Almost half of dementia cases worldwide could be prevented or delayed, a study found, as experts cited 14 risk factors.
The number of people living with dementia worldwide is expected to nearly triple to 153 million by 2050, and researchers warn that it poses a rapidly growing threat to health and social care systems. Global health and societal costs associated with dementia exceed $1tn (£780bn) a year, the research shows.
But in a seismic report published by the Lancet27 of the world’s leading dementia experts concluded that many more cases could be avoided or delayed than previously thought.
By addressing 14 modifiable risk factors, which begin in childhood and continue throughout life, 45% of dementia cases can be prevented or delayed, even as people live longer, the Lancet Commission on Dementia said. The findings were presented at the Alzheimer’s Association’s international conference in the US.
In an interview with the Guardian, the lead author of the research, Prof Gill Livingston, said it was becoming increasingly clear that there was much more that millions of people could and should be doing to reduce the risk of dementia.
Speaking at the conference in Philadelphia, Livingston said: “Many people around the world believe that dementia is inevitable, but it is not. Our report concludes that you can greatly increase the chances of not developing dementia or delaying its onset.
“It is also important to emphasize that, although we now have stronger evidence that longer exposure to risk has a greater effect … it is never too early or too late to act.”
People at all stages of life, from children to the elderly, can take steps to reduce their risk of developing the disease – which has no cure – or at least stave it off until later in life, said Livingston, of University College London added.
Based on the latest available evidence, the report adds two risk factors associated with 9% of dementia cases. About 7% of cases are linked to high low-density lipoprotein or “bad” cholesterol in midlife from around age 40, while 2% of cases are attributed to untreated vision loss in later life.
These new risk factors are in addition to 12 identified by the Lancet Commission in 2020, which together account for about 36% of dementia cases, according to Livingston.
They are lower levels of education, hearing impairment, high blood pressure, smoking, obesity, depression, physical inactivity, diabetes, excessive alcohol consumption; traumatic brain injury, air pollution and social isolation.
The experts wrote in the report: “The potential for prevention is high and overall almost half of dementias could theoretically be prevented by eliminating these 14 risk factors. These findings give hope.”
Livingston said there was also new evidence showing that reducing the risks of dementia not only increased years of healthy life, but also reduced the time people who developed dementia spent in poor health.
“Healthy lifestyles involving regular exercise, not smoking, cognitive activity in mid-life – including outside formal education – and avoiding excess alcohol can not only lower the risk of dementia, but can also delay the onset of dementia ,” she said.
This meant that those who developed dementia lived with it for a shorter period of time, Livingston said, adding: “This has huge quality-of-life implications for individuals as well as cost-saving benefits for societies.”
Livingston said one of the easiest things people can do to reduce their risk of dementia is to fit exercise into their day if they are primarily sedentary, whether it’s a walk or even seated exercises.
To reduce dementia risk throughout life, the Lancet Commission made 13 recommendations, including making hearing aids available to those with hearing loss and reducing harmful noise exposure, and detecting and treating high cholesterol from around age 40.
Other recommendations include making screening and treatment for visual impairment accessible to all, and providing children with good quality education and being cognitively active in mid-life.
In a separate study published in the Lancet Healthy Longevity journal together with the commission, researchers modeled the economic impact of implementing some of these recommendations, using England as an example.
They found that public health interventions that tackled the risk factors could deliver £4 billion in savings by reducing dementia rates and helping people live longer and healthier lives.
Fiona Carragher, the chief policy and research officer at Alzheimer’s Society, which part-funded the study, said: “Some dementia risk factors, such as alcohol consumption and physical exercise, can be managed by changing your lifestyle, but many need to be addressed on a ‘ a societal level.
“Social isolation, educational inequalities and air pollution are beyond the control of individuals and require public health interventions and joint action between government and industry.”
Dr Susan Kohlhaas, the executive director of research at Alzheimer’s Research UK, which helped fund the research, warned that age and genetics remain the biggest risk factors for dementia.
But she said the finding that several other health and lifestyle factors were at play was “good news” because it presented a “huge opportunity” for people and governments to introduce preventative measures to reduce the devastating impact of dementia on society and reduce loved ones. in the future.
