Q: Is lockdown and all this infection prevention bad for my immune system? Don’t we need to be exposed to enough colds and bugs to keep our immune systems strong?
A: Great question from one of our followers! This is a tricky concept for sure. You might have heard of the “hygiene” hypotheses, which suggests that immune-related disorders like allergy and asthma are more common today because of decreased exposure to everyday microbes in our sanitized environment.
This hypothesis has been refined over the years (see link to PNAS article), with the key point being that “early exposure to a diverse range of “friendly” microbes—not infectious pathogens—is necessary to train the human immune system to react appropriately to stimuli.”
So yes, let your kids play in the dirt, cuddle your pets, visit a farm, and don’t feel too bad about the 3 second rule (even if like most of us your floors are a bit dirtier these days). Even if you don’t have access to dirt, a few months inside will not make a measurable difference to your immune system.
On the other hand there is NO evidence that additional exposure to infections like colds, flu, norovirus, or many of the awful infectious diseases we have (mostly) put behind us such as measles, smallpox, and tuberculosis are beneficial for the immune system. On the contrary, too many pathogenic infections may increase the risk of inflammatory diseases later in life.
Let them eat dirt!
