Not sure how widespread this advice is, but my son’s pediatrician had us start introducing peanut butter before he was eating solids by adding progressively more peanut butter to his bottle. So it feels like this is becoming the recommended approach to avoiding food allergies.

It’s become more widespread guidance in the last decade. There are a few studies iirc comparing cousins living in the UK as opposed to Israel. The Israeli kids get a peanut based cracker as a common snack and have much lower incidence of peanut allergies.

I think in the US the issue is that there isn’t a ton of published material on it. My info may be out of date as my kids are well past this stage.

One thing to be careful about here, and I don't have any data or skin in the game here, is survivorship bias. It would be worth noting the difference in deaths from anaphylactic shock in very early childhood by country.

I guess what I'm getting at is that you might not be counted as having a peanut allergy if you're dead.

Essentially illegal in the US though, given school requirements.

Decidedly not. There's plenty of meals given to kids outside of school to perform this intervention, it doesn't need to be in every meal on top of what other people have said about the timing.

No, its not. For one thing, schooling (even preschool) starts well after the target age for this.

How many kids do you think there are in schools who aren't eating solid foods yet?

Many many people put their kids into daycare at 3 months of age since that’s all they get for maternity leave.

In the US 25% of mothers are back at work within 2 weeks of childbirth (https://www.vox.com/2015/8/21/9188343/maternity-leave-united...). FMLA requires jobs to let mothers take time but does not require they be paid, and most folks are living paycheck to paycheck and need the money.

It's 25% of the all mothers or 25% of the mothers that were working before the birth?

It's a Department of Labor study, so presumably done on people already in the labor force. Doesn't change how terrible the stat is, even assuming 50% of mothers aren't in the labor pool that'd still be 12% of mothers back in work in under two weeks.

I knew this before, as a fact like any other.

Now that I've recently become a parent, it's... it's shocking. The idea of handing someone that young and helpless off to strangers raises a strong "NO!" reaction, right from the gut instead of the brain.

In my neck of the woods we get 1.5 years maternity leave, and experiencing it myself I'm honestly not sure even that is enough.

Strong agree. My son is nine months old now and if we had to put him in day care tomorrow, I wouldn’t mind. It takes a village and all that. Happy to delay that a little while longer, though.

But three months is just unthinkable.

A relevant book, coming out next week:

https://www.penguinrandomhouse.com/books/675683/poverty-by-a...

Where I live (The Netherlands) we had multiple child care professionals recommend we feed the baby both egg and peanut butter as early as possible specifically to prevent allergies as well, so I don't think this is controversial in the medical community at least.

however, there are other factors to keep in mind.

you mention giving your chewed up food: I read a few years ago that babies who sleep in the same bed as the parents have a much higher mortality rate; assuming it's true, I guess that with mouth to mouth germ exchange it would be even worse.

Also, a lot of food today is full of chemical residues etc that are tolerated by adults, not quite so by babies.

Why would exposure to more germs be bad? Seems like it would be positive.

If you’re talking about sudden infant death, I don’t think it’s related to germs, although it’s a poorly understood phenomenon.

Isn't the mortality because of SIDS? It has not much to do with germ transmission.

SIDS and also suffocation, which is now separated out from SIDS.

However, in recent years there has been a backlash to the backlash, and under certain conditions (no drugs/alcohol, exclusive breastfeeding, no blankets) some doctors will recommend co-sleeping. It’s controversial.

> Isn’t the mortality because of SIDS?

SIDS isn’t a cause, SIDS is a name for when no cause is known.

Is also a concession to the parents whose kid probably just died of suffocation. Much like the historical trend of not reporting overdose deaths.

SIDS is very poorly understood, but highest probability seems to be that it’s not germ related but related to breathing (more like complex sleep apnea for infants, where sometimes a baby has a messed up breath response. This tracks with SIDS seeming to have a strong genetic component). For what studies we do have, yes sleeping with the parent seems to have a marginal increase in SIDS, although less of one than things like having a loose blanket in a crib.

Ultimately risk falls off around four months though, so yeah maybe 2.5 months is a bit early to try weird things.

Afaik, babies have weak neck muscles and can't lift their heads. I remember also reading that really small babies can't breathe through their mouth. So it seems easy to imagine a situation where the babies airway is blocked and it can't help itself.

Both things you say are correct. And as far as I've seen on most recent studies it is indeed related to some sort of deficiency in the signaling from the brain to "wake up" when oxygen is low, with suggestion that there's a genetic component to it (sorry no link to the study I saw).

Basically the SIDS risk as understood currently is like you said: obstruction getting in the way, baby not waking...bad outcomes. Co-sleeping with the parents increase risk by bringing pillows, blankets, themselves into the bed to add obstacles or opportunities for the infant to suffocate.

It's a highly nuanced topic. In my parent's day it was common for babies to be put to sleep on their stomach whereas now the advise is to back sleep even though there's increased risk for flat head, but lower risk for SIDS. Once the kid is able to turn themselves it becomes much more simple as they'll move around throughout the night so back/stomach becomes a non-issue once they reach that age.

A parent rolls over in their sleep and suffocates their infant. A tragic accident. Writing up the cause of death as unintentional homicide, or even an accident, won't do anybody any favors; it would only cause emotional anguish to the parents. So instead the cause of death is "SIDS."

I'm not saying this is what happens in every instance, but it's probably the way it happens at least some of the time.

>Train how you live as soon as possible.

There are dangerous caveats to this advice! For example, don't feed infants fish or shellfish more than this allergy test. They contain one of the highest levels of mercury in the entire food web. Best to wait until the they've grown.

Unless you feed them huge quantities of seafood, I fail to see how this is an issue.

From an allergy standpoint small exposure would be enough to reduce risk of developing an allergy.

The new FDA risk-benefit analysis is currently ongoing and will be published later this year. Right now, it's no more than 2oz/week for certain fish.

https://www.nationalacademies.org/our-work/the-role-of-seafo...

Even small amounts of mmercury during early development can have significant effects.

Most seafood is actually very low in mercury, only a few species that are high in the food chain (e.g. shark) are high in mercury due to bio-magnification.

Moreover, it has been observed that traditional fishing cultures that have a high mercury intake have zero symptoms of mercury toxicity. The leading hypothesis of this is that the high selenium content in these same fish is protective against mercury exposure[1]. Consider also the observation that cultures with high fish intake have good health outcomes, and that omega-3 supplementation fails to recover those benefits. This makes me feel that eating a lot of fish is likely much healthier than avoiding it, and avoiding it is probably leading to nutrition deficiency, including possibly selenium, which is a much bigger risk than the potential for mercury toxicity.

[1] https://www.sciencedirect.com/science/article/abs/pii/S01618...

Did I not read at some point that nursing mother eating the allergenic foods offer some benefits to the child as well?

This is one of those grandma’s tales that I’ve heard. Feeding pregnant women (and nursing mothers) a diet that is varied in nature allows the child to be healthier and allergy free.

On the other hand, my mum did the same to me with muesli and I developed a nut allergy.

Could also be related to hay fever if you have that. [1]

I had allergies for basically all my life but the food stuff only started at around 10 or 11 years. Now I can't really eat any uncooked fruit, vegetables or nuts. Interestingly enough, most citrus fruit are just fine, something with not being exposed to those pollen maybe...

[1] https://en.m.wikipedia.org/wiki/Oral_allergy_syndrome

yeah 70% not 100% some people will still develop allergies

Exactly

How in tarnation did anyone think keeping babies away from the allergens would help with allergies is beyond me

Which countries has the least amount of peanut allergies? Countries where people give it without much concern

Thanks to these misguided though there are people severely allergic to peanuts

> How in tarnation did anyone think keeping babies away from the allergens would help with allergies is beyond me

No one, AFAIK, thought it would reduce the rates of people developing allergies.

What people thought was that it would reduce the rates of people having dangerous allergic reactions as infants (which it does) and that the longer term effects would not be so negative as to outweigh that benefit (which seems, in the case of certain allergens – particularly peanuts – to very much not be the case.)

Not saying that you're wrong, but your line of reasoning is incorrect. It could also have been because all the people with peanut allergies have died and the people surviving all have some sort of genetic advantage against peanut allergy.

Again, the above reasoning is wrong but not completely baseless.

I see what you mean, I'm not so sure if there's a genetic connection to allergies (specific to allergies, not intolerances, which are a different thing) and/or how strong it is relating to different elements

> This advice was never based on science.

No, it was based on common sense. If X causes problems, not doing X is generally a good idea.

It turns out that in this particular scenario, common sense was wrong. But allergies weren't understood by science, so all we had to go on was common sense.

What’s “common sense” is drastically different depending on whether you assume a complex system is static or adaptive.

You can expose a six month old to honey as well but their complex and adaptive digestion system still isn't going to kill the botulism spores that might be in it.

"I don't know how this bad thing works, better rub it on my gums" is not a good strategy in general.

It's like vaccination ... few spores won't kill the child, and will train its immune systems.

Botulism spores do not "train immune systems". Babies don't have strong enough digestive systems until they're at least six months old to kill the spores.

https://www.cdc.gov/botulism/infant-botulism.html.

And that we should use the real scientific method instead of "common sense" disguised as science.

I have three children, and they had three different pediatricians when they were babies. The three pediatricians had a different incompatible list of food the children must eat when they had between 6 and 12 month old. And if you go to the web, there is even more disinformation and snake oil.

It was funny to compare the list of food of the pediatricians of my children with the list of foods of the pediatricians of the children of my friends. Also, sometime people get too attached to this recommendations and make a big mess if the children of a friend does not follow the rules of their own children.

(I think the only food in the intersection was honey, because it's too difficult to pasteurize. It make sense, but I'm not sure how thoughtfully it was tested.)

> common sense was wrong

I don't think that's been proven conclusively.

This is literally an article with proof that the previous guidance we was wrong and actively harmful to the children that were subjected to it.

This is literally an article that is pointing to a research paper that doesn't definitely conclude anything.

I'm not sure which article or paper you are reading?

The paper the article references says:

> A 77% reduction in peanut allergy was estimated when peanut was introduced to the diet of all infants, at 4 months with eczema, and at 6 months without eczema. The estimated reduction in peanut allergy diminished with every month of delayed introduction. If introduction was delayed to 12 months, peanut allergy was only reduced by 33%.

Edit: While I'm not sure what your standards are for "conclusive", the author's of the paper have drawn pretty strong conclusions and any doubts I see are around precisely how much the effectiveness of peanut introduction drops off with infant age, not about wether such a drop occurs.

Based on a population of jewish children in england vs. a population of jewish children in Israel, literally a repeat population from the first study 8 years ago.

The paper in question also states: "Moreover, it should be noted that since the change in Australian guidelines in 2016, consumption of peanut during the first year of life increased from 28.4% before the guidelines (2007-11) to 88.6% after the implementation of the guidelines (2016-18). Despite this change, a recent publication has shown no decline in the observed prevalence of peanut allergy in Australia in 2020, which remained stable at 3.1%."

It's been tried in a large population with literally zero effect.

No, it was based on what we now phrase as “an abundance of caution.”

One of these days I will draw a one panel image that demonstrates the fallacy of this thinking.

No, this was done from fear. My generation were given peanut butter early, and it was tested in a small amount to see if there was a problem first. This was common sense for a long long time, and it seemed to work fine.

A generation later parents were told to avoid it until age 3 or 4 for no real reason, and it created a ton of peanut allergies in those kids. They were scared of their kid having a peanut allergy. This was fear, counter to the common sense they themselves were raised with.

Peanut allergies were exceptionally rare decades ago when nobody worried about peanut allergies in the first place. In the 20th century everybody in America sent their kids to school with peanut butter sandwiches and virtually everybody was fine. I didn't even know people could be allergic to peanuts until I was an adult. Now schools ban peanut butter sandwiches and it seems like every other family claims their child is allergic to peanuts. Common sense says that we need to give kids more peanut butter sandwiches, like we used to, and it would stop being a problem.

Also, we should stop testing for allergies unless there is a good reason to test a specific person for a specific allergy (e.g. they already had a bad reaction to something, and need to figure out what.) Those allergen tests have many false positives, people that could have gone their whole lives eating peanuts without thinking twice about it will instead spend their whole lives avoiding peanuts because a precautionary allergen test came back sliightly positive and they "don't want to take the risk". More medical testing is not always a good thing.

This history seemed dubious, so I looked up a random 1989 allergy journal: "Peanut allergy is one of the most common food allergies and probably the most common cause of death by food anaphylaxis in the United States."

https://www.google.com/books/edition/Allergy_Proceedings/ecU...

Just because it was the "most common" doesn't mean much. It was still more rare in the past. Food allergies in general were more rare. It also says nothing as to how much it has grown if it is still the most common, eg. maybe it was most common being 20% of total food allergies where as now maybe that number is 50%. IDK just saying on surface this isn't much of a counter-argument.

This could easily be attributed to a lack of diagnosis. Less than 70 years ago it was common for the official cause death to be “natural causes”, which was the default catch-all when the cause couldn’t be attributed to anything else. Not for lack of trying, we just didn’t have the technology and wealth of research and knowledge until fairly recently.

Go read the obituaries in the historic New York Times archives, it’s insane. Infants and children would die and best we could do was shrug it off and say “god works in mysterious ways” or some such bullshit.

The narrative you are presenting is also based on common sense though.

We have observations that populations of kids eating peanuts early have lower allergy rate, but it´s not like we isolated 300 babies and experimented on them for 30 years, we just can´t. Short of other stronger evidence we assume it´s true, but if tomorrow we found that there were other causes specific to the US, independent from peanuts themselves, we´d have the same reaction: we didn´t know so we did our best.

> The narrative you are presenting is also based on common sense though.

Yes that's my point. Common sense was never with the peanut bans. Common sense was with peanut eating the entire time.

> Now schools ban peanut butter sandwiches

My kid's school bans anything that has those warnings about "not produced in a nut free factory". It's insane actually how limiting it is for a family with no allergies like ours.

> Common sense says that we need to give kids more peanut butter sandwiches, like we used to, and it would stop being a problem

Not sure if it was medically wise, but this was my common sense thinking too. Around 3-6 months, I figured we consume enough peanut butter in the house that if he had a severe allergy we'd have known by then (eg. accidental cross contamination). I also figured at this point he could survive the quick trip to the ER if needed. So I gave it to him and closely monitored his condition. First, just put a little on inside of forearm to see if any signs of irritation. Thinking perhaps a mild allergy may show itself this way, also thinking maybe his airway wouldn't swell up as initial symptom as it might with ingestion (would like to avoid that). It went well so shortly after let him eat a little. No problems. We did this similar approach with all of the common allergy stuff, no issues for us, although I don't know if I was fully informed of how allergies work or naively being cavalier with risk or something (I obviously didn't think so).

My daughter developed (non life-threatening) allergies to corn, eggs, and apples, all of which she had been exposed to plenty beforehand, so it's not necessarily that straightforward.

I don't see how it's common sense to avoid certain foods at a young age to avoid allergies later on. Am I missing some obvious connection? If allergies are caused by the immune system not recognizing X, probably the solution is to introduce X earlier.

They had "peanut-free" lunch tables when I was in elementary school, and all I thought was people just need to stop being so sensitive. Even then, guess I was right.

> They had "peanut-free" lunch tables when I was in elementary school, and all I thought was people just need to stop being so sensitive. Even then, guess I was right.

I'm pretty sure that by elementary school some kids have already developed severe peanut allergies. Keeping peanuts away from someone that might go into anaphylactic shock seems the right amount of sensitivity.

Per the article, the time to be "less sensitive" is much earlier when introducing peanuts can reduce their chance of developing an allergy. By elementary school (ages 6-13) it's mostly too late.

Yeah, that's true.

Perhaps the fact that the food could literally be poison for the person eating it? And if this person has no communication skills...

At least when you're 3 and talking you can be more clear about what's going on with your body if there's a problem.

"Why give them any food at all" is a very glib reply to them. I'll let you figure out why people might avoid certain foods and not others, and why people feed small children

So then I'm either underthinking or overthinking this.

> If you IDS has never seen X and X is unlike anything it has seen, it will probably flag it.

It's a whole lost more complicated than this, see for example antigens https://en.wikipedia.org/wiki/Antigen and epitopes https://en.wikipedia.org/wiki/Epitope

Feeding infants and toddlers food which an adult has pre-chewed for them is an old practice. Older than humankind, actually - https://en.wikipedia.org/wiki/Premastication

> At one point, families were once told to avoid peanut until their child was three years old.

> This advice was never based on science.

I'm like 99% sure this was to avoid babies/young kids choking on peanut

Maybe at first it was a sane reason like this. When we were having a kid, though, we were definitely told by reputable sources (like an obgyn) not to feed the kid peanuts in any form until 3 years old. We decided that the bureaucracy of what advice to give hadn't caught up to the science we'd read, and just tried small amounts of peanut butter when we moved to solids.

An OBGYN isn't a scientist. Move to "solids" is such a weird thing to say. Once you're off breast milk / formula you just go to whatever. The pureed food has to be one of the biggest scams in human history and leads to required orthodontia.

Even the article mentions this: "Experts warn whole or chopped nuts and peanuts are a choking risk and should not be given to children under five."

On the other hand, I wonder if infants without a mature immune system might do better not being exposed to a lifetime of pathogens in found adult saliva.

I think the normal way babies ramp their immune system is breastfeeding - their body struggles with soemthing, it is transferred to mom's nipple when breastfeeding, the mother forms an immune response, it is incorporated into the breast milk, the baby retrieves it next breast feeding.

I mean too early. Not sure when too early is.

I am always worried about sharing my caries or gum disease bacteria, so I avoid sharing spoons and food. And then I've seen mothers pick up a pacifier from the ground and put it in their mouth to "clean" it before giving it back to the baby.

Do you [personally] have specifically bad bacteria in your gums?

I do have some gum recession, and a lot of fillings. My wife has better dental health, even though she gives her teeth less attention than me in terms of hygiene. But I've also found articles online about spreading cavities. Here is an example.

> Dental caries, commonly known as tooth decay, is the single most common chronic childhood disease. In fact, it is an infectious disease. Mothers with cavities can transmit caries-producing oral bacteria to their babies when they clean pacifiers by sticking them in their own mouths or by sharing spoons.

https://www.sciencedaily.com/releases/2014/02/140220112402.h...

I think this advice was more about not giving the baby a known allergen because they are a baby and it could kill them and it could be difficult to even tell they are having a problem because babies are often crying for any number of reasons.

I'm not saying the advice is sound, just giving a perspective on what led to that advice. It's not about "they might develop an allergy so don't give it to them" it's "they may be allergic already and cause significant harm".

This is a point of frustration between my wife and me and it repeats every 6 months or so. "Honey, let's feed the girls some shrimp so they don't get allergies." "No. Not yet. I don't want them to get mercury poisoning. It can wait."

I was under the impression that shrimp was among the lowest mercury seafood, along with herring, anchovies, and a few others.

The smaller the fish, the less mercury it has. The ones you have to watch out for are the big fish that eat lots of medium fish that in turn eat lots of smaller fish; each stage in the food chain concentrates more and more mercury. Sharks and tuna have a lot of mercury. And smaller tuna, like skipjack, have less mercury than larger tuna.

Also I think the threat of mercury in fish is greatly overstated anyway. Look at Japan; they eat tons of fish and they're not all brain damaged dummies.

I thought mercury was mostly an issue with apex predators?

That was more of a paraphrased quote. Her concern is primarily in farm raised seafood I believe. It is an issue with apex predators though, since I'm married to one.

You'd have to be eating an unreasonable amount of seafood to get enough mercury in you to be a problem.

>Cultures where infants are fed on the same broad spectrum of foods that adults eat have MUCH lower incidence of allergies.

Most mammalian wild animals (and humans until 100 years or so ago) drink their mothers milk up until they're able to eat regular food and then from that point on eat whatever adults of their species eat. They don't go through 5 different levels of Gerber before eating real food.

> I started giving my own child chewed up food I was eating at about 2.5 months

You gave a TWO AND A HALF MONTH OLD CHILD chicken??? this is so incredibly careless that I HAVE to call out this crazy misinformation on HN. DO not ever replicate this please, everyone else.

What's the risk exactly? Googling around mentions the choking risk and the correlation behind obesity and early life introduction of solid foods. But if a small amount of chicken is pre-chewed by the parent and given as a rare one-off under observation those risks seem to be mitigated. Based on your strong reaction though I'm guessing there's risks? Inability to digest the chicken perhaps? Just curious

it is extremely bad for the child's digestive system etc. not everything is a "life or death thing"

Careful with that. You likely are also transferring the bacteria that cause cavities from your mouth to your babies mouth.

https://www.sciencedirect.com/science/article/pii/S199179021...