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Subscribe to RSSThe very tools we use to battle bacteria and viruses may actually end up 'training' our immune systems to attack allergens. NBC's Dr. Nancy Snyderman reports.
If you’ve been feeling guilty because you can’t keep your house spotless, stop.
As it turns out, allowing the odd germ to flourish here or there just might be saving your kid from a lifetime of allergies, Dr. Nancy Snyderman explained on "NBC Nightly News with Brian Williams" Monday.
It seems counterintuitive, but that’s exactly what the so-called "hygiene hypothesis" suggests. You can actually be too clean for your own good.
Scientists came up with the hypothesis as a way to explain the explosion of allergies and asthma in America’s youth. And what they discovered was intriguing, if a little disconcerting: kids who grow up in less tidy environments end up with a lower risk of developing sensitivities to benign substances, like pollen and dog dander.
A study released in June added to the growing mound of evidence that the too-clean-for-health hypothesis might be on track. That study, published in the Journal of Allergy and Clinical Immunology, found that Amish children who were raised on farms were less likely to develop allergies and asthma than their peers.
Why would exposure to dirt and microbes make a kid less sensitive to pollen and the like?
For one thing, it’s exposure to pathogens that allows the immune system to become fine-tuned as it learns to differentiate between harmful and harmless irritants.
Beyond this, exposure to certain bacteria gives the immune system's dedicated "fighters" something to do.
“I believe that the immune system is like an army,” explains Dr. Samuel Friedlander, an allergist at University Hospitals Case Medical Center in Cleveland. “So, if the army doesn’t have something to fight like microbes, it’s going to fight things like allergens in many cases. People [who] live on farms are exposed to more microbes and as a result the immune system tries to fight those bugs and then, in turn, the body doesn’t have to fight allergens.”
Dr. Richard Gallo puts it a little differently. If you keep your environment too clean – by using too many bacterial soaps and hand sanitizers, for example – then your immune system becomes more sensitized to any irritant that comes its way.
“It’s a change in your allergic set point,” says Gallo, a professor and chief of dermatology at the University of California, San Diego. “So being too clean can lead you to have a high allergic set point that will overreact to the environment.”
Does that mean we can all throw out our mop buckets and soap? No, experts say. We still need to keep things clean, just not Bubble Boy antiseptic.
And there's an interesting side note: Some really intriguing animal studies have shown that you might be able to reset your immune system even after you’ve grown up by exposing yourself to certain types of bacteria.
“Some very recent studies that have been published in very excellent scientific journals have shown that with the introduction of specific bacteria in laboratory animals, you can completely reset their immune status and their capacity for certain allergic responses,” Gallo says.
And keep in mind, experts say, that some bacteria are fairly benign.
“So my advice is that some hygiene is good, too much is bad,” Gallo says. “In many cases you have to use common sense. You’re in a situation where you’re likely to be exposed to pathogens – germs that could cause disease – it’s a better idea to use sanitizers to remove them.
"But indiscriminate use - overusing hand sanitizers, anti-microbial soaps and so forth - is also going to be doing harm. So you have to balance the two.”
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Wow. Next thing you know they'll be saying that quivering in fear, hiding from any exposure to sunlight for years isn't really good for you either.
Basically, I agree, you can have "too clean an environment". However, the other part of the picture that may be confounding to the study is that Amish children have a much cleaner diet and that will also boost the immune system tremendously. The nutrients that we think we are feeding our children are mostly chemical versions of the original foods! If you grew up in a poverty environment and have asthma and allergies the likelihood statistically (read: not ALL kids but many )is that you were exposed to smoking, dust mites and/or roaches, and fed mostly processed foods. Those factors will all contribute to allergies and asthma.
No one is suggesting that you have a filthy home if you don't sanitize endlessly every day. Stop using the chemicals, make your own cleaners. Directions for these are everywhere. I make my own laundry detergent, dishwashing detergent, glass cleaner, air freshener, carpet cleaner, etc. I also suspect the overuse of antibiotics play a role here. They should be prescribed and used carefully and not handed out like candy.
Carlin was right about so many things......
http://straightuptruth.blogspot.com/2006/09/eating-boogers-is-like-really-grody.html
This is ridiculous. My father grew up on a farm, didn't have allergies until he was stationed in Hawaii (sugar cane). My mother grew up with brothers that don't have allergies/asthma but her mom had an auto-immune illness, RA. My mom developed asthma/allergies as an adult, at a time when most cars used lead gas and were not fuel efficient (but there were record numbers on the road as the population increased). She remembers that the smog was so bad that it would burn your eyes and you couldn't see the end of the block. These are the conditions under which she was also pregnant.
My siblings and I did not "outgrow" asthma, rather we grew into it. We had pets. And we did not have brand-name spray-cleaners or air fresheners in the house. The house was clean, not spotless (what house is actually germ free?). And we have something else that none of these researchers consider: All of us spent time outdoors year-around because we were not ALLOWED to bring our friends into the house to play. We literally spent every waking moment of our free time outdoors getting DIRTY. And still we have multiple allergies and asthma.
Now think of what has happened the past 50 years. We have more power plants to serve greater populations (they output mercury, also a player in the contamination of fish and possibly more so to Autism than vaccines). We have more pollution impacting the western US from as a far away as China (where industrial pollution would also appear to be driving an epidemic of asthma). There are more people, 7 billion on the planet and counting, so there is more of everything circulating in our environment --- more flame retardants in furniture, more car tires, more asphalt (living next to major highways has been implicated in asthma and cardiac problems). There are also more children than ever before attending daycare and preschool, thanks to the phenomena of two-income households, than there was some 40-60 years ago. (And this is supposed to be protective, meanwhile we have an epidemic of asthma/allergies take hold during the same time period as early childhood education has become the norm?)
Rather than our world becoming more clean, it is becoming more dangerous. In comparison to 50+ years ago there is more international travel, particularly by air, spreading more pathogens (swine flu, bird flu, SARS, Legionnaires), there is still more drug-resistant bacteria (MRSA, anyone?), a resurgence of food contamination recalls in recent decades (Lysteria, E-coli), more EPA super fund sites (to include municipal water tables), big agriculture pumping antibiotics into livestock (with enough runoff and damming of waterways that most fish in the ocean or fresh water are unsafe for pregnant women), more petro-chemicals dumped on genetically modified crops (with proteins from unrelated biological sources infused in non-related foods, and little to no blocks on the part of the FDA on turning consumers into unwitting lab rats as a result of decades of liberal policies toward DOW chemical and Monsanto (Hello! Now we even have pollinators such as honey bees that are exhibiting compromised immune function, resulting in mass die-offs as a result of "colony collapse disorder"!)
The Hygene Hypothesis is naive on just about every conceivable level. Among the worst, the underlying assumption of scientists that the majority of overworked two-income households have adults residing in them who have ample time by which to spend days spraying Lysol on everything in sight. (That would have been a more believable conclusion in the days when stay-at-home moms were the norm!) If these "researchers" honestly believe our world has become too sanitary to properly to properly challenge our immune systems, I've got a a bridge to sell them...
Medical history really ought to play some role in informing this too-clean-for-our-own-good theory. Native Americans were nearly wiped out, in some cases, by small pox because there was less natural immunity compared to immigrant populations (European pioneers/settlers). Similarly, Native American tribes have suffered higher rates of alcoholism and diabetes, both of which are genetically-predisposed disease processes, presumably because their societies did not evolve in crowded European city/state conditions, where disease was rampant and resistance therefore evolved.
If anything, modern conditions have thrown more at our immune systems than we are evolved over the course of the past 200 years to deal with, thus manifesting as an increase in auto-immune, degenerative disease, heart disease and cancer. The Industrial Revolution, coupled with an upsurge in migration/travel that has allowed both DNA and disease from all parts of the world to converge, most likely has contributed to the hastening of epigenetic changes, which may trigger in the birth mother or even a grandparent, only to impact the health of the child/grandchild (largely as a result of environmental factors, famine, toxins, even stress). This probably has more to do with the upsurge in allergies, Autism and other disorders of the modern era more so than anything the "Hygiene Hypothesis" can ever hope to explain.