Those mud pies were actually good for you.

November 6, 2007 6:11 PM

Have You Eaten Your Dirt Today, Honey? A New Approach To The Hygiene Hypothesis. The hypothesis argues: The reason why there is so much asthma, eczema, allergies and maybe even childhood diabetes in the modern world is because we — well infants really — live in too clean a universe. What our baby immune systems need is a kickstart by exposure to viruses, bacteria, worms, pollutants and so on. If you don’t get an infant hit from these icons of uncleanliness, the immune system goes haywire and your body over-reacts to all sorts of invasive things that normally could be ignored. Via.

More information on the Hygiene Hypothesis:

Are We Too Clean For Our Own Good? (2004)

Hygiene Hypothesis from PBS' Evolution series (2001)

Modern Hygiene's Dirty Tricks (1999)

Hygiene Hypothesis on Wikipedia

posted by amyms (96 comments total)

I've always thought that was kind of the case, but I'm not sure I would want to expose an infant to worms.
posted by delmoi at 6:14 PM on November 6, 2007

My 75 year old crank of a mother has been saying this for as long as I can remember. She doesn't have either an M.D. or an advanced degree in immunology so far as I know.
posted by psmealey at 6:16 PM on November 6, 2007

Yes, this always made sense to me. It seems the people I know with the most allergies & illnesses are the ones whose mothers were the most protective of their children with regard to germs. I always let my kids play around in the dirt (I don't think they ate worms...) and they are quite healthy.

Of course, it could be coincidence.
posted by MtDewd at 6:20 PM on November 6, 2007

There have been discussions about this idea in the Blue before.
posted by suckerpunch at 6:20 PM on November 6, 2007

One of my friends, growing up, had a mother who would make me take a shower when I showed up to play, even if we were going out riding our bikes. He now has more weird infections - foot rot that put him in bed for two weeks, monthly ear infections - than any five other people I know. His older brother is apparently the same way. We both blame his mother.
posted by notsnot at 6:21 PM on November 6, 2007

I've always used this as a somewhat joking excuse for my indifferent housekeeping, and pointed to the fact that my kids get sick way less often than their friends and schoolmates.

On the other hand, it could just be genetic: my kids could have inherited my iron-clad constitution, just as I inherited my mother's homemaking style, and on back through the ages, really. I'm from a long line of really healthy but kind of sloppy stock.
posted by padraigin at 6:21 PM on November 6, 2007

I've heard mention of this here and there, from some friends, acquaintances and family members, and it seems to me, on the face of it, that these theories probably have validity. This, plus over-medication from a very early age (everytime junior gets a sneeze or a sniffle he's whisked to the doctor for antibiotics) is almost certainly contributing to the weakened immune system problems we're seeing.
posted by flapjax at midnite at 6:23 PM on November 6, 2007

My wife does have an MD, and she feels exactly the same way.
posted by 1adam12 at 6:24 PM on November 6, 2007

New? Hardly. Geophagy: a vestige of palaeonutrition? (pdf)
posted by furtive at 6:25 PM on November 6, 2007

Every so often, I call up my mother and thank her for letting me crawl around on the ground and eat bugs when I was wee.
posted by TheGoldenOne at 6:29 PM on November 6, 2007

Ah. I always wondered why people in Western countries seem allergic to everything, whereas allergies are relatively rare in the developing world.
posted by pravit at 6:29 PM on November 6, 2007

Standard folk wisdom round our way too, and I remain the type to pick up dropped food, give it a quick dust-off and keep scoffing. Never been ill in my life. It's science! Well, it's an anecdote.
posted by Abiezer at 6:31 PM on November 6, 2007

flapjax said: This, plus over-medication from a very early age (everytime junior gets a sneeze or a sniffle he's whisked to the doctor for antibiotics) is almost certainly contributing to the weakened immune system problems we're seeing.

Absolutely. The misuse of antibiotics is a very big deal.
posted by amyms at 6:32 PM on November 6, 2007 [3 favorites]

Beyond the debate about whether or not bathing infants in bacteria is good, the other thing that struck me as, well, interesting was the idea of parents using weblogs to report findings in a "clinical trial". It's cute and all, but surely it would lead to wildly inaccurate reporting. A good way to change patterns of everyday decision-making is to make people conscious of those decisions - asking for them to be remembered and recorded would probably skew things even further from the truth.
posted by bunglin jones at 6:36 PM on November 6, 2007

It's common folk wisdom that a bit of dirt will help build up kids' immune systems. And it makes sense from an evolutionary perspective that babies need to be thrown in the deep end if they're to survive the germ-ridden world outside the womb. But the problem with applying that to modern developed societies is that the high infant mortality that accompanies the "trial by fire" approach to the immune system is unacceptable to most of us. Comparing infant mortality rates may also help explain pravit's observation about the lack of sickly people in developing countries: it's not the case that everyone there grows up healthy because of exposure to dirt (and/or worms), but rather, the subset who survive exposure are the healthy ones.
posted by nomis at 6:36 PM on November 6, 2007 [8 favorites]

Word. Grant Morrison's The Filth is a surreal and pornographic take on this idea at a cultural level.
posted by papakwanz at 6:37 PM on November 6, 2007

Heck, while we're doing that let's open up those sewers and put the pump handle back on. Then we'll all be supermen!

I got to the end of the article and was stunned. The idea of using a blog as the basis for this kind of incredibly multi-factor experiment seems like a bad idea.
posted by Mercaptan at 6:39 PM on November 6, 2007

yep. i'm fucking FILTHY most of the time. i work outside a lot, and my housekeeping makes 'lackluster' look like martha fuckin' stewart. last time i had cold? 4 1/2 years ago.
posted by sexyrobot at 6:43 PM on November 6, 2007

It definitely sounds like there's an element of truth to the idea.
posted by drezdn at 6:44 PM on November 6, 2007

I have always believed in the conventional wisdom that it's good for kids to get dirty, and to be exposed to germs, in their normal daily environment. It's interesting that it's become an issue of scientific study, but I'm not sure the research can produce any concrete results, especially in light of my own experience...

My kids were exposed to their fair share of dirt and dust as infants and toddlers. They regularly played outdoors, and traded sniffles and germs with the other children in our neighborhood. I was not an "over-protective" mother in those areas, but my daughter developed juvenile diabetes at age 4 and my son developed life-threatening food allergies at age 2. I've come to the conclusion that these things were going to happen no matter how they were raised, but who knows?
posted by amyms at 6:45 PM on November 6, 2007 [2 favorites]

Kids today. GET ON MY LAWN!
posted by DU at 6:45 PM on November 6, 2007 [12 favorites]

it's not the case that everyone there grows up healthy because of exposure to dirt (and/or worms), but rather, the subset who survive exposure are the healthy ones.

seriously. People are forgetting that those drugs weren't initially developed just because people were bored or something. There were downsides to the natural system, even though it works well enough on a species-wide basis.

I suppose the key is making the natural system work as hard as it possibly can for us, and then stepping in with our assistance only when necessary, so as not to weaken the natural system. The problem is knowing when it's necessary to step in ourselves - nature doesn't always make it clear ahead of time, though I think we're getting better at making these judgments.
posted by mdn at 6:45 PM on November 6, 2007

What I meant is that I wouldn't want to expose an infant to parasitic worms. In my mind "bacteria, viruses, and worms" means worms that can infect humans.
posted by delmoi at 6:47 PM on November 6, 2007

There's a probiotic called "Primal Defense" that has "Homeostatic™ Soil Organisms"- i.e. dirt.

It helps immensely with my food allergies
posted by bhnyc at 6:47 PM on November 6, 2007

mdn - nobody is talking about throwing sick people to the wolves or whatever. We're talking about not trying to keep kids an an antiseptic bubble.
posted by Justinian at 6:49 PM on November 6, 2007

New Dirtalin™ for children, standardized 300mg caplets.
"Because crapping in your pants isn't enough"
posted by kuujjuarapik at 6:51 PM on November 6, 2007 [2 favorites]

I'm pretty willing to take this at face value, even though my own family might be a bit of a counterexample. My mother was a neat freak when my brother and I grew up, but I'm more or less free of all the things that affect him - asthma, allergies, he even had scarlet fever as a kid which I thought went the way of polio.

Granted, I did get pneumonia, salmonella poisoning, and more cases of bronchitis than I can remember, but never had any lingering effects from them. Having chicken pox and poison ivy at the same time was fun, too.
posted by backseatpilot at 7:14 PM on November 6, 2007

Nomis reminded me of an anecdote from a friend who lived in Indonesia for many years: one of their household employees was a woman who was considered remarkable because none of her many children had died in infancy. She said that her secret was to keep them in a hammock for the first 7 months of their life, never letting them touch the ground. Presumably in a typical lower-class Jakarta home, there's enough dirt blowing around that even a baby suspended in midair will get exposed to enough crud to trigger a healthy immune response without totally overwhelming the little tyke.

There's undoubtedly an optimum amount of dirt to expose a kid to, but there's always a tradeoff. I'm too lazy to look up a reference now, but it's been well known for years that polio infections were far more common in "clean" countries than in places where kids rolled around in the dirt picking up all sorts of other diseases. Polio or hookworm, ringworm, dysentery, ... I guess you pays your nickel and you takes your choice.
posted by Quietgal at 7:16 PM on November 6, 2007

So now I can be GLAD that I just ate a quesadilla I dropped on the floor?
posted by obvious at 7:32 PM on November 6, 2007

obvious said: So now I can be GLAD that I just ate a quesadilla I dropped on the floor?

Garnish it with a worm or two, and you'll be good to go.
posted by amyms at 7:38 PM on November 6, 2007

I grew up in a vacuum. Never got sick.

Sneezed a lot.
posted by hal9k at 7:39 PM on November 6, 2007 [2 favorites]

As someone who was once forced face-down into a pile of goat poop (long, dull story that ends with me losing), I'm grateful to that bully for boosting my immature immune system. Haven't been sick a day in my life.

*knocks on wood*

Coprophagy: it's what's for breakfast!
posted by BitterOldPunk at 7:43 PM on November 6, 2007 [1 favorite]

I lived in a pigsty when I was a kid and played in the dirt all the time. That is, when I wasn't really sick with ear infections and sinus problems.
posted by goatdog at 7:50 PM on November 6, 2007

Saying that our immune systems will thrive in a sterile environment is like saying that our muscles will grow strong without exertion.

"You eat a pound of dirt before you die" my mom says (quoting her mom).
posted by McLir at 7:54 PM on November 6, 2007

Let the cookies hit the floor. Let the cookies hit the floor.
posted by Ambrosia Voyeur at 8:07 PM on November 6, 2007 [6 favorites]

Clean-crazed parents or not, it doesn't make a difference. Kids are little petri dishes.

I hardly ever got colds before I had kids. Now, I can't tell when one stops and another one starts. And there's not a damn thing I can do about it, short of keeping 'em caged.
posted by fungible at 8:11 PM on November 6, 2007 [1 favorite]

This theory sounds great, except that my mum has allergies and grew up in the countryside, certainly not the sterile environment portrayed in this story.

I wonder how many of these "hypotheses" are written by the powers-that-be, wanting to distract everyone from rampant air and water pollution that sicken otherwise healthy people.

In particular, you'll find a lot of the "white northerners" in this hypothesis in industrial zones, or areas otherwise affected by this type of pollution.
posted by Blazecock Pileon at 8:16 PM on November 6, 2007 [1 favorite]

There is an interesting study on exposing kids from the developing world to peanut butter. Peanut butter is an excellent food for malnourished kids because of it's high protein and fat content. The incidence of anafalaxis is almost nil.

We have good friends who are ANAL++ regarding cleanliness, their kids are always sick. We're comparatively slobby, ours and us are never ill. We have pets.
posted by mattoxic at 8:27 PM on November 6, 2007

Natural exposure to microbes through the pathways of our body that are made for that - mouth, nose, skin - is good, I agree. The corollary to that is that unnatural exposure that bypasses that - immunizations - may have problems that are being overlooked.
posted by BinGregory at 8:34 PM on November 6, 2007

OMG, I'm going to agree with Blazecock Pileon.

It wasn't that long ago that we were all talking about asthma and cockroaches. Now dirt is supposed to be good for you?

There is an interesting study on exposing kids from the developing world to peanut butter. Peanut butter is an excellent food for malnourished kids because of it's high protein and fat content. The incidence of anafalaxis is almost nil.

I saw a similar report about Plumpynut, a peanut-based food used for famine relief. While I'm sure mild allergic reactions are over-reported in the U.S., you have to wonder if mild allergic reactions are under-reported in Third World countries.
posted by Cool Papa Bell at 8:36 PM on November 6, 2007 [1 favorite]

mattoxic said: There is an interesting study on exposing kids from the developing world to peanut butter. Peanut butter is an excellent food for malnourished kids because of it's high protein and fat content. The incidence of anafalaxis is almost nil.

One of the many foods my son is allergic to is peanuts (and all members of the legume family). He had two episodes of anaphylaxis before he was finally properly diagnosed. The incidence of peanut allergy is increasing in the developed world and there are many theories as to why, but I don't think a too-sterile environment is one of them.
posted by amyms at 8:40 PM on November 6, 2007

My anecdotal evidence meter is on high. I grew up in often not clean conditions, with pets of all sorts. I remember being treated for worms in first grade, apparently which I caught from the sandbox or a cat. (Either way, eww.)

No one likes to think of themselves as sickly, but I am. I'm the first one to go down with a cold in my family and at work, and I'm likely to have it the longest. I have weird food and fragrance allergies.

So, dirt=healthy? Not for me. Or maybe I'm just one of those kids that would have been a childhood mortality statistic if it weren't for MediCal.
posted by Gucky at 8:40 PM on November 6, 2007

More anecdotal and professional IMO!

My father, a doctor, a half a century ago, encouraged us to eat food we'd dropped on the floor specifically to build up our immune systems.

Has it worked? I don't know, but none of his six children get sick very often. I take a sick day once every few years. (And a mental health day once or twice a year.)
posted by kozad at 8:42 PM on November 6, 2007

I wonder when the now-ubiquitous bottles of purell will need to be reformulated to combat the germs they are helping to evolve. I also used to chew gum that I found on the ground so maybe I'm not the expert here.
posted by autodidact at 8:47 PM on November 6, 2007 [1 favorite]

What the hell are all you people talking about?

None of these articles are talking about the immune system being "boosted" by exposure to pathogens, they're talking about the immune system being less likely to overreact to otherwise benign foreign substances or the body's own cells, if it's exposed to certain pathogens/stuff at a critical period
posted by 517 at 8:50 PM on November 6, 2007

Nomis reminded me of an anecdote from a friend who lived in Indonesia for many years: one of their household employees was a woman who was considered remarkable because none of her many children had died in infancy. She said that her secret was to keep them in a hammock for the first 7 months of their life, never letting them touch the ground. Presumably in a typical lower-class Jakarta home, there's enough dirt blowing around that even a baby suspended in midair will get exposed to enough crud to trigger a healthy immune response without totally overwhelming the little tyke.

Or perhaps her kids were simply not infected with the various parasitic worms that are incredibly common in tropical regions, since they weren't crawling around on the ground.
posted by desuetude at 9:10 PM on November 6, 2007

they weren't crawling = the kids weren't. The worm larvae, of course, were indeed crawling on the ground.
posted by desuetude at 9:11 PM on November 6, 2007

My son has most of the big allergies -- peanuts, tree nuts, dairy (might be outgrowing) and eggs (almost outgrown). Plus dustmites, mold and cats, just for fun and a permanent sniffle problem.

I don't keep a clean house (I'm a packrat with a clutter problem), don't believe in antibacterial soaps, and had a roommate with cats in the house who moved out just after he was born, so there was plenty of cat dander around the house.

He puked and got hives after a taste of yogurt at 8 months old. That also explained his eczema and crankiness from when he was a newborn until I stopped eating dairy. So basically, he was born allergic to dairy, and probably peanuts, too.

Apart from rampant pollution as a cause, I also want someone to research if there's a correlation between smoking and allergies. Our parents were the first generation to have unfettered access to cigarettes. (The generation before them was the war generation; the one before that wasn't exposed to smoking as an incessant social activity.)

Oh, and as a followup to the peanut allergy, the British government is reversing its advice to avoid peanuts in pregnancy: "It is quite striking that the increase in peanut allergies is rather in step with the increasing Government advice not to expose tiny children to them."

But for what it's worth, here's my experience:
* peanuts -- I avoided, and he's allergic
* cashews -- ate them, and he's allergic
* almonds -- ate them, and he's NOT allergic
* milk -- drank TONS, and he's allergic
posted by wenat at 9:16 PM on November 6, 2007

More anecdotal... My siblings and I literally had a giant pile of dirt for a playground. This pile of dirt was supposed to fill in a low area in the yard, but once it was there... we played on that pile of dirt for ages. Plus lot's of running around in 'the woods' around the house. When my parents divorced, "wow, the new house has a low place in the yard, you'll need some dirt."... I literally had a 10 ft. high pile of dirt for a playground most of my life (it's totally awesome to have a giant pile of dirt to play with your Tonka trucks).

I was accident prone as a kid, I have burn scars, and stitch scars on every extremity. But not sick much, except for a couple of ear infections (we also always had a pool in the back yard).

I was homeless for a while, living under freeway off-ramps and lucky to bathe once a month. Still I can't remember the last time I was 'sick' (except for that food poisioning incident when I ate something from the 'fridge that I shouldn't have... spewing out both ends for a couple of hours). But I can't recall anytime in the last 15 years or so when I was actually sick.... Otherwise, I'm sick at least one day per month because "use them or loose them" sick days at work.

So, I either inherited some anti-sickness genes from my parents, or I'm in the "let your kid eat dirt" camp.
posted by zengargoyle at 9:17 PM on November 6, 2007

See also: Spillage in aisle 29561 — sporks at the ready!

grumblebee: Hi, honey! What's for dinner?
mrs. g: Casserole.
g: What's in it?
mrs. g: Oh, this and that.
g: (thinks to himself) But she hasn't been shopping in days....
* DUH DUH DUHHHH!!!! *

posted by rob511 at 9:24 PM on November 6, 2007

The New York Times had an article related to this recently.
posted by gudrun at 9:37 PM on November 6, 2007

Apart from rampant pollution as a cause, I also want someone to research if there's a correlation between smoking and allergies. Our parents were the first generation to have unfettered access to cigarettes. (The generation before them was the war generation; the one before that wasn't exposed to smoking as an incessant social activity.)

Indeed, we should consider grandparents' behaviors, allergy incidence rates and epigenetic factors.

Basically, this hypothesis is too simple and anecdotal to be useful or correct.
posted by Blazecock Pileon at 9:47 PM on November 6, 2007 [2 favorites]

I also want someone to research if there's a correlation between smoking and allergies

I bet there is. However, I think the causality goes like this: The more obsessively anti-smoking a person is, the more likely they are to attribute any disorders their children experience, both real and imagined, to smoking-related allergies.
posted by PeterMcDermott at 11:43 PM on November 6, 2007

'"You eat a pound of dirt before you die" my mom says (quoting her mom).'

Hell, I ate a pound of dirt before I was 8! (Why? I don't know)
posted by The Light Fantastic at 11:46 PM on November 6, 2007

There is some pretty stupid shit being said in this thread. It should be apparent to any rational adult that the biggest threat to a child's long-term health and wellbeing are their retarded I-ate-dirt-as-a-kid parents.
posted by ogre at 12:47 AM on November 7, 2007

Well I've always believed there is an element of truth in the old wives tale that what doesn't kill you makes you stronger.

Obviously, everything in moderation.

Ogre, has it not been your experience that parents obsessed with cleanliness and keeping their children super clean bring up the weakest children? That's certainly been my experience. Mollycoddling is so detrimental to your kids.
posted by twistedonion at 1:16 AM on November 7, 2007

the people I know with the most allergies & illnesses are the ones whose mothers were the most protective of their children


Well, of course. If your child had allergies & illnesses all the time, wouldn't you be more likely to be protective? Correllation does not equal causation.

More anecdotal evidence: my father is from a very remote part of Guatemala. He never had allergies until he came to the US. Perhaps it has something to do with pollution, since he's a factory worker?
posted by honest knave at 1:20 AM on November 7, 2007

And it makes sense from an evolutionary perspective that babies need to be thrown in the deep end if they're to survive the germ-ridden world outside the womb.

What? No it doesn't. That's not how evolution works.
posted by grouse at 1:29 AM on November 7, 2007

Well, of course. If your child had allergies & illnesses all the time, wouldn't you be more likely to be protective?

Well maybe you could put it down to poor genes, but that's one hell of a co-incedence that over zealous parents just happen to have the weakest children.

In some cases it may be the over protectiveness that causes the allergy and illness. Obviously you must never over generalize.
posted by twistedonion at 1:52 AM on November 7, 2007

Let's reset some misconceptions

1. if it is natural and the way it has always been, doesn't imply it is good for you . Example: influenza virus is natural, can kill you with certain conditions
2. regular exposure to minimal doses of allergen may desensitize you (over a long time) , but may also kill you immediately (Anaphylactic shock can kill in minutes)
3. pollution by industrialization ? Could be. A interesting study could focus on incidence of allergies in far less polluted countries or in countries in which there is still not much access to privatized industrialized food production
posted by elpapacito at 2:02 AM on November 7, 2007 [1 favorite]

that's one hell of a co-incedence that over zealous parents just happen to have the weakest children.

First, it wouldn't be an interesting coincidence at all, for the reasons honest knave points out. Second, I don't think there's any proof that overzealous parents tend to have weaker children, only anecdotes.
posted by grouse at 2:23 AM on November 7, 2007

3. pollution by industrialization ? Could be. A interesting study could focus on incidence of allergies in far less polluted countries

You'd have trouble accounting for the fact that "less polluted" correlates with "less developed" which correlates with "less likely to have infants and small children living in more antiseptic environments".
posted by Justinian at 2:45 AM on November 7, 2007

Second, I don't think there's any proof that overzealous parents tend to have weaker children, only anecdotes.

Fair enough, I'll wait and see if future research supports my own belief that this sanitized life is doing us as much harm as good. I don't support (and I doubt that anyone does) the notion that living in filth is good.

My problem is parents who shower their kids 4-5 times a day, wrap them up in bubbles, freak out at the tiniest cut or bump, won't let their kids play outside... child abuse imo.
posted by twistedonion at 2:50 AM on November 7, 2007

Well I've always believed there is an element of truth in the old wives tale that what doesn't kill you makes you stronger.

Wow. Friedrich Nietzsche was just cribbing from folk wisdom with "Was mich nicht umbringt, macht mich stärker." Who knew?
posted by pax digita at 3:06 AM on November 7, 2007

I was one grubby kid (rolled in the mud, ran around in the woods, mucked about in the stream) and I have asthma and get the usual colds. I was lucky, though, to be in the (overall) hygienic US because I avoided parasites for the most part (I did get chiggers) and feces-spread illnesses, and managed not to lose any fingers, limbs or eyes.
posted by Peach at 3:18 AM on November 7, 2007

woah woah woah, y'all...allergies are VERRRY different than germs (bacteria, viruses, etc), as allergens aren't living things.
a lot of allergies (or a tendency to be affected by allergens) tend to be genetic...my mother and i are allergy free, but my dad is allergic (severely) to cats, and my sister to shellfish...

allergies can be weird in that you can get them from either overexposure (my sister ate tons of shellfish very early on...being raised in new orleans at the time) or from strange new things in your environment...usually in conjunction with other stuff going on with your immune system...like honest knave's father...it was probably while his immune system was getting used to the GERMS here that it assumed that some allergens were germs, too. the trouble is, since allergens aren't alive, they can't be killed...but damned if your immune cells aren't gonna try...the symptoms of allergies don't come from them actively making you sick...it's just you body over-reacting to their presence...once the body flushes the allergens out, you're generally fine...
posted by sexyrobot at 3:36 AM on November 7, 2007 [1 favorite]

and oh yeah, stay away from worms. worms are bad. (not earthworms...those are fine)
posted by sexyrobot at 3:42 AM on November 7, 2007

Parasite Rex, by Carl Zimmer, makes this argument, suggesting that having a moderate load of parasites gives your immune system something other to do than develop auto-immune conditions. It's a great book, and will make you wonder what might be living inside your brain.

I think a moderately dirty environment is good, particularly if it isn't that closed-in, dusty and skin-mite filled indoors kind of dirt that cluttered houses in cold places get. But there is a balance point between suggesting that playing in the dirt is good, and acknowledging that the public health gains in building sewage systems and developing antibiotics are very real and save untold millions of lives. I have known several hippy families who like in rural places, and who assert that germs don't really exist, and that therefore they don't need to worry about protecting their water sources from fecal contamination. Guess who is always getting giardia and worse?
posted by Forktine at 3:44 AM on November 7, 2007

allergies are VERRRY different than germs (bacteria, viruses, etc), as allergens aren't living things.

Some allergens are alive (such as molds), and viruses aren't. And many of the symptoms of non-allergic infectious diseases are also caused by the immune system.
posted by grouse at 3:56 AM on November 7, 2007

This century, the reduction in child (and adult) mortality from all kinds of infections thanks to improved hygiene is truly astonishing. Saying "kids eat dirt" is great, but the first time Jr picks up a severe case of salmonella, ETEC, or dysentery you'll probably make him stop putting random shit in his mouth.
posted by a robot made out of meat at 4:28 AM on November 7, 2007

"You eat a pound of dirt before you die" my mom says (quoting her mom).

Peck of dirt was the phrase I've always heard. And many before me if the link is to be believed.
posted by IndigoJones at 5:33 AM on November 7, 2007

My siblings and I literally had a giant pile of dirt for a playground.


You lucky bastard!
posted by DreamerFi at 5:55 AM on November 7, 2007

Pretty anecdotal subject. I got pretty dirty as a kid and my mom was an indifferent housekeeper; I had a lot of problems with allergies and sinus infections. As an adult I stay pretty healthy though; I haven't had the flu in over 20 years or a bad cold in about 5 years. My brothers have a similar experience so I think it's genetic. My wife is constantly sick it seems; she points out that my brothers and I were all breastfed while she was not. This might account for the lower incidence of observed childhood allergies in non-western countries. My theory is that kids nowadays get exposed to a lot of chemicals and junky foods that my generation wasn't exposed to. As far as the anal parenting, methinks they overreport mild health problems.
posted by coldhotel at 6:20 AM on November 7, 2007

And it makes sense from an evolutionary perspective that babies need to be thrown in the deep end if they're to survive the germ-ridden world outside the womb.

Your reasoning does not make sense. Evolution (and/or natural selection) is not what you think it is. You should read more.
posted by OmieWise at 6:58 AM on November 7, 2007

Our parents were the first generation to have unfettered access to cigarettes. (The generation before them was the war generation; the one before that wasn't exposed to smoking as an incessant social activity.)

I'm not sure where you're getting your information, but I think you are certainly wrong about the "unfettered" relative nature of smoking in the boomer generation. Smoking was very prevalent for most of the 20th century in the US.
posted by OmieWise at 7:04 AM on November 7, 2007

"You eat a peck of dirt before you die." My college roommate said the same, but always following it with, "Why not eat yours now?"
posted by cairnish at 7:43 AM on November 7, 2007

Just to be contrary. Neither of my parents ever smoked, our house was moderately clean but not overmuch, I was breastfed, I played in dirt and on a farm and was quite an outdoor kid. However, I am also allergic to damn near everything with fur or feathers. I have asthma and so many freaking sinus infections over my 30 mumble years that I've lost count.

Despite all that, I was never restricted in my access to animals. I showed horses (one of my biggest allergies), I had cats and dogs and rabbits, and although I'm allergic to milk, I drank it a great deal.

I'm fortunate that none of my allergies are life threatening, they merely cause sneezing, hives, and some wheezing. I manage them. They don't manage me. As an adult I smoke, I have two indoor cats and two dogs. And I'm the office canary. If I get sick, everyone in the office knows that the next illness is on its way. I'm usually well by the time everybody else comes down with it. It's just life.

Basically it comes down to some kids are just sickly. I was, and am. I probably wouldn't have made it if I were in an undeveloped country or in an age before penicillin. But I'm here and I will be for a while yet.
posted by teleri025 at 8:17 AM on November 7, 2007

I'd eat all the dirt in this yard for you. And all the weeds, and all the dogbones too, if you asked me.
posted by everichon at 9:36 AM on November 7, 2007

There are so many additional factors. Immunizations have saved untold numbers of lives, so maybe people who have less robust immune systems are living longer. Worldwide travel means that microbes travel, too, so we are all exposed to many more bugs than ever before. Many more people eat much more meat, and the meat industry, in fact the entire food industry, seems to be filthier than ever. (I have no stats here.) The foods we eat are highly hybridized and now gene-modified and irradiated. Most of us eat a much wider variety of foods. We are also exposed to many, many more chemicals, from antibiotics in our meat to plastic food containers that may mimic hormones.

There was a story linked on mefi, though I'm too sluggish to find it, about a guy who intentionally contracted intestinal parasites to cure his asthma, and he contends that it worked very well.

I'll keep feeding the dropped toast to the dog, who is responsible for my distrust of the kitchen floor in the 1st place. I'm not terribly fussy about kitchen germs, but I carry hand sanitizer in flu season. Dirt doesn't really taste very good.
posted by theora55 at 9:41 AM on November 7, 2007

Makes sense to me. That's why I make my daughter sleep in the trash can. Just like Oscar the Grouch...
posted by jefbla at 10:35 AM on November 7, 2007

Dang it DreamerFi. You beat me to the punchline! I just started reading this thread and was like "Four Yorkshiremen!". Alas.
posted by Dantien at 10:45 AM on November 7, 2007

Second, I don't think there's any proof that overzealous parents tend to have weaker children, only anecdotes.

Really? The anecdotes are pretty strong.

Think about it. How many UFC fighters and Boxing champions had happy childhoods and doting parents?
posted by tkchrist at 10:56 AM on November 7, 2007

I don't know, tkchrist, but for the avoidance of doubt, when I said "weaker" I meant to allergies and disease, not that they couldn't bench press as many kilos.
posted by grouse at 11:56 AM on November 7, 2007

And it makes sense from an evolutionary perspective that babies need to be thrown in the deep end if they're to survive the germ-ridden world outside the womb.

Whatever, no child of mine is getting a 9-month free ride. I'm keeping my future babymama's womb as filthy as possible. That little tyke is going to crown made out of iron.
posted by cobra_high_tigers at 12:14 PM on November 7, 2007

mdn - nobody is talking about throwing sick people to the wolves or whatever. We're talking about not trying to keep kids an an antiseptic bubble.

sure, but what you're missing is that that "antiseptic bubble" is exactly what saves some small portion of individuals. As others have said, it can make you stronger if it doesn't kill you, but you actually can get a fatal infection from some dirt or mold or worm or whatever. In most cases, especially if you have a fairly robust system, you'll manage to fight it off. And in the long run, that will strengthen your system, to practice fighting things off.

But the harsh reality is, sometimes the immune system is just not enough, and the bacteria or virus or little invisible piece of nastiness will get inside you and cause irrepparable damage. And you will die a painful death because you ate some dirt. Sucks for you.

Now, these are limit cases - most of the time, you'll be all right. But not everyone makes it. That's why modern medicine started trying to correct for the imperfection of the natural system - started trying to make a better system. The problem now is, if we implement the artificial system too fast, we weaken or even destroy the natural system - if we use antibiotics every time, then the immune system never learns to fight infections to start with. But if we never use antibiotics, we go back to letting some portion of the species just die off.

So the trick is working out how to supplement nature without overriding nature, which is easier said than done, because it's obviously what everyone wants to aim for, but "how much dirt is the right amount of dirt" so to speak, is not nearly that easy to answer, especially since it's all a game of probability. The majority of people lived fine before the invention of antibiotics etc to begin with, so it's the limit cases we're concerned about to start with.
posted by mdn at 12:33 PM on November 7, 2007

Thank you, sexyrobot. People really don't understand allergies. They have a very strong genetic component and don't "make sense" to outside observers. And of course then you even have people doubting you have a real allergy at all, which can be dangerous.
posted by agregoli at 12:46 PM on November 7, 2007

And of course, yes, molds. But I think the explanation is good. Your body attacks the allergen and that's what makes you sick - not that the allergen itself is dangerous, like a virus.
posted by agregoli at 12:48 PM on November 7, 2007

agregoli, in both allergy and infectious disease, symptoms can be caused proximately by your immune response.

The real distinction was alluded to by sexyrobot—allergens do not reproduce inside your body, while disease pathogens do, even the ones that are not alive.
posted by grouse at 12:57 PM on November 7, 2007

There is definitely a thing as too much dirt. My friend has worked in many rural West Virginia hospitals. One woman brought in her son who had been feeling poorly and coughing a lot. While she was examining his throat, he started on one of his coughing fits, and right there she saw the end of a worm poke out of his throat, so she grabbed hold of it and pulled out all 2 feet of it.

I can't remember what kind of worm it was, but I do remember how she explained most of its life cycle. It's eggs can lie dormant in shit-contaminated dirt for years. When ingested, the eggs travel to the stomach where the outer layer is burned off. The inside of the egg makes it to the intestines where they can travel through the bloodstream to the lungs. The worm hatches and matures there. When mature, the host will start coughing so that the worm can travel up the windpipe and back down the esophagus. I'm a little unclear on that last part, because it would place the worm back in the stomach which seems like an inhospitable place for it. Eventually the host eliminates the worm's eggs in its waste so the cycle can begin again.

My friend still has the worm in formaldehyde. It was a quite uncommon worm for North America, so she ended up giving a presentation on it for her fellow doctors. For some reason they were disgusted that she had bowls of gummy worms for snacks.
posted by Hubajube at 1:02 PM on November 7, 2007 [1 favorite]

NUKE WEST VIRGINIA IMMEDIATELY!!!

Tell me when you are done. I will be showering.
posted by tkchrist at 1:26 PM on November 7, 2007

yeah...worms are fuckin' gross...they have the sickest lifestyles...there's one that lives in the stomach of birds, the birds crap out eggs, snails eat them along with bird crap on leaves, they hatch, crawl up into the snails eyestalks (a process which drives the snails crazy and makes them seek out heights) where they begin a dance inside the snails head to attract birds to come eat them...so they can lay eggs. grody.

and...(for grouse and agregoli) your talk of molds reminds me...i AM allergic to penicillin (which, now that i think about it...first manifested when i was undergoing surgery...i.e. in a hospital =fulla germs+strange chemicals (anaesthetics, drugs, etc)...and i seem to remember being fine with it before then...had it a few times as a kid, ear infections and such...[ok, now DIAGRAM that sentence! ;)

molds cant survive in the body though, right? (at least most of them) due to the conditions being so different and all...its their proteins that invoke the immune/allergic response.

and i LIKE thinking of viruses as alive (y'know...because of the reproduction...i won't argue that there's a lot of homeostasis maintenance going on)...it gives one justification for being angry at them...otherwise you're just shaking your fist at the toaster.
(although, to be fair, the crumb tray in my toaster hasn't been cleaned in so long, it's likely far past 'organism' and well into 'ecosystem')
posted by sexyrobot at 1:01 AM on November 8, 2007

molds cant survive in the body though, right?

There are some molds that can. For example one of the Penicillum species is pathogenic. And there are plenty of molds that survive on the body surfaces, such as Athlete's foot (sometimes a mold).
posted by grouse at 1:22 AM on November 8, 2007

...its their proteins that invoke the immune/allergic response.

I was under the impression that all allergies are reactions to proteins, but I could be wrong. I have them and yet I still don't understand it that well.
posted by agregoli at 6:58 AM on November 8, 2007

agregoli: Not necessarily. I believe one can have allergic responses to carbohydrates as well.
posted by grouse at 7:04 AM on November 8, 2007

More on the cigarettes/asthma connection:
A child whose maternal grandmother smoked while pregnant may have double the risk of developing childhood asthma compared with those with grandmothers who never smoked, say researchers from the University of Southern California, US. And the risk remains high even if the child’s mother never smoked.
Full article at: Pregnant smokers increases grandkids' asthma risk

The "allergic march" goes from infant eczema to food allergies to asthma, so it's not that big a leap to connect research on smoking and asthma and make the link between smoking and allergies.

I can't find a good chart on smoking through the ages, but I did find this: "Cigarette smoking was rare among women in the early 20th century and became prevalent among women after it did among men." (from lungusa)

So women didn't smoke much in the early 20th century, but really took it up after WWII, when the marketing campaigns started their work. Those women were the grandmothers of the kids who are suffering in the allergy epidemic today. (Disclaimer: I'm no historian, but I do know that the Virginia Slims ads were classics for their time, which was the 40s and 50s.)
posted by wenat at 12:24 PM on November 8, 2007

Allergies are weird. I don't think detergent is a protein, but you can be allergic to detergent. And detergents are used everywhere, to wash food as well as clothes.

And you can be allergic to cold.

Correction. The human body is weird.
posted by wenat at 12:29 PM on November 8, 2007