New research published in Epidemiology found that people living in northern latitudes have a significantly increased risk for dementia compared to those living in southern latitudes.
Researchers have long been interested in the relationship between the latitude, environment and climate and risk of different diseases.
It has been suggested that the higher risk and prevalence of certain diseases seen in those living at a northern latitude is due to the reduced ability to make adequate vitamin D from the limited sunlight in these regions.
A research team from the United Kingdom recently looked at two large cohorts to determine if latitude of residence affected the risk of developing dementia.
The two large studies used were the Swedish Twin Registry, through which the researchers collected data on 27,680 twins, and the 1932 Scottish Mental Survey cohort, through which the researchers collected data on 37,597 individuals.
The researchers looked at where these 65,277 individuals lived to determine if latitude played a role in the risk of dementia.
They found a 2-3 fold increased risk of developing dementia among twins born in northern Sweden compared to southern Sweden.
There was no relationship between latitude and risk of dementia among children in Scotland, but among adults, there were similar results as that seen in the Swedish twins.
“Further work is required to confirm these findings and identify any potentially modifiable socioenvironmental risk factors for dementia responsible for this geographical variation in risk,” the researchers concluded.
“However, if these factors do exist and could be optimized in the whole population, our results suggest that dementia rates could be halved.”