If you read about children's health, you've heard a lot of this before: Microbes, vilified because they cause infectious diseases, can be beneficial to a child's well-being. Our society's penchant for hyper-cleanliness is actually making our children less healthy and more prone to allergies.
But microbiologists B. Brett Findlay and Marie-Claire Arrieta make that case with an unusually convincing display of evidence - as well as historical anecdotes and a parent-friendly sense of humour - in their new book, Let Them Eat Dirt: Saving Your Child from an Oversanitized World.
They lay out the 19th-century discoveries that identified microbes - germs! - as dangerous carriers of diseases, and the discoveries of the past two decades that have shown us how vital microbes are to our very existence. Then they translate that evidence into accessible, understandable advice.
They explain about avoiding the unnecessary use of antibiotics, and they advocate exposing your children to the great, messy outdoors. Their guide to transitioning babies to solid foods warns: "Don't delay the introduction of allergenic foods. Offer peanuts, soy, shellfish, etc ... between four and seven months of age." This is followed by an entertaining recitation of what babies eat in other countries, concluding, "The next time your child refuses to eat something you offer, remind her that she should be thankful she's not in Tibet, where babies eat barley flour mixed with yak butter tea!"
Get a pet, they say, if you can take care of one. Specifically, get a dog instead of a cat, because a cat will probably spend more time indoors and not be very effusive, while a dog has to be taken out for walks a couple of times a day and will come inside and jump on you and lick your face. ("Bring on the slobberfest!" cries one section's title.) Yes, the authors acknowledge that people can develop allergies to dogs. But "dogs keep us dirtier," they say, "and as we have come to learn, kids benefit from this kind of exposure early on."
Probably the fastest-reading and most fun chapter is the Q&A, for which Findlay and Arrieta polled parents to come up with a list of cleanliness-related questions: When should children wash their hands? What kind of soap? Should I let people hold my baby? Are sandpits unsanitary? Is antibiotic ointment necessary when treating scratches and cuts? Is it safe for a child to put something in his mouth after it's been dropped on the ground? And so on.
(From the answer to the last question: A recent Swedish study found that babies whose parents clean the dummy by sucking on it get fewer allergies than those whose parents rinse the dummy in tap water. On the other hand, the dummy-sucking parent may pass on cavity-inducing microbes. The takeaway: Life is complicated.)