June 6, 2018
[emphasis mine throughout]
The brain has an internal drain which needs to be kept clear to prevent neurodegenerative diseases like Alzheimer’s, scientists believe.
Researchers at University College London (UCL) have discovered a combination of sleep, exercise and a small amount of alcohol all help stimulate the ‘brain drain’, preventing the dangerous build up of sticky plaques which drive dementia.
Scientists have known for some time that regular exercise and getting a good night’s rest help prevent mental decline, but until now did not know how.
But animals studies have shown that they boost the brain's self-cleaning, or glymphatic, system which clears out amyloid protein which clumps together and prevents brain cells from communicating with each other.
Dr Ian Harrison, from University College London, told the Cheltenham Science Festival that research was now focusing on finding ways of preventing the glymphatic system from failing.
He said studies had shown that the system is 60 per cent more active at night proving that sleep is crucial for its correct function. [Isn't the emphasis on the amount of sleep, not whether it's done in the night or daytime? Asked Pundita the night owl.]
"This is good evidence that the glymphatic system is active during sleep,” said Dr Harrison. “If that is anything to go by we should all be sleeping a lot more than we are.
"That kind of makes sense because, if you think about it, when your brain is active during the day these brain cells are going to be actively producing all these waste products, so it is only at night when our brain switches off that it has the chance to switch on our glymphatic system and get rid of all these waste products."
Dr Harrison said studies in mice had shown similar results with exercise.
"When the animals have voluntary access to exercise there is massive increase in the amount of lymphatic function," he said.
"The research has postulated that it is the increase in heart rate that drives this cerebrospinal fluid into the brain."
They also treated mice with low-level, intermediate and high-level doses of alcohol for 30 days and looked at the impact upon the glymphatic function.
He said that with low-level doses of alcohol - the equivalent of a third of a unit a day - there was a 30 per cent to 40 per cent increase in the brain's self-cleaning but a corresponding reduction following exposure to both intermediate and high-levels of alcohol.
"So 25ml of wine could actually increase your glymphatic system, according to this mouse study," Dr Harrison said. "But the intermediate dose of one unit of alcohol - a small dose of wine - suggests that if the mouse data can be extrapolated the lymphatic system can be lowered.
"So, sleep more, exercise and, as the data suggests, you can have a drink, but only a third of a unit of wine per day."