Does excess hygiene affect the incidence of neurodegenerative diseases ? Yes, according to a study by the University of Cambridge (UK). Using data that predicts Alzheimer's rates in the hypothetical case that all countries had the same birth rate and identical life expectancy, Molly Fox and her colleagues have found a link between sanitation levels and the frequency with which it occurs. develop this type of dementia. The study reinforces the "hygiene hypothesis", since everything points to the fact that the sterilization of environments in developed industrialized countries, which reduces exposure to a large number of microorganisms, could have led to a lower development of the immune system that has supposed exposing the brain to inflammation associated with Alzheimer's disease, among other diseases.
Using information from 192 countries, the authors found that in places where everyone has access to safe water, such as the UK and France, there are 9% more people with Alzheimer's than on average, and a lot more than in places with a low level of drinking water such as Kenya or Cambodia. And in Switzerland and Iceland, where the frequency of infectious diseases is lower than anywhere else in the world, Alzheimer's rates are 12% higher than in infection-rich countries like China and Ghana. To this is added that, regardless of life expectancy, in countries where more than three-quarters of the population lives in urban areas, such as the United Kingdom or Australia, Alzheimer's disease is more common .
