1 in 3 Alzheimer's cases 'preventable'
14th July 2014 – Around one-third of Alzheimer's disease cases are preventable, according to research by the University of Cambridge.
The study identifies 7 risk factors, with lack of exercise topping the list.
A previous study published in 2011 suggested as many as 1 in 2 cases of Alzheimer's disease could be prevented, but the researchers say these earlier findings are likely to be less accurate because it did not take into account overlapping risk factors.
Soaring number of cases
Current estimates suggest that by 2050, more than 106.2 million people worldwide will be living with Alzheimer’s disease – a huge increase on the 30.8 million people affected by Alzheimer's in 2010.
In the UK, 800,000 people have a form of dementia, with 62% of these having Alzheimer's. In less than 10 years a million people will be living with dementia, and this is expected to rise to 1.7 million people by 2051.
The Cambridge researchers analysed population-based data to work out the 7 top risk factors for developing Alzheimer's disease. These are:
The team then examined how reducing each of these factors would cut the number of cases of the disease.
The results varied according to whether they looked at the UK, US, Europe or the world as a whole.
Cutting risk factors
The researchers estimated that by reducing the relative risk posed by each lifestyle factor by just 10%, nearly 9 million cases of dementia could be prevented by 2050.
For the UK they estimated that a 10% reduction in risk factors would reduce cases by 8.8%, or 200,000, by 2050.
In the UK, lack of exercise was found to be the main risk factor for Alzheimer's disease, followed by low educational attainment and smoking.
Worldwide, lack of education was identified as the main risk factor, followed by smoking and lack of exercise.
The research is published in the journal Lancet Neurology.
A healthier old age
Lead author Professor Carol Brayne, from the Institute of Public Health at the University of Cambridge says in a statement: "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. We know what many of these factors are, and that they are often linked.
"Simply tackling physical inactivity, for example, will reduce levels of obesity, hypertension and diabetes, and prevent some people from developing dementia as well as allowing a healthier old age in general – it’s a win-win situation.
Commenting on the findings in a statement, Dr Doug Brown, director of research and development at the Alzheimer's Society says: "This valuable study adds to a growing body of evidence strongly suggesting that simple lifestyle changes can help lower our risk of developing dementia.
"With 106 million people on this planet expected to be living with the condition by 2050, the prospect of preventing up to 1 in 3 cases of Alzheimer's disease is something we cannot ignore. We must now carefully consider how this new evidence influences public health messaging for dementia risk.
"In the meantime, we already know that what is good for your heart is good for your head and there are simple things you can start doing now to reduce your risk of developing dementia. Regular exercise is a good place to start as well as avoiding smoking and eating a Mediterranean diet."