A country childhood may put people at more than twice the risk of Alzheimer’s disease much later in life, new research suggests.
However, the study from Edinburgh University has been unable to cast light on the reasons behind the phenomenon.
Alzheimer’s experts have urged caution about the findings and say there is no compelling reason to flee the countryside for urban life.
The researchers reviewed 51 academic papers published over several decades which contained 12,580 medical records from several countries, including the UK, US, Italy, Canada, Peru and Nigeria. They looked at national and local rates of dementia and noted a very small increase in the prevalence of dementia among people living in country areas.
However, people who were born and brought up in rural areas had more than twice the risk of developing Alzheimer’s disease in later life.
The authors say further good quality research is needed before firm conclusions can be drawn. For instance, the risk of dementia in Scotland might be linked to other factors, such as smoking rates, social deprivation, blood pressure and body mass index (BMI), as well as a rural childhood.
There are also doubts over whether the exposure to rural living in early life might be behind the increase in Alzheimer’s cases or the length of the time spent in the countryside.
The authors write: “The next question is whether the causes of this observed variation can be identified, and, if so, could they highlight modifiable socio-environmental risk factors, thus making dementia a preventable disease.”
Dr Simon Ridley, head of research at Alzheimer’s Research UK, said in an emailed statement: “This data review observes a link between rural living and increased Alzheimer’s incidence and prevalence, but the complicated evidence is insufficient to prompt an exodus to the city.
“The review team acknowledges great variety in the quality of dementia data across the world, even down to inconsistencies in the definition of a rural area. We should remember this is an amalgamation of global data that may not hold true for the UK.
“Big questions remain over whether particular exposures in early rural life or duration of rural living are at play. It will be a huge challenge to move from observing these possible links towards determining what causes them, and more rigorous data collection and analysis are still needed.”
Hannah Clack, media manager at the Alzheimer’s Society said in a statement: “While there is no definitive way of preventing dementia, there is positive action we can all take to reduce our risk. Leading a healthy lifestyle with regular exercise, a good balanced diet and keeping a healthy weight can help cut down our chances of developing the condition by up to a third.
“We wouldn’t advise people to consider a move to their nearest city in order to reduce their risk of developing dementia; in fact a nice long stroll in the countryside may be a much better idea.”
Citation: Russell, Peter. “People Who Grew up in Rural Areas ‘at Twice the Risk of Alzheimer’s'” WebMD, Web. 19 Sept. 2012. http://www.webmd.boots.com/alzheimers/news/20120919/people-who-grew-up-in-rural-areas-at-twice-the-risk-of-alzheimers