Published: Sat, January 12, 2019
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Belly fat 'linked to brain shrinkage' and could raise risk of Alzheimer's

Belly fat 'linked to brain shrinkage' and could raise risk of Alzheimer's

The study, published in the journal Neurology, found no significant differences in white matter volume.

Grey matter in the brain consists mostly of nerve cells while "white matter" is made up of connecting nerve fibres.

Researchers from Loughborough University found that people with ahigh body mass index (BMI) and high waist-to-hip ratio had brains 12 cubic centimetres smaller. A 2018 study, for instance, has shown that people with excess belly fat have twice the risk of suffering from heart attack or die from cardiovascular problems regardless of their weight.

A new study has linked carrying extra weight around the middle to a smaller brain size. Are you heavier or shorter than the average American?

Only five per cent of those invited to participate in the study took part, and that group tended to skew healthier.


About 500 participants with a high BMI but not a high waist-to-hip ratio also had an average amount of grey matter. What did they find? People who have bigger bellies compared to their hips have a higher ratio, with men above 0.90 and women above 0.85 considered to be centrally obese. "The reductions in brain size increase in a linear fashion as fat around the middle grew larger", Hamer wrote.

Brain shrinkage was less for people who were obese but did not have a high waist-to-hip ratio, suggesting both are important.

"We also found links between obesity and shrinkage in specific regions of the brain". Potential causes of lower brain volume Cara Bohon, an assistant professor in the Department of Psychiatry and Behavioral Sciences at the Stanford University School of Medicine, wrote in an email that the study's findings are "not particularly new or surprising".

Looking at both BMI as well as waist-to-hip ratio clarifies what role different types of body fat may play in affecting the brain, Hamer says. This connection between reduced brain volume and abdominal fat could suggest that inflammation and vascular factors may be at work. It is possible that individuals with lower volumes of gray matter in some brain areas have increased the risk of obesity. Get CNN Health's weekly newsletter Sign up here to get The Results Are In with Dr. Sanjay Gupta every Tuesday from the CNN Health team.

'The study adds to existing evidence highlighting a link between a healthy weight and a healthy brain, but the researchers didn't look at whether participants went on to develop diseases like Alzheimer's and this will need to be explored in future research'.

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