Recent study suggests that the country you live in should
be taken in consideration, while assessing general Alzheimer’s development
risk. In particular, the risk of dementia development depends on how far north
a person lives.
Researchers say that a higher occurrence of dementia
among people living in northern parts of Scotland and Sweden suggests that
environmental factors - such as levels of sunlight - may influence adults' risk
of developing the disease.
Scientists say that the finding could help halve rates of
dementia, which affects 850,000 people in the UK and 36 million worldwide.
Researchers from the University of Edinburgh carried out
two studies mapping the disease - one in Scotland among people born in 1921 and
the other, in Swedish twins.
In Sweden, the further north people lived, the greater
their risk of dementia.
Researchers found that twins living in the north were two
or three times more likely to develop dementia compared with those in the
south, after they accounted for factors such as age, gender, and genes.
In Scotland, the study revealed a substantial change in
disease risk depending on where people lived as an adult. There was no change
in risk linked to where people lived as children.
Experts say that this variation is likely to be caused by
common environmental factors that affect people in adulthood - such as lack of
sunlight exposure and Vitamin D, which has been linked to healthy brain
function and dementia.
Dr. Tom Russ, of the University of Edinburgh's Alzheimer
Scotland Dementia Research Centre and the Division of Psychiatry, says,
"If this geographical variation in dementia risk is the result of one or
more environmental risk factors, and if these could be improved in the whole
population, our findings suggest that it might be possible to halve dementia
rates."
