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Get down and dirty: It’s time to let go of your germ phobia because grubby kids are healthier

Research News
Thursday, October 20, 2016 - 10:00am
Northern beaches mum Rebecca Merritt is ahead of the curve by doing something generations of parents did before her — letting her daughter Lexi, 3, muck around in dirt in the backyard.

“I don’t care at all when she starts digging in the dirt, which she does often. We did it as kids and it didn’t do us any harm,” she says.

Far from doing harm, letting little ones get filthy in dirt and mud is actually doing them a lot of good.

“I think it would be a great thing if having a grubby, shopsoiled child became a status symbol,” laughs Kaz Cooke, author of Up The Duff, Kidwrangling and the upcoming Girl Stuff For 8-12 Year Old Girls.

“Rather than total avoidance, some friendliness with germs will help trigger the immune system enough to start protecting itself, but not enough to make you sick,”
she explains.

It’s just that we don’t allow that anymore — and at the same time as keeping our kids clean, we swoop on any perceived grubbiness with antibacterial soaps, wipes and sprays. It’s a worry.

So much so that, last month, the US Food And Drug Administration banned the most common antibacterial agent used in them — a compound called triclosan and its related products.

Here in Australia, local experts have welcomed the move and would like to see the Australian Government’s Therapeutic Goods Administration follow suit. The TGA is looking at the US decision.

“There’s an increasing accumulation of data that shows when bacteria gets exposed to triclosan and associated compounds, it gets resistant to them, so it diminishes in effectiveness, but it also gets resistant to antibiotics,” explains University of Sydney microbiologist Dr Nicholas Coleman.

“You are killing germs on the spot, but it leads to more serious germs down the track. But the other issue is that there are question marks over the safety of these compounds and the main issue is endocrine disruption.”

What happens is that by evolving a resistance to the compounds, bacteria also makes themselves resistant to frontline antibiotics, while at the same time, the presence of such compounds in our environment can have a feminisation effect, leading to much lower sperm counts in mammals across all species. That’s all longer term. In the immediate term, however, by wiping out such bacteria and creating super-clean environments, we are creating allergies and asthma in our kids. Simply put, we need a bit of dirt on us.

“As somebody who writes for parents and who has been the parent of a very small person, it is incredibly reassuring to know that the kid crawling around with the dirty face, looking like they’ve been dragged through the hedge backwards is the kid whose body is doing exactly what it’s supposed to be doing,” Kaz Cooke observes.

While the move to super-clean kids can be tracked to the rise of indoor plumbing, increasing urbanisation and more efficient cleaning products over the past century or so, the realisation that a little bit of dirt can be a good thing is very recent. It’s called the hygiene hypothesis and was coined in 1989 by US academic David Strachan.

It posits that the lack of exposure to bacteria, viruses and parasites leads to stunted development of immunity, and can lead to allergies and asthma, which have jumped dramatically in the past 20 years.

“Over the past few generations, there has been a change to the way we live our lives — we’re not as exposed to the outdoors, to grass, to dirt and animals and pets generally, we have smaller families and a cleaner water and food supply,” says Murdoch Children’s Research Institute researcher, paediatric gastroenterologist and allergist Professor Katie Allen. “And the quality of detergents has changed; they are much stronger and harsher and people are also washing much more frequently.”

That’s all happened very quickly to a system that has evolved over millennia to keep us safe.

“It’s been used by our bodies for tens of thousands of years to fight parasites and so the concept is the bugs in our gut are there to help train the immune system to protect us against parasites and other bacteria. If we’re not training it in the right way, it gets bored and misfires.”

About 5 per cent of Aussie kids have an allergy, and in Melbourne, where the institute is based, 10 per cent of babies have developed a food allergy by 12 months.

Research shows that farm kids are less susceptible to allergies and asthma, as are children with pets and kids with siblings.

Learn more about Professor Katie Allen's research here:

As originally published via the Herald Sun
October 15th 2016