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Dirtying Up Our Diets
June 22, 2012 11:46 PM   Subscribe

Increasing evidence suggests that the alarming rise in allergic and autoimmune disorders during the past few decades is at least partly attributable to our lack of exposure to microorganisms that once covered our food and us.

Dirt can also make you happy.

Most people are familiar with the concept of terroir in wine. But what about terroir in meat and produce?

We watched as Parker shook dirt from a large Mason jar into each wine glass. Parker poured a bit of water into each glass and then furiously stirred the water into the brown, dry earth. As she worked, she passed the jar of dry dirt, encouraging us to smell the soil and discuss its aroma.

Next we tasted produce grown in the same dirt we’d just spent 10 minutes smelling and discussing. I was stunned. I’ve had some miraculous food experiences, but nothing that illustrated so convincingly the connection between the health of the land and the food that I put in my mouth.


Some chefs even cook with it:
video showed Roca trudging through the woods of his homeland with a shovel and a bucket. He dug up a few shovelfuls of dirt and returned to his kitchen.

He then added some of this mud to a large glass beaker, fitted the beaker into a distilling machine and turned it on. The beaker rotated and the mud heated up and gave off a vapor which went up through some glass tubes, condensed and dripped down into a smaller beaker, crystal clear liquid, a literal distillation of his terroir. And this was the technique, eau de dirt.
posted by j03 (84 comments total) 45 users marked this as a favorite

 
Next up, dirt pills.
posted by aeschenkarnos at 11:53 PM on June 22, 2012


Next up, dirt pills.
posted by j03 at 11:59 PM on June 22, 2012 [8 favorites]


I thought this was pretty much conventional wisdom.

The interesting thing: vaccinations are basically given to trigger the immune system. Would not giving kids vaccinations make these problems worse? Maybe we should be giving kids more vaccines (and more often) to make up for the loss of real antagonistic microbes.
posted by delmoi at 12:01 AM on June 23, 2012


This is perfectly obvious. This is why people who use those germ-blitzing hand "hygiene" products and so on really ought to think things through a bit more. A bit of muck is good for you.
posted by Decani at 12:05 AM on June 23, 2012 [11 favorites]


I'm going all out and moving into a butcher shop dumpster.
posted by Brocktoon at 12:09 AM on June 23, 2012 [6 favorites]


I thought it was dirt, but poo injections that were supposed to cure ya. I guess this is less objectionable, provided the dirt isn't full of heavy metals. Oh wait, I live in Texas, never mind.
posted by emjaybee at 12:20 AM on June 23, 2012 [2 favorites]


When people say "salt of the earth", I didn't realize they meant it literally!
posted by Greg_Ace at 12:22 AM on June 23, 2012


It's a popular theory, and it fits snugly within my worldview, but is there any actual evidence that lack of exposure to microorganisms is responsible for this rise in allergies, or even evidence of the extent of this rise?

The evidence in this article is pretty light on.
posted by fonetik at 12:28 AM on June 23, 2012 [12 favorites]


Naah, it's just another middle class way to make conspicuous consumption acceptable as a lifestyle choice.
posted by MartinWisse at 12:34 AM on June 23, 2012 [2 favorites]


Distance from equator 'influences allergy risk'
posted by robcorr at 12:43 AM on June 23, 2012


Googling suggests there is some evidence from mice. Published in SCIENCE. This page gives the article abstract and some other related reading, but the actual contents are not provided to us:
Microbial Exposure During Early Life Has Persistent Effects on Natural Killer T Cell Function

posted by alasdair at 12:56 AM on June 23, 2012 [1 favorite]


Next we tasted produce grown in the same dirt we’d just spent 10 minutes smelling and discussing. I was stunned. I’ve had some miraculous food experiences, but nothing that illustrated so convincingly the connection between the health of the land and the food that I put in my mouth.

And miracle of miracles, the soapy taste of confirmation bias was nowhere to be found!



...but seriously, I'm sure that healthier soil does generally make for better food. But this is as big a "cite, please" as I can imagine.
posted by lumensimus at 1:23 AM on June 23, 2012 [12 favorites]


Howzabout worms?
posted by lordaych at 1:25 AM on June 23, 2012


Everybody knows licking doorknobs gets you more immune boosters than eating dirt.
posted by bigbigdog at 1:53 AM on June 23, 2012


Do more shopping at Walmart, and touch as many cart handles as you can. This should solve the problem.
posted by Malice at 2:05 AM on June 23, 2012 [2 favorites]


This is why people who use those germ-blitzing hand "hygiene" products and so on really ought to think things through a bit more

nonsense! Everyone knows Purel exists to wipe away the smell of cigarettes so you don't get in trouble when you get home. It has nothing to do with hygiene.
posted by Hoopo at 2:07 AM on June 23, 2012 [9 favorites]


fonetik: [I]s there any actual evidence that lack of exposure to microorganisms is responsible for this rise in allergies, or even evidence of the extent of this rise?
Yes, along with the article that alasdair linked to on T cell function, an article in the Proceedings of the National Academy of Sciences published in May answers your exact question (a news article in Science as well as a Science Daily article summaries the findings for us normal folk).

Further, recently another research group found that in early life gut bacteria helps regulate serotonin levels in the brain with life-long effects. In other words, a healthy gut microbiome as a child literally makes you a happier person for the rest of your life (the paper in Molecular Psychiatry).
posted by thebestsophist at 2:16 AM on June 23, 2012 [17 favorites]


...but seriously, I'm sure that healthier soil does generally make for better food. But this is as big a "cite, please" as I can imagine.

Have you ever had hydroponic vegetables? They are awful, just awful The tomatoes, in particular, are a travesty.
posted by fshgrl at 2:19 AM on June 23, 2012


So if we send the kids outside to play more we might be allowed to have PB sandwiches at school again? I'm all for that.
posted by DU at 2:30 AM on June 23, 2012 [3 favorites]


So, they're saying it's finally time to end the War on Terroir?
posted by Joakim Ziegler at 2:39 AM on June 23, 2012 [35 favorites]


My grandmother used to say "you need to eat a peck of dirt before you die", meaning "don't worry about wasting a lot of time washing those veggies you just pulled out of the ground". She lived into her 90's.

I don't worry much about dirt.
posted by HuronBob at 2:44 AM on June 23, 2012 [9 favorites]


Not only can bacteria be our friends - - they are us - - the human body includes up to six pounds of bacteria.
posted by fairmettle at 2:46 AM on June 23, 2012 [2 favorites]


I remember a professor showing us a global chart of parasitic worm infections that had a global chart of autoimmune/allergic disorders on top of it. On the whole, wherever the worms weren't, the rates of the autoimmune/allergic disorders were quite high.
posted by Renoroc at 3:11 AM on June 23, 2012 [2 favorites]


Do more shopping at Walmart, and touch as many cart handles as you can. This should solve the problem.

Better yet, pump your own gasoline.
posted by Kirth Gerson at 3:51 AM on June 23, 2012


MetaFilter : We are 10 percent human, 90 percent poo. ^
posted by jeffburdges at 3:53 AM on June 23, 2012


Distance from equator 'influences allergy risk'

Damn. I knew growing up in Perth was bad for me. Severe nut allergy here despite playing in dirt daily.
posted by wingless_angel at 4:02 AM on June 23, 2012


I grew up in the country, playing in the dirt almost exclusively because my parents thought being a kid meant running wild outside, eating food that I helped raise in the family garden, and spending as much time as possible in (and occasionally drinking from) a lake.

I have an auto-immune disease.

I grow very weary of yet another pop science article that allows people to blame me for being sick and to be smug that they have somehow earned their good health.
posted by hydropsyche at 4:04 AM on June 23, 2012 [61 favorites]


Renoroc: On the whole, wherever the worms weren't, the rates of the autoimmune/allergic disorders were quite high.

Radiolab and This American Life both did a story about a guy who flew to Africa for the sole purpose of infecting himself with hookworms. Believing the worms would alleviate his asthma and allergies, he walked barefoot around latrines until he was infected. Apparently, it's called helminthic therapy and that guy now runs a business offering patients hookworm infections for $2990.
posted by quosimosaur at 4:21 AM on June 23, 2012 [3 favorites]


I interpret the broad epidemiological statement above the fold as advocating a future research direction for auto-immune disorders, not an attempt to blame anyone, hydropsyche. There are certainly people who corrected horrible auto-immune problems by changing their gut flora, injecting the parasites their body desperately wanted to fight, etc., well quosimosaur's link's guy could not even find his hookworms without going to Africa.

I found the "He's found, among other things, that germ-free mice gain more body fat when fed microbiota from obese mice than microbiota obtained from lean mice." tidbit from the poo injections article interesting. Auto-immune disorders are an important market, but weight loss is a spectacular market.
posted by jeffburdges at 4:41 AM on June 23, 2012 [2 favorites]


Or the "growing number" of auto-immune disorders and allergies could have to do with the increasing availability of diagnosticians, tests, and accessibility to same: just because more people are being diagnosed doesn't mean that there is a sudden increase in what they're being diagnosed with.

Here's what -- as near as I can tell -- we're not tracking: the rates of people growing out of the allergies, and/or the rates of incorrect diagnosis.

Anyway, this has the feel of an underlying theme: the nervousness induced in some people by the modern world and then, over thinking a plate of beans about it. At the opposite end of this "eat dirt" campaign, are the lunatics who choose to "protect" their children from everything, including vaccines -- because they don't understand the technology/science, or it seems like an awful lot, etc. etc. ad nauseum.

We're still evolving. Things change. We don't know what any of this means in the grand scheme of human life. Best not to panic.
posted by gsh at 5:16 AM on June 23, 2012 [5 favorites]


I think it's a pity that the plausible potential finding of "if kids play in the dirt more then fewer kids will have allergies and auto-immune disorders" is inevitably going to be read as "if you have allergies you are either lying or a bad person who did not play outside enough and your parents are bad too". And that therefore there will be a lot of entirely reasonable resistance from allergic and ill folks who are tired of being blamed.

It's also interesting that things that used to be free and basic - being outside, eating food that was grown in ordinary healthy soil - have been taken away and replaced by expensive alternatives of indoor/secure play and heavily treated produce, and now the dirt and outdoorsness will be sold back to us again on top. Like processing food to make sugar cereals and then charging people for a bottle of the very vitamins that were extracted when the cereal was made. This is why I feel that enclosure is the best metaphor for capitalism, not so much the appropriation of surplus value created by labor.
posted by Frowner at 5:19 AM on June 23, 2012 [20 favorites]


Wow, great links in the comments here. Thanks emjaybeeand thebestsophist and fairmettle and quosimosaur and everyone else. I'd heard of the hygiene hypothesis before, but some of this research is kind of blowing my mind; this is some serious Gaia hypothesis shit, you know? The idea that we're collections of cells, but not just collections of human cells, is pretty fascinating, especially when you get into this "gut-brain connection" stuff that thebestsophist linked, suggestion that even our moods and behavior are influenced by the bacteria that inhabit us.
posted by OnceUponATime at 5:22 AM on June 23, 2012 [4 favorites]


Dirt is important at my house. I garden in the same spaces, year after year, and eat what I grow, so I'm careful to amend the soil regularly and maintain compost piles destined for the gardens (with help from the horse farm next door). We all eat right out of the garden. We can and freeze and dehydrate, and yes, call it confirmation bias, but what we grow and process is much, much tastier than what we can buy in the grocery store.

And the pork from our pigs? OMG, best bacon ever, partly because these animals are outside, rooting around like pigs should. This year, my husband--mindful of growing antibiotic resistance in the human realm and dismayed by coming home and dumping antibiotic-laden feed in the feeder--decided that we'd be giving our pigs antibiotic-free grub. That's possible, because our pigs are living in natural conditions rather than being closely packed into a confinement facility. We are not under the same pressures to bring pigs to market quickly, and don't need to give feed that increases the protein conversion rate. Our pigs grow at their own pace.

Despite the death of one piglet, we feel somewhat vindicated in our choice now that the FDA is making noises about reducing antibiotics in animal feed. [And really, there should be a FPP about this. It could be important. I am flying from memory, here.] A federal judge ruled that the FDA can go ahead and act in this matter, and the FDA has recently issued a statement encouraging farmers to cut back on the amount of antibiotic feed given, and to concentrate on giving antibiotics under veterinary supervision. Important: At this point, compliance is voluntary. There are no teeth behind this. But there could be. The pork industry is, of course, fighting back with its own propaganda. My own belief in this matter is that when pigs live like pigs--playing in dirt--they thrive. When they're deprived of that, and live in un-piglike conditions, crowded together and biting at one another and not exposed to the microorganisms in dirt, there will be more infection and illness. Hence the need for medicated feed. Which may cure, but which may also only mask illness, and encourage development of antibiotic-resistant illnesses. It's a mess.

My kids are out playing in the dirt all the time. We will not speak of the other night when my little boy stripped down to his skivvies so he could jump in the pigs' watering hole to cool off. The pigs were entertained. His sister thought it was a great idea, and so she joined him. Instead of grabbing the hand sanitizer, I grabbed the camera. Because I won't join the OMG Mommy Brigade. It's dirt, for Pete's sake, life-giving, food-making dirt, and I will not be afraid of it.
posted by MonkeyToes at 5:51 AM on June 23, 2012 [12 favorites]


I grow very weary of yet another pop science article that allows people to blame me for being sick and to be smug that they have somehow earned their good health.

None of these "pop science" articles declare that all allergies and auto-immune diseases in all people are caused by this. It's a factor which appears to have a significant influence. I don't think there's any blame in establishing a correlation that may help control a growing health problem.

It just seems to me that something has to be going on. Something has changed. I'll meet your anecdote with my own - when I was a kid, not long ago, playgrounds were full of peanut butter sandwiches and I don't recall ever hearing, in those days, of kids dying. I understand that in the US there was a restaurant chain whose gimmick was that people could eat peanuts and throw the shells on the floor - they stopped that practice after a shop caught fire, not due to anaphylaxis killing customers. I can't necessarily put it down to "more diagnosticians", because with something like a peanut allergy, it happens pretty bloody fast and the connection between the food and the response would be obvious to all involved. It is fascinating to me, a puzzle that needs solving.
posted by Jimbob at 6:09 AM on June 23, 2012 [1 favorite]


I suspect we used to hear about peanut allergies less because those kids died before they were diagnosed with anything.
posted by modernserf at 6:18 AM on June 23, 2012 [5 favorites]


I think this is an interesting hypothesis which deserves investigation.

But if the New York Times is going to write an editorial promoting a scientific hypothesis, why don't they include some actual science? I'm not saying they should include scatterplots and technical lingo and p-values; obviously they shouldn't. But why do I have to get links to studies from the MetaFilter comment thread? Why can't they include the name of a single scientist who's studied this, or a link to a single paper with evidence in support? Without that, the op/ed is just someone identified as a science writer who asserts "Increasing evidence suggests....."

"an article in the Proceedings of the National Academy of Sciences published in May answers your exact question (a news article in Science as well as a Science Daily article summaries the findings for us normal folk)."

I liked the paper at thebestsophists link. Note that the paper finds that every class of microbiota but one fails to be significantly correlated with atopy (their measure of "allergy") and some of those correlations are positive, some negative. The class of microbiota where they get a positive result are the gammaproteobacteria. And here again, the prevalence of gammaproteobacteria in the skin was unrelated to atopy. What they found is that having a lot of different kinds of gammaproteobacteria is associated with lower atopy. They also note that, while all kinds of bacteria are common in soil, gammaproteobacteria are especially notable in flowering plants; in fact another part of their study associates diversity of plant cover with lower atopy.

So it would be a big, big stretch to say that this study provides evidence that eating dirt is good for you. Maybe better to say "there's some evidence that living in a biodiverse above-ground plant environment is associated with less allergy, and it's not crazy to imagine that this association might somehow be mediated through microbiota, but we have no idea whether manipulation of microbiota would have any effect on allergy."
posted by escabeche at 6:27 AM on June 23, 2012 [10 favorites]


Well, I will say that part of the reason I think my cat is so indestructibly healthy is both due to genetic diversity (all I know is that he is part Maine Coon) and his time out in the world (he is a rescue kitty).

On a further note, I am 45 and I remember as a child that allergies were much, much less known/common among my peers than it seems to be nowadays. The kids with major allergies were rare and unusual beasties. Now you can't seem to swing a dead cat (allergen trigger warning!) without hitting one.
posted by Samizdata at 6:29 AM on June 23, 2012


Something has changed. I'll meet your anecdote with my own - when I was a kid, not long ago, playgrounds were full of peanut butter sandwiches and I don't recall ever hearing, in those days, of kids dying

Yeah, but that's because dying of peanut allergy was spectacularly rare then, just like now.
posted by escabeche at 6:34 AM on June 23, 2012 [4 favorites]


The fact that children may not be carrying sufficient variety of pathogens had not occurred to me.
posted by RobotVoodooPower at 6:37 AM on June 23, 2012 [2 favorites]


Yeah, but that's because dying of peanut allergy was spectacularly rare then, just like now.

Like the fears of kidnapping, I think the fears of severe food allergies have far outpaced its actual incidence. A certain level of germs and parasites are probably good for us, but at the same time high levels are very much not good.
posted by Forktine at 6:53 AM on June 23, 2012


For the record, I am not blaming the researchers, or even the NY Times, for the fact the American public will once again use this article as part of their Just World Hypothesis.

If any one group is to blame, it's probably science educators like myself who have clearly not taught our students the difference between a hypothesis and Absolute Truth, between correlation and causality, or how to understand statistics.

So, I will redouble my efforts with my non-majors this fall, so maybe one day I will not have people telling me that their veganisn, vitamin supplements, Cross-Fit, or dirty childhood has protected them from unpleasant conditions like mine.
posted by hydropsyche at 7:07 AM on June 23, 2012 [9 favorites]


You know, it's possible to make an observation without it being a blame, YOU FAILED YOUR CHILDREN kind of thing. There is a correlation between early stimulation of the immune system and fewer allergies in adulthood; this does not mean OMG IT'S YOUR OWN FUCKING FAULT if you develop something of that nature in adulthood.
posted by Jilder at 7:20 AM on June 23, 2012 [2 favorites]


We don't have to guess about whether "fears of severe food allergies have outpaced its actual incidence." According to the CDC:

From 1997 to 2007, the prevalence of reported food allergy increased 18% among children under age 18 years.

Four out of every 100 children have a food allergy.

From 2004 to 2006, there were an average of 9,537 hospital discharges per year with a diagnosis related to food allergy among children 0 to 17 years, whereas from 1998 to 2000, there were 2,615.


If the death rates are low, that is at least in part thanks to the fact that most people who are diagnosed with severe allegeries are prescribed epi pens, and are supposed to carry them wherever they go. Epinepherine is like magic.
posted by OnceUponATime at 7:22 AM on June 23, 2012 [4 favorites]


i know someone who is both against anti-bacterial hand soap and vaccinating her child.
posted by cupcake1337 at 7:25 AM on June 23, 2012


Like the fears of kidnapping, I think the fears of severe food allergies have far outpaced its actual incidence.

They have. Allergies only cause several hundred deaths annually. Of those, about 150 are due to food allergies of some kind and about 400 are due to penicillin allergy. To put those numbers in perspective, deer kill about 150 people each year. So all food allergies combined are about as deadly as deer. Both are non-trivial problems, but the response to food allergies has been a bit overwrought.

Anyway, in a few years it may not matter. It is possible to effectively cure peanut allergy.
posted by jedicus at 7:30 AM on June 23, 2012


It could be my own confirmation bias, but it seems every time there is noise about increasing incidence of disease, someone pops up to say its just more knowledge and better diagnosis.

But I have to wonder if that is the case when the diagnostic knowledge has been around a couple decades and the incidence is still on the rise.
posted by tommyD at 7:36 AM on June 23, 2012


We don't have to guess about whether "fears of severe food allergies have outpaced its actual incidence." According to the CDC:

From 1997 to 2007, the prevalence of reported food allergy increased 18% among children under age 18 years.


I think it's fair to say that fears of severe food allergies have increased more than 18% over that time scale.
posted by escabeche at 7:38 AM on June 23, 2012 [1 favorite]


See e.g.

http://books.google.com/ngrams/graph?content=peanut+allergy&year_start=1990&year_end=2007&corpus=0&smoothing=3
posted by escabeche at 7:38 AM on June 23, 2012


I suspect we used to hear about peanut allergies less because those kids died before they were diagnosed with anything.

I wonder if peanuts were widespread as a food/snack until the early 20th century anyway? I have a severe peanut allergy, but made it through childhood ok. I can still remember being given pb cookies by some kindly old lady and not being able to explain that it would make me sick.
posted by sneebler at 7:39 AM on June 23, 2012


BTW, I also grew up on various farms and played in/ate a lot of dirt.
posted by sneebler at 7:40 AM on June 23, 2012


Believing the worms would alleviate his asthma and allergies, he walked barefoot around latrines until he was infected. Apparently, it's called helminthic therapy and that guy now runs a business offering patients hookworm infections for $2990.

There has been considerably less insane research done on this hypothesis using pig whipworm. Those worms can infect the human body for a short time (weeks) but are eventually rejected, so it's a fairly safe therapy. The treatment used a steady supply of replacement whipworm eggs.

Unfortunately, while early results have been promising, there is reason to doubt that it will prove effective. A 2010 Danish study concluded that, "Based on a population-based analysis, enterobiasis [pinworm] does not reduce risk for asthma, type 1 diabetes, arthritis, or inflammatory bowel disease."
posted by jedicus at 7:43 AM on June 23, 2012 [1 favorite]


jedicus: "Like the fears of kidnapping, I think the fears of severe food allergies have far outpaced its actual incidence.

They have. Allergies only cause several hundred deaths annually. Of those, about 150 are due to food allergies of some kind and about 400 are due to penicillin allergy. To put those numbers in perspective, deer kill about 150 people each year. So all food allergies combined are about as deadly as deer. Both are non-trivial problems, but the response to food allergies has been a bit overwrought.

Anyway, in a few years it may not matter. It is possible to effectively cure peanut allergy.
"

And speaking of cats, I used to be fairly allergic to them (sneezing, itching eyes, and, with continued exposure, the membranes at the side of my eyes would swell up, eventually occluding the sides of my irises). Later experimentation showed me I am allergic to cat saliva.

When I was married my ex-wife wanted a cat, and being the big softie I am, I agreed, as long as she would bathe the cat when my allergies flared up.

A couple of years later, I started having virtually no negative response to cats, and to this day, I live with a little yellow heathen with almost no immunoresponse. (Granted, as I understand it, some of his genetic antecedents are known for not generating much of the protein in cat saliva assumed to be the major allergen). So, in conclusion, I concur with the idea of isolation from potential allergens and pathogens being the reason for the surfeit of allergies and medically related issues with people today, based on my own limited experience.
posted by Samizdata at 7:50 AM on June 23, 2012


Good point, escabeche, but I wonder if it doesn't make sense for the rate of change of "fears of x" to increase, not in proportion to x, exactly, but in proportion to the rate of change of x (ie, it's like the second derivative.) 18% in ten years is kind of ridiculously large. It's not the absolute incidence or even the absolute increase in the incidence, but the fact that it's increasing so quickly, that's sort of terrifying. It implies some underlying process that is not under our control.

Disclaimer: I spent 8 hours in the emergency room with my 15 month old daughter, three months ago, after she got her first taste of peanut butter. Totally terrifying: face swollen beyond recognition, vomiting, screaming. And nobody in my family or my husband's is allergic to peanuts, or much else. So I'm one of the scared, I guess.
posted by OnceUponATime at 7:59 AM on June 23, 2012 [2 favorites]


New plan:
1. Go around to San Francisco foodie-snob things.
2. Get them to eat dirt, telling them it's a Ruritanian delicacy.
3. Profit.
posted by madcaptenor at 8:08 AM on June 23, 2012 [4 favorites]


If any one group is to blame, it's probably science educators like myself who have clearly not taught our students the difference between a hypothesis and Absolute Truth, between correlation and causality, or how to understand statistics.

When I taught statistics, I told my students that "if there's one thing you should take away from this class, it's that correlation does not equal causation."

As a result (or maybe not?), I found students writing "correlation does not equal causation" as the answer to a very large number of questions on exams that had nothing to do with correlation or causation.
posted by madcaptenor at 8:13 AM on June 23, 2012 [4 favorites]


i know someone who is both against anti-bacterial hand soap and vaccinating her child.

This is not much of a puzzler. The person you know is against two artificial ways to prevent diseases, i.e. he or she prefers to rely on natural sources of resistance and immunity.
posted by michaelh at 8:17 AM on June 23, 2012 [1 favorite]


She. I missed the "her."
posted by michaelh at 8:18 AM on June 23, 2012


Samizadata: doesn't work quite as well for food allergies. I used to crack nuts often for my dad to eat. I have no problem with getting nut protein on my hands, but I still can't eat them.

I think nut (not peanut) allergies are also up because they were once a luxury food, and quite expensive. They used to be easy to avoid. I managed to avoid eating any by accident (other than Nutella once, and whatever I ate when first diagnosed at the age of 2) until I was 26.
posted by wingless_angel at 8:19 AM on June 23, 2012


People who teach statistics might consider teaching that correlation can sometimes be a valid line of evidence for determining causation, but that it represents only one such line of evidence, and a perilously easy to abuse one at that. But just teaching them reductive rules of thumb that reflect one's own personal reactionary biases against the misuse of statistics just sends the metaphorical scale off balance in the opposite direction.
posted by saulgoodman at 8:21 AM on June 23, 2012 [5 favorites]


frowner suggested that now the dirt and outdoorsness will be sold back to us again. Not sure how this would work, but they'll find a way. It's like how lightly salted nuts cost twice as much as salted nuts. Reminds me of the old cartoon with a hippie waitress telling her customer: "That's not dirt, it's earth." Coming soon: "Now with real immune-building elements!"

Not blaming anyone who's sick for not eating enough dirt, but, as I've remarked before, back in the middle of the 20th Century my MD father encouraged us to eat food we'd dropped on the floor for this very reason. Although, all you CITE NEEDED folks have a point. My father would cite so many studies in the arguments we had about human nature it made my ears bleed, but I doubt he had any studies to back up this bit of common sense wisdom.
posted by kozad at 8:47 AM on June 23, 2012


I ate plenty of dirt as a child in the 50s. Still do. I had allergies and asthma back then. Still do. Though since my husband stopped smoking, I can sleep with the cat again and don't have to use the neti pot, which worked better than all the prescriptions doctors gave me. They won't give me the inhaler that works for once-a-year emergencies any more, because it's supposed to be bad for you, so I just cross my fingers.

I am getting tired of this stuff. It bewilders me. I grew up on MICROBE HUNTERS, taught science for ten years, and have always enjoyed reading science journalism, but just as a plain old human being, as opposed to a smart consumer of information, I don't know what to think any more.
posted by Peach at 8:56 AM on June 23, 2012 [2 favorites]


Scientific American: Microbes Manipulate Your Mind
posted by the man of twists and turns at 9:05 AM on June 23, 2012 [2 favorites]


When my son was born, we lived in a rural area and had well water. We lived there until he was 3, and when we were ready to sell the place, discovered that the well was contaminated with E. coli. My son is now 21 and, to this day, has never had any sort of GI issues, never had a "stomach flu," never had diarrhea, nausea or vomited. He likes to brag about this and attributes it to the fact that his parents fed him "E. coli water" when he was a baby.
posted by SweetTeaAndABiscuit at 9:07 AM on June 23, 2012


18% in ten years is kind of ridiculously large.

Is it, though? It's way smaller than the increase in diabetes over the same period, which grew more than 50%. And of course it's nothing compared to autism diagnoses, which grew 10-fold during the 90s.

18% in a decade is somewhat less than liver cancer, which was up 20% in just five years. Skin cancer, growing at about 2% per year, is more in the ballpark. And these were just the first few things I looked at. But you probably don't think of these diseases as things that are exploding, or growing ridiculously fast; and that's because the attention paid to them is roughly commensurate to their scale as public health problems and their likely scale in the future.
posted by escabeche at 9:26 AM on June 23, 2012 [4 favorites]


Wow! It turns out Zonker was right all along.
posted by The Confessor at 9:37 AM on June 23, 2012 [1 favorite]


jedicus, the overall risk of death by peanut allergy to the general population certainly is low, because despite the increase in incidence of food allergy, only about 1% of the U.S. population is allergic to peanuts. However, the risk of death from peanut allergy to certain individuals with peanut allergy sometimes does justify some organizations, such as schools, taking extreme precautions if a person with a peanut allergy is a member of their community.

If you picked 100 children off the street and fed them each a peanut, the risk that you would cause one of them to have a life-threatening reaction is still quite low.

If you fed my child a peanut, the risk that you would cause him to have a life-threatening reaction is 100%.

There is not really no good reason for a school that has no students with a peanut allergy to ban peanuts. There are plenty of reasons for a school that has even one student with a peanut allergy to do so.

There may only be 150-200 deaths from food-related anaphylaxis each year, but there are about 29,000 cases of food-induced anaphylaxis. Anaphylaxis is not pleasant even when it is "mild." Symptoms may include hives, extreme itching, extreme facial swelling, swelling of the airways, coughing, wheezing, shortness of breath, nausea, vomiting, headache, dizziness, and fainting,. In addition to death, potential complications from anaphylaxis include brain damage, kidney failure, and damage to the heart.

Also, many children with peanut allergies, which are a particularly nasty form of food allergy, also experience contact reactions to peanuts or peanut butter that can cause hives and / or a rash.

My own son has come home from his non-peanut free school numerous times with hives all over his arms from being touched by other children who had eaten peanut butter without washing their hands. And once he got a four-inch welt on his face from laying down on a carpet that some other kids had spilled peanut butter cookie crumbs on.

The way we found out he had an allergy in the first place? We had a nice trip to the ER after one bite of a peanut butter cookie at school caused his tongue to double in size and his throat to nearly swell shut; he almost stopped breathing several times on the way. Because he had not shown allergic symptoms before that incident, we did not, of course, have an EpiPen; if we had, he would have been much better off. (This is a reason why I think all schools should stock them as part of a standard first aid kit.)

My child is unlikely to die from his allergy, even though it is severe, but that's not because his risk of a serious reaction is low -- it's because I remind him regularly to watch what he eats, I religiously read ingredient labels, research factories on the web, and interrogate restaurant managers over the phone, and I follow him around everywhere he goes with Benadryl and an EpiPen (because he is not old enough yet to be trusted with to always remember and administer the medication himself). I'm not taking these precautions because I'm paranoid, or because I've been mentally poisoned by the media. I'm taking them because four separate medical professionals have told me that if he ate two bites of a peanut butter sandwich, and had no access to an EpiPen or a hospital, my child would almost certainly die.

Also, the oral immunotherapy you mentioned can only be performed safely by skilled medical professionals in a hospital environment, is still in very early clinical trials, and has not been approved by the FDA. Please, please, please, other parents of kids with peanut allergies: do not try this therapy at home. All it takes is one magnitude error on a dose to cause anaphylaxis. I do hope the therapy will be tested further, proven safe and effective, and become more widely available soon.

I let him eat crackers he dropped on the floor, took him to petting zoos without hand sanitizer, and forced him to play outside as a toddler almost daily when weather permitted. We also had a cat and several houseplants and he played a lot with other kids with dirty hands and runny noses.

I do find the hygiene hypothesis convincing, and I hope we can use it to prevent more kids from developing food allergies, because food allergies TOTALLY SUCK. But apparently some of us are just damned if we do or don't.
posted by BlueJae at 9:38 AM on June 23, 2012 [10 favorites]


Yes, let's not vaccinate our children, and instead send them to play in the dirt!

Tetanus for everyone!
posted by Sys Rq at 10:00 AM on June 23, 2012 [1 favorite]


From the original link:

"And by asking why an individual’s natural defenses failed, we insert personal responsibility into our national food safety strategy and draw attention to the much larger public health crisis, of which illness from food-borne pathogens is but a symptom of our minimally challenged and thus overreactive immune system."

Wait, this is not even a sentence, is it? What the actual eff, New York Times?
posted by escabeche at 11:22 AM on June 23, 2012


quosimosaur: Apparently, it's called helminthic therapy and that guy now runs a business offering patients hookworm infections for $2990.

That TAL piece was pretty interesting. I think it was the Radiolab piece, though, or a later follow-up, that mentioned that worm guy's business had been shut down by the FDA pending scientific validation. I'll be the first in line to stuff myself with worms if this actually works, but anecdotes alone aren't worth much.
posted by qxntpqbbbqxl at 11:40 AM on June 23, 2012


Autism and diabetes are much bigger public health scares than allergies, I think, while skin cancer seems about comparable. Hadn't heard of the increase on liver cancer, but then, it has so much other cancer news to compete with. But it seems to me that everything you mentioned is a legitimate cause for concern and discussion, precisely because of those insane rates of increase.
posted by OnceUponATime at 12:08 PM on June 23, 2012


I sat my infants down in the outdoors and encouraged the eating of dirt (and flowers, sticks, leaves, bugs, rocks, etc*) as often as possible. I did it for the stimulation but perhaps my girls gained more benefits than I expected.

I, too, grew up very rural - played in creeks and farming ditches, pitched manure, and ate things from the wild. Too bad that didn't save ME from an auto-immune condition. Or, possibly, my health would be even worse without that outdoors-y foundation.

*I do not recommend this unless you are knowledgeable about dangerous flora and fauna in your environment AND constantly watch your infant.
posted by _paegan_ at 1:07 PM on June 23, 2012


How about allergies getting WORSE? I used to only be allergic to oak trees. After I moved to Vermont I became highly allergic to birch (there are a lot of birch trees here) and a little allergic to a few other trees. After several years, those minor trees are now major allergens and now I only have 1 tree with no sign of allergy.

In addition, because birch pollen protein is close to many food proteins, I cannot now eat some foods. (This is called Oral Allergy Syndrome.)

WTF body???

I guess all I have to contribute is that allergies are weird. I agree with others that say this should be a research area, and that it is just one possible contributing factor. From my own experience, the cause/source of allergy problems is a great unknown (I rarely get a cold/flue, have an iron stomach, yet can't handle pollen).
posted by evening at 1:26 PM on June 23, 2012


Another person here who grew up in the country, ate vegetables from the garden (my grandmother also said "You'll eat a peck of dirt before you die," but my neurotic child mind parsed this as "Once you've eaten a full peck of dirt, you'll die" and I was terrified partly because I had no idea what a peck was, and thus didn't know how close I was to death), played in the dirt, helped friends muck out stalls and clean coops, drank raw milk...

...and yet, autoimmune illness with concomitant over-the-top allergies showed up in my late 30s.

I know, anecdata, but.
posted by Sidhedevil at 2:04 PM on June 23, 2012 [5 favorites]


Or the "growing number" of auto-immune disorders and allergies could have to do with the increasing availability of diagnosticians

This is a confounding factor that people are aware of, though, and people account for it and study it as a possible source of error. For example, this study based on testing stored blood samples found "The rate of undiagnosed [celiac disease] was 4.5-fold and 4-fold greater in the recent cohorts, respectively, than in the [c. 1950] Air Force cohort (both P ≤ .0001)". I seem to remember another study based on allergy testing done by the military on new recruits over a long period of time, which found a similar actual increase, though I can't find that study right now.

my neurotic child mind parsed this as "Once you've eaten a full peck of dirt, you'll die" and I was terrified partly because I had no idea what a peck was

My over-literal child mind always took it in the opposite direction— "you'll live forever as long as you don't finish your peck of dirt!"— but then dismissed it and went back to eating dirt, because I was a kid and messing in dirt was basically my life.
posted by hattifattener at 2:43 PM on June 23, 2012


My favorite place to eat subs in Austin is Thundercloud. They handle money and the food with their hands, no gloves.

Eat a little nasty every day.
posted by hanoixan at 3:28 PM on June 23, 2012 [1 favorite]


Is there a growing number of auto-immune disorders, I wonder? Or just a growing awareness of what they exactly are?

Perhaps today's people with Celiac were yesterday's "puny and sickly" children with "weak stomachs." Today's woman with lupus was yesterday's "neurasthenic" or "invalid." Today's kid with Asperger's was yesterday's "weird kid." A lot of children with various learning disabilities or sensory issues were probably just "quirky" or "clumsy" or "naughty" and treated accordingly.

So I am not convinced there is necessarily an explosion in some of these conditions. Allergies, on the other hand, certainly do seem more prevalent even than in my childhood. I have no idea why that is. I never ever heard of anyone with peanut allergies until about 10 or 15 years ago. There have always been people with hay fever and pet allergies, but the really severe kind of food allergies really seems to be a new thing to me.

Pet allergies - again, in my childhood (the 1970's) there were fewer indoor animals. Lots of dogs and cats lived their lives entirely outside, or allowed into just the kitchen or garage. There's a difference between being around an outdoor cat and living with one in an enclosed space. Our pets live in much closer contact with us than they did before, and I think that pet allergies are consequently more apparent and harder to live with.

With cancer, I wonder if it's because so many other causes of death have been reduced or eliminated - even heart problems are not the killer they once were - so people are dying of cancer because they aren't dying of other things.

I have heard that one reason multiple sclerosis is more common at northern latitudes is because of low levels of vitamin D. I think it's important to get some sunshine. Fifteen minutes of sun exposure in the morning isn't going to trigger skin cancer (for most people) - it's not like lying out baking for hours. And getting early morning sunshine helps with many cases of depression and sleep problems.
posted by Rosie M. Banks at 3:29 PM on June 23, 2012


Is there a growing number of auto-immune disorders, I wonder?

There is— read the link I posted.
posted by hattifattener at 3:43 PM on June 23, 2012


Some people blame transgenic food crops.
posted by 0rison at 3:49 PM on June 23, 2012


You can't get a reliable diagnostic for celiac from blood samples, though--hence the need for intestinal biopsy.
posted by Sidhedevil at 4:01 PM on June 23, 2012


The people I personally know who are germophobes do not get sick less than other people. I know a woman who goes to the grocery store and buys her bags of groceries. Then when she gets home she sets the bags on unfolded newspapers one step inside her front door. Then she washes everything with soap and water (including the outside of canned goods, dairy cartons, plastic spaghetti wrappers, potato chip sacks) before placing the items in her cupboards. Then she folds the bags inside the newspapers, takes them out to the trash can, and sprays her hands with sanitizer.

The other extreme is the guy who infected himself with hookworms. Yikes. That old crackpot Aristotle's golden mean for the most part looks good to me.
posted by bukvich at 5:42 PM on June 23, 2012


There may only be 150-200 deaths from food-related anaphylaxis each year, but there are about 29,000 cases of food-induced anaphylaxis.

Yes, and there are tens of thousands of injuries caused by deer every year, many of them quite serious, not to mention billions of dollars in property damage. They are really roughly equivalent problems. It is very interesting to compare the response to an allergic child at a school to the response to deer in a community. We ban peanuts at the school but don't, say, cull all the deer or build 12 foot fences everywhere. In fact, in many communities it's difficult to get the residents to agree to even a partial cull (for example).

Note: I'm not saying that because we don't do one we shouldn't do the other. Rather, I think it bears thinking about whether this tells us something about how society addresses different kinds of problems. Maybe it's because one can sue the school but if you hit a deer there's only insurance. Maybe it's because we can identify the allergic children but deer threaten everyone roughly equally. Maybe it's because we get a little irrational when children are involved. Maybe it's all three or something else entirely. But it is interesting.

Also, the oral immunotherapy you mentioned can only be performed safely by skilled medical professionals in a hospital environment, is still in very early clinical trials, and has not been approved by the FDA. Please, please, please, other parents of kids with peanut allergies: do not try this therapy at home.

Yes, the article was clear about that. I certainly hope you weren't implying that I was implying that people should go out and try it at home.
posted by jedicus at 8:54 PM on June 23, 2012


Don't worry, jedicus, I didn't think you were implying that people should try the therapy at home. I've just had multiple people who are NOT you who've heard about that study say to me that I could totally fix my kid and stop him being such an inconvenience to everyone if I just fed him a little bit of peanut butter now and again. Which is totally wrong. And I also know how desperate you can get when your kid has to live the way mine does, with all the terrible social consequences that come alongside the health issues and anxiety, and how tempting the promise of a cure feels. So I felt the need to insert a PSA.

Here's a key difference between solving the deer-caused deaths problem and solving the peanut exposure-caused deaths problem: In order to prevent people from being killed by deer, you literally have to kill deer, or spend a ton of money literally changing the landscape around your neighborhood, or release some wolves in a residential setting.

In order to prevent kids from being killed by peanut butter, you have to ask some other kids to please bring something different to school for lunch. Hell, that's not even the only way to reduce risk; a lot of reactions would be prevented if kids who did bring peanut-based lunches just sat at a designated table and washed their hands after eating. If my own kid's school had been capable of adequately enforcing that rule alone my son would have had far fewer reactions last year.
posted by BlueJae at 9:42 PM on June 23, 2012 [2 favorites]


This reminds me of something interesting about longevity in my family. It is basically a lie I tell people. It is a lie because I am only telling half the truth.

The truth I usually tell is this: My great-grandfather lived to 106. He was never sick in his life. Most of my great-grandparents lived to their 90's. Healthy. Three of my four grandparents lived to their 90's. In fact, my surviving grandmother turns 100 this year. She still walks on her own. She has also led a very healthy life. She has a scarily clear mind. A sharp, intelligent woman. Why have they all lived so long? Is it because they had access to better food? Perhaps because they grew up with dirt and parasites in Mexico?

Here's the other half of the story: All of the above mentioned people had lots of siblings. And many of those siblings died at birth or soon after. Many others made it all the way to their teenage years and then died of something else. It is a story of death and tragedy. The number of kids that died is something we would find intolerable. And they often died of simple causes - stuff we could cure today.

So what I'm saying is that my grandparents and great-grandparents are extremely healthy people because they are the survivors of a ruthless selection mechanism. The fact that they made it to their 20's alive already means they had developed a fantastic immune system that had survived countless deadly bacteria and viruses and infections and strange diseases during their most fragile years. Making it to 90 or 100 was a cakewalk by comparison.

So, yes, many of us may live longer if we lead a dirtier life. But perhaps many others of us would find our life to be much shorter?
posted by vacapinta at 3:30 AM on June 26, 2012 [2 favorites]


Time: Food Allergies: Dangers Still Lurk for Food-Allergic Kids

Journal article in Pediatrics: Allergic Reactions to Foods in Preschool-Aged Children in a Prospective Observational Food Allergy Study (Full Text)

Food Allergy Education Program
posted by cashman at 2:39 PM on July 17, 2012


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