Home Hygiene & Health
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October 2012: Rising allergies? No, we're not too clean, just losing touch with "Old Friends"

IFH has prepared a new report “The Hygiene Hypothesis and its implications for home hygiene, lifestyle and public health”. The report examines the scientific and epidemiological evidence relating to the hypothesis, and our relationship with the microbial world we live in. Both the full report and a summary of the key findings and conclusions are available from the IFH website.  

The report challenges the idea that the recent epidemic rise in allergies has happened because we’re living in sterile homes and overdoing hygiene. However, far from saying microbial exposure is not important, the report concludes that losing touch with microbial “Old Friends” may be a factor underlying rises in an even wider array of diseases ranging from allergies to Type 1 diabetes to inflammatory bowel disease and multiple sclerosis.  

The “Old Friends” hypothesis suggests that the required “exposures” are not to infectious diseases, but to environmental, and human and animal commensal microbes. The report also concludes that altered exposure is not about day-to-day cleanliness, but the result of a broader range of measures and activities, vital to protecting us from infectious disease, but which have also inadvertently reduced or altered exposure to the microbial friends that regulate our immune systems. This includes food and water quality, sanitation and environmental cleanliness together with medical advances such as the introduction of vaccines, or antibiotic usage, which may have altered the way our bodies interact with microbes.

The good news is that this means we aren’t faced with a stark choice between running the risk of infectious disease, or suffering allergies and inflammatory diseases. The threat of infectious disease is increasing rather than decreasing because of antibiotic resistance, global mobility, the ageing population and so on. This means that the need for hygiene is as great as it ever was.

The report concludes that it’s time we recognised that talking about home and personal cleanliness as the cause of a problem that has a much more complex set of causes is ill-advised because it’s diverting attention from finding the true causes and workable solutions for this serious public health problem.