A deep sigh and intake of breath with arms stretched back in a lazy arc: yawning is rarely a good look when it comes in the middle of a conversation.
But yawning – as rude as it can come across – is probably healthy, researchers now believe.
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University of New South Wales (UNSW) neuroscientists in Australia say yawning appears to clear waste from the brain – a “speculative” finding that potentially clears up at least some of the mystery behind the reflex.
In tests based on magnetic resonance imaging (MRI) scans, the team found that yawning triggers a “specific manoeuvre in which cerebrospinal fluid and venous blood move out of the skull together”.
According to UNSW, the fluid “is important because it cushions and protects the brain and spinal cord from injury, and also helps carry nutrients in and waste products out”.
“Yawning is a body movement that can influence the flow of fluids around the brain,” said study co-author and UNSW Paul Trainor chair Prof Dr Lynne Bilston.
“There has been speculation that yawning can help clear waste from the brain, but so far there has not been solid proof,” added the Neuroscience Research Australia (NueRA) senior principal research scientist.
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Perhaps even more intriguingly, the researchers believe they have uncovered another facet of yawning – that each person does so with a particular movement of the tongue, and therefore, could be identified by a yawn as easily as with a fingerprint.
“Yawning remains very mysterious, even though it’s a primordial process that has been preserved throughout evolution,” said study lead author and UNSW neuroscientist Dr Adam Martinac, who explained that “nobody has really worked it out for certain”.
The team’s findings will be published in the July (2026) edition of the journal Respiratory Physiology And Biology, which is already available online. – dpa
