Overweight people have smaller brains, study suggests

Scientists have learned more about the brain in the past 10 years than in all other time periods combined. Take a look at these discoveries to see how to improve your memory and boost your mental power

Scientists have learned more about the brain in the past 10 years than in all other time periods combined. Take a look at these discoveries to see how to improve your memory and boost your mental power

"Our research looked at a large group of people and found obesity, specifically around the middle, may be linked with brain shrinkage".

Scientists looked at a total of 9,652 people with an average age of 55.

However, those with both a high BMI and high waist-to-hip ratio had an even lower grey brain matter volume than participants who did not have a high waist-to-hip ratio.

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.

Researchers from Loughborough University and University College London discovered that people with a high body mass index (BMI) and high waist-to-hip ratio had brains that were 12 cubic cms smaller than people of a healthy weight. It's tied to greater health risks than subcutaneous fat, or fat that's stored just under the skin.

The lowest grey matter brain volume, seen in 1,291 participants, was 786 cubic centimetres (cc). "This will need further research but it may be possible that someday regularly measuring BMI and waist-to-hip ratio may help determine brain health".

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Some previous studies have also found a link between visceral fat or a high waist-to-hip ratio and lower brain volume, but these studies tended to be small and did not look at the combined effect of BMI and waist-to-hip ratio.

A limitation of the study was that only 5% of those invited to participate ended up taking part, the researchers pointed out.

Grey matter contains most of the brain's nerve cells and includes brain regions involved in self-control, muscle control and sensory perception. 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. Hamer notes that he recently published data showing how physical activity may increase grey matter, suggesting that exercise may be a way to counteract some of the negative influences obesity might have on the body and brain.