Early exposure 'cuts peanut allergy' by over 80% | Hacker News Reader

Early exposure 'cuts peanut allergy' by over 80%

bbc.co.uk

128 pointsbasisword68 comments

Something's still missing. Peanut allergies seem to be very common in the US, but almost unheard-of in the EU. Yet, I would say the US is the country with way more peanut products and more peanut exposure. In northern Europe (my main experience is Germany), peanut butter has made the mass market only relatively recently (I'd say about 20 years max), while before most peanuts were being consumed by adults in the form of salted nuts as a late-evening snack. Compare that to the US where peanut butter has been a staple food ingredient since at least the sixties.

An allergist I spoke to said that the recent explosive increase in child peanut allergies has them examining the possibility that some recent change in the ingredients in some medication, or possibly a food, given to pregnant moms or babies or toddlers is somehow tricking the immune system into an extreme reaction to peanut proteins.

I realize that my recollection here amounts to an uninformed rumor, but my point is that there may be some, possibly very minor, mystery ingredient that has recently been added or substituted for something else in some food or medication, that just happens to have the right chemical structure to trigger a crazy mal-adaptation in a new immune system. If so, identifying it might require years of detective work.

Entirely possible that Parent in the United States are paranoid over what they feed their children, and have been given strict guidance by their pediatricians to not feed peanuts prior to age three under threat of being a "Bad Parent."

We have suspected that parents are too protective.

http://www.m.webmd.com/a-to-z-guides/features/kids-and-dirt-...

I don't know if it's better to give children under three peanuts or not, but I don't see why it's fair to characterize the people who advise against it, as accusing people of being "Bad Parents".

Has the advice been presented in a particularly emotive or extreme way, that would justify your characterization? If not, I think you are muddying the debate by using this kind of language.

I'd say that giving children under three peanuts is a bit miserly - give them at least half a dozen. They're pretty cheap... :)

I read it this way the first time, too.

I've also heard a theory that U.S. federal assistance to mothers gave lots of peanut butter, possibly leading to more allergies. I can't find the reference, though.

Giving more peanut butter to people might discover an existing allergy, but I was under the impression that more exposure to allergens lowers the risk of the immune response to the allergen. That's the idea behind allergy shots.

I'm not a doctor, though, so some clarification on that would be helpful from anyone who knows more than I do.

That doesn't explain the massive increase in wealthy children with these allergies.

Which is entirely contrary to the results of this research, which indicates that exposure to peanut proteins at a young age radically reduces peanut allergies.

> almost unheard-of in the EU

Not really true in my experience in the UK. Most schools around here have no nuts policies for food brought in by children, because of the prevalence of nut and peanut allergies. (And I know peanuts aren't nuts, still).

Schools do have that policy, but in my years in school and indeed adult life since then I've never been aware of knowing anyone with a peanut allergy (anecdote not data etc.)

My wife's an infant teacher (5-6yo), and I'm a governor of my son's school (they take 4-11yo). There are about 200 students in each. And there is at least one severe nut allergy in each (i.e. epi pen level), and in both my wife's class and my son's class there is one more minor nut allergy (rash level).

I live in the US and I don't think I've ever known anyone with a peanut allergy either...

If we're doing anecdata, I know two people in England with peanut allergies.

Same here.

Also, if nut allergies were unheard of in the EU.. why would nut-allergy news be on the BBC's front page?

Some allergies are activated by exposure. For instance, health care workers (or any other job that requires latex gloves) have a far higher rate of latex allergy than the general population.

And some are mitigated by exposure. Cashew shell / mango skin / poison ivy, as an example.

It's what makes addressing it so difficult - we know it's an immune response, but don't understand the mechanism that triggers it.

Yep! New research couldn't come sooner - while luckily I'm not deathly allergic to anything, I have moderate reactions to a wide spectrum of environmental stuff. I got shots for years in my teens which helped a lot, but now I've noticed in my early 30's some of that immunity seems to be decaying.

Could that just be that health care workers are more likely to notice a latex allergy due to repeated exposure?

Somewhat unlikely. Latex is in LOTS of stuff you might not think about - like bath mats, baloons, etc. Even duct tape contains latex. Anything containing natural rubber.

Maybe there's a spectrum of responses and the people on the gentle end just don't have difficulty putting up with the symptoms unless the material is literally pressed to their skin for hours on end?

My hands feel slightly puffy and look slightly red after handling some types of rubber. I can wear latex gloves without issue, so that's not it, but if there are people who react to latex like I react to certain kinds of rubber then I can easily imagine the allergy going unreported.

True, but it's one thing to blow a balloon or stick a piece of duct tape, another is to use a glove for hours a day.

Are dishwashers less common in the EU than the US?

NPR had a piece on washing dishes by hand vs. using a dishwasher: http://www.npr.org/blogs/health/2015/02/23/387553285/kids-al...

According to the "hygiene hypothesis" people are growing up in environments too clean to properly train their immune system, and it leads to allergies and other autoimmune disorders.

> Are dishwashers less common in the EU than the US?

Everyone I know here in Norway has a dishwasher. Of course, we didn't have one growing up (I'm late 30s).

That addressed specific things, like hayfever, asthma, eczema. Kids are exposed to lots of peanuts via ingestion, so that would not be it. Unless you're seeing a linkage between those allergies and peanut allergy. to me that would be unlikely.

I thought we already knew that allergies can be activated by exposure and existing allergies can be exacerbated by repeated, intermittent, exposure; what this suggests that is new is that peanut allergies can be prevented by early and continuous exposure (I think that there is already information that at least some allergies that are already formed can be mitigated by continuous exposure, as well.)

What's "missing"?

I live in the UK and I'm relatively good friends with 3 people with potentially fatal peanut allergies, all in their mid 20s. I wouldn't be surprised if I've known more to a lesser degree who haven't said anything about it.

Fortunately we have statistics! In the UK[1] it was 1 in 200 (0.5%) (no date given) and in 2002 was found to be 1 in 70 (1.4%). In the US the prevalence has also risen, from 0.4% in 1997 to 1.4% in 2010.[2]

So certainly the UK doesn't have less peanut allergies. It would be interesting to know how it varies across Europe. It would be interesting to know to what extent genetics is a factor (although that would probably require genetic sequencing of everyone involved in a study, which would be expensive)

[1]: http://www.anaphylaxis.org.uk/userfiles/files/statistics%20-... [2]: http://well.blogs.nytimes.com/2014/02/03/as-peanut-allergies...

The local college here in Sweden is a peanut free zone, with signs at the entrance and in the cafeteria declaring it so.

The dutch think they invented it.

European here. I tried peanut butter once. It was disgusting.

Also European here. You might not have tried the right peanut butter. Many big-name brands add sugar and salt, and also palm oil (to prevent separation). If you try peanut butter that's actually just 100% peanuts (you'll know if you have to stir it first) then you might have a different experience. Or you might not.

I lived with a guy from France a few years ago and he absolutely hated peanut butter and couldnt figure out why we all ate it so much. Had no problem adjusting to pepperoni cheese steaks though!

> The research team in London had previously found that Jewish children in Israel who started eating peanuts earlier in life

If you wonder why Israel specifically, it's because of the food called Bamba which is very very popular there.

They compared with Jews in the UK, who were otherwise similar except, no Bamba.

I'm Jewish, and I grew up in Australia, and I never got to eat bamba with my friends as a child because of my peanut allergy.

I wonder if this is part of a feedback loop, where the gradual creation of peanut-free areas leads to more severe peanut allergies

Original paper: http://www.nejm.org/doi/full/10.1056/NEJMoa1414850

This all seems to come down to a couple of factors, namely the hygiene hypothesis and the gut microbiome. I suspect that many of the dietary changes which several posters have mentioned as having helped their allergies may have in fact just allowed them to develop a healthier gut microbiome. Overuse of antibiotics, especially amongst the very young, necessarily plays into this, as well.

http://news.sciencemag.org/biology/2014/08/gut-microbe-stops...

They specifically excluded any kids who already showed signs of severe peanut allergy, so I think this has to be taken with a grain of salt.

They don't claim to have reduced allergies from people showing signs of severe allergies. The control group and the experimental group were of the same composition. They claim to have reduced the development of allergies for people who were at risk.

I wonder how this would influence approaches to other allergies (a similar 'cure' for hay fever would make a huge difference to my quality of life from May-Sept each year).

There was an article on NPR Morning Edition, this morning about the Hygiene Hypothesis. A study in Sweden found that children in homes without dishwashers had 50% fewer cases of allergies including hay fever.

The assertion being that exposure to bacteria and other microbiota early in life mediate sensitivity later in life.

http://www.npr.org/blogs/health/2015/02/23/387553285/kids-al...

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

To continue - I had awful allergies of the same type (spring being the absolute worst) growing up and was basically non-functional without Allegra or some other similar drug. I went to Ranger School when I was 22 and we weren't allowed to take any kind of drugs throughout the entire course. So for 3 months I had no access to any kind of my usual meds to ward off the usual misery. For the first 2 weeks it was hell (among other reasons) but then it was like my body just quit being allergic.

Haven't needed anything since, though I'm definitely not suggesting Ranger School as a cure for hay fever.

Now I'm picturing your body's immune system yelling at the wayward cells. "I don't know what your major malfunction is, but I'm gonna unfuck you, one way or another."

That or it was the Motrin, sock changing, and hydration. Cures everything, dontchaknow.

Purely anecdotal, but I used to have terrible allergies (dander, pollen, dust, etc.) for ~25 years.

The past few years living with my wife has changed my diet significantly. Very little dairy, way less sugar, no soda, more vegetables, better meat ...and so on.

My allergies are now almost nonexistent. I have friends with cats that I couldn't visit because of my allergies. Now, absolutely no problems when I'm in their homes.

I don't know what your current diet is like, but it may benefit you to remove certain items for a while (at least several months) and see if that helps.

Another anecdotal is that I used to get allergies due to dander, pollen and dust for the first 20 years of my life. Without changing my diet, things greatly improved for me. I presumed I had been exposed to so much that I eventually built up immunity.

Another allergy anecdote - I used to be alergic to cats, then I got a cat, and now I'm not allergic to cats!

My anecdote: similar to you, but still allergic to cats. I have asthma attacks in the middle of the night if she curls up on my pillow, I have antihistamine eyedrops at hand, and not even my ADHD-brain dares to forget to take meds.

I've moved and gone on various diets and nothing really did anything. I give myself another year or two before I look into allergy shots (at the moment, trying to get pregnant and my allergist refuses to start them). It's rather frustrating, but oh well.

What kind of cat do you? Mine a persian with long hair and I groom him every day (10 minutes with a metal comb) so he leave less furr around the flat.

The bedroom is the only room he's not allowed, although sometimes he does manage to sneak in. On those occasions I'll probably change the bedding just to be safe.

I have an okay diet, but nothing special.

When you tried incorporating changes into your diet, can I ask how long you stuck with it?

In my experience, it takes more like 6 months to see positive health results from diet changes as opposed to only a few weeks.

Disclaimer: I'm not a doctor or a dietitian

Have you ever gotten allergy shots? I've been allergic to cats and dogs all my life. About six months ago I started getting allergy shots and my allergies are already improving!

I was once told about shots available to me by my doctor but it didn't sound too promising. She said the improvement wasn't always great and I think I had to take them every few weeks for 6 months and then every x months for several years. My allergies are debilitating for several weeks during the Summer and very difficult the rest of the Summer so if it sounded promising I definitely would have got them. This was about 10 years ago though so it's maybe worth checking out again, thanks.

They aren't a cure, but they are an improvement. I started taking allergy shots 2 years ago (now just getting them once a month).

I used to suffer badly in the spring, even having to go home early from work on occasion (despite taking claratin or zyrtec). I still take a daily allergy pill, but that is now sufficient to curb my allergies.

The downsides are the time and the cost over the course of years. The first 6 months or so, I was getting allergy shots 3 times a week (which also requires waiting in the waiting area for 30 mins). I got a lot of reading done, but it is still a lot of time. It's also pretty expensive (or at least mine is, may have to do with the antigen being custom made for my allergies, I've heard some places have generic "grass" or "tree" vials).

I have bad allergies to cat and dog dander, as well as a bunch of other stuff. After getting stabilized by a lineup of drugs that put my grandmother's to shame, I slowly backed off a number of the nastier prescriptions.

I opted against the shots based on my allergist's recommendations - essentially she told me that if I couldn't commit to the incredibly frequency (at least once a week) and duration of the treatments (several years), it might not be a good fit... particularly because there's always a chance of a severe reaction to the treatments, and no guarantee it'll help.

What has helped, anecdotally, is:

- Diet... my diet has changed substantially in the same timeframe. I was a vegetarian with enough soy intake in spite of an apparent (per testing) late-onset soy allergy. After 8 years I started eating meat again. While adding meat back in, I've also cut out essentially all processed foods, most dairy, excessive sugar, and essentially all grains. There were a lot of benefits - I'm not going to lecture anyone on diet, and I'm hardly a model of perfect health, but this has been a good experience for me. I cook almost every meal, and from scratch - no prepackaged meals, everything starts with fresh foods I buy myself.

- Exposure... while one of my worst allergies has long been cats, about 18 months ago my now-wife moved in with two cats. Before they moved in I was clearly allergic to them - visiting her apt. meant stocking up on drugs, and fortifying myself. It wasn't overnight, but with the initial assistance of drugs to supress the allergic responses, I'm now able to live with these two cats with very rare, if any, allergic reaction. I still react, though less, to other cats, in other homes.

I went from a big lineup of prescriptions to taking a single, OTC pill a day, in spite of more exposure to one of the biggest sources of my allergies.

I didn't have the luxury of double blind experiments, or of minimizing the variables - so I can't swear to which, if not all, of these changes had the greatest effect... but I was able to make a huge change in my allergic responses in less than 2 years.

I am holding out for ToleroMune, which isn't approved yet but is supposed to require only a few shots.

I had (have?) a minor cat allergy. Itchy skin/eyes and difficulty breathing (tight chest, wheezing, etc). Unfortunately, I've always been a cat lover.

My girlfriend got a cat (big fluffy persian) and the first few months were pretty bad. Even though the cat was never allowed in the bed I had difficulty sleeping (weezing, difficult to breath). I medicated with over the counter allergy tablets.

Within a few months my symptoms were gone. It's been two years now and I rarely have problems. If I'm away for more than a week, I'll have a few hours of itchy skin when I'm back, but that's it. I can happily let him roll around on my face and I won't notice any negative effects.

The sad part is that there are many schools were you can be excused from immunization that do not permit you to send your child to school with a peanut butter sandwich.

Anecdotal, we have a coworker who developed this late in life and his doctors cannot give him a reason why. This is from a guy who one day after at the yearly family barbeque went to the hospital. His only ideas were that medicines prescribed for other conditions may have contributed. This always makes me wonder if the prevalence of some food allergies is not only because they are identified better but brought on by diet; through fortified foods; and/or medicines.

My experience: I never had allergy issues, but after moving across the country (Alberta to Ontario), I started having a terrible time in spring and summer. I read that eating local honey can help, so I introduced it into my regular diet and since the next year I haven't needed antihistamines since. It could be a placebo effect, but I think it is worth a shot. The experience has made me much more sympathetic of people suffering allergies, I wish you luck finding relief.

I've been meaning to try that. I grew up on a farm and never had any allergies to anything, then last year moved to another state. Dear lord. Someone suggested local honey but I never got around to getting to a store that sells it. I'll have to try it this year.

I've anecdotally heard of a number of people with allergies who's allergic reactions are reduced by repeated exposure.

The most common refrain of those I've spoken with (primarily animal allergies), is that (e.g. for those with cat allergies) the allergic reaction was reduced (in some cases to nothing) for a specific cat after repeated exposure to said cat. The most interesting thing was that the effect only applied to encounters with that specific cat.

That does not really surprise me since allergen immunotherapy is based on that idea http://en.wikipedia.org/wiki/Allergen_immunotherapy

After moving out of my parent's house for a year, my allergy to my family cat has returned.

Might not always work for things like hay fever. I had plenty of early exposure to pollens and everything else that'd cause them and never had allergies for my early life. Then one year around my 17th birthday (springish birthday so not thinking it's time based so much) i got probably the worst attack of allergies i've ever seen. All the sudden my body decided that it had had enough and I've had hayfever and other symptoms since. Moving to a different area has helped tremendously but hasn't eliminated it.

Just anecdotal but I wouldn't be surprised if seasonal allergies like that happen through a different mechanism that might not be affected like the peanut one.

The period of early exposure was at least 4 years of continuous exposure (the subjects were at least 11 months old, the 3-days a week feeding was until they were 60 months old). The nature of seasonal allergies tends to be that while early natural exposure is common, early and continuous natural exposure is not.

So I wouldn't view natural environmental exposure to seasonal allergens as a valid basisi on which to reject the idea that the kind of early and continuous exposure at issue here might work for seasonal allergens.

Freaky... I had the exact same thing except it was when I was 18. I also ended up moving to another area which has helped my allergies out a lot.

Anecdata, but try moving somewhere else in the world. A few years away may cure it.

Reported on the (BBC) radio news this morning, but without the warnings in the web article, which say 'don't try this at home' and that kids under 5 shouldn't be given whole nuts as they're a choking hazard (yes we can guess that, but people sometimes don't).

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