Crossword puzzles, fancy detoxes and expensive supplements – people will try almost anything to boost their brainpower and ward off cognitive decline.
But researchers have posited that a simple way to keep the brain sharp is to listen to something called pink noise.
Pink noise is a sound similar to white noise but the pitch frequencies slightly vary: the lower pitches are louder and the higher pitches are softer, creating a calm sound similar to a waterfall.
Researchers found that tiny bursts of this noise during sleep could strengthen slow brain waves and trigger larger waves of cerebrospinal fluid (CSF).
Slow brain waves, also called delta waves, are specific oscillations that occur during deep sleep. These waves push out toxins such as lactic acid and worn-out proteins, which strengthens memory and helps the body repair muscles and tissues.
CSF is the clear fluid surrounding the brain and spinal cord, it protects the brain and also helps excrete waste. Without CSF’s ‘clean-up’ mechanism, the toxins can cause inflammation.
The research team wanted to see if they could strengthen CSF waves for better toxin ‘clean-up.’ To test their pink noise hypothesis, researchers had study participants sleep in an MRI machine so their brain waves could be analyzed while pink noise played.
Researchers discovered playing the sound enhanced delta waves, which increased CSF waves – but only at precise times during sleep.
Researchers found that tiny bursts of ‘pink noise’ during sleep could strengthen slow brain waves and trigger larger waves of cerebrospinal fluid
The findings, published in Science Translational Medicine, studied 14 healthy volunteers who had their brain activity monitored while they slept in an MRI scanner.
Closed-loop auditory stimulation was then used – a technique that monitors brain waves in real time and delivers precisely timed sounds to influence those brain waves.
A 50-millisecond burst of pink noise was delivered when the delta waves peaked, and results showed it increased the amplitude of delta waves and CSF waves during sleep.
The sound appeared to boost a natural electrical rhythm of sleep, which then affects blood flow and ultimately CSF movement.
The precisely timed sound helped strengthen the brain waves that occur during deep sleep, which may improve the brain’s natural system for clearing out waste.
‘We found that we were able to increase the size of the CSF flow wave during sleep, which as far as we know, there hasn’t been a method to do before,’ senior study author Laura Lewis said in a press release.
‘Now that we can enhance CSF flow during sleep in healthy adults, we’re really excited to bring this technology to clinical populations to see what effects we can have.’
The research team plans to use these new findings to conduct more studies in improving CSF for better sleep, specifically for those with insomnia.
The buildup of toxins in the brain has been linked to neurodegenerative diseases such Alzheimer’s, but researchers plan to explore if boosting the method of waste excretion could help those with cognitive decline.
‘Brain waste clearance is really important for Alzheimer’s and other forms of dementia, which are caused, in part, by the buildup of molecules like amyloid and tau in the brain,’ Joshua Levitt, the paper’s lead author, said in a statement.
‘If we can improve brain waste clearance, we may be able to help prevent the buildups of these plaques that lead to disease,’ Levitt added.
An estimated seven million Americans are living with dementia. Around 6.7 million of those cases are Alzheimer’s dementia specifically and that number is expected to nearly double to about 14 million by 2060 as the US population ages.
Early warning signs include struggling to remember appointments or how to do something they have done for a long time before. Some also struggle to concentrate or follow conversations.
In later stages, patients also suffer from severe mood swings, deepening confusion about time, place and life events and suspicion of family or friends.
There is no cure for the disease, but medications are available that may help to slow its progression.
