When it comes to brains, it’s women who have staying power, according to the latest research.
A study suggests the female brain is on average three years ‘younger’ than that of an equivalent male.
The discovery may help to explain why women tend to stay mentally sharp longer than men in their later years.
Scans of men and women aged 20 to 82 examined their brains based on their use of glucose, and how it is burned for energy, which can affect brain performance.
It was already known that men’s brains shrink faster with age than women’s, but the new results suggest their brain metabolism is different too.
It may account for the fact that older men see a bigger drop in their memory and language skills than women, whose ‘younger’ brains may protect them from forgetfulness for longer.
Dr Manu Goyal, who led the study at the Washington University School of Medicine in St Louis, said: ‘We’re just starting to understand how various sex-related factors might affect the trajectory of brain ageing and how that might influence the vulnerability of the brain to neurodegenerative diseases.
‘Brain metabolism might help us understand some of the differences we see between men and women as they age.’
Researchers used PET scans to judge the biological age of 121 women and 84 men based on their brains’ use of glucose and oxygen. The brain’s metabolism slows as people grow older, with pensioners using less glucose for brain development and more to complete everyday tasks. But women may be better than men at resisting this decline.
Scientists believe that a ‘younger brain’ uses a higher proportion of glucose to fuel development, possibly strengthening certain areas.
That may help protect against the loss of grey matter which causes thinking problems in old age, although more research is needed to discover if this is the case.
The researchers found women used a higher proportion of glucose to develop their brain, they wrote in the journal Proceedings of the National Academy of Sciences.
A computer algorithm devised by the researchers to judge a brain’s biological age found that women’s brains were on average 3.8 years younger than their true age and men’s brains 2.4 years older than their true age.
The researchers said the approximate difference, based on the two results, is that women’s brains are three years younger.
Dr Goyal said: ‘It’s not that men’s brains age faster – they start adulthood about three years older than women, and that persists throughout life.
‘What we don’t know is what it means. I think this could mean that the reason women don’t experience as much cognitive decline in later years is because their brains are effectively younger, and we’re currently working on a study to confirm that.’
Scientists have accidentally found the ‘funny bone’ – and funnily enough, it’s not a bone but a spot in the brain which causes people to laugh when stimulated.
The discovery was made during brain surgery on a patient who was awake under local anaesthetic. Surgeons stimulated an area known as the cingulum bundle, causing immediate laughter.
A paper in the Journal of Clinical Investigation says the patient ‘reported an involuntary urge to laugh that?…?evolved into a pleasant, relaxed feeling over the course of a few seconds of stimulation’.
The researchers from Emory University in the US said the discovery could lead to ‘potentially transformative’ treatments for anxiety and depression.