IF YOU think that it’s better to be clean than dirty, you will arrive at the wrong destination as far as your health is concerned.
The microbial communities established in our bodies at birth and in early childhood shape our health as we grow and are major players in determining whether or not we develop illness as adults.
Our super-sanitized lifestyle has threatened those essential communities and created health challenges we never anticipated, including a new breed of diseases, which have emerged in the last century.
In the late 1950s, Professor David Strachan, a lecturer at the London School of Hygiene and Tropical Medicine, was tasked with figuring out why rates of autoimmune diseases, particularly hay fever and eczema, were skyrocketing in British children. The study followed seventeen thousand children from birth to adulthood, and the results revealed two startling and unexpected associations: both conditions were far less common in large families with lots of early childhood infections from exposure to siblings, and in less affluent households with lower standards of personal hygiene.
This finding was counter to everything we thought we knew about germs. Could exposure to more germs really be better for us? And could living a cleaner lifestyle be making us sicker?
If we look at a map of the world today, one of the striking observations is that autoimmune illnesses like Crohn’s disease are common in more developed countries and rare in less developed ones.
Strachan’s hygiene hypothesis accounts for this uneven distribution by suggesting that less childhood exposure to bacteria and parasites in affluent societies like Australia and the United States actually increases susceptibility to disease by suppressing the natural development of the immune system.
We spend a lot of time making sure we’re clean — scrubbing ourselves with harsh soaps, sanitizing our hands and environment with chemicals, and eliminating any trace of dirt from our homes and lives — but more and more, the evidence points to germs as being essential for our wellbeing, so it may be time to rethink our approach to health and disease.