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Obesity could raise risk of dementia

 A combination of greater body mass index and waist-to-hip ratio may be an important risk factor for atrophy of the brain, a study shows

 A combination of greater body mass index and waist-to-hip ratio may be an important risk factor for atrophy of the brain, a study shows


Picture: SPL

Having extra body fat, especially around the middle, may be a risk factor for brain shrinkage, according to a study that looked at the effects of greater body mass index (BMI) and waist-to-hip ratio.

The researchers found that a higher level of obesity was associated with lower levels of grey matter volume in the brain.

‘Obesity was associated with lower gray matter brain volumes,’ the authors say. ‘It is unclear whether structural brain abnormalities drive obesity or whether obesity induces changes in gray matter volume that play a mechanistic role in future risk of neurodegeneration.’

Dementia cannot be cured or slowed

The study analysed data from more than 9,000 people aged 40-69 years whose details, including magnetic resonance imaging brain scans, had been recorded as part of the UK Biobank study.

Visceral fat, stored around the waist, is known to be a major site for inflammatory cytokine production. This has been linked to hypertension and diabetes mellitus, both of which increase the risk of dementia.

BMI is thought to be more reflective of fat stored peripherally in the hips and limbs, which may be less of a health risk.

It is predicted that by 2021 a million people in the UK will have dementia. As there is no cure or way to slow down the disease, the focus must be on ways to prevent people getting dementia in the first place.

Disguised relationship

Some studies have found that obesity is associated with lower rates of dementia, but this may have been because weight loss is common in the early stages of the disease. The weight loss may have disguised the relationship between high body weight and loss of brain function.

The mechanism underlying the association between obesity and neurogenerative diseases is not well understood.

The authors say some data suggest there is greater risk of cardiovascular disease in people with elevated BMI and waist-hip ratio, which may be relevant to neurodegenerative disorders.


Ruth Sander is an independent consultant in the care of older people

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