Nice little article! And it confirms my anecdotal evidence, so it feels good. ;)
I had a wild childhood: it happened to me to eat hamster food from his cage, eating dirt, eating sand, raw tomatoes directly from the plant, drinking waters from random streams; drinking raw milk without boiling it few minutes after milking it by hand, eating raw eggs, and when I wasn't in school, like during the summer, I had one shower per week, or less...
Don't worry: growing up I am back to civilization. But I have to say that I am never sick. Also during winter.
I pity all those kids and their urban childhood, they will have to endure weird intolerance to random things. I am grateful to my parents.
Back then growing children was still a simple thing, nowadays mothers and fathers are so scared by society.
Doesn't always work though. I grew up in the countryside and similar to you I ate dirt, wild fruit (best ever was a egg plum tree we found, though the natural laxative effect was unwelcome), drank from streams etc etc.
Unfortunately, I developed an allergy to dogs, despite living with one for nearly 10 years! I left for literally 3 months and upon my return I was allergic.
Also I still get colds and illnesses like most people (not regularly but I get them) so it's not conferred any super powers in that respect either. That might be because I have my own kids now as kids seem to take their disease spreading role seriously!!
So, I'm sure that there are big benefits to our respective early lifestyles but they're not a panacea unfortunately.
I'm trying to find the source, but I remember reading something about allergies appearing in people later in life, and overexposure in that case was also a factor, IIRC
And possibly something to do with antibiotics too? I had just finished a very heavy course when I was reintroduced to the dog, apparently there is some suspicion that such a scenario could have something to do with it?
I, too, spent my childhood playing outside. And I was never on antibiotics.
At 30 I would have told you I was in perfect health. No allergies or asthma or anything remotely like that. Then one day my immune system got out of whack and develop chronic urticaria. (Thankfully modern medicine makes it a minor issue).
My childhood didn't retroactively change during that interval. Sometimes you're lucky. And sometimes your luck suddenly runs out.
I am the same. Always outside, lived on a farm for a few years, lived in the city. No problems with any allergies, and then, about 15 years ago, I worked in a store with photochemistry, but no ventilation. I was diagnosed with asthma some months later. I was pre-disposed to it, though.
Recently, I developed a new allergy to certain types of grass. Now I end up with white dots in my eyes, and a lot of pain.
Hospitals are not sterile, let any uncooked food, air etc. The idea that most things a germ free is really far off base. A more likely consideration is the massive amounts of pollution people deal with.
Consider people lose 0.5 to 1.5 pounds of dead skin a year. That's a great food source for a huge range of micro organisms and it shows up anywhere people wonder around.
The "hygiene hypothesis" as you described would then prescribe that by getting "dirty" we'd improve our immune health. An interesting article was posted on HN a few months ago, a good read on "if being too clean makes us sick, why isn't getting dirty the solution."
Let's not forget that the reason people get sick is because they are infected. Increasing population density will clearly lead to more transmissions, especially in cities.
Actually, TFA makes the case that people living in developed societies are not infected early enough in life, which makes their immune systems vulnerable in the long run.
@verroq is correct though, but that is a different subject than the one of the article.
(Infectious) diseases generally spread more easily in higher population density. That's basic epidemiology, more contacts = opportunities, but it's of course more complicated than one single statement, disease spread models need a lot more variables than just population density to make useful predictions.
Well, it used to be that infant mortality was a lot bigger, some of which was probably infants dying to things they were exposed to. So we can't just ignore survivorship bias in considering these things.
In general, we're probably better off with controlled, safe exposures (e.g. vaccines) than uncontrolled exposure and simply hoping we'll survive anything we catch.
Lets not also forget how allergies are more common in the developed world and particularly in children living in the cities who don't generally get a lot of outside play time.
> Lets not also forget how allergies are more common in the developed world and particularly in children living in the cities who don't generally get a lot of outside play time.
The evidence for this is not clear. Actual research is needed, and such research is complex, expensive, and unfortunately potentially political. This article describes a very nice A/B experiment for this one autoimmune condition but makes no general claims.
But outside these few cases we don't know. One factor is reporting. Do poor kids in India suffer fewer allergies or are they simply dwarfed by the other problems -- or just not reported? How do various cultures report and recognize allergies? Did feudal serfs suffer hay fever from close contact with all those grass proteins and pollens or did they develop immunity? Who knows?
It does seem to appear that certain allergies (e.g. tree nut) are on the rise in the US, but the rate is not restricted to urban populations. But if kids have any symptoms they are isolated from nuts just in case, so surely the rate is overstated in the legitimate interest of keeping kids safe (though unnecessary restriction has its own problems). And other "allergies" can be fashionable (e.g. gluten response) which both helps and hurts those with legitimate problems.
> But outside these few cases we don't know. One factor is reporting. Do poor kids in India suffer fewer allergies or are they simply dwarfed by the other problems -- or just not reported?
This is a great point that gets overlooked: lack of data is often taken as non-existence, even implicitly. When the average life expectancy is under 50 and there's fewer than one doctor for every 10,000 people, sneezing and occasional sinus pain doesn't even warrant a mention.
I mostly stayed inside and played games, everything was kept clean, I bathed every day, all food was prepared very strictly (mother was a professional). And I never get sick. Anecdotes prove nothing.
Do you have children now? I had a similar upbringing and similarly didn't get sick very much. However, once we had a kid, I have been sick way more and more severely. Generally immediately after my child. Do I want to protect my child from getting sick so I can stay productive, or do I want to allow him to exercise his immune system more but reduce my own health and productivity?
I did all that except the milking by hand and the rare showering (grew up in 36-40 °C place), in addition to being barefoot in the mud everywhere, and all I got for all that is a propensity for catching the flu every year.
My brother grew up when we started moving out of this sort of environment (so he had 4 years less of this) and he falls sick much less than I do.
I don't think that a faraway childhood affects resistance to the flu, right now, significantly. Maybe to some of the maladies mentioned in the article. The fact is the immune system is an engine, just like everything else in the human body. People who exercise more get sick less often. People who exercise more get sick less severely. People who have sex more often have more immunoglobulin A. People who sleep more, get sick less often.
If you get the flu more often than you'd like, start exercising more, having more sex, or sleeping better. Ideally all three.
I promise there are plenty of patients with autoimmune disease who had childhoods just like yours. I don’t want to sound hostile but “I am not sick, because I do/did X” is a) not scientifically useful and b) somewhat insulting to patients who suffer from chronic illness. The truth is everyone has risk factors for most diseases and there is still an incredibly large probabilistic element involved - some people are just lucky. This will likely change in the future as true causes are identified of course.
The hygiene hypothesis is interesting but it’s far from proven and there are competing theories for many autoimmune diseases involving pathogens. The trendy attitude of “people were so healthy back when society was simple”, however, is blatantly false. People overall, by any reasonable metric, have better health today than they have even had in the past. As we invent vaccines and improve treatment options we simply forget about the burden of diseases that no longer exist.
There's no need for comments here to be scientifically useful. HN threads are simply conversation. Anecdotes are not only welcome, they're conversation's life blood.
Indeed; when John Leal added chlorine to water in the early 1900s infant mortality was cut in half. After chlorination spread to most US cities this effect was replicated everywhere else too. Typhus outbreaks went from a sea-saw pattern to almost zero within a few years.
Yes we need some exposure to germs. Vaccines are an excellent way to do that without the risk of catching the disease.
Yes we shouldn't go overboard with antibiotics or stop kids from playing in the dirt. But there are plenty of health measures that are clearly beneficial despite lowering our exposure to germs.
This isn't a peer reviewed journal, we're just a community chatting about stuff, so that's not really a germane standard. Anecdotes are a perfectly reasonable input into our personal Bayesian inference filters, since no one has all the answers yet (not even close).
But beyond being a humblebrag, it's also bordering on a just-world view of the universe that's basically superstition.
Without reference to a larger dataset, the inference "I"m never sick because I played in the woods and ate weird stuff. If you get sick a lot, it's partially your fault because you didn't do that." could easily be replaced with "I'm never sick because I prayed to the right god every day. If you get sick a lot..."
Don't know exactly where to leave this comment but:
could it be that some of the cases we see are linked to the nocebo (I think this is the word, opposite of placebo) effect?
People who are used to dirt knows that they'll handle this alright because they always have lived in these conditions? While people who grew up in cleaner conditions get tricket into a bad feedback loop where any sign of anything wrong gets amplified by the brain and fed back to the autonomous part of the nervous system? (I happily admit I'm on thin ice here.)
Placebo and nocebos are pretty strong effects. Recently we had an incident where a number of postal workers were sent to hospital with rashes after having handled a suspect package which contained white powder. The powder later turned out to be flour.
I have also managed to get, and cure myself from side effects by 1. Reading about the side effects and experience them first hand. 2. Get rid of them immediately once I could proove to myself that they were related to me thinking I had taken my pills, while they were actually still on the countertop.
Maybe for minor ailments but absolutely no way for real hardcore autoimmune disease. Usually there are several objective abnormalities in blood results, on x-rays, colonoscopy, MRI etc. Have a look at some images of the hands of someone with rheumatoid arthritis - there's a lot more going on than placebo/nocebo/anxiety.
It's placing blame for a general problem on the decisions and values of certain people and societies.
In terms of logical structure, taking an anecdote and universalizing it without a falsifiable explanatory mechanism is indistinguishable from blaming faraway natural disasters on other people sinning against the gods.
In both cases, people and society are held to be at least partially culpable for something bad that happened to them without presenting any evidence other than that they don't do all the same things that you do, and you're doing fine.
A wild hypothesis here. One thing I noticed in "pre-Western" diets that's absent from modern ones is unpasteurized dairy. All milk sold in Western countries is pasteurized (treated thermally to kill most of its bacteria). If you leave on a shelf, it will remain unspoiled for quite a long time compared to unpasteurized, but when it does spoil, it becomes completely undrinkable, with foul smell. Unpasteurized milk, on the other hand, has a much shorter shelf life, however the spoiled product is acidic and yogurt-like, has no foul smell, and is (mostly) safe to consume, even by people with some degree of lactose intolerance (it has had most of its lactose converted to lactic acid, hence the sour taste). This so-called Soured milk (https://en.wikipedia.org/wiki/Soured_milk) is extremely commonly consumed in many Eastern European countries that don't have Western food safety standards.
While there may be other beneficial (to the immune system) things happening in Russian Karelia, I can't help but wonder if the absence of unpasteurized dairy is the single massive thing that causes failure of gut microbiomes in the modern world.
Considering that eating dairy at all is a relatively modern invention (post-agriculture), I suspect not. Is there any evidence at all for the beneficial effect of bioactive dairy products on the gut microbiome, beyond yoghurt commercials for middle-aged women?
> Is there any evidence at all for the beneficial effect of bioactive dairy products on the gut microbiome, beyond yoghurt commercials for middle-aged women?
1) Considering that the original article is about autoimmune disease, it's possible that there is a critical time period during early age (<3-4 years) when it is important to consume a particular substance, and beyond which the substance is completely ineffective---i.e. marketing to middle-aged ladies is great because they have money to spend, but the fact that this marketing exists is besides the point. 2) It wasn't my goal to present a finding for which there is lots of available evidence, but rather the opposite---to suggest a possibly under-explored area.
When presented with milk, many adult mammals (including some humans) will drink it. Humans are simply better than most at getting their way with other species -- this is the primary difference, is it not?
For example, I have seen apparently healthy and non-starving adult black bears, some dogs, and cats happily consume cow milk if it is available. There are pros and cons to it, for sure, but there is clearly nutrition present.
That's because they don't get it isn't it? Many of them will happily drink if they get. Like cats as has already been mentioned, or our horse when we were young, who would sneak upon our dairy cows to steal milk.
Drinking milk has been around for more than long enough for (some of) us to have evolved dependence on it. Not saying that we have, but "other animals get by without it" is not a slam-dunk case.
I find it really interesting that all of the replies to this comment take the fact that animals will consume dairy if it's available as an argument in favor of human consumption of it. Humans are the only animals, that as adults, take the milk of another mammal for their own consumption.
For that matter, other than the isolated, exceptional cases of a lactating mammal adopting the orphans of another mammal and nursing them, humans are the only mammals that consume the milk of a different species.
Cats drinking from a saucer of milk put on the floor in front of them is nothing like milking a cow — except, I suppose, at the level of digesting lactose.
What I find interesting is that the health benefit (or non-benefit) of milk for adult humans is completely irrelevant to the discussion. Autoimmune disease (the topic of the original article) develops at a very early age.
> Name one mammal besides humans who drink milk as adults?
I'm sorry, but your comment is completely irrelevant to the discussion. The original article is about autoimmune disease that develops at an early age. Whether you drink milk as an adult or not would have had no impact on the development of the disease. If you like your non-milk diet, you can keep your non-milk diet.
I lived most of my life in St.Petersburg and was spending each summer vacation in the country side near Karelia. Homemade soured milk is nowhere as popular as kefir from stores. Also all the shelf milk is pasteurized, you need to know a cow owner to get raw milk.
It's possibly one of the things, but I doubt there's a single factor in play here. You could have a similar hypothesis about urban people having less contact with dirt and mud and animal feces and all kinds of wild plants and insects that one living in a rural area would commonly encounter throughout her life. The other theory blames the lack of parasites that suppress our immunes system reactions. Some say it's the pollution in urban areas. And it's probably some sort of the combination of all of these, since they all are certainly a factor influencing our immune systems.
The scientists had periodically sampled the children’s microbes, and when they looked back at this record, they discovered that the microbiome of children who developed the disease changed in predictable ways nearly a year before the disease appeared. Diversity declined and inflammatory microbes bloomed. It was as if a gradually maturing ecosystem had been struck by a blight and overgrown by weeds.
I wonder if they looked at antibiotic use. Wealthier countries often have better medical access. Perhaps it isn't that poor countries are "dirtier" so much as that when kids do get ill, they are less likely to get nuke-em-from-orbit antibiotics, use of which is known to have a scorched earth effect on the gut. The gut is about 70 percent of the immune system.
I really dislike the hygiene hypothesis. I have reversed a lot of the symptoms of my so called auto immune disorder in part by staying impeccably clean and avoiding exposure to germs as best I can. To me, this "a dirtier world is better for you" line of reasoning just does not make sense. It would make a great deal more sense to me if the conclusion was that casual use of antibiotics does egregious harm to the biome in the gut, from which some people never recover. Modern doctors are perfectly happy to prescribe antibiotics and I don't think I have ever had one tell me that I need to consume yogurt afterwards to foster healing of the damaged gut biome.
Autoimmune disease rodent models don't translate well to the clinic, so an academic group tried to look for reasons. They found that normal, healthy humans have far more memory B cells than lab mice, which may be a major factor.
So they looked at wild mice and pet store mice. Wild mice had a lot of memory B cells, but pet store mice had the most. They found you can house pet store mice with lab mice, and the lab mice will eventually increase the number of B cells, but you lose about 20% of them.
- In Finland 80% of 3-year olds have had ear infection.
- 53% of 2-year olds are in daycare. Due to various reasons group sizes are getting bigger and bigger, new normal can be around 30 kids in a single daycare group (=constant infections...)
- Half of the kids have private health insurances (public outpatient care has some issues..)
- Typical treatment for ear infection(although many times unnecessary) is antibiotics.(=to keep parents happy / easier for the doctor)
These findings are very preliminary, but they support a decades-old
(and unfortunately named) idea called the hygiene hypothesis. In
order to develop properly, the hypothesis holds — to avoid the
hyper-reactive tendencies that underlie autoimmune and allergic
disease — the immune system needs a certain type of stimulation
early in life. It needs an education.
I think it's funny that we Western people get so quickly sick from street-food in Asian countries (e.g. Thailand), while most locals have no problem eating the food.
> I think it's funny that we Western people get so quickly sick from street-food in Asian countries (e.g. Thailand), while most locals have no problem eating the food.
I can eat food in Shanghai without suffering from traveler's diarrhea afterward. It took a while to get to that point.
With exposure, you'll develop tolerance for the local food. Hopefully, all of the locals have already had that exposure.
A study with low power is perfectly alright for an exploratory study that is not meant to prove anything but to check if it's worthwhile to spend a lot of resources on an idea in the first place.
> 1. Exploratory research generally utilizes small sample sizes and, thus, findings are typically not generalizable to the population at large.
> 2. The exploratory nature of the research inhibits an ability to make definitive conclusions about the findings.
> ...
The problem is when exploratory studies make it to the media and people confuse them with studies meant to settle questions rather than just raise them.
As an illustration of LionessLover's point, compare "under treatment, two patients regrew their lost arm, compared to zero in the control group". The statistical power of that study just isn't relevant.
>The newborns were equally divided among Finland, Russia and Estonia, where the prevalence of Type 1 diabetes is on the rise, but still well below Finland’s.
very telling giving the history of Estonia during last 25 years.
> Preventing autoimmune disorders may require emulating aspects of that “dirtier” world: safely bottling the kinds of microbes that protect the Russian kids, so we can give them to everyone
Ok, so where's the productization? Where's the startup?
Surely this product/service already exists in some form or other, somewhere
I like your thinking, kinda surprised you got downvoted on HN for it.
One angle is the use of parasites to treat autoimmune diseases. It wasn't mentioned in the article, but hookworms are being studied for their ability to secrete a wide range of immune-modulating molecules. Companies are trying to determine which molecules are especially useful, and in what combination, so they can synthesize them and sell them.
But, you can get their beneficial effect right now, which is very appealing to people with major autoimmune diseases. Some companies are selling parasite eggs by mail to people who otherwise can't get them. I have MS, I take them.
It's not a lucrative business, and there are a lot of regulatory hurdles, but the treatment is quite safe.
Most people are disgusted by the idea of infecting their self with parasites. The reality is that humans evolved with parasites constantly inside of their bodies. It's only in the last 100 years that widespread anti-parasitic medication has wiped them out.
That did a lot of good for society in general, but we took it too far, essentially, by wiping out parasites entirely. There are a lot of benign "parasites", which should be thought of as symbiotes.
The way that big pharma is dealing with this is as mentioned above: they're trying to synthesize the right stew of immune-modulating chemicals to deal with this. But the immediate solution is to educate people, and sell them clean, safe parasites (or their eggs).
It's also nice if they live a long time in their host, and don't reproduce inside of the host. This is why Necator Americanus is mostly used; it fits all of these characteristics.
The way that big pharma is dealing with this is as mentioned above: they're trying to synthesize the right stew of immune-modulating chemicals to deal with this. But the immediate solution is to educate people, and sell them clean, safe parasites (or their eggs).
Coronado Biosciences was running clinical trials using pig whipworm ova to see if it had an impact on inflammatory bowel disease (Crohn's and ulcerative colitis). Turns out there was no observable effect.
Thanks for your reply. (Yeah, it's not clear to me why some of my comments get downvoted. Maybe in this case it's because I seemed insincere, as if I were promoting someone's pre-existing business or something? Or maybe they figured I should just research this for myself. Or maybe they thought I was trying to just put a low-information comment, cheap-shot, for more karma points. Or something. Not sure.)
Anyway, it's interesting to hear about the hookworms and your direct experience with them. I'd be curious to hear more about your experience with that therapy, if you are willing/interested to share it.
Basically, I wonder in what circumstances would you recommend that therapy to others who have an autoimmune condition? (e.g. for all cases, just some cases, cases that did not respond to drugs, diet, etc.) Is it a first resort, or a last resort or something in the middle, etc. ?
It already exists as an informal social arrangement!
When I was a small child and caught chickenpox several of my friends were brought round to play so they could 'safely' catch it as children, rather than waiting to catch the altogether nastier grown-up version later in life.
I suspect my mother didn't charge for the product/service , although that may be because she couldn't get a node.js stack up and running.
I've read speculation that chickenpox is a seasonal disease, and that one difference between severe cases and mild cases is the child's vitamin D level.
It is unfortunate that children are now commonly vaccinated against chickenpox. This is a weakling virus that barely kills anyone, and more good could be done by figuring out factors that help children have a mild case.
Why would I not say that face to face? Do you think any negative reply to anyone is bad? What horrible rose-colored world do you live in? How about you adjust your sensitivity setting? It's on an unhelpfully low level that prevents normal function and utilization of normal communication.
I also find it how remarkably consistent my experience is that people who complain about "tone" never, ever have anything to say about the actual subject.
Drive-by snark is deprecated on HN, but personal attack, which you crossed into here ("What horrible rose-colored world do you live in? How about you adjust your sensitivity setting"), and have unfortunately done previously as well, is outright not allowed.
Please stop doing this and post civilly and substantively, or not at all, from now on.
Sarcasm is a valuable tool in the human communication arsenal. If you want to do without it, be my guest, but don't try to dictate your subjective preferences to others who have what I would claim is a more mature and more healthy attitude towards the beauty and variety in human language.
And the "petty" is all in your head. There are too many people who blame others for what's in their own head.
Sarcasm can be very valuable. It can also be used to contemptuously insult someone when a simple rebuttal would suffice.
The latter is an immature, weak intellectual position (see Appeal to Ridicule and Question Begging Epithet) that says nothing more than "you are so wrong as to look asinine".
This only fosters more emotional, insult-riddled dialogue, which is why the user above quoted HN guidelines, which you are now impotently raging against. This is a pretty civil place, we like to keep it that way.
I had a wild childhood: it happened to me to eat hamster food from his cage, eating dirt, eating sand, raw tomatoes directly from the plant, drinking waters from random streams; drinking raw milk without boiling it few minutes after milking it by hand, eating raw eggs, and when I wasn't in school, like during the summer, I had one shower per week, or less...
Don't worry: growing up I am back to civilization. But I have to say that I am never sick. Also during winter.
I pity all those kids and their urban childhood, they will have to endure weird intolerance to random things. I am grateful to my parents.
Back then growing children was still a simple thing, nowadays mothers and fathers are so scared by society.