Meet Mark

Let me introduce myself. My name is Mark Sisson. I’m 63 years young. I live and work in Malibu, California. In a past life I was a professional marathoner and triathlete. Now my life goal is to help 100 million people get healthy. I started this blog in 2006 to empower people to take full responsibility for their own health and enjoyment of life by investigating, discussing, and critically rethinking everything we’ve assumed to be true about health and wellness...

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February 07, 2009

The Dirt on Dirt

By Worker Bee
36 Comments

The prevailing opinion at MDA is that listening to one’s body is good policy. Natural instinct has been kind to us over the years – just as long as we listen to it. Oh, sure, some instinctual behaviors have little relevance nowadays and should be ignored (like our tendency to tribalize and shun newcomers for protection – made sense when we were living off the land in small inclusive clans competing for resources, but today it just causes war, racism, and nationalism), but most instincts are hard-wired into us for a reason. Consider salivation, which tells us delicious, wholesome food is to be had (I know I’m not the only one with an utterly Primal tendency to drool at the prospect of a rare steak), or our sense of fairness, which makes for a more harmonious environment (good for survival and for everyone involved). We like to stress the importance of listening to your body’s natural inclinations.

By definition, pretty much any instinctual behavior confers evolutionary advantages (otherwise it wouldn’t have been kept around for so long) – this is the basis of the Primal Blueprint, with our focus on living in accordance with our Primal ancestors (whose actions, behaviors, and diets were highly instinct-driven).

A series of recent studies examined a young child’s tendency to eat dirt, lick stuff on the ground, and put whatever he can find in his mouth. Is there some evolutionary benefit to be conferred from eating dirt? We have a rather unhealthy (or is it?) obsession with dirt, so we were interested to read the results.

Dirt vindicated, once again! Mud pies, it seems, aren’t just a tasty way for a fledgling baker to get his start in life. The ingestion of dirt introduces a number of bacteria and viruses that actually spur the development of our immune systems. And certain worms have been shown to redirect messed up immune systems that would normally result in autoimmune disorders, asthma, and allergies.

When he puts random things in his mouth, a child is letting his “immune system… explore his environment,” writes immunologist Mary Ruebush. That kid with a dirty mouth isn’t increasing his chances of getting sick; he’s actually giving his immune system “practice” figuring out what’s benign and what’s dangerous.

As we’ve discussed before, over-sterilization of our environments can actually be counterproductive. Scientists suspect that even as the increasing sanitization of developed countries has eliminated some health concerns – contaminated food and drinking water, for example – it has also introduced a whole host of other issues, including rising levels of multiple sclerosis, Type 1 diabetes, inflammatory bowel disease, asthma, and allergies – all potentially stemming from a reduced, or eliminated, exposure to bacteria early on. We’ve gotten “cleaner,” but in doing so we’ve eliminated both good and bad dirt. We’ve also strengthened the bad stuff. All those antibacterial products – Purell and the ubiquitous variants you see in purses, attached to kids’ wrists, in “fun size” – might actually be creating antibiotic-resistant strains of dangerous bacteria. Remember, evolution works both ways (and much more rapidly in bacteria).

That’s not to say we shouldn’t wash up. We should, especially if we’ve been touching dirty diapers, handling raw meat, or using the toilet. Just don’t go overboard with it. Basic soap and water are good enough.

And of course, it goes without saying that kids should have access to plenty of dirt growing up – if not for their immune systems, then for the fact that playing in the dirt is an awesome part of childhood that no kid should be without. It’s in line with the Primal spirit of play, too.

Oh, and you might want to ease up on the strict “wash your hands before dinner” rules – we might be doing more harm than good.

beccaplusmolly Flickr Photo (CC)

Further Reading:

Should I Get a Flu Shot?

8 Ways to Reduce Your Chemical Load

The Dope on Energy Drinks

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36 Comments on "The Dirt on Dirt"

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new_me
new_me
7 years 7 months ago

I love the caption under the picture! I think I’m going to use that in my scrapbooking, I have the perfect picture for it.

Ryan Denner
7 years 7 months ago

I couldn’t agree more about society going overboard on “cleanliness”, and thus, making our immune systems weaker!

Hell, I survived 3 years in a fraternity house with 35+ dudes. If people can do that, then they can live through just about anything 🙂

Tom Parker - Free Fitness Tips
7 years 7 months ago

Haha good point Ryan. I shared my University house with 11 other guys and I think some new organisms started growing in our kitchen it got that bad.

fasching
fasching
7 years 7 months ago

Problem is that the dirt that is present in most urbanized areas isn’t the kind of dirt we used to ingest. The chemical and bacteriological load is likely to be quite different – and not different in our favor, sadly.

Todd
7 years 7 months ago

Overprescription of anti-biotics, not ethanol-based hand sanitizers, are causing the evolution of superbugs. Just sayin.

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[…] through imitation, but they figure out how to move their bodies much like they learn about their environment in general. The problem is that once walking is achieved, much of the learning stops, especially […]

aisha
aisha
7 years 5 months ago

what in the hell is dirt lick?

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[…] I’d argue. And we still fear nature, by and large. Camping is “exciting.” Bugs are icky. Dirt is, well, dirty. Though these can easily be avoided (pristine luxury cabins, bug spray, and massive […]

Mert
Mert
6 years 6 months ago
Dear Mark, As a person making his PhD on children’s soil eating and object mouthing behaviour, I must say ingesting little amounts of even natural, uncontaminated soil may be HIGHLY dangerous, because the natural levels of metals in soil can have toxic effects. This is especially valid for children ingesting soil. We are already exposed to heavy metals via food, air and water (called background exposure) and no matter how clean we eat, drink or live, we cannot prevent it. Additional exposure to heavy metals through soil ingestion, environmental pollution or any other reason adds to the present risk levels.… Read more »
Matt Forrester
Matt Forrester
6 years 6 months ago

Leave it to someone getting his PhD to ruin eating dirt. Darn you Smart PEOPLE!!!

Mert
Mert
6 years 6 months ago

What do you mean? Have you read my post with an intention to learn something new, or what? I’m trying to contribute.

I’d rather prefer to hear what do you think about the arguments stated, and I’d better like to know yours, as well as other people’s.

Adam Long
Adam Long
4 years 6 months ago

I think he meant: you make a really good point… damn you for ruining what could have been playful and fun (it’s all. your. fault.)

Can you link a few sources on the nutrient/contaminant/bacterial profile of dirt for us? Where is the Arsenic coming from, apple juice spills on playgrounds (sort of kidding… stupid juicy-juice)?

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[…] for the rest of their lives. Exposure to bacteria is another growing concern for parents. Too little bacteria, and we risk allergies and significantly compromised immune systems later on. Too much isn’t as much of an issue, though […]

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[…] gut flora, destroying the good with the bad. Think indiscriminate carpet-bombing. Living a sterile, bacteria-less early existence (dirt avoidance, lack of breastfeeding, C-section) has a similar effect by limiting the variety and […]

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[…] the infant stage, toddlers naturally supplement probiotics by putting everything, dirt included, into their mouths. If given the proper resources, these beneficial bacteria grow and flourish, boosting immunity and […]

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[…] traits or behaviors pique my interest. When people seem instinctually drawn to something – playing with dirt, sunbathing, delicious animal flesh – I go looking for an explanation, because more often […]

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[…] allt annat, saxat ur MDA förstås: ”When people seem instinctually drawn to something – playing with dirt,sunbathing, delicious animal flesh – I go looking for an explanation, because more often than […]

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[…] gut flora, destroying the good with the bad. Think indiscriminate carpet-bombing. Living a sterile, bacteria-less early existence (dirt avoidance, lack of breastfeeding, C-section) has a similar effect by limiting the variety and […]

trackback

[…] that we look a little more closely into whether or not there’s something to it. From babies putting items they found on the ground into their mouths to introduce novel bacteria to their bodies, to weight lifters craving meat after a hard workout to introduce protein to their hungry muscles, […]

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[…] that we look a little more closely into whether or not there’s something to it. From babies putting items they found on the ground into their mouths to introduce novel bacteria to their bodies, to weight lifters craving meat after a hard workout to introduce protein to their hungry muscles, […]

trackback

[…] that we look a little more closely into whether or not there’s something to it. From babies putting items they found on the ground into their mouths to introduce novel bacteria to their bodies, to weight lifters craving meat after a hard workout to introduce protein to their hungry muscles, […]

trackback

[…] about the benefits of dirt. Yup, you read that, dirt. Paleo superfood? Mark Sisson has talked about dirt as well at […]

Kes
Kes
4 years 4 months ago
Absolutely, there are contaminated in dirt. Granite rocks are responsible for leaching uranium for example (if I am remembering correctly, I’m in chemically induced menopause for breast cancer). There are also a lot of contaminates in the air, in our household chemicals, our vinyl shower curtains, in food from California organically grown but dusted from fallout from rocket testing, etc.. Consider the source of your dirt. We have a garden and a greenhouse and have built up our own soil, it’s about as safe as we can make it and I my kids eat a dirty carrot or two, so… Read more »
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[…] of your produce in the raw state, just for variety and because it could be a good way to eat some dirt (as long as you’re getting produce from a farm you trust), but for the most part, […]

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[…] that we look a little more closely into whether or not there’s something to it. From babies putting items they found on the ground into their mouths to introduce novel bacteria to their bodies, to weight lifters craving meat after a hard workout to introduce protein to their hungry muscles, […]

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[…] drinking water was a common, ancestral source of minerals for most of human history. Much like the modern obsession with sterility (hand sanitizers on keychains, etc.) has robbed us of important exposure to dirt and microbes, […]

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[…] drinking water was a common, ancestral source of minerals for most of human history. Much like the modern obsession with sterility (hand sanitizers on keychains, etc.) has robbed us of important exposure to dirt and microbes, […]

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[…] Protecting your child from all possible bacterial dangers is really not very helpful, and is basically impossible. Get a pet, visit a farm (agritourism is booming business and lots of fun), don’t freak out when your kid eats some dirt (it don’t hurt, and could even be helpful). […]

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[…] Mark on “Eating Dirt” […]

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3 years 5 months ago

[…] is available, and putting whatever can fit into his/her mouth. This is okay. The little one is introducing foreigners to his or her immune system. This is practice for the immune system. This is practice to distinguish from what is safe and what […]

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[…] our war on dirt, we may be causing more harm than good. Helicopter parents shriek when their two-year old takes a bite of the mud pie she proudly made. […]

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[…] our war on dirt, we may be causing more harm than good. Helicopter parents shriek when their two-year old takes a bite of the mud pie she proudly made. […]

Lauren
Lauren
3 years 2 hours ago

I’m more concerned with washing my hands after handling tons of stuff at a store (because of dirty people) than I am with dirt or raw meat. I don’t even think I wash my hands – just rinse of debris – after handling meat or touching stuff outside.

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[…] able to instantly end its influence over you. For example, at one point, by reading articles like this one, I learned that sometimes it’s okay to eat something you dropped on the ground. So I stopped […]

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[…] able to instantly end its influence over you. For example, at one point, by reading articles like this one, I learned that sometimes it’s okay to eat something you dropped on the ground. So I stopped […]

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[…] bacteria, stronger immune systems). Seriously, getting dirty and getting a little in your mouth is okay. I’m not saying serve your family a plateful of dirt and sandy vegetables. Although Elizabeth […]

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