quickly it flows through the brain. The third clue has to do with how diluted the cleaning solution is when it is in small capillaries. “Although we must be cautious about indirect evidence, our work provides good evidence that disruption of the glymphatic system plays a role in dementia,” says Chen. “That is exciting, because it raises the question of how we can improve this system.”
High blood pressure
The researchers also found that high blood pressure may be associated with poorer cleaning function. This is probably because very small capillaries can become damaged in the brain, which can be seen on an MRI scan. This creates a cautionary tale: cardiovascular diseases may damage the delicate structure of small capillaries, impeding the flow of the ‘cleaning agent’. This would reduce the cleaning capacity of the brain.
“We already had evidence that diseases that affect capillaries in the brain could accelerate the onset of Alzheimer’s. Now we have a likely explanation why,” says team member Hui Hong of Zhejiang University. “Disruption of the glymphatic system likely undermines the ability to remove waste products from the brain that cause Alzheimer’s.”
Thanks to the research, we now have two factors that we know have something to do with dementia. So the first factor has to do with the health of the blood vessels in the brain. We already knew the second factor: sleep. We have known for some time that the body activates the brainwashing function while sleeping. However, we now know that disrupting that ‘beauty sleep’ can cause harmful substances to remain in the brain, increasing your risk of not only Alzheimer’s but also dementia.
Cerebrospinal fluid
The research represents an important step in the fight against Alzheimer’s and dementia. Researchers can now see whether there are possible medications that affect the flow and production of cerebrospinal fluid. In addition, it has been proven that the risk of dementia can also be influenced by behavior: by always going to bed on time you reduce the risk that this terrible disease will also attack you.
Finally, there may also be a plausible theory that can explain how cardiovascular disease can ultimately lead to Alzheimer’s. Bryan Williams of the British Heart Foundation says: “This study provides a fascinating look at how problems with the brain’s waste disposal system can silently increase the risk of later dementia. This study also highlights the importance of controlling high blood pressure to lower dementia risk.”