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Brains of overweight persons 10 years older than lean counterparts

Published:Wednesday | August 10, 2016 | 12:00 AM
Human brain

A new study has found that the brains of overweight people are 10 years older compared with their lean counterparts - but only when they reach middle age and up.

In a study published in the journal Neurobiology of Ageing, researchers from the Cambridge Centre for Ageing and Neuroscience in the United Kingdom analysed 473 people between the ages of 20 and 87 and divided them into two categories, depending on their weight: lean and overweight. In the end, they found that overweight people had less white matter (the part that transmits information) in their brains compared with their leaner counterparts.

From there, they calculated how white matter volume relates to age across the two groups. In doing so, they found that an overweight person had a white matter volume comparable to a lean person who is 10 years older than them.


Interestingly enough, however, they only found this to be the case in people who are middle age and above, giving credence to the belief that our brains are particularly vulnerable during that period of ageing.

"The fact that we only saw these differences from middle age onwards raises the possibility that we may be particularly vulnerable at this age," noted senior author, Professor Paul Fletcher, in the report. "We're living in an ageing population, with increasing levels of obesity, so it's essential that we establish how these two factors might interact, since the consequences for health are potentially serious."

However, while researchers now know what obesity can do to people in those age groups, they still don't know why that is the case.

"As our brains age, they naturally shrink in size, but it isn't clear why people who are overweight have a greater reduction in the amount of white matter," Dr Lisa Ronan of the Department of Psychiatry at the University of Cambridge stated. "We can only speculate on whether obesity might in some way cause these changes or whether obesity is a consequence of brain changes."

Similarly, they still don't yet know the full implications of these changes in brain structure.

"This must be a starting point for us to explore in more depth the effects of weight, diet and exercise on the brain and memory," the report stated.

The study also found that despite the differences in the volume of white matter between lean and overweight individuals, there was no apparent connection between being overweight or obese and an individual's intelligence or cognitive functions.