The research has found a "very significant" relationship between a nation's wealth and hygiene and the Alzheimer's "burden" on its population. High-income, highly industrialised countries with large urban areas and better hygiene exhibit much higher rates of Alzheimer's.
Using 'age-standardised' data - which predict Alzheimer's rates if all countries had the same population birth rate, life expectancy and age structure - the study found strong correlations between national sanitation levels and Alzheimer's.
This latest study adds further weight to the "hygiene hypothesis" in relation to Alzheimer's: that sanitised environments in developed nations result in far less exposure to a diverse range of bacteria, viruses and other microorganisms - which might actually cause the immune system to develop poorly, exposing the brain to the inflammation associated with Alzheimer's disease, Dr Molly Fox, lead author of the study and Gates Cambridge Alumna, who conducted the research at Cambridge's Biological Anthropology division said.
Countries that have much lower rates of infectious disease, such as Switzerland and Iceland, have 12 percent higher rates of Alzheimer's compared with countries with high rates of infectious disease, such as China and Ghana.
The study is published in the journal Evolution, Medicine and Public Health.
--ANI (Posted on 05-09-2013)