I also wonder about this. They say that children who grow up on farms have stronger immune systems because they are exposed to the natural environment more. Weirdly, they also have low incidence of food allergies.

Do children who attend daycare eventually develop a much stronger immune system? (No idea how this could be scientifically measured.) I also wonder about doctor's who work in the emergency room. How are they not constantly sick with some kind of common cold / flu / bronchitis? They must have the immune system of a super hero.

> They say that children who grow up on farms have stronger immune systems because they are exposed to the natural environment more. Weirdly, they also have low incidence of food allergies.

I have many siblings (more than 9). All of us grew up on an active farm except the youngest one. None have had any food allergies except from my youngest brother.

> I also wonder about doctor's who work in the emergency room. How are they not constantly sick with some kind of common cold / flu / bronchitis?

A colleague of mine told me his wife would eat anything that had expired best before date etc while she was in training, just to build her defenses.

I cannot vouch for this theory but maybe someone else can tell if it is a common tactic.

(I think it sounds weird.)

> A colleague of mine told me his wife would eat anything that had expired best before date etc while she was in training, just to build her defenses.

I lived for 5 years in a college dorm sharing bathroom/toilet and a communal kitchen with 14 other students. I am not quite sure it built up my immune system. I managed to get the swine flu back then, too.

This reminds me of another dorm story, a friend of a roommate always washed his hands when he came of the bus and visited. And I distinctly remember how we all felt that this was somewhat weird, obsessional, when in retrospect it just feels prudent and I don't really think he showed signs of pathological obsession. Its interesting how standards change.

As to eating stuff past expiry date: my wife tends to stockpile yogurt and dairy products in our fridge, not that uncommon that they were past their date. Turns out, since they are pasteurised they are often still good weeks after their best-before date. I actually don't think there is much in them to train your immune system (unless they are spoiled and I don't think fungal toxins is something you voluntarily want to put in your body).

Best-before dates aren't meaningful.

> Contrary to popular impression, the current system of food product dating isn’t really designed to help us figure out when something from the fridge has passed the line from edible to inedible.

> For now, food companies are not required to use a uniform system to determine which type of date to list on their food product, how to determine the date to list or even if they need to list a date on their product at all. [1]

[1] https://theconversation.com/how-do-food-manufacturers-pick-t...

Children who grow up with dogs and cats are also less likely to have allergies and asthma. [1] Lovable little filth monsters drag in all sorts of stuff, I guess haha.

[1] https://www.webmd.com/allergies/news/20180716/can-dogs-keep-...

Sadly pets and farms still aren't a cure all. I grew up/live on a farm with cows, cats, and usually a dog. I've got a lot of environmental allergies and a few food ones, and my day to day symptoms can be pretty bad, especially this time of year. Oh well, who knows how much worse I'd be if I hadn't grown up on a farm.

> Do children who attend daycare eventually develop a much stronger immune system?

I would say so, yes. Your body remembers what viruses it's already fought, and will remain primed (for a significant time) to fight it again. Kids exposed to lots of illnesses when young, should end up with a more robust immune system in adulthood.

This is why chicken pox parties are a thing.

Yeah, we have a toddler right now too, and if I’m estimating, during the months of October - February over the last three years I would guess I’m at least a little sick half the time.

The one that shocked me was rotavirus. At the time my kids were little it wasn't part of the regular vaccination regimen here in Ontario yet, was optional and our doctor didn't tell us about it. The kids both got it at the same; wasn't a huge deal for my son who was still breastfeeding, just had some diarrhea. But my daughter is three years older and couldn't keep food down for many days and lost a few pounds was very unwell. Awful.

Both our kids had stints in an isolation ward being fed/hydrated through a tube with rotavirus at ages around 3-4. They couldn't even hold down small amounts of water for days. I could see how it kills so many kids in developing countries without access to that.