LONDON (Reuters) - When Ireland's Katie Taylor was taking hits and striking blows for boxing's Olympic debut in an east London ring last year, John Hardy did not want to look.
To this leading neuroscientist and molecular biologist, a boxing bout is little more than a session of mutual brain injury. He was horrified to see women boxing at Olympic level for the first time at the London 2012 Games.
"We shouldn't get our fun out of watching people inflict brain damage on each other," said Hardy, who is chair of Molecular Biology of Neurological Disease at University College London's Institute of Neurology. "To me as a neuroscientist it's almost surreal."
Hardy, whose research work focuses on Alzheimer's and other types of dementia, said having women in an Olympic boxing ring was "a terrible thing" - not because he thinks women should not compete alongside men in sport, but because women boxing simply meant more people inflicting more damage on more brains.
That, in turn, was highly likely to mean more people suffering the devastating, incurable symptoms of brain diseases such as Alzheimer's.
Advances in modern neuroscience mean scientists know more than ever about chronic brain damage and the long-term trauma that can result from frequent knocks to the head.
"You get tiny lesions along the blood vessels where they have torn the nerve cells around them. This damages those nerve cells, and those cells start to develop the tangles that you see in Alzheimer's disease," Hardy said.
"And what we now understand is that this process spreads."
Partly due to this new understanding, now is a time of intense sensitivity about and scrutiny of brain damage in sport - particularly among North America's National Football League (NFL) players.
Former San Diego Chargers player Junior Seau committed suicide last year after what some believe were years of depression stemming from multiple concussions he suffered as a player.
Last week, the NFL and General Electric Co announced a $60-million effort with leading neurologists to speed up research on brain injury to improve diagnosis and treatment amid growing concern about sports-related concussion.
RULE CHANGES
A study published last year found that even minor repeated head blows during sports such as hockey and American football may damage the learning ability of sports men and women after just one season.
The brain debate has even reached the White House, where President Barack Obama suggested in January that changes be made to NFL rules to reduce the level of violent impact.
In soccer too, concerns are growing about the damage players might be doing to their brains when they head the ball.
A small study of female soccer players published last month found evidence of mental impairment caused by repeatedly bouncing a football off the head. The U.S. researchers who conducted that study said the effects suggested headers caused "mild traumatic brain injury of the frontal lobes".
When it comes to boxing, health experts and scientists - and even some competitors themselves - have been worried about brains for decades.
The Irish former featherweight world champion Barry McGuigan, perhaps fearful of what damage might already have been done, said in 1988: "Boxing damages your brain; don't let anyone tell you any different".
Around the same time, fellow lightweight fighter Terry Marsh, who was later diagnosed with epilepsy, said: "I don't need the British Medical Association to tell me getting hit on the head can't do me any good."
As far back as 1928, the American pathologist Harrison Stanford Martland wrote a paper entitled "Punch drunk" in which he showed that prize fighters were suffering from brain injury caused by the rupture of blood vessels.
The "punch drunk" condition, known more formally as chronic traumatic encephalopathy (CTE) or as its variants, dementia pugilistica or boxer's dementia, is a neurodegenerative disease that can affect boxers and others who suffer knocks to the head.
It can cause depression, aggression, impulsivity and memory loss and has been linked to suicide.
"A lot of boxers, and indeed American footballers too, have a period in their 30s and 40s where they are depressed, they drink, they show explosive tempers, and have basically pretty messed up lives," said Hardy.
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