Three lifestyle factors that can cause dementia - how to reduce risk

23 February 2024 , 17:02

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Each of 12 lifestyle factors increases the risk (Image: Getty Images/iStockphoto)

Nearly half of all dementia cases are down to 12 key factors, according to new research.

It says each lifestyle factor increases the risk and tackling these could cut scary results by 40 per cent. Factors include drinking more than ten pints or two bottles of wine a week, having head knocks from accidents or sport, and living near a busy street.

These three have been added to nine others that were known before. Within this 'dirty dozen', they say, is the secret to fighting Alzheimer's disease. Lead author Professor Gill Livingston, from University College London, said: "Our report shows it is within the power of policy-makers and individuals to prevent and delay a significant proportion of dementia." There could be ways to reduce risk "at each stage of a person's life", from childhood to old age, she said.

The three new factors makeup 6% of cases worldwide - with half attributed to having head injuries between your 30s and 50s. One in fifty occurs due to air pollution experienced in older age - and 1% is because of consuming more than 21 units of alcohol every week in middle age.

A group of 28 top dementia experts have updated a report on how to prevent the disease, which was presented at a virtual meeting of the Alzheimer's Association in America. The report builds on their previous findings from 2017, which identified factors contributing to about a third (34%) of dementia cases.

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The report found that hearing loss in middle age (8%), leaving school early (7%), and smoking (5%) were major contributors. Loneliness and depression (both 4%), high blood pressure and lack of exercise (both 2%), and obesity and diabetes (both 1%) also played a part, reports Wales Online.

The experts suggested that governments and individuals should ensure all children receive primary and secondary education. They also recommended limiting alcohol intake to less than 21 units a week and running campaigns to prevent head injuries, especially for those in high-risk jobs and transport.

They also encouraged the use of hearing aids, protection from loud noises, and urgent improvements in air quality. They advised that systolic blood pressure - the highest reading - should be kept to 130 mm Hg or less from the age of 40. Avoiding smoking, passive smoking, obesity, and type 2 diabetes was also recommended, as well as staying active at all ages. Currently, around 50 million people worldwide live with dementia, a number expected to rise to 152 million by 2050.

Dementia is a big problem, affecting people, their families and even the economy. It costs around £770bn every year worldwide. But in some places, fewer people are getting dementia, probably because they're living healthier lives. Prof Livingston said: "As societies, we need to think beyond promoting good health to prevent dementia, and begin tackling inequalities to improve the circumstances in which people live their lives. We can reduce risks by creating active and healthy environments for communities, where physical activity is the norm, better diet is accessible for all, and exposure to excessive alcohol is minimised."

The potential is particularly high in low and middle-income countries where around two-thirds of people with dementia live. Fiona Carragher, director of research at Alzheimer's Society, said: "The news 40% of dementia cases are, in theory, now preventable is certainly welcome, but stopping thousands of people from being stripped of their memories, relationships and identities will rely on more than just this knowledge alone."

"While we don't have all the answers yet, we can take action now to tackle the risk factors within our control, including excessive drinking, obesity and high blood pressure. Meanwhile, we need public health policies to address other factors, such as air pollution and inequalities in childhood education."

"This Lancet Commission update, part-funded by Alzheimer's Society, must spur action from the Government. Greater investment in high quality, in-depth research will help inform how we can effectively tackle these risk factors and is vital if we are to buck the trend of increasing dementia cases."

The other 60 per cent of risk is thought to be potentially non-modifiable. Dementia patients are particularly prone to Covid-19 due to their age and having pre-existing illnesses, such as hypertension.

They should not be admitted to care homes to protect the existing residents, said the researchers. In the UK more than 850,000 people live with dementia - a figure set to rise to 2 million by 2050.

With no cure in sight there is an increasing focus on healthy lifestyles - such as eating a nutritious diet and getting plenty of exercise - that can help stave it off.