A third of all cases of Alzheimer’s disease could be prevented, according to a major new study.
Research shows around 30 per cent of cases are directly linked to key lifestyle factors that could be changed.
The disease is caused by a complex interplay of genetic and behavioural elements, but evidence shows some of the greatest dangers stem from lack of exercise, smoking and lack of awareness on the disease and how to protect yourself from it.
The number of worldwide sufferers was estimated at almost 34 million in 2010, and the figure is expected to increase to more than 106 million by 2050.
Experts behind the study suggest that by changing lifestyle habits, almost nine million people could be saved from developing the condition in the next 36 years.
Dementia has emerged as a major societal issue, with an ageing population and absence of any effective treatment.
Dementia describes a group of symptoms including memory loss, confusion, mood swings and difficulty with everyday tasks.
There are many causes, but Alzheimer’s is the most common form, accounting for around two-thirds of cases.
Figures show more than 820,000 people are currently living with dementia in the UK, around 86,000 of them in Scotland. Alzheimer’s affects around 500,000 Britons today.
But researchers say if action is taken to combat seven major drivers of the illness, many lives could be saved and millions of potential sufferers could be spared its devastating effects.
Improving access to education, combating depression and reducing rates of physical inactivity, smoking, high blood pressure, obesity and diabetes would help tackle the crisis and create a “win-win situation”, they say.
“Although there is no single way to prevent dementia, we may be able to take steps to reduce our risk of developing dementia at older ages,” said study leader Professor Caroline Brayne, from the Cambridge Institute of Public Health at the University of Cambridge.
“Tackling physical inactivity, for example, will reduce levels of obesity, hypertension and diabetes, and prevent some people from developing dementia as well as [giving them] a healthier old age – it’s a win-win.”
They estimate that cutting the risk factors by ten per cent per decade could cut the number of worldwide sufferers by 8.3 million by 2050. Dr Deborah Barnes, from the University of California in San Francisco, who co-authored the report, said: “It’s important that we have as accurate an estimate of the projected prevalence of Alzheimer’s as possible, as well as accurate estimates of the potential impact of lifestyle changes at a societal level.
“Alzheimer’s is placing an ever-increasing burden on health services worldwide as well as on both patients and their carers.
“Our hope is that these estimates will help public health professionals and health policy-makers design effective strategies to prevent and manage this disease.”
Dementia costs the UK economy £23 billion each year, with £12bn of that being met by unpaid carers.
Although old age is the greatest risk factor for developing dementia, there are around 3,000 under-65s suffering from early-onset Alzheimer’s in the UK.
Overall, more than two thirds of those hit by dementia are female as a result of their longer life expectancy and the higher prevalence in older age groups.
According to official figures, a third of people aged over 65 will die with some form of dementia.