Kids and teens risking dementia as ‘unhealthy habits’ cause brain changes decades before diagnosis

DEMENTIA risk may start accumulating as early as childhood, experts have warned.

A child’s body mass index (BMI), blood pressure and physical activity levels have been linked to changes in the brain by the age of 20 – particularly in the areas linked to dementia.

While it’s known a person’s health in mid-life can be a potential predictor for dementia in their later years, researchers haven’t previously tracked whether there could be an impact from childhood onwards.

In a new study, published in the journal eBioMedicine, the researchers suggested being unhealthy in childhood and adolescence could set the stage for later decline in brain health.

The team at the University of Oxford‘s Department of Psychiatry, in collaboration with University College London, examined data from 860 people who are taking part in the long-term Avon Longitudinal Study of Parents and Children.

The study is tracking people’s data over a long period of time by examining various measured linked to their health.

The academics looked at blood pressure and BMI when children were aged seven to 17, their physical activity levels when they were aged 11 to 15 and brain scans from young adulthood when they were around 20 years old.

They found markers of poorer cardiovascular health – such as higher childhood blood pressure and faster growth of BMI across teenage years – were associated with differences in the structure of a type of brain tissue called grey matter, including its thickness and surface area.

The links were particularly evident in brain regions that are known to be affected in dementia in old age.

Similar links between heart health and brain health have already been shown in older patients with memory difficulties and dementia, they added.

The researchers said their findings provide “preliminary evidence” that dementia risks could be identified and mitigated earlier in life.

But they called for further work to look into the finding but suggested it may have implications on timings of “preventative measures“.

“Our research shows that cardiovascular health in the earliest stages of life may already be important for the structure of brain regions known to be affected in dementia in old age – much earlier than previously thought,” said lead author of the paper Holly Haines.

The co-author of the paper, Associate Professor Sana Suri from the Department of Psychiatry at the University of Oxford, added: “The findings suggest that we should be thinking about targeting modifiable lifestyle risk factors, such as obesity and exercise, decades before current lifespan models of dementia suggest.

“The early adolescent years merit greater consideration in the context of dementia prevention.”

David Thomas, head of policy and public affairs at Alzheimer’s Research UK, said the study may influence the risk of developing dementia.

He said: “Up to 45 per cent of dementia cases can be prevented by avoiding risk factors that we can influence, such as physical inactivity and smoking. These are habits that some people pick up in early life, without knowing the potential long-term consequences for their brain health.

“Recent action from the Government to support the health of future generations, including the landmark Tobacco and Vapes Bill, are positive steps towards tackling some of the factors that affect our risk of developing dementia. But with the number of people affected by dementia on the rise, more must be done.

“Some factors which impact our risk of developing dementia are beyond our control, such as the affordability of a healthy lifestyle.

“The Government’s upcoming 10 Year Health Plan is a crucial opportunity to join up efforts to prevent ill health and tackle the range of factors that impact brain health across the whole of society.

“Dementia is not just an inevitable part of ageing. By supporting research like this study, we are gaining insights into how people might be able to prevent dementia happening in the first place, which is vital if we want to reach a cure for this devastating condition.”

Dr Richard Oakley, associate director of research and innovation at the Alzheimer’s Society, pointed out some limitations to the study.

He said: “This study mainly included participants who were white, male and upper or middle class, and so further research is needed to confirm these findings in a more diverse group.

“Additionally, because this is a preliminary study it does not confirm that poor cardiovascular health in childhood will definitely cause dementia later in life and more research is needed to understand this link.”