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What Are the Hidden Costs of Modern Hygiene?


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In this show I give a summary of the talk I delivered at the Ancestral Health Symposium in Atlanta. Enjoy!

Note: The Prescript-Assist supplements discussed in this article are no longer available. Please click here to learn more about a substitute, the Daily Synbiotic from Seed.

In this episode, we cover:

3:45 What Chris ate for breakfast (and a few local sources revealed)
9:40 The hidden costs of modern hygiene
26:50 Other ways to control inflammation
34:30 Should we inoculate our kids with hookworm?

Links We Discuss

Full Text Transcript:

Steve Wright:  Hey, everyone.  Welcome to another episode of the Revolution Health Radio Show.  This show is brought to you by ChrisKresser.com, and I’m your host, Steve Wright, from SCDLifestyle.com.  Now, with me is integrative medical practitioner and healthy skeptic, Chris Kresser, so Chris, how are you doing today?

Chris Kresser:  I’m pretty good overall.  I’m a little tired.  It’s been pretty crazy for me lately, but overall well.  How are you?

Steve Wright:  It’s been pretty crazy for me.  I know we’re both coming back from Atlanta from the AHS conference, and I can tell you one thing:  Don’t go to health conferences to get healthier.

Chris Kresser:  That is one of the big paradoxes, isn’t it?  I think I’ve mentioned this on the show as well, but I distinctly remember right around the time I was starting to write my book and Diane Sanfilippo was just finishing her first book, she did a tweet that said:  Writing a health book is the most unhealthy thing I’ve ever done!

Steve Wright:  Yeah!

Chris Kresser:  And I can relate to that, for sure.  I think the treadmill desk helped me avoid some of that, but it has still been a really intense time with the book and the editing process and then on top of that, preparing a talk completely from scratch for AHS, which I wasn’t even sure I was going to be able to do.  And the organizers were really great about that.  They basically told me I could cancel right up until the day before, which took a lot of the pressure off and just allowed me to take my time to get the talk ready.  But I could probably use a couple weeks lying on the beach somewhere right about now.

Steve Wright:  I am with you on that one.  I think from my perspective, I wasn’t speaking, but there are just so many people to talk with, so many conversations to have, and you want to maximize your time with all these great minds in one area, and so the first thing that goes is sleep.  Just gone.

Chris Kresser:  Mm-hmm.  So did you have a good time there?

Steve Wright:  I did.  I was really kind of weirded out by the weather down there.  It was pretty overcast all the time, kind of chilly, but despite Atlanta not giving us the sun and warmth that it’s known for, I thought the venue was big enough this year.  You didn’t have to do a lot of walking to get where you needed to go.  The food was really good.  Speakers were great as well.

Chris Kresser:  Yeah.  Cool.  So maybe we’ll talk a little bit about that.  I can maybe share a little bit about my talk, although it will be available for free online, assuming that the video went well this year, which I hope it did.  Last year my video was lost, and it wasn’t the fault of the Ancestral Health Symposium organizers.  It was the video crew that was used.  But this year, I think, they had it.  Perhaps the videos will be up faster.  That’s what we’ve been told, and so we’ll, of course, link to that when it’s ready.  And if worse comes to worst, I can always just narrate the slides like I did for last year’s talk.

What Chris Ate for Breakfast (And a Few Local Sources Revealed)

Steve Wright:  Awesome.  Well, before we get into any of that stuff, Chris, everyone is dying to know, what did you eat for breakfast?

Chris Kresser:  Let’s see… today I did my intermittent fasting thing where I just had coffee and cream for breakfast.  And then for lunch I had a pork and green bean dish that is from Three Stone Hearth, which is a local community-supported kitchen.  It’s based on a Weston A. Price type of approach to nutrition and food preparation, and it’s an amazing resource here locally in the Bay Area, and we sometimes will order food from them if we have a really busy week.  Sometimes we get things like beet kvass if we’re not making it ourselves and broth.  But they have this dish with ground pork and green beans, and so I had that, and then I had some potato hash browns cooked in a little bit of bacon fat.  And I had the freshest batch of homemade sauerkraut that we just took out yesterday and a little bit of beet kvass.  That was it.

Steve Wright:  Delish.  Now, do you make your own beet kvass, or do you buy that?

Chris Kresser:  We’ve done both.  Sometimes we make it; sometimes we buy it from Three Stone Hearth.  We usually have several different ferments happening at any given time.  Lately Elanne has been doing more pickles.  We have a lemon tree in our backyard, so she just made some preserved lemons, which turned out really well.  She’s been experimenting with sodas, which are just different lacto-fermented beverages made sometimes with fruit.  Let’s see… Yeah, that’s been the routine lately.  We always have raw milk kefir and yogurt going on.  Then sometimes we’ll do water kefir, sometimes we’ll do beet kvass, sometimes we’ll do more kind of experimental ferments, but those are the basics.

Steve Wright:  Nice.  So do you make your own yogurt, then, too?

Chris Kresser:  Yeah, we do.  We get A2 milk from Jersey cows from a farmer who lives about an hour and a half north of San Francisco in the Sonoma County area, and he actually brings it down to Three Stone Hearth, the kitchen I was just talking about, and we pick it up when we pick up our Three Stone Hearth order on Wednesdays.  So it’s convenient for us.  We don’t have to drive an hour and a half to get it.  And we usually get enough so that we can make kefir.  That’s the main thing that we do with it.  And then if we have enough, we’ll make yogurt from that, or sometimes we’ll go to the store and get Straus milk, which is great.  It’s not raw, but it’s grass fed and organic.  And we’ll use that to make yogurt because you heat up the yogurt anyhow, which with raw milk, and especially the Jersey milk, which is much fattier, there are still benefits when you heat it.  Even though you’re losing that raw aspect of it, it still would have higher nutrient value because the cows are raised exclusively on grass, and the fat content is much higher with the A2 milk, but Straus makes fantastic yogurt as well.

Steve Wright:  Sounds like you have it down to a science.  I need to move soon to a place where I can get all these delicious foods!

Chris Kresser:  Yeah, we’ve been doing this for a while, and it’s definitely part of our routine.  I will say that since we had Sylvie, we’ve been relying a little more on Three Stone Hearth for certain things, like broths, different kinds of broths, whereas we always used to make all of the broths [indiscernible] make quite a bit of it, but it’s a real luxury to have them nearby.  I doubt there are very many places like that, if any other places at all that are like that where you order online.  Each week they publish a menu.  You go on the website and you order whatever you want, and then you just show up there and pick it up.  It’s so cool.  It’s a cooperative, so it’s owned by all of the employees, and there are internships there.  People can go and work there and learn how to do nutrient-dense food preparation.  All the stuff comes in reusable glass jars.  They’re cooking in traditional fats rather than vegetable oils that even most good restaurants use.  They have a lot of paleo-friendly stuff.  They do have some stuff with grains and legumes, but they’re soaked and prepared properly according to the Weston Price principles.  Then they even have some GAPS-friendly type of dishes because an increasing number of people who are in that community are turning to the GAPS diet for a therapeutic approach.  It’s a pretty amazing resource, and if anyone lives in the East Bay or San Francisco area and you don’t know about it, you definitely should.

Steve Wright:  Yeah, that sounds pretty amazing.

Chris Kresser:  Yeah.  I’ve done a couple of talks there as well in the past.  They have an educational series.  They do some talks for the local community, which is another great aspect of what they do.

Steve Wright:  Awesome.  Well, shall we move on to talking about your presentation from AHS?

The Hidden Costs of Modern Hygiene

Chris Kresser:  Sure.  I can just give a brief topline summary.  We’ve talked about this before in more detail when we had Moises Velasquez-Manoff, author of An Epidemic of Absence, on the show to talk about the “old friends” or hygiene hypothesis, which is the idea that we co-evolved with certain microorganisms that turn out to play a crucial role in regulating our immune system, and the disappearance of those microorganisms over the last hundred years in the industrialized world has led to a dramatic increase in chronic inflammatory disorders that can basically be separated into three categories:  autoimmune disease, allergies, and then just general inflammatory conditions like asthma and arthritis, eczema, psoriasis, etc.

There’s a lot of evidence to support this hypothesis.  You can look at epidemiological studies which show that the incidence of these inflammatory conditions is basically a mirror image of geographical maps of the incidence of helminth infections.  Helminths are worm-like parasites that are considered to be “old friends,” meaning we evolved over a very long period of time with them, and they plan an important role in regulating our immune system.  And so if you look at maps of helminth infections, they’re basically a flip-flop of maps of chronic inflammatory diseases, and the same is true when you look at levels of exposure to things like saprophytic mycobacteria, which is a kind of bacteria that are present in soil and untreated water that we’ve been exposed to throughout our entire evolutionary history but is increasingly absent in the modern environment because of changes.  Essentially there is what we might call, not just a Paleolithic approach to food, but there’s a Paleolithic microbiome, and that microbiome has profound impacts on our physiology and particularly our immune system, and the shift in that microbiome may actually even be more important in some ways in terms of its effect on our health than the shift from a hunter-gatherer lifestyle to agriculture.

You may remember, Steve, when I talked about this in my presentation, what’s really interesting is there’s the theory that’s prevalent in the paleo community that the shift from a hunter-gatherer lifestyle to agriculture led to an increase in inflammatory disease and worsening in health, and there’s no doubt that there’s evidence that moving from a hunter-gatherer lifestyle to agriculture did lead to a decline in certain measures of human health, but the idea that compounds like gluten and saponins and lectins and capsaicin in peppers were responsible for this decline isn’t very well supported by the evidence because the significant increases in chronic inflammatory disease didn’t happen, really, until the last hundred years, and the change from a hunter-gatherer lifestyle to agriculture happened a full 10,000 years ago at least, maybe more like 11,000 or 12,000 years ago in certain areas.  So there has to be something else that explains this because if it was true that gluten and capsaicin and lectins significantly increase the risk of inflammatory disease, it would have done that a lot longer ago than it actually did.  And when you look at the evidence, one of the things that might clarify this or tie this together is it’s possible that those compounds in Neolithic foods are not a significant risk factor for inflammatory disease as long as the Paleolithic microbiome is still intact, whereas if the Paleolithic microbiome has been depleted or altered by sanitation and hygiene and other aspects of the modern lifestyle, then those foods do become risk factors for inflammatory disease.

I think actually this is probably the most important part of my whole talk, and it was a little bit buried in there.  I hope it came across clearly because, for me, this has been one of the big challenges of resolving some of the apparent conflicts in this ancestral paradigm, is that if you ever talk to someone who’s well informed about anthropology and the history of human health and you say to them that grains have significantly increased the risk of inflammatory disorders, they might turn around and say:  Really?  Well, how did that not happen when all of these cultures were eating grains for thousands of years and those disorders were incredibly rare?  Weston A. Price, for example, studied the people in the Lötschental Valley in Switzerland and the Scottish and Gaelic living in the Outer Hebrides both of whom relied on grains and dairy as staples.  And then there are contemporary agricultural communities in South America and other parts of the world that really rely on tomatoes and grains and other foods that contain these Neolithic compounds, and yet autoimmune disease and asthma and things like that are really rare in those places.

We have to be able to resolve that contradiction if we want people to take us seriously when we talk about this diet, and so this “old friends” hypothesis is a way of really tying that together.  And the way I would explain it to people now is by saying, look, it’s possible that if we still had the Paleolithic microbiome intact, we could tolerate grains and all of these compounds with no problem.  And perhaps that explains why some people are able to tolerate those foods with apparently no problems.  But given that the microbiome has changed so significantly because of things like sanitation and hygiene and also increased use of antibiotics and decline in the consumption of fermented foods and fermentable substrates that lead to a better gut microbiome, and increased use of soaps, which actually deplete the skin from certain types of ammonia-oxidizing bacteria that we’ve evolved with for a long time, a decline in breastfeeding – because of all of that, these foods which didn’t really bother us that much for many thousands of years when our microbiome was still intact are now significant risk factors for inflammatory disease, and that’s the reason why I tend to recommend that people avoid or minimize them because we’re not living with that microbiome still intact, and there are many other aspects of the modern lifestyle that are problematic and hostile to our immune system.  So given all of that, it makes sense to me to minimize the inputs that could potentially dysregulate the system in spite of the fact that it’s theoretically possible and even epidemiologically likely that those foods are not the sole cause of an increase in inflammatory disorders.

Steve Wright:  So if I understand what you just said and if I understood the talk correctly, basically the prevalence of a different gut microbiome, which your talk specifically centered in on some specific parasites, but also talked about how there was typically probably a completely different makeup because we know that that changes based on what you eat and where you live and everything, but if we focus more on this other microbiome, then it basically modulated the immune system so it made us less reactive to potential problematic foods or other things in our environment, right?

Chris Kresser:  Yep.  That’s pretty much it.  Let’s take helminths as an example.  These are the worm-like parasites that we co-evolved with for millions of years, and in fact, helminth infections first started between 564 and 528 million years ago, so we’re talking about a very, very long time.  There’s evidence that not only all humans, not only all hominids, not only all mammals, but all vertebrates in the history of evolution have been exposed to helminths and infected by helminths.  And if that’s true, which it certainly seems to be, based on the fossil record, then there’s actually evidence suggesting that the adaptive immune system, which is one part of our immune system that evolved in response to helminth infection, which indicates that our immune system can’t really even function as it was designed to do without helminths being present, which is kind of a mind-blowing concept, right?!  That are immune system is really not normal if helminths, which are parasites, are not present, and I think that’s a difficult concept to grasp.  We’re conditioned to think that parasites are harmful, and of course, some are.  Some are very harmful.  This is not to suggest that we have this relationship with all parasites.  But helminths have been around for a long time, and our immune system is tuned to expect their presence.

What they do is they have gently suppressed inflammatory responses, and that has acted as a type of brake, if we’re going to use an analogy.  Our immune system has one foot on the brake throughout most of its history, and then there are these other genetic variants that were selected for that restored inflammatory responses when helminths were present.  Why would this happen?  Well, let’s say you live in an area where malaria is endemic, and inflammation is the body’s way of fighting malaria off, so if you had helminths that suppress your inflammatory response, that could potentially be a disadvantage in that situation, and any genetic variants that arose that restored inflammatory responses in that situation would have been selected for.  Those genetic variants were like having one foot on the accelerator, so we had one accelerator and one foot on the brake, and it kept our immune system in a type of dynamic balance.  Then all of a sudden in the last hundred years or less – because in 1947 in Europe, for example, a third of the population or more than a third still had helminths; we’re talking about a relatively recent period of time – helminths completely disappeared from the environment and from our guts, and so that foot on the brake that was providing that dynamic tension with the accelerator, so to speak, was gone, and the pedal was to the metal [indiscernible] this really dramatic epidemic of inflammatory disease because there’s nothing now that’s preventing excess inflammation that’s caused by those genetic variants.

Steve Wright:  This wasn’t part of your talk, but I think it’s a question on my mind and probably others who watched your talk:  How do we start to reconcile the fact that only some of us – well, it is a big enough portion of the population – are having allergies, asthma, inflammatory disorders, but nowhere near the majority yet are having those?  Are do we begin to reconcile that?  We know that everything has changed.  The food has changed, the environment has changed, and the microbiome has changed, and there are only some of us who are extremely affected by this.

Chris Kresser:  Well, actually 1 in 2 people now has allergies in the industrialized world, so that is nearly a majority, and it’s shocking when you really contemplate it.  It’s 1 in 10 for autoimmune disease, and it’s tens of millions for chronic inflammatory conditions.  The numbers are pretty impressive when you think about it, but nevertheless, the answer to that question, I already alluded to it.  It’s a combination of genetic susceptibility, so I just talked about these genetic variants that evolved in places where other acute infections were endemic, like malaria, and they evolved as a way of protecting us from those life-threatening infections, especially when helminths were present because helminths kind of suppressed the immune response or the inflammatory response, and that’s beneficial in a certain way in that it protects us from autoimmune disease and allergies and inflammatory conditions, but it’s potentially harmful when we can get an infection like malaria and die unless we’re able to mount a sufficient inflammatory response.

There were certain areas where those genetic variants were selected for and more common.  An example of this is Sardinia.  Right now in Sardinia, 1 in 430 people has multiple sclerosis, and 1 in 270 has type 1 diabetes, which are extraordinarily high rates when you consider the global averages.  So why are rates so high there?  Well, malaria was very common in Sardinia up until it was eradicated from the island in the 1950s, and so all the people who live on Sardinia had these genes that promoted inflammation in order to help them fight off malaria infection, and as long as malaria was present at the same time, those genes didn’t lead to excess inflammation because the malaria was keeping it in check.  But then when malaria was eradicated from the island in the 1950s, everyone still had those genes that promote excess inflammation, but the malaria was no longer keeping it in check, so those genes, all of a sudden, became a risk factor for autoimmune disease.

So definitely genetic predisposition is playing a big role here.  Some people have these genetic variants that promote inflammation, and if they had helminths, those genetic variants wouldn’t be an issue and they wouldn’t be subject to an increased risk of autoimmune disease.  And not just helminths, also the saprophytic mycobacteria and early exposure maybe even to certain viruses, like hepatitis A, and certain bacteria, like H. pylori, which is harmful later in life but may even be protective earlier in life.  There are all these different aspects of the microbiome that help suppress inflammatory responses and protect against any excessive inflammation that would have been caused by these genetic variants.  So that’s number one.  And then number two is just exposure to other aspects of the modern lifestyle that predispose us to autoimmune disease and inflammatory conditions.  For example, if you’ve taken a lot of antibiotics when you were a kid, that had a significant impact on the microbiome, which, again, as I mentioned, shifts our susceptibility to inflammatory disease.  It makes it more likely that you’ll have a leaky gut, which Dr. Fasano, who we’ve had on the show in the past, suggests is a big risk factor for autoimmune disease and may even be a precondition, which means that you can’t even develop autoimmune disease without having a leaky gut.  And there’s exposure to environmental toxins.  There’s exposure to food toxins.  The poor-quality Western diet certainly affects the microbiome.

Basically what determines whether someone will manifest autoimmune or allergies or inflammatory disease is a combination of genetics, the status of their microbiome, and then the presence of environmental triggers, like poor diet, stress, sleep deprivation, and environmental toxins, to name a few.

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Other Ways to Control Inflammation

Steve Wright:  OK, awesome.  So that kind of leaves us with the question, and you’ve spoken about this before, that as you just said, H. pylori early in life seems to show a lot of benefit but late in life can be potentially carcinogenic, and you’re saying some people respond to helminth therapy and others don’t.  I don’t hear you advocating for everybody getting helminths, so what are some other ways that people can take action and maybe do things to help downregulate their inflammatory response?

Chris Kresser:  Well, let me just clarify something:  I think the evidence is fairly clear that early exposure to helminths while the immune system is still developing is protective, meaning people who have helminths early on in life have a lower risk of developing inflammatory disease.  What’s less clear is whether inoculating yourself with helminths after inflammatory disease has already manifested or after the immune system is fully developed has the same protective effect.  There’s some evidence that it can be therapeutic and even reverse some of these conditions, but as you pointed out, as I mentioned in my talk, not all evidence supports that.  There have been some disappointing results.

So really, I do think actually that if we’re exposed to helminths early on in life, we have less of a risk of developing autoimmune and inflammatory disease.  The question is for those of us who are adults is, does inoculating ourselves with hookworm, which is not easy or possibly even legal – There’s some gray area in terms of legality here.  I mean, certainly there’s no law against somebody developing a parasite infection unintentionally or even intentionally if they want to do that to themselves, but the gray area is around people who offer that as a service and when money is changing hands and things like that.  It’s being done, certainly, in the scientific community to study it, but the commercial application is a little fuzzy, shall we say?

But certainly there are other things that can be done that have already been accepted in the mainstream to help improve the microbiome, and that includes things like eating fermented foods.  Fermented foods contain these kinds of bacteria that we’ve been exposed to for most of our history, and we’ve likely been eating fermented foods for a very long time because we didn’t have refrigerators until very recently, and fermentation was really one of the few ways that we could preserve food, so it’s been a part of our path.

And then there’s the idea of eating prebiotic foods or foods with a prebiotic effect, and these prebiotics essentially stimulate the growth of bacteria that are already present in our gut.  Studies have shown that prebiotics actually have a more quantitative impact on the gut microbiota over time, which means that they increase the levels of healthy bacteria in the gut more than taking probiotics does.  Taking probiotics tends to have more of a qualitative impact, meaning it cause dendritic cells to become anti-inflammatory, it drives the development of T regulatory cells, so essentially it helps regulate the immune system, but contrary to previous belief, studies have shown that probiotics don’t really have a significant quantitative impact over times.  In other words, they don’t really “top up” depleted bacteria in the gut in the same way that prebiotics do.

There are three options for prebiotics.  One is soluble fiber that has a prebiotic effect, and that’s found in certain vegetables like onions and Jerusalem artichokes and starchy tubers, other fruits and vegetables.  And then resistant starch, which is harder to come by in the diet but is found in potatoes that have been cooked and cooled for around 24 hours, green bananas, green plantains, which are virtually impossible to eat raw unless you dehydrate them, which is one way to do it.  You can put them in the dehydrator and make dehydrated green plantain chips.  Or you can use potato starch.  Richard Nikoley has written a series on resistant starch on his blog, Free the Animal, so you might want to check that out if you’re interested.  He did some experimentation with it himself and had a guest blogger who has done a lot of research on it come in and talk about it, too.  So those are the ways you can do it with diet.  I mean, it essentially involves eating a lot of fermentable fibers, if we were going to summarize it.

Then there are supplements that you can take that are commercial prebiotics that contain things like inulin and galactooligosaccharides. Now, the caution here is that many foods with prebiotic effect, with the exception of starch, are FODMAPs, and those can be problematic in people who have gut issues like IBS or IBD, especially if they’re eaten indiscriminately.  What I’ve found, which is interesting, is that even in people who are FODMAP sensitive, if their flora is really disrupted, taking a commercial prebiotic at a very low dose to start with and then maybe increasing very slowly over time can still be beneficial is though that seems somewhat contradictory because they’re really trying to avoid FODMAPs in food for the most part.  Taking a little bit of things like inulin and galactooligosaccharides, if they start at a low enough dose and build up slowly, can significantly increase the gut flora, which then paradoxically can make them less sensitive to FODMAPs over time.  That’s what I’ve noticed in working with patients, and I’ve also seen that prebiotics, in general, tend to be more helpful for constipation than probiotics, with the exception of some probiotics, like Prescript-Assist and maybe Mutaflor.

Steve Wright:  Awesome.  Yeah, I’ve actually seen the same thing with constipation and based on your work with other people on our blog and clients that we have.

Chris Kresser:  Mm-hmm.

Steve Wright:  So I also have come to similar conclusions working with people that the FODMAP diet seems to work really well to alleviate symptoms, yet paradoxically, as people heal, they almost need to reverse their thoughts on the FODMAPs and begin to eat those foods again.

Chris Kresser:  Sure.  I mean, if they can or even just, like I said, using maybe some resistant starch, like potato starch, or some commercial prebiotics in a therapeutic way because sometimes it’s a little easier to control your dose of things like that than it is to control the exposure to prebiotic ingredients in food.

Steve Wright:  Right.  That’s makes sense.

Chris Kresser:  Yeah.

Steve Wright:  So what are you thinking about doing with Sylvie?

Should We Inoculate Our Kids with Hookworm?

Chris Kresser:  Yeah, interesting question.  A number of people did ask me that during the conference, and we certainly have considered inoculating her with hookworm.  As I mentioned, the logistics in terms of how to go about doing that are a little fuzzy, and I hesitate to even bring it up because I know a lot of people listen to this show and I don’t want people running out and doing this in an irresponsible way, and it’s quite difficult to do it in a responsible way, so actually right now my advice would be not to do it unless you have some kind of connection with a university research group and you’re doing it under supervision of a medical practitioner who knows about this stuff.

A couple of my hesitations are, number one, there’s very little… there’s no, actually, not even very little, none that I’m aware of, there’s no comparative studies that look at different dosages.  When you inoculate with hookworm, sometimes people start with 5 or 10 worms.  Sometimes they start with 25.  Sometimes people will continue to build up.  They’ll do an initial inoculation of 25 and then they’ll do another one of 25 a couple months later.  We don’t really know what the optimal number of organisms is for this protective effect.  There aren’t really any comparative studies.  There are just a lot of anecdotal reports from people who are doing this kind of therapy, and that’s not conclusive.

We don’t know if the dose in children is different than it would be in adults, although, of course, if you think about it from an evolutionary perspective, there was no moderating or controlling exposure to these worms in the wild.  I mean, the way that people got them was just by contact with soil where these organisms live, so they were getting an uncontrolled infection, and that can be problematic if a child is malnourished and not getting enough nutrition, like in the developing world, and then they keep accumulating more and more worms and they eventually end up with hundreds of hookworms.  That can be a problem.  That can lead to anemia and other issues.  I think that’s less of a concern in the developed world and where the infection would be controlled and where adequate sanitation exists to prevent uncontrolled infection.  There are some studies where people have gotten worse rather than better.  That’s a bit of a concern.  And certainly with a 2-year-old who is only just learning to communicate verbally, it would be difficult to know what she was experiencing with any kind of certainty and to know whether intervention was needed to clear the worms.

So it’s very problematic.  I don’t think we’ll end up doing it, and I wouldn’t recommend that anybody else do it unless they have access to information that I don’t have access to!  And then there’s, of course, the question of how to source them.  Yeah.  Someday we may get to the point where we take our babies to the doctor or a client or whatever to get inoculated with hookworm just like some people take their babies to get vaccinated now, but we’re not there yet, and who knows?  We may never get there.

Steve Wright:  Well, thanks for being open and honest enough to share that with everyone because I know that was on the minds of a lot of people.

Chris Kresser:  Sure.  I wish it was different.  I mean, I wish we had more information.  I wish we could make decisions with more confidence.  The path we’re taking with Sylvie is the path that I can recommend, which is fermented foods and foods with prebiotic, fermentable substrates in them.  That alone will have a big impact on the microbiome.  Avoiding antibiotics wherever possible, practicing what I called “targeted hygiene” in my presentation, which means avoiding exposure to infectious doses of pathogens, for example, after contact with feces or during food preparation, but being more relaxed about exposure to microorganisms when the infection risk is low, for example, when you’re petting your dog or encouraging your kids to play in the dirt or eating fermented food.  We don’t have a dog right now, but we have friends with dogs and neighbors with dogs, and she loves dogs and she plays with them.  They lick her face, and she kisses them on the mouth, and rather than discouraging that, we’re completely fine with it.  And we encourage her to play in the dirt.  She hasn’t taken antibiotics.  Hopefully she won’t have to.  Of course, you need to be responsible with that because there are certain times where antibiotics are necessary and lifesaving, but if, for some reason, your child has to take antibiotics, then for sure do some probiotics and prebiotics and bone broth and things like that to help support the recovery of the gut microbiome.

We might also even go as far as saying using soap on the skin every day is not only unnecessary, but it might even be harmful because this ammonia-oxidizing bacteria I mentioned that colonized our skin for most of our history is very sensitive to detergents and soap, and what it does is it converts urea and ammonia and sweat into nitrite and nitric oxide, which is then reabsorbed, and nitrite and nitric oxide play a really important role in regulating our immune system and even, in the case of nitric oxide, preventing hypertension.  That might be one of the many reasons behind the epidemic of hypertension.  I tend to think it’s one of the smaller reasons, but it doesn’t mean it’s not there.  I’m not necessarily encouraging people to abandon soap altogether.  I think I would have a lot of unhappy spouses and girlfriends and boyfriends writing to me if I did that!  But I do think it’s probably a good idea to lather up a little bit less frequently than some people might be doing because of this principle that I just mentioned.

And then breastfeeding, of course, six months of exclusive breastfeeding.  I recommend 22 months at a minimum for complementary breastfeeding.  Let’s see if there’s anything else… I think those are the main ones.  If you do all of those, if you check all of those boxes and you give your kid a really nutrient-dense diet, I think they’ll be far, far, far ahead of the majority of people living in the industrialized world in terms of their susceptibility to inflammatory disease.

Steve Wright:  Awesome.

Chris Kresser:  OK, everybody, so I hope you’re enjoying the summer, and I’ll look forward to the next time that we do this.  We’re going to try to get in touch with Jeff Leach from the American Gut Project to do an interview with him on his fascinating research, and it’s certainly relevant to the microbiome discussion that we just had, so perhaps that will be our next show.

Steve Wright:  Yeah.  Thanks so much for listening to the show, and thanks, Chris, for all the work you’ve been doing.

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Join the conversation

  1. Hi Chris,

    In Chapter 2 of the book Protein Power by Michael and Mary Eades, the authors talk about ancient Egyptian society (2500 BC to 395 AD) being afflicted with rotten teeth, severe atherosclerosis, obesity, high blood pressure, and heat attacks – i.e. similar to modern western societies. Their diet was high in complex carbohydrates (whole grains), low in fat, no refined sugar, and almost no red meat.

    This seems to conflict with your comments above about “significant increases in chronic inflammatory disease didn’t happen, really, until the last hundred years…”

    I’d be very interested to get your thoughts on this apparent contradiction.

    Thanks for all the amazing work you do!


  2. Hi Chris,

    Thank you so much for your great article. I agree with you that using soap on the skin every day is not only unnecessary, but it might even be harmful because this ammonia-oxidizing bacteria you mentioned that colonized our skin for most of our history is very sensitive to detergents and soap.

  3. It seems to me that ‘innoculating’ yourself (or anyone else) with hookworms for anti-inflammatory affect is an action similar to releasing a few mosquitos out into a world that had irradicated them.

    Possibly beneficial, but the word IRRESPONSIBLE doesn’t begin to touch it.

    I am fine if you want to experiment on yourself while you are out in some capsule out in space.


    Am I missing something? Chris knows a Chinese herb that irradicates hookworm anyway, so it is not an issue?

  4. Thanks for the great podcast! What do you think about apple cider vinagar as a soap alternative?

  5. Helminthic Therapy also involves using human whip worm or pig whip worm (Trichuris trichiura ova or Trichuris suis Ova respectively). There is currently a lot of research using pig whip worm as this cannot reproduce or cause illness in humans. Conditions that respond to whip worm include autism and ulcerative colitis. Whip worm is actually more benign than hookworm in potential side effects.

    Se more here: http://realfoodforager.com/old-friends-the-hygiene-hypothesis/

    and here: http://realfoodforager.com/beyond-probiotics-helminths/

  6. I just finished reading An Epidemic of Absence which was fascinating. The thing that was lacking for me in the book was the food link. Chris, you have linked it all together so thank you very much for making it all clear.

  7. I was interested in the comment on converting urea to beneficial nitrites and reabasorbed etc. I have a supplement regime that in combination with Paleo 3 years ago knocked my cholesterol in half and dropped my B/P 25 points so that I got off 5 years of B/P medication (age is 63). After a lot of reading on the subject I decided 8 months ago to give urine therapy a 2 year try and ingest 8-10 ounces twice a day and rinse my face and hair with it daily. I about to have my first blood panel since starting, so I am interested in that, but my energy level is a lot higher, my metabolism is more like in my 30s than 60s. I also massage it into my hands and forearms nightly and got rid of an extreme case of dry skin. I haven’t touched a hand cream in the 8 months. Intuitively I am convinced there is a connection, maybe a third leg to the supplements, paleo, plus therapy that is extremely beneficial. I never discuss it so I am lacking feedback but interested in any other connections to the paleo/alternative univers.

  8. Chris,

    Which brand of prebiotics do you recommend? Does powder vs capsules make a difference? I imagine powder is easier to dose, if say you want to start with a very small amount and work your way up.


  9. It seems that cooked and cooled potatoes have a high percentage of resistant starch. Do they have to be eaten cold or can they be heated up? Does this mean that something like potato salad can be beneficial? I’m a long term Type 1 diabetic with recent Celiac who seems to have more stable glucose control on a grain free diet, as opposed to even a gluten free diet. I’ve also suffered from constipation most of my life and have been underweight all my life too. Going grain free, while controlling my glucose levels, causes me to lose weight. I’m wondering if potato and possibly other resistant starch intake might help on all fronts: weight gain, glucose control and constipation. Opinions? Or more importantly, research to back up any of this?

  10. Great show.
    I’m infected with hookworms myself. I’m hosting 105 worms for about 3 months now.
    I have noticed some beneficial changes but I’m staring to believe that correct gut bacteria is far more important.

    Bacteria will cover much more surface area in the gut that hookworms can.
    Besides modulating the immune system the bacteria also synthesize vitamins and enzymes.

  11. Chris:

    Thanks for the shout, man. I really appreciate it and I’m convinced this is a very important topic. Sure has made some interesting differences for me and others.



  12. Can you provide some links to studies relevant to this podcast topic? I have been looking around, but haven’t found much.

    • You can buy them at Wegman’s if they are in your area but other grocery stores may have them. They may be called Sunchokes in the store and are usually prepackaged in the produce section. They are a root so look for knobby brown roundish roots. Also they are easy to grow but be careful since they spread easily. In some parts of the US you will see them growing wild along the side of the road. They are tall daisy like flowers.

  13. I’ll tell you what, for a non-scientist that Richard Nickoley has gotten a lot right! I got turned on to him a couple months ago and haven’t been able to stop reading his blog. He is a bit rough around the edges and gets into some pretty heady stuff concerning our social condition, he likes F bombs, and seems to have been in some big drama in the past with other bloggers.

    His view on minimal soap, whole foods, and staying away from paleo dogma is so ‘on-target’ with me, I just can’t say enough. I’ve been doing a mixture of tapioca starch and potato starch for 4 weeks @ 2TBS/day roughly, mixed with yogurt at meals and I can say that for the first time in years I have regular bowel movements, sleep like a baby, and feel completely energized during the day. I have never had blood sugar issues, but one of the effects of the starch is blood sugar regulation, so I assume it’s a huge part of the puzzle.

    I feel so ripped off by ‘paleo’ because even though I was eating yogurt, kefir, and fermented veggies–I was eating absolutely minimal fermentable fibers that feed gut flora. I’m also increasing legumes, cold potatoes, and plan on trying the plantain chips very soon. Why these type foods were ‘outlawed’ is the biggest mistake made by the earliest paleo writers ever, and perpetuated by Jaminet, Sisson, and the rest.

    Here’s a link to probably the best blog ever written on resistant starch:

    And his latest: http://freetheanimal.com/2013/08/ive-got-a-gut-feeling-but-im-not-going-to-eat-anything.html

    So much science on such an important topic, but it got lost to all of paleo because of the word ‘Starch’ what a shame!

  14. http://www.plosntds.org/article/info%3Adoi%2F10.1371%2Fjournal.pntd.0000538#s4…I don’t understand most of the article – but this part jumped out at me.
    “…Helminth infection can have a broad impact on the entire immune system. Infection with trematode and nematode parasites, for example, correlates with a reduced incidence of atopic, allergic-type disorders [64]. Thus, helminth infection might potentially be useful as a novel therapy for allergic or autoimmune diseases [65]. Recently, worms, eggs, or purified nematode parasite protein have been used in preclinical and clinical trials to protect humans from allergy and autoimmunity (reviewed in [66]–[70]), including Crohn’s disease and ulcerative colitis [71],[72]. Other studies have shown that substances produced by helminths, for example Ascaris suum, Nippostrongylus brasiliensis, and Acanthocheilonema viteae, can directly interfere with allergic responses or with development of allergen-specific Th2 responses [73]–[75]. ES-62, a molecule secreted by the filarial nematode A. viteae, directly inhibits the FceRI-induced release of mediators from mast cells, protects against mast-cell–dependent hypersensitivity in skin and lungs [76] and inhibits collagen-induced arthritis [77]. Research is underway to develop molecules that mimic the activity of ES-62 as drugs for allergic and autoimmune diseases [66]. Other helminth-derived products have the potential to reduce allergic responses. These products include schistosomal lysophosphatidylserine (lyso-PS) [61] and thioredoxin peroxidase from the liver fluke Fasciola hepatica [78]. These findings demonstrated that helminths produce products that can interfere with both the development of allergic responses and the workings of host effector mechanisms.”

    Of course this research will be used to create drugs.

  15. Funny you should mention soap; about three weeks ago, I gave up using my usual bodywash during my evening shower. It started out as an experiment, but so far, so good: no stink, or even aroma. (Confirmed by careful monitoring by my wife!) I do mildly scrub armpits, etc., with a washcloth. At the same time, I gave up shampoo, and was imagining the worse (greasy, filthy hair), but that didn’t materialize, either. Actually, my occasional mild dandruff went away, and the hair feels non-oily and quite nice. Nor does it smell bad, either (I had imagined it might have a wet-dog smell when wet, but nope). I rinse it once a week, to get rid of loose dust and dirt from working in the yard.
    So far I’m feeling pretty good about this move.