A Swedish study found more pets in a household in early life. The less likely a child will go on to develop conditions like asthma, eczema and hay fever.
For instance, kids aged 7-9 years that shared a house with four pets when they were a baby were half as likely to have a new allergy compared to their pet-free counterparts: 17 per cent compared to 33 per cent respectively.
Published in the journal PLOS One today,
the study is the first of its kind to show pet ownership dose-dependency on allergy risk, said Bill Hesselmar, University of Gothenburg paediatrician and paper co-author.
He suspects it’s all thanks to the microbes and the microbial components found on our fluffy friends: “We didn’t measure them, but I think that’s the case.”
an immunologist at the Murdoch Children’s Research Institute in Melbourne who was not involved in the research said a person’s earliest life environment sets their risk of developing non-communicable disorders during their entire lifetime.
“And it’s not just allergies, but also an autoimmune disease, inflammatory bowel disease, metabolic conditions such as obesity and vascular disease.”
The paper, at a glance
Subjects: A group of 1,029 children aged 7 to 8 years old, and another group of 249 8-to-9-year-olds who were followed from birth
Survey: Parents of children in both cohorts were asked if their child had experienced asthma, eczema or hay fever ever and in the past 12 months.
Pet ownership details were also collected from parents from the large group; researchers already had that information from the birth cohort
Results: Children in the smaller group had, on average, consistently fewer allergy symptoms ever and in the past year when they grew up with more pets, with a similar trend seen in the large group.
In other words, more pets mean more protection against allergies
It appears that living with more creatures — and a variety of them — safeguards us further, even when we’re still in the womb, Professor Tang said.
“What’s fascinating to me [about the new Swedish study] is the more pets you have, the more protection you have.”
So what is it about pets that protect us?
There are a couple of theories why pets, especially those that live indoors, confer allergy protection on youngsters.
Dogs and cats have fur that traps all sorts of microbes, even if they look clean, as well as bits of bacterial membrane called endotoxins.
This fits with the so-called “hygiene hypothesis”.
Inhaling, eating and generally being immersed in a whole bunch of different microbes and endotoxins as a child leads to a healthy microbiota, the community of bacteria that lives on and in the body, Professor Tang said.
“This, in turn, provides appropriate programming of the immune system, as well as the metabolic system and neurodevelopment.”
But it must be in the first three years of life or so, she added.
And it seems dogs, in particular, are great at helping a kid’s microbiota along.
Anyone who’s ever owned a dog knows that when you bring a pooch inside your house, you’re welcoming whatever rotting matter it’s rolled in, eaten or snuffled too.
Cats, by their nature, are usually cleaner, relatively aloof and don’t drool on your face as much.
Cat peeking out from under a blanket
But there are plenty of smoochy cats that like to sit close to their humans. (Pixabay: Stocksnap)
A 2013 study found dog-owning families had around 42 per cent more types of microbe on their pillowcases than households without a dog.
Whether they had a cat or not, though, made no difference.
While today’s Swedish study examined asthma, eczema and hay fever rates, our furry friends also appear to fortify young children against food allergies later in life.
But, again, not all pets. Just dogs.
Still, pet ownership isn’t the be-all and end-all when it comes to allergy protection. It’s one of a whole slew of protective factors, including having older siblings and washing dishes by hand.
The effect of your fur baby on your human baby is probably most significant in urban areas, where dogs and cats are more likely to be kept inside, and less so in rural areas — “at least in industrialised countries with a similar lifestyle”, Dr Hesselmar said.
“But I don’t think to have a pet or two will make any difference if, for example, you’re living somewhere where you’re exposed to a lot of microbes.”
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