Being Too Clean Can Make People Sick 333
An anonymous reader writes "Young people who are overexposed to antibacterial soaps containing triclosan may suffer more allergies, and exposure to higher levels of Bisphenol A among adults may negatively influence the immune system, a new University of Michigan School of Public Health study suggests (abstract, full paper [PDF]). Triclosan is a chemical compound widely used in products such as antibacterial soaps, toothpaste, pens, diaper bags and medical devices. Bisphenol A is found in many plastics and, for example, as a protective lining in food cans. Both of these chemicals are in a class of environmental toxicants called endocrine-disrupting compounds, which are believed to negatively impact human health by mimicking or affecting hormones."
Yawn (Score:5, Interesting)
It's not new that our immune system has to be trained to work well. And only some kind of idiot doesn't make the link that keeping the kids away from every source of infection must result in an inferior immune system. Where's the news here?
Marketing Gone Wrong (Score:4, Interesting)
I place a lot of blame on the marketing people for this. Soap manufacturers were the first. Despite the fact that soap already kills like 99% of the germs on contact, soap marketers started dumping stuff like triclosan into their products to tout their "antibacterial effects". Now triclosan and its ilk are in everything and everyone must have it, even if it's completely pointless. Seriously, do we really need triclosan covered toothbrushes? Has anyone in the past 100 years really gotten sick because of their toothbrush?
Correlation != Causation (Score:1, Interesting)
Sounds like another possible confirmation of the hygiene hypothesis and the increase of autoimmune diseases and allergies.
I suspect those that use triclosan and BPA would tend not to live with farm animals, eat dirt and be exposed to parasites.
Would be interesting to get some cross referencing to see exposure to these elements is causal or additive to the hygiene hypothesis' supposed imbalances in the immune system which would do these all by itself.
Wake up and read (Score:1, Interesting)
It's not new that our immune system has to be trained to work well. And only some kind of idiot doesn't make the link that keeping the kids away from every source of infection must result in an inferior immune system. Where's the news here?
Except that this proves almost the opposite. It's not that their immune systems are not working; it's that, in the absence of real targets (bacteria) the immune system is targeting harmless compounds (allergens.)
Which is why.... (Score:1, Interesting)
I only shower once every 4 days. I also only eat one large meal per day... Some days I even skip eating! However, I have a perfectly healthy weight for my height (~140-150lbs, 5'8"), and for some reason I hardly ever smell bad. Correlation?
Re:Yawn (Score:2, Interesting)
'Antibacterial' soap kills almost no bacteria that regular old soap doesn't. It is a marketing term that means nothing in the world of reality because soap itself destroys most strains of bacteria on contact. Therefore, this is something more going on here than just "not enough germs weakens immune system". The actual article is about possible negative effects that some chemicals, including Triclosan which is one ingredient used to make 'antibacterial' soap, have on the immune system.
Re:Anti-bacterial soap will kill you all. (Score:5, Interesting)
My kids will turn on the taps, wait, and then turn the taps off just to avoid washing their hands. I was asking why the towel wasn't damp and they started rinsing their hands. Pests.
I stopped caring about germs. I bike to work, I exercise at the Y (26 minutes ago, excellent!), I have one kid in school and one in daycare, I SCUBA dive in the ocean (we discharge screened sewage here), and I eat at a pub about once a week on average. (the chefs there don't exactly use antibacterial soaps...) I've had someone puke in my mouth. (My daughter; she was very young and the game was very high.) Normal germs don't stand a chance in my body.
I licked my keyboard while I was posting this. I'm not afraid of germs.
OTOH (Score:1, Interesting)
Not using approved hand washing procedures (including soap) will get you fired.
And alcohol based hand sanitizers dry your skin out too much.
Re:I've suspected this for years. (Score:3, Interesting)
Actually, it's quite harmful to living cells, especially when they aren't in a supportive environment. Your hands aren't harmed because they're protected by a layer of dead cells and under that there IS a supportive environment.
Bacteria are about as likely to evolve resistance to anti-bacterial soap as we are to evolve resistance to being run over by a bus.
Re:I've suspected this for years. (Score:5, Interesting)
Except instead of your "hey wouldn't it be totally ironic if anti-bacterial soap made people SICKER!!??" observation, they have identified Triclosan and Bisphenol A as an endocrine disruptor with the specific function of inhibiting the immune system not by protecting it from exposure or selectively breeding resistant germs (the two popular "well duh" observations here) but by actually inhibiting the effectiveness of the immune system. Knowing this, as opposed to say "knowing that for sure, antibacterial soaps are totally bad because they don't let your body *learn* about bad germs!!!" is what leads to advances in medicine and pathogen control.
I'm not a doctor but I appreciate what they do.
Let's not get hasty here. They took some data previously collected:
Methods: Using data from the 2003-2006 National Health and Nutrition Examination Survey, we compared urinary bisphenol A (BPA) and triclosan with serum cytomegalovirus antibody levels and diagnosis of allergies or hayfever in US adults and children age 6 years. We used multivariate ordinary least squares linear regression models to examine the association of BPA and triclosan with cytomegalovirus antibody titers, and multivariate logistic regression models to investigate the association of these chemicals with allergy/hayfever diagnosis. Statistical models were stratified by age (
Then ran a series of statistical tests to see if there were any correlations between the body burden of BPA and triclosan and putative proxies for immune function (CMV titer and hayfever diagnosis).
They "adjusted" for a bunch of variables and come out with a correlation between the markers and their effects. They then go on to state that the chemicals may depress immune function.
It may be true but this sort of analysis is prone to a host of problems - poor data collection, poor data analysis, over correlation by the statistical software and god knows what else by the statistical software (disclaimer - I've only read the abstract, I don't know exactly how they did it but unless they have a very good statistician looking over their shoulders, they open to making any one of a number of mistakes).
And of course, our favorite logical fallacy: Correlation implying Causation. Specifically, the charge that the endocrine disruption mechanism of BPA and Triclosan is the cause of the immune changes is not addressed at all. It's simply assumed.
Unfortunately, this is like the vast majority of the literature in these areas. Because good science is so hard to do, we gets lots of these little studies that may or may not mean much of anything. They're fine, it's the way we have to do things, but don't flush all of the soap down the toilet.
Clean vs. Unclean (Score:2, Interesting)
Re:Yawn (Score:3, Interesting)
Er. Detergents also destroy bacteria.
You know all those stories recently of growing organs? In many cases they just plop an organ into a detergent bath, let the cells be dissolved, then grow the new organ on the collagen scaffold.
Another example.
You can use ordinary dish soap in DNA extraction.
Emulsification of cell membrane lipids appears to be the term.
People have lost how to do hygiene properly. (Score:4, Interesting)
And then we're not being too clean, we're just cleaning the wrong way, the wrong things, the wrong time.
My understanding of the hygiene-hypothesis and modern auto-immune disorders is that its nothing to do with the over use of sanitation products, and more to do with we don't spend enough time outdoors in the natural environment which our immune system seems to need to be calibrated by. Instead of contact with environmental bacterial, dust, spores, we're exposed to artifical chemicals in our indoor environments and food/water and our immune system gets the wrong idea about what to fight.
I'm disturbed by the lack of handwashing in the general population. Almost nobody remembers to wash their hands before they eat, barely do it after visiting the bathroom, and it certainly never happens when your eating out. Blame fast food which is "finger food" to some extent. Some kids these days don't know how to use a knife and fork let alone name vegetables and fruit. Some are genuinely perplexed by the need to wash hands before handling food - and don't really grasp the reasons why - from experience managing a food kitchen.
Previous generations were much more fastidious about washing and scrubbing themselves and everything, perhaps because before antibiotics it was the only defence against the spread of pathogetns. Perhaps because these people had deadly global flu pandemics in living memory.
It's ironic that we are both over using antiseptic compounds where they aren't needed, poisoning ourselves, and not cleaning when it actually is needed to prevent the spread of potentiall deadly pathogenics (salmonella, campolybacter, hepatitis A, influenza and many more). Virtually all human to human or human to food transmission of this stuff is due to some dim wit not washing his hands after taking a dump. Influenza is weakly spread airbone, but strongly spread by touch.
Re:Anti-bacterial soap will kill you all. (Score:3, Interesting)
The soap's main deadly effect is to breed antibiotic resistant super-bacteria. These bacteria will not discriminate against those of us smart enough to avoid overuse of antibiotics.
Anti-bacterial and antibiotic are not synonyms. The "main deadly effect" you're concerned about is not a result of anti-bacterial soap, it's a result of people misunderstanding basic science but thinking they still have a valid opinion.
Re:Marketing Gone Wrong (Score:4, Interesting)
Re:I've suspected this for years. (Score:3, Interesting)
But note that such bacteria have not taken over the planet. That's because there's a biological price to be paid for the resistance that limits their viability in less hostile environments.
Note that c-diff can be wiped out by discontinuing antibiotic treatment, that is, by allowing less resistant bacteria to compete it to death.
We won't evolve to resist being run over by a bus because there are far too many compromises to be made for that that would limit our viability whenever we're not being run over.
It wouldn't help much anyway since the hard exoskeleton would make us much heavier and so require bigger heaver buses. :-)
MOD PARENT DOWN (Score:3, Interesting)
Conventional wisdom has once again survived the onslaught of someone with just enough information to draw the wrong conclusion. You seem to have discovered that ordinary soap doesn't kill bacteria. Great, but that's not what soap is used for.
Pathogens are typically transmitted in droplets of fluid or on the surface of small particles. (Soap won't help with a direct exchange of fluids, either with parasites or members of the same species.) Washing removes pathogens by removing the foreign matter in which they are present on the surface of the skin. Further, only the skin's outermost layer of dead, keratinized cells and oil is directly exposed to bacteria. Ordinary washing with ordinary soap removes a portion of these dead skin cells and sebum, taking a percentage of surface bacteria with it.
You're "magically clean" after washing because there are less bacteria present. It's not necessary to kill that which can be easily removed.