Being overweight or obese in mid-life could increase the risk of developing dementia in later life, scientists in Sweden have found.
Researchers at the Karolinska Institutet, in Stockholm, looked at information on 8,534 twins aged 65 or older, taken from the Swedish Twin Registry.
Out of the group, 350 had a diagnosis of dementia, while 114 had possible dementia. The scientists calculated their body mass index (BMI) at mid-life, using self-reported height and weight measurements that were recorded about 30 years earlier.
Their results showed 39% of those with dementia had been classified as overweight in mid-life, compared to 36% of those with possible dementia and 26% of those without dementia. Similarly, 7% of participants with dementia were obese in mid-life, compared to 5% of people with possible dementia and 3% of those without the condition.
However, further analysis showed that where one twin had dementia and the other did not, there was no link between BMI in mid-life and the risk of dementia.
The researchers believe their findings, which are published today in the journal Neurology, suggest that our genes and environment in early life could affect the link between mid-life weight and the risk of dementia.
Dr Simon Ridley, Head of Research at Alzheimer’s Research UK, said:
“This study adds to existing evidence that excess weight in middle age could increase our risk of developing dementia. We know that keeping healthy in mid-life may help reduce the risk of dementia in later life, as well as bringing countless other benefits.
“It’s likely that dementia is caused by a complex mix of genetic, environmental and lifestyle factors. However, we still need to know much more about the causes of dementia if we are to find an effective treatment that is so desperately needed. Research is the only answer to dementia, but we must invest more to have the best chance of tackling the condition.”