How your belly can predict when you’ll get dementia

If you’re carrying extra weight at this stage of life, you probably already know that it is bad for your health, but new research shows that being overweight has devastating impacts on your brain as well.

Scientists have long suspected that the increase in rates of both obesity and Alzheimer’s disease is no coincidence, but this is the first study to look closely at just how excess weight and dementia are linked.

Now a team from the US government-affiliated National Institute on Ageing has found that having a BMI (Body Mass Index) just one point over your safe level speeds up the onset of dementia for people aged 50 or over by almost seven months.

This means people who are seriously obese in middle age could develop the neurodegenerative disease a whole decade before they would have if they were a healthy weight.

This research is incredibly terrifying considering 75 per cent of Australians aged 65-74 years are considered overweight or obese.

 “We think these findings are important because they add to a substantial amount of knowledge about how obesity affects Alzheimer’s disease,” lead author Dr Madhav Thambisetty said, as reported in The Telegraph in the UK.

“But more importantly, it indicates if we can maintain a healthy body mass index even as early as midlife, it might have long-lasting protective effects towards delaying the onset of Alzheimer’s disease decades later.”

Body Mass Index is worked out by dividing a person’s height by their weight. For most adults an ideal BMI is between 18.5 and 24.9. A BMI of 25 to 29.9 is considered overweight, while 30 to 39.9 is obese, and 40 or more is morbidly obese.

The researchers studied 1300 people aged over 50 for an average of 14 years, testing them every two years for cognitive ability and weight. Over that period 142 people went on to develop dementia.

Those who were overweight or obese developed Alzheimer’s far more quickly, on average 6.7 months sooner for each extra point of BMI over their normal weight.

Of the people who died during the study, it was found that those with high BMI had far more neurofibrillary tangles in the brain, a hallmark of Alzheimer’s disease.

Alzheimer’s Society manager Dr Clare Walton, said, “We know dementia can begin to develop years or maybe decades before symptoms begin and so keeping healthy through midlife and into later life is important for reducing dementia risk.”

Will these findings make you redouble your efforts to achieve or maintain a healthy weight? Does the prospect of dementia concern you?

Stories that matter
Emails delivered daily
Sign up