One in three dementia cases could be prevented by lifestyle changes

A third of dementia cases could be prevented by making environmental and lifestyle changes starting in childhood, new research suggests.

According to an international study published in the Lancet, better education in early life and addressing high blood pressure, hearing loss, and obesity in mid-life, could reduce the rates of dementia by up to 20 per cent.

Whilst in later life, treating depression, stopping smoking, managing diabetes, increasing physical activity and increasing social interactions could reduce the incidence of dementia by a further 15 per cent.

Professor Gill Livingston (UCL Psychiatry), lead author of the study, said: “Acting now will vastly improve life for people with dementia and their families, and in doing so, will transform the future of society.

“Although dementia is diagnosed in later life, the brain changes usually begin to develop years before, with risk factors for developing the disease occurring throughout life, not just in old age.

“We believe that a broader approach to prevention of dementia which reflects these changing risk factors will benefit our ageing societies and help to prevent the rising number of dementia cases globally.”

Dementia is not an ‘inescapable’ part of ageing

With an estimated 47 million people believed to be living with dementia globally, the new report from the Lancet Commission on dementia prevention, intervention and care, is the first to quantify ‘potentially modifiable risk factors’ for the condition from childhood to old age.

It reveals that 35 per cent of all dementia cases could be prevented if the following nine modifiable risk factors were fully eliminated – poor early school education, hearing loss, hypertension, obesity, smoking, depression, physical inactivity, social isolation and diabetes.

The three most common modifiable risk factors identified were poor early school education, hearing loss in mid-life and smoking.

Dr Doug Brown, director of research at Alzheimer’s Society, says the findings are a cause for celebration but to achieve a reduction in cases, two important challenges must be considered.

Firstly how risk factors like education, obesity and depression apply not just at a population level, but to individual people who all have their own unique genetic risk profiles, and secondly how people can be motivated in mid to late life to change their behaviour and adopt healthier lifestyle choices.

He said: “Not all of the nine risk factors identified are easily modifiable – factors like poor education and social isolation are incredibly challenging to address. But there are easier wins, particularly cardiovascular factors like lowering blood pressure and smoking cessation."

Dementia set to be the 21st century’s biggest killer

He added: “Though it’s not inevitable, dementia is currently set to be the 21st century’s biggest killer. We all need to be aware of the risks and start making positive lifestyle changes. Understanding how to bring about changes in behaviour in people at risk of dementia should be a firm priority for future research and policy experts.

"The NHS Health check pilot we’re supporting, where GP practices are raising awareness of dementia risk reduction amongst people in midlife, is an important first step in raising public awareness and shifting behaviour.”

While interventions for these risk factors would not delay, prevent, or cure all dementia cases, researchers suggest there is much to gain, with other studies suggesting that dementia prevalence would be halved if its onset were delayed by five years.

The study is being presented at the Alzheimer's Association International Conference in London, and combines the expertise of 24 international experts to provide a comprehensive review of the disease including 10 key messages to help improve dementia care.