This is a common line of thinking that you may have heard before. The idea is rather intuitive- if asthma rates are going up despite the improved hygiene of the modern world, then maybe these advancements are actually to blame?

Maybe your mum’s obsession with antibacterial soap is the reason you have asthma? Well, hold your horses on that angry text message because it turns out it might not be that simple.

Hygiene hypothesis

The hygiene hypothesis was first introduced in 1989 by David P. Strachan, a professor of epidemiology. Strachan found that children in larger households had fewer instances of hay fever because they are exposed to germs by older siblings.

If you want to sound even cleverer at parties, you could call it the ‘biome depletion theory.’ If you want to confuse people by making them think you’re about to launch into a critique of American network television, you could even call it the ‘lost friends hypothesis,’ as some people apparently do.

Anyway, if the hygiene hypothesis seems to work when it comes to hay fever, does it apply to asthma too?

Asthma and hygiene

Asthma rates are indeed soaring, but if you take a closer look at the figures, they don’t necessarily support the hygiene hypothesis. Asthma rates have skyrocketed in urban areas in the US that aren’t particularly clean, and the big increase in asthma rates in developed countries did not kick off until the 1980s. This was long after sanitary conditions in the richer parts of the world had improved. Some studies are even beginning to show that, far from protecting children from asthma, respiratory infections in early childhood may actually be a risk factor for it.

The link between the hygiene hypothesis and asthma was originally made because it seemed to explain the rising rates of allergies, but a landmark review of asthma studies in 1999 by Professor Neil Pearce demonstrated that at least half of asthma cases in the general population have no connection to allergic reactions at all.

Woman outdoors breathing fresh air
The link between asthma allergies such as hay fever is less defined than you might think.

What are the other theories for rising asthma rates?

There have been other theories since that particular study which attempt to explain rising asthma rates, but scientists just aren’t sure what accounts for it yet. It could be related to an increase in sedentary lifestyles, obesity or the types of bacteria people are exposed to, but conclusive evidence remains elusive.

So, modern living might not be to blame for the increase in asthma rates, but perhaps it can help you to manage it. PostMyMeds allows you to easily order a Ventolin inhaler online, wherever you are. All you need to do is fill out a short online consultation form and you can have it delivered to your door within 24 hours. You can save your card details securely via SagePay and choose from two delivery options: free 1st class delivery by Royal Mail, or Royal Mail special delivery, which is guaranteed to arrive by 1pm the next working day.

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Although all of our content is written and reviewed by healthcare professionals, it should not be substituted for or used as medical advice. If you have any questions about your health, please speak to your doctor.

Authored Oct 01, 2018 by Thomas Hall
Reviewed Jan 11, 2021 by Prabjeet Saundh, MPharm