Scientists believe Alzheimer's could be linked to better hygiene
- 05 Sep
According to scientists improvements in hygiene could partly explain the increased rates of Alzheimer's disease in developed countries.
Researchers have studied the prevalence of the neurodegenerative disease Alzheimer's across 192 countries and compared it with the diversity of microbes in those places to come to the conclusion that hygiene improvement could be the cause of the increase in the disease.
Taking into account differences in birth rate, life expectancy and age structure, scientists found that levels of sanitation, infectious disease and urbanisation accounted for 33%, 36% and 28% respectively of the discrepancies seen in Alzheimer's rates between countries.
In their report, published in the journal Evolution, Medicine and Public Health, the researchers concluded that hygiene was positively associated with risk of Alzheimer's disease. Countries with a greater degree of sanitation and lower prevalence of pathogens had a higher burden for the disorder.
Whether hygiene is the cause for the pattern is not fully clear but the team does have a speculative hypothesis for how the two factors may be linked. This is due to exposure to micro-organism - good and bad - is important for the body to develop proper immune responses. Therefore the reduced level of contact with bacteria and other kinds of infectious agents may stall the proper development of important elements of the body's immune system such as white blood cells.
"Alzheimer's disease (AD) shares certain etiological features with autoimmunity," the researchers wrote in the journal Evolution, Medicine and Public Health. "Prevalence of autoimmunity varies between populations in accordance with variation in environmental microbial diversity. Exposure to micro-organisms may improve individuals' immunoregulation in ways that protect against autoimmunity, and we suggest this may also be the case for AD."
Image source: http://www.sxc.hu/photo/982475
Related articles
Responding to the DWP Consultation: Housing Benefit Reform - Supported Housing "I thought this briefing was very good and very useful. The presentation was clear, well argued and I always find Michael gives me food for thought even if I don't agree with everything he says. I really like the way he facilitates a discussion in the room and I learn as much from other participants as I do from the presenter which is always good. Right length, right tone." R.P. - Richmond Fellowship