Our paediatrician told me that using antimicrobial soaps and over-sanitising our house could give my 4-year-old son asthma later in life. Is he kidding? Grace P.
Bacteria — even disease-causing bugs — are important for good health. The indiscriminate annihilation of those little creatures may deny a young one’s developing immune system the opportunity to meet its adversaries and build its germ-fighting muscles properly.
That’s the so-called hygiene hypothesis in a nutshell: Lack of exposure to some germs weakens the immune system, allowing certain parts to overdevelop unchecked. The result is autoimmune diseases in which immune system cells designed to battle invading bacteria decide, like bored delinquents, that they’ve got to get some action somewhere, and kill off the body’s own healthy cells. That’s what happens in diseases like type 1 diabetes (insulin producing beta cells are killed) and Hashimoto’s (thyroid-hormone producing cells die); and allergic asthma.
As the use of home-cleaning products and soaps containing an antimicrobial chemical called triclosan has gone up in the past 40 years, reported cases of asthma have almost tripled. Now researchers at Johns Hopkins have found a significant association between children’s allergies and exposure to antimicrobial agents in toothpastes, soaps and cosmetics. One other downside of our bug-killing spree and antibiotic overuse is the altered balance of our intestinal bacteria that evolved over centuries to help protect our bodies.
What’s the solution? Soap (without anti-bacterials) and water is just as effective at killing bacteria as fancied sterilisers. Unlike antimicrobials that may trigger antibiotic resistance, soap does its job and the battle is over, until the next time you need to wash your hands.