[justaj]

For me this link results in a 503

I've read the gist of this article in my local news org feed. What it basically comes down to is that Finnish scientists noticed that Russian children who grew up in rural areas usually had way less asthma cases than Finnish city children, and thus began to research why this was the case. They hypothesized that early (first 10000 days) exposure to micro-organisms might play a key role in training the immune system not to over-react to (harmless) micro-organisms later on in life, and thus "train" the immune system better. Their hypothesis now seems to have been validated.

Basically this comes down to the hunch I had for quite a long time: Isolating children into an almost clinical environment is not a great way to boost the immune system. This might explain why there are so many people with allergies. People living too cleanly and not getting exposed to (benevolent) micro-organisms so that their immune system prepares them when exposed to later in life. I think that's one of the reasons that kids that are around pets early in life usually have lower risk of developing allergies later on.

The reasoning went like this: We've spent most of our evolution in caves digging in dirt, and now (relatively) recently we have been transported into an environment where we can pretty much have the cleanest settings. What do you think this will do to our immune system?

[stavros]

When I was young, I would play in my (outdoor) sandbox and then lick the dirt off my hands, because it tasted good. I still got asthma, though.

My hypothesis for why children in rural areas get less asthma is because there's less air pollution, not because they eat dirt.

[rwyinuse]

It's all quite random and also depends on genetics. I lived in rural area with very little air pollution, played outside. Yet I got multiple allergies, including hay fever, and hay was plenty in the area. Many of my close relatives have some auto-immune related diseases as well.

[xboxnolifes]

These sort of events tend to happen at the statistical level, not the individual level. You can't disprove them from one instance of a negative outcome. It's like saying you smoke but never got cancer, or you don't smoke but still got cancer.

[somedude895]

Licking dirt off your hands isn't the same as being exposed to pollen.

[lazide]

In an outdoor sandbox? Sure it is. Where do you think all that pollen goes when it falls out of the air?

[TheSpiceIsLife]

Is there more or less pollen in rural areas?

[DebtDeflation]

This is known as the "Hygiene Hypothesis".

https://en.wikipedia.org/wiki/Hygiene_hypothesis

The basic rationale for it is that the human genome did not evolve in a sterile environment, it evolved in an extremely hostile environment, and so developed pretty harsh defense mechanisms, which if not trained (via early exposure) on the appropriate targets will instead learn to target harmless compounds as well as the body itself.

[rdedev]

I see it as more of a side effect of an immune system that is designed to adjust itself for whatever pathogens are present in its environment.

Depending on where you are born, you can be exposed to a completely different set of microorganisms or compounds present in the environment. Your body first needs to know which of those are benign and not. A simple heuristic is to tolerate most of these that you have been exposed to till a certain age.

But hey this is just my armchair biology. Don't know if there is anything supporting it

[krisoft]

> first 10000 days

A 10000 day old “child” is in their late twenties.

[jl6]

Whippersnappers, we call ’em.

[grues-dinner]

Reminds me of the comment in Gattaca that his heart is 10000 beats overdue. Which is about 3 hours.

[kbelder]

First 10000 days, second 10000 days, then you die.

[makeitdouble]

This reasoning seems to work for some cases and not others, so there might be a ton of other factors, potentially more impacting depending on your situation and genes. The article points at food and other immune elements (e.g. smoking, so I assume pollution also) for instance.

For instance Japan has a known pollen problem. There there's no correlated action to keep small kids out of pollen (that would mean masks, not playing outside at school etc. which are measures extremely hard to take), nor to prevent anyone from getting pollen if they're not known allergics. They go to school and have to be outside for significant time.

Yet the allergy rate increased twofold in a decade, as the pollen presence also increased.

https://www.asahi.com/sp/ajw/articles/15622459

[cyco130]

Reminds me of a dark joke I sometimes make: Why are there no Turkish people above forty with nut allergies? Because they all died in early childhood.

[selcuka]

I get the joke, but I was born and raised in Turkey and I have never met a child or adult with nut allergy while I was there. I'm not saying it doesn't exist, but it's incredibly rare.

[cyco130]

I’m Turkish as well (and over forty). It’s a joke, I have no data on its prevalence except anecdotal. It does seem much more common nowadays than when I was a kid though.

[lazide]

Eh, no idea about Turkey, but sometimes it’s also a ‘what do people talk about when you’re around’ thing, and what do people actually recognize?

For instance ‘Asthma is incredibly rare in India’. Yet, having lived in India, I constantly ran across people with telltale Asthma symptoms (loud wheezing, lethargy, difficulty exercising, etc.).

I bet if you put those people on a peak flow meter, they’d all be diagnosed. I only knew 1 that got diagnosed though because ‘Asthma is incredible rare in India’, and also who can afford the time and energy to go to the Doctor?

Talking to a couple pulmonologists about Asthma in India (I got it when there!), they basically just laughed and said ‘at least this isn’t Delhi here, that is a gas chamber’.

For allergies, lots of people over time I’ve heard complain about things ‘tasting spicy’ that weren’t spicy, or seen people get facial swelling or hives after eating things. They just chalk it up to ‘oh yeah, that does it for me somehow. I guess I should stop?’. If asking if they have allergies, they just said no, we don’t get allergies here.

[lotsofpulp]

My parents' generation (1950 to 1970), born and raised in South Asia, had near zero infant mortality, and have zero food allergies. I have never met an aunt or uncle (out of hundreds) who have had a dietary restriction, and south Asian food uses just about every nut and spice and vegetable on earth.

In addition, the subsequent generation, my cousins, also have zero allergies. It isn’t until the kids born in 2000 and later that we see any allergies.

I found it funny when US doctors prohibit honey for kids until 1 year old due to risk of botulism, but one of the first things my culture does after a baby is born is give it a drop of honey for good luck. I wonder what the risk of botulism really is, because I have never heard of a baby suffering from botulism in my parents’ and my generation.

[lostlogin]

Are you claiming that their country had zero infant mortality, or zero infant mortality from allergies?

[lotsofpulp]

Sorry, I meant only my family, not the country. As in no parents experienced the loss of a child (born ~1950s and beyond) due to an allergy or an unknown cause (e.g. maybe they did due to a car collision, but not an undiagnosed allergic reaction). Point being that exposing all of those kids to all foods very early did not result in a single one dying. And neither did their kids.

Obviously, I am not advising anyone to not follow their doctors’ instructions, but the sheer numbers in my anecdotal study make me wonder.

[lostlogin]

You wouldn’t be the only one to question that. There is a theory that a popular children’s snack which contains peanuts is responsible for a low rate of peanut allergies in Israeli children.

https://pubmed.ncbi.nlm.nih.gov/19000582/

[MostlyStable]

For peanuts specifically, early childhood exposure is pretty well validated to reduce allergy incidence at this point [0]. It's by far the most well validated case of the allergen exposure hypothesis. Interestingly, for the high-risk subset of children, early exposure is likely to increases incidence. Children with conditions like eczema, where the skin barrier is broken and allowing peanut proteins to get through the skin rather than purely orally, is thought to be an allergy development risk factor.

[0] https://scholar.google.com/scholar?hl=en&as_sdt=0%2C38&q=ear...

[potamic]

Checks out in India as well where allergy levels are as low as hygiene levels.

I think you have typo with 10000 days.

[justaj]

I suppose as with everything, there's supposed to be some kind of balance / ideal set of circumstances.

And yes, I mistakenly added an extra 0.

[addicted]

India doesn’t have low hygiene levels.

Thats nothing more than a racist TikTok trend.

Indians do have a different conception of public urban space which matches more closely with how the urban public in Europe would treat public space a 100 years ago, but that’s not surprising because proper urban cities in India are about as old as urban cities in Europe were a 100 years ago.

[rdedev]

Look I've lived in India my whole life and this is how it is there. People take a lot of effort to keep their homes clean but public property? Nope. Not my responsibility not my problem, that's how the thinking goes there.

And besides what is the point of talking about how Europe did it 100 years ago? We know better now and still we are not taking an effort to instill some basic civic sense here.

[birksherty]

You are wrong. Either you don't live in India or live in a bubble in rich area and too privileged.

It's not racist when it's true. People are disgusting here and makes me want to vomit in times from what I see. There is no self awareness among Indians unless they live in rich well off area in India and move in their expensive cars.

[mightypirate]

you either never been in India or outside of India (not Pakistan)

[ajuc]

I have allergy, asthma, colitis ulcerosa. I'm allergic to hay, pollen of trees and grasses, dust mites, cat saliva, etc. I've lived in countryside till my 20s, then moved to a big city.

My allergies got better when I moved to a city (probably because there's less allergens), but when I return to the countryside it's still bad (usually it's the worst for the first few days). At least it's not as bad as when I was young (I usually spent a few weeks each year at hospital because of asthma befoer I got 18).

When it comes to air pollution - I grew up during communism in Poland - we had asbestos roof (eternit), everybody was heating their homes with dirtiest and cheapest coal during the winter, and A LOT of people smoked like locomotives. It changed slowly over time.

IMHO there's way too many factors to reduce this to one factor (like sterile environment early on). It probably helps not to have it, but it's not a simple 1-1 relationship.

[sofixa]

> The reasoning went like this: We've spent most of our evolution in caves digging in dirt, and now (relatively) recently we have been transported into an environment where we can pretty much have the cleanest settings. What do you think this will do to our immune system?

The same it did to our infant and maternal mortality, make it lower?

[mixermachine]

Less protection then? Yes. So when something hits you later on, the system is not trained for it.

It's not about throwing infants in a dunghill first thing after birth and let nature take its course. It's about gradual exposure when the system can slowly get used to it.

[giardini]

"They hypothesized that early (first 10000 days) exposure to micro-organisms might play a key role in training the immune system not to over-react to (harmless) micro-organisms later on in life, and thus "train" the immune system better. Their hypothesis now seems to have been validated."

10000 days is 27 years, which seems an order of magnitude too large. 2.7 years(~ one thousand days) would be about right, perhaps?

[greg_V]

Anecdotal backup: as a child I had a horrendous dust allergy that led to multiple hospital visits. To mitigate the problem, my mom became a clean freak, trying to keep our apartment dust-free. The allergy persisted until I grew up and moved out on my own without having a vacuum cleaner. Living in a messier environment led to the allergy basically disappearing.

[makeitdouble]

Could it have been an allergy to something other than dust ?

I have an allergy to a specific cleaning product ingredient for instance, although I never got to know what exactly. It was not something commonly used, I never triggered it by myself and only reacted when helping cleaning a friend's house decades ago.

My kid also seems to have it, but again it only ever happened once at a shop, and no allergy test raised it (other stuff were found though)

"dust" allergy is sometimes complicated.

[ajuc]

Counter-anegdote. I grew up in the countryside, I am allergic to hay, pollen, dust mites, cat and horse saliva, and more.

I moved to a big city when I was ~20 and my symptoms got better, but I'm still allergic to all that - it's simply not putting me in hospital anymore.

Doctors told me most people grew out of the worst symptoms over time.

BTW I also somehow got allergic to kiwi fruits between primary school and my late 20s. I ate them rarely and at one point I found out they make me throat swell like a balloon. Didnt' happened before.

[matsemann]

I always joke the reason I'm never sick is that I don't wash my hands after using the toilet. I do of course wash my hands, it's mostly to get a reaction out of my GF, but I guess there is a balance between cleanliness and exposure. It's how vaccines work, right.

But being exposed to the wrongs things can also be bad. The small mountain village I grew up in is partly famous for it's children hospital ("Geilomo barnesykehus"), where kids from the 1930s and onwards would come to live, since they would be better here than in the city. Like kids with asthma and lung diseases could live a much more normal life here.