Are We Too Hygienic?

Washing your hands before preparing food is always a good thing, but have we gone OTT with cleaning in general? Top Santé investigates…

- Lisa Buckingham

IT’S WIDELY ACKNOWLEDGED that improved hygiene habits have enabled us to be free of many of the diseases that at one time used to kill adults before old age and saw one in four children not making it to their fifth birthday. Clearly, modern sanitation routines, such as washing hands after using the toilet and thoroughly cleaning chopping boards with detergent and hot water after preparing raw foods, are a good thing.

However, there are some who say we have taken the level of sanitation too far For example, you might have heard of the hygiene hypothesis. It emerged in the late 1980s after a study found that children with lots of siblings were less susceptible to allergies. It hypothesised that this was because they were exposed to more infections, and that modern hygiene is a factor leading to fewer infections. The media ran with this, branding modern society as ‘too hygienic’. But since then, thinking has shifted to a broader look at our lifestyles as a whole and our exposure to an array of harmless microbes.

OUR NEED FOR NATURE

Enter a more recent theory called the ‘old friends mechanism’. This was put forward in 2003 by Graham Rook, Emeritus Professor of Medical Microbiology at University College London, and looks at the way modern life has reduced our exposure to the huge diversity of microbes, referred to as ‘old friends’, with which we have co-evolved since we were hunter-gatherers. If we’re exposed to these old friends in the womb and early childhood when the immune system is developing, we learn to tolerate them and they help our immune system stay balanced and regulated so that it doesn’t over-react to the wrong things such as pollen, or attack itself as in autoimmune diseases such as multiple sclerosis.