I HATE housework,” said the late Joan Rivers. “You make the beds, you wash the dishes, and six months later you have to start all over again.”
If only. I can’t stand a dirty kitchen sink, a grubby bathroom or cobwebs hanging from the ceiling, so I spend precious hours every week cathartically cleansing.
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The doubts set in 18 months ago when I moved in with my boyfriend. It didn’t take us long to discover that we’re in opposing corners when it comes to housework – he’s dirty but tidy, while I’m clean but messy. He suddenly had to deal with my clutter spread all over his dining table and sofa, while I nursed a growing preoccupation with the art of disinfection.
We have learned to live with each other. And my new position of compromise has led me to question some of my preconceptions. Is cleaner necessarily better? I’d heard in a vague sort of way that perhaps it’s not; that an obsession with the elimination of germs might be behind many a modern malady. But what did the science say? I set out to see whether there might be such a thing as too much cleanliness.
How clean is too clean? The truth about hygiene and your health
We drill our children to wash their hands, but kids who grow up on farms or with a dog seem to be healthier. Uncover the dirty truth about cleanliness.
We’re bombarded with seemingly contradictory information about being clean. Good hygiene helps ward off countless infections and illnesses, that much is clear. But then there are the bacteria that turn out to be good for us; the whispers that some ingredients in our cleaning products might be hurting us; the hypothesis that too much hygiene is behind rising rates of allergies and other disorders.
On that last point, something definitely seems to be out of whack. More than 150 million people in Europe are thought to have allergies, a number that’s rising. By the 2020s, half of all Europeans could have at least one. Food allergies are becoming more common, especially in children. Between 1997 and 2007, there was an 18 per cent rise in children who had one in the US – now nearly one in every 25. Then there is asthma. Between 1971 and 1991, the number of family doctor consultations for the condition , while appointments for allergic rhinitis – inflammation of the nose in response to things like pollen and dust – more than doubled.
It was back in 1989 when , then an epidemiologist at the London School of Hygiene and Tropical Medicine, first proposed his . He suggested that modern lifestyles, with their lack of unhygienic exposure, mean we catch fewer infections in early childhood, and that this predisposes us to developing allergies.
Too much hygiene
Some of the evidence is fascinating. Children who grow up on farms , as are children , and those who (my personal hygiene nightmare). But as a lover of cleanliness, the study that turns my stomach the most is a 2014 paper that found that children are less likely to develop precursors to asthma if, in their first year, they’re exposed to particles from .
Many of us have embraced the idea of a link between a little bit of dirt and good health, perhaps eager for an excuse to cut down on the housework. “This wonderful idea that we’ve become too clean for our own good, whatever that means, has just stuck,” says Sally Bloomfield at the London School of Hygiene and Tropical Medicine.
There’s just one problem: things probably aren’t that simple. In recent years, thousands of studies have linked changes in the microorganisms living inside our bodies to everything from allergies and asthma to obesity, depression and Alzheimer’s disease. This emerging understanding of what’s known as our microbiome suggests that rather than there being a clear distinction between “clean” and “dirty”, we have a complicated relationship with bacteria. Being exposed to some kinds is good for us, to others not. .
One thing is becoming clear – it’s diversity that counts. A 2015 study of nearly 400 infants in Germany hinted as much, when researchers found , and their caregivers’ personal and home cleanliness.
What did make the difference was their exposure to bacteria. Several studies show that healthier people tend to host a wider range of microbes. Western lifestyles may have adverse effects on this diversity, which was found to be 40 per cent lower than that detected in an isolated, traditional hunter-gatherer society. And while I can’t help wrinkling my nose when I see a parent pick a dropped dummy off the street, suck it clean, and then hand it back to their child, a 2013 study found that these infants were less likely to . The organisms in their saliva were also different from the ones inhabiting infants whose parents would never do such a thing, prompting the researchers to suggest that the protective effect is down to the transfer of beneficial microbes from parent to child.
There is now also evidence for why living on a farm is so good at reducing allergies – the bacterial components in farm dust . This seems to indicate that the hygiene hypothesis is in need of revision. “It’s not infections so much as exposure to a wide variety of bacteria that helps control the development of our immune systems,” says Dennis Ownby, an allergy and immunology specialist at Augusta University in Georgia.
Mixed messages
When we are exposed to these beneficial microbes is also crucial, and the most important time seems to be early childhood. “It is probably very important to take children, starting at a young age, outdoors and let them play on the ground,” says Ownby. So if you’re old enough to be reading these words, I have some bad news. By the time we are adults, our microbiome may be largely set. According to current thinking, the cut-off is as early as 3.
So any suggestions that shirking the chores – or – during adulthood could increase your diversity of good bacteria are spurious. After all, while we may lack a full understanding of which bacteria are good for us and how, we are more clued up on the ones that are unequivocally bad.
For example, there are about in the UK, caused by microbes including Norovirus and Campylobacter. Many cases are picked up in restaurants, but a study of 18 European countries suggests that nearly a third of food-borne outbreaks occur . “I’ve seen houses that are absolutely, completely filthy,” says Lisa Ackerley, a food safety adviser at the British Hospitality Association, who has gone into homes to swab for bacteria as part of her work. “It’s easy to say we’re too clean, but who’s got the evidence?”
Filth has consequences. About 50 per cent of chickens in the UK , the country’s , and the bacteria can easily transfer from the raw meat to your hands or a chopping board. Seen in this light, Bloomfield says, anything that encourages people to is dangerous.
But while being too slovenly stands a good chance of giving us diarrhoea, neither do we want to be too clean. In particular, you might want to cut back on antibacterial handwashes and laundry detergents. Not only might some of these have less benefit in the home than advertised, there is some evidence they might to antibacterials and even antibiotics. There’s also growing concern about indoor pollution connected with overzealous use of certain household products (see ““).
Right, so being too dirty could hurt me, but so could being too clean. What’s a girl to do?
The good news is that there might be a science-approved hygiene sweet spot. Bloomfield and Ackerley are among a growing group of experts who advocate ““. This has been a well-known strategy since the 1950s, says Bloomfield, but it was limited to hospitals and industries like catering, pharmaceuticals and cosmetics – anywhere it’s important to “identify critical points for transmitting infection”.
The suggestion now is that targeted hygiene should be the strategy behind everyone’s basic housework. “It’s still important to be hygienic in the places and at the times that matter,” says Bloomfield. But instead of striving for a sterile home, we need focus only on removing harmful bacteria, from important surfaces, at critical times.
Most of the cleaning should focus on doorknobs, light switches and the bathroom – anything we touch a lot. It’s also crucial to thoroughly clean everything you use while cooking. That includes all surfaces, chopping boards and utensils that come into contact with raw meat, as well as unwashed dirty vegetables, whose bacteria can give you food poisoning just as raw chicken can. The most important advice is to wash your hands, after cooking, before eating and after using the toilet.
But beyond that? Well, Joan Rivers fans can take heart: cleaning the walls, floors or the furniture really can wait six months. If you’re not allergic to dust mites, vacuuming is entirely optional. And you can forget about making the bed – especially if you’re allergic to dust mites. Mites need a humid atmosphere to survive, so leaving the covers open in the morning might help to kill the beasts.
It all seems great news for my relationship: as long as I can encourage my boyfriend to be clean in the right places, I needn’t fear for my health. And in return, I can take comfort that being tidy might not be the be-all and end-all either (see “The upside of chaos” in “Attack of the household products: Hygiene’s hidden risks”).
Beyond the basics, it seems there is one big thing we can do to improve our health beyond worrying too much about the state of our homes: leave them more often. “We don’t spend enough time outdoors,” says Bloomfield.
Preliminary findings hint that spending more time doing social sports and other outdoor activities can help restore a healthily diverse microbiome. Exposure to soil may be key, says Ownby. “We all end up ingesting between 50 and 60 milligrams of soil a day,” he says. Gardeners get about twice that amount.
It’s all quite pleasingly wholesome and old-fashioned: boost your health by getting out in the open air. Use cleaning products, but not so many that your home fills with pollution, and open the windows after you do.
We’re trying to put it into practice. It’s certainly nicer to spend time in a well-aired flat, and I now eye air fresheners and antibacterial soaps – not to mention the recent proliferation of – with suspicion. I’m even seeing pets in a new light. The thought of having a dirty animal in my home used to fill me with dread, but I’m beginning to revise my views, much to the delight of my dog-loving boyfriend.
But despite what the studies say, I’d still really like to get a dishwasher before too long, and no microbiome hypothesis is likely to change my mind there. In the words of one of my friends, who is pretty unequivocal about her own household preferences: “Anyone who tells me I need to handwash all my kids’ dishes can get bent.”
This article appeared in print under the headline “Germ warfare”
