Environmental Toxins and Gene Expression

It’s the heart of the Primal Blueprint: understanding that our lifestyle factors direct influence the expression of our genetic code. While the DNA itself is set, the structure fixed, that’s hardly the end of the story – our story. How we live – even where we live – holds significant sway over the final picture. And by picture I mean, of course, the picture of our genes’ activity: when proteins are produced (and how much), when or whether certain genes are turned on or off. This activity, researchers are increasingly finding, is key in the development – or avoidance – of any number of conditions like Parkinson’s, Alzheimer’s and cancer. Rather than a predetermined formula simply set in motion in the womb, our genes demonstrate a much more complex, nuanced interplay. The sum of all our daily choices and exposures direct our epigenetic signaling and the course laid out by that ongoing sequence of gene activity. As I’ve said many a time, our original genetic heritage doesn’t design our physiological fate. How we live determines how our genes play out their hand. No doubt a powerful concept, the comprehension can take us by surprise. The quickly expanding field of epigenetics has, indeed, rewritten old school genetics. It’s even ruffled a few feathers here and there, but isn’t that always the case with new breakthroughs?

As scientists study the physical principles (e.g. methylation, etc.) behind gene expression, they’re also able to examine what in the environment incites the switch flipping, so to speak. Of course, our bodies are in constant interaction with any number of influences in our environment. We take in air, food, and water – as well as the extraneous substances contained in them. We use medications and personal hygiene products. We lick the adhesive to seal an envelope. The list goes on and on. A few months ago members of the National Academies met for a workshop entitled “Use of Emerging Science and Technologies to Explore Epigenetic Mechanisms Underlying the Developmental Basis for Disease.” (Check out the full program online for yourself.) The workshop was part of the Emerging Science for Environmental Health Decisions initiative and standing committee within the National Academies. In a nutshell, the group focused on the demonstrated influence environmental toxins exhibit on gene expression as well as the impact this evidence should have on public education and regulation of these substances.

Compounds that may not appear dramatically or immediately harmful on a cellular level nonetheless trigger significant havoc on an epigenetic level, throwing off normal methylization patterns and causing the dysregulation of microRNAs, which direct gene expression. Among the implicated substances presenters highlighted were tobacco carcinogens, asbestos, ionizing radiation, arsenic, nickel, cadmium, benzene and polycyclic aromatic hydrocarbons (PAHs – components of common air pollution). Early/in utero exposure to these chemicals appears most destructive. As one presenter noted (PDF), in utero exposure to PAHs, for example, has been identified as a significant “risk factor” for childhood asthma. Although in utero exposure has been identified as a particularly “critical period” for epigenetic impact, it doesn’t mean we’re out of the woods as soon as we’re out of the womb. Researchers are examining the possibility of other “critical periods” and emphasize (PDF) the ongoing vulnerability to epigenetic alteration throughout life. The real problem with exposure to many of these substances isn’t the immediate impact on cells but the previously unseen changes to genes’ subsequent activity throughout an individual’s lifetime. Genes are silenced and lose their ability to manage the production of proteins for ongoing cell function and repair. Others are activated when they shouldn’t be. The resulting complement of abnormal down-regulation and overexpression can set the stage for cancer, metabolic disease and neurological impairment. Researchers have already begun to identify epigenetic changes that foretell cancer development.

It will be interesting to follow how this conversation continues to unfold in the scientific and public policy arenas. Although these issues aren’t exactly at the forefront of the mainstream media or public classrooms, the information is out there. Individual knowledge is personal power. While scientists continue their research and officials from every sphere wrangle over the public implications of these findings, we can start making decisions in the here and now. Just as negative experiences and exposures have the ability to instigate damaging epigenetic changes, our positive efforts can support normal epigenetic patterns by providing the healthy conditions our bodies expect and by counteracting the environmental challenges our modern bodies encounter each day in traffic, in our food supply, in the stress of work, and so on. Eating a clean diet, minimizing emotional tension, exercising smartly, and supplementing wisely can go a long way to reducing our exposure to modern toxins and offsetting their influence.

Let me know what you think. Send your comments and questions. Thanks for reading.

About the Author

Mark Sisson is the founder of Mark’s Daily Apple, godfather to the Primal food and lifestyle movement, and the New York Times bestselling author of The Keto Reset Diet. His latest book is Keto for Life, where he discusses how he combines the keto diet with a Primal lifestyle for optimal health and longevity. Mark is the author of numerous other books as well, including The Primal Blueprint, which was credited with turbocharging the growth of the primal/paleo movement back in 2009. After spending three decades researching and educating folks on why food is the key component to achieving and maintaining optimal wellness, Mark launched Primal Kitchen, a real-food company that creates Primal/paleo, keto, and Whole30-friendly kitchen staples.

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45 thoughts on “Environmental Toxins and Gene Expression”

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  1. There are so many things in this world whilst not proven to cause harm in the short term, the long term effects are unknown and/or doubtful. The one thing that springs immediately to mind is CFCs, and then margarine – the latter supposedly better than butter, but i wonder why incidences of heart disease increased so dramatically in numbers when margarine was introduced and people were steered away from ‘bad for you’ butter?

    My comment is way, way below the quality of your post, but then I’m just a relatively well-read user of the PB way. I know that there will be others here that have far more to contribute – but I thought I’d add my tuppence worth, anyway.

  2. The Primal Blueprint is about putting our best epigenetic foot forward. I’m curious about what you and the rest of the primal community thinks about fermented foods, such as yogurt, kefir, miso, sauerkraut, kombucha, etc.? There is some evidence, much of it discussed by Seth Roberts, about the benefits of fermented foods in beneficially altering how our immune system responds to environmental threats, including communicable illnesses and asthma. I know that foods made from milk or soy are not primal, but in their fermented forms have been used for millennia by cultures around the world, and perhaps for good reasons. One angle to consider is to what degree their health benefits are due to the symbiotic relationship between the active cultures and our body or to altered gene expression. Of course both are likely (they are not mutually exclusive), but it seems to still be an open question. Thoughts?

      1. I’ve been meaning to get my fermented post out for weeks now. I’m a slow writer and have been bogged down with work obligations.

        Damn you if you beat me to it! 😉 LOL

    1. I just want to point out that, just like dairy and soy, olive oil and edible olives are not primal. And yet I never see anyone bring up that point as a reason to not eat olive oil. Hmmm.

      Regarding the meat of your post, in my opinion (which is probably less well-informed than Mark’s, but what can you do) fermented foods are perfectly harmless, and maybe beneficial. I think the main reason to eat them is that they reduce the harmful or at least undesirable aspects of foods.

      Soy, in my opinion, is nearly inedible unless it has been fermented. Coincidentally, soybean products weren’t widely eaten in Asia until the fermented forms – soy sauce, tempeh, natto, etc. – were invented. Prior to that soy was used mainly as a rotational crop to renew nitrogen in the soil, because, like other legumes, it is a nitrogen-fixing plant.

      Dairy, of course, can cause many problems for those who lack the ability to produce lactase. But for the bacteria that eat the lactose and “ferment” the milk, turning it into cheese or kefir or yogurt or what-have-you, dairy might, like soy, be more or less inedible for these people. (Casein is another issue for another day; I think in most cases bad reactions to casein are secondary reactions caused by gluten-induced intestinal damage.)

      As for foods that are perfectly edible without fermentation, such as cabbage, I think the main reason to ferment is flavor – sauerkraut is just too yummy to pass up. As to the subject of bacteria in your body, well, you really can’t help it – there are more bacteria living in you and on you than there are human cells, after all. I think the fact that people have been eating these foods for thousands of years *with few (if any) signs of negative affects* indicates that they are of the “harmless” bacterial type.

        1. I’m with you here; I don’t follow that reasoning. If you’re going to tell us it’s because the domestic olive hasn’t been around very long, you’re going to have to drop carrots and strawberries and probably 99.9% of all the produce you eat today, because it’s all been engineered by human agriculture over the millennia to be bigger, tastier and more productive. You’ll (be trying to) hang off of a deer and eating berries and leaves in no time if you deny all the products of agricultural activity…

          As for fermentation; yum. Makes everything better; soy, cabbage, pickles, whatever. If you ever make sauerkraut (easy-peasy, by the way), throw in some chunks of tart apple during the fermentation for a nice variation.

      1. Icarus,
        You may have given me a clue to a mystery I haven’t been able to solve for the past 25 years. While a vegetarian, I developed an intolerance to dairy. Oddly, it caused my hip joints to be painful and stiff but no problems otherwise.

        A year ago I became primal. In the last month as a test, I have cautiously eaten cheese with no apparent problems. I have eaten a few other dairy foods recently, again with no problems. So, maybe it was the grains at the root of the problem all along? Gluten induced intestinal damage? Seems very possible. Thanks.

  3. In my discussions with others it seems that genetics is used as an excuse for laziness and not making efforts to improve your health. Overweight and those with heart disease just tell me that “well, my whole family has had bypasses, so it’s just genetic”.
    Going without junk food, and grains and actually getting off your rear and moving is a very tough pill to swallow for most. They’d rather wallow in excuses then let their insurance company (and increasingly, the government) pay for it. It’s so much easier to be a victim than to take responsibility.

  4. Thank you for this. I truly believe in all of this. I’ve been diagnosed with MS and gluten intolerance. I have taken a natural approach by changing my diet and taking supplements. I can say, I have never been healthier in my life. I go to a functional medicine doctor. I recently brought my son in for testing because there is something “off”. I always have to explain to others about my medical choices. I don’t mind because I want to inform everyone that they can choose to live a healthier life. My motto is: Every human being is the author of his own health or disease.

  5. Great post as usual Mark.

    I was wondering just this week about the PB stance on topics such as actively detoxifying the body (or a part of the body such as the colon or liver).

    Put simply, if supplementation, which is not something that Grok would have done, is a good idea today because of the changes in our environment; does the same hold true for detox?

    1. Another good question worthy of a blog post. I’ll likely share my full thoughts on detoxification in an upcoming post. Thanks, Joe.

    2. I’ll give you a preview; there is no evidence that “Detox” schemes do anything but lighten your wallet. Your body has an incredible set of organs that do an incredible job of scrubbing and excreting the toxins producted and taken into the body. If we trust our bodies and the natural state they should be in, why would we think that somebody has built a better filter system than our upper respiratory tract, kidneys and liver?

      1. While I agree that our body has an incredible set of organs that scrub and excrete toxins, I also think that evolution hasn’t had a chance to catch up to our industrial age and the exposure we face to toxins that didn’t exist in such concentrated forms in Grok’s time.

        Our bodies didn’t evolve an an era of 6 billion people and aren’t really a match for many of the toxins that have appeared in the last 100 years.

        1. Maybe so, maybe not. That doesn’t change the facts that detox kits or treatments or any of the rest offered on the market don’t do anything to address those points. They prey on those fears, nothing more.

        2. I’m not picking on you here, but I’ll repeat the same mantra I always do: Show Me. Show me the proof that they work. Show me the quality research and the science. Don’t show me testamonials and hearsay and magical thinking and fear-mongering. I can bring the science behind my argument, so if somebody wants to stand up and say that detox works, they need to prove it with hard, cold facts.

        3. I don’t think detox kits do any good. Colon cleanse? Please! The best course of action is to try to minimize exposure to toxins and to eat and exercise primally. People spend too much time worrying about things that are beyond their control when they could focus that energy on the things they have control over.

        4. @Dave: Absolutely! Take full responsibility for that which you have control and don’t worry about the rest.

  6. The scary parts include foods we never suspect having toxins that do such as our protein choices in the grocer.

  7. An excellent post. So often people who are sick really believe that they have done something specific. In fact, they may have lived some place or eaten things that they were told were good for them and not even know what “triggered” the problem. Given our overall state of diet and health in the US many of these issues may have started before birth, when they had absolutely no control.

    In response to David’s post about the laziness and using genetics as an excuse–most of these people have probably tried a lot of things–but they are medications and low fat diets etc that do nothing for them. They are feeling powerless so they turn to the only excuse they have–it’s my genes. They are suspicious of any diet because they’ve done so many. Re-educating them that they do have some level of empowerment takes a great deal of time and compassion.

    1. Bonnie, you are right. People have been “fed a load of baloney” to steal Tom Naughtons term, in regards to diet. Wince it doesn’t work, they give up. On the other hand, I ‘m a bit cynical because working in the healthcare industry, I’ve seen so many patients that flat out refused to do the very things that would help them. Not only that, they hid their bad behavior from their doctors to make it look like they were being “good”. It’s more prevalent than you might think. Change is hard.
      It really does get difficult to stay the course. Even now, there are some very good interventions that will substantially improve those with CHF (congestive heart failure) Ubiquinol and vitamin for example. We have hundreds of CHF patients. Not one on Ubiquinol or vitamin D. Or if they take D, it’s 400U, not enough to do anything. I have to personally take 10,000U a day to keep my level at 75.

      1. Holy crap Dave! Is 10,000 IU of D safe? Just curious. This website gROKS!

  8. I’m looking forward to reading your take on fermented foods. Our family has been making it’s own sauerkraut for a little over a year now. Even though you CAN find ‘kraut in the store that was fermented, it’s not anywhere as near tasty as the stuff we make for ourselves.

    1. The other thing that is true of most (all?) store bought sauerkraut is that it is pasteurized, effectively killing the beneficial bacteria from the fermenting process.

      Homemade kraut and kimchi are easy to do. It also allows you to experiment with recipes to find new combinations you might enjoy much more than the traditional recipes.

  9. Interesting post and timely as I just returned this morning from Lima Peru and will be heading to cities like Jakarta and Bangkok in about a week.

    As I was waiting for a taxi in Lima yesterday I was acutely aware of the pollution I was breathing in and wondered what long term effects it has on its citizens (that in addition to the other toxins they face daily living in a city of 10 million people).

    As wealthy (by world standards) Americans it is a lot easier for us to control our environment and minimize or mitigate exposure to toxins, but what about the majority of the population of our planet? They most likely aren’t aware of the dangers they are exposed to and even if they were, there isn’t much they could do about it.

    As our world leaders begin to gather in Copenhagen to try and hammer out a replacement treaty for Kyoto I can’t help but feel that they are fiddling while the world is burning. People in cities like Mumbai, Beijing, Jakarta, and Sao Paulo face much bigger threats to their health and even their lives than a changing climate.

    In terms of thinking globally and acting locally I’ll continue to follow the Primal Blueprint laws (like avoiding dangerous things) but I know that eating and exercising primally will have a greater impact on my health than the minimal exposure to carcinogens and other toxins I as a typical American face on a daily basis.

  10. I don’t have a comment or question in particular, but I really would like to hear more of this in the future, because I think this is an issue that didn’t get covered here at MDA in such a great detail.

  11. Oh boy! Now they have more ammo to keep my peanuts off the plane…I mean really, God made us to survive about 100 years…Most don’t make it because they desire food drink and cigarettes. I live my life as healthy as i want to. I eat burnt meat becase I like it…Now I may have some idiotic politician telling me I have to take my grass fed hunk of beef off of the BBQ before it’s crispy on the outside and bloody on the inside….Why? Because othere people want power so they can show their importance…If you want to eat bean sprouts and wipe your backside with banana tree leaves, go do it. Leave my grok ass alone….If you want to warn me, thats fine, put it on the label and warn me…But do things like banning DDT because a mouse gets sick and then see millions die of malaria??? Just butt out along with the LYING global warming aholes!!! Ahhhhhhhhhhh I feel much better now…Excuse me while I go slay a fresh deer while I still can afford the license to do so…

  12. My first post. I have been reading Art Devany’s blog everyday for about 4 months and for the last couple of months I have been reading this as well. I really like both. I actually bought my 62 year old dad the PB for his birthday since he is skinny fat, eats tons of carbs, and doesnt lift heavy enough. I am someone actually carb addicted and its amazing when I dont eat them for a few days the cravings disappear. Then of course I tell myself I cant live forever like this and I have found myself on multiple day binges until I cant take the (FAT)igue if you get my drift. My question is to Jessica, can you please help me find a functional medicine doctor? It is for my brother who has OCD. I guess I should also pose the question to Mark if he thinks that OCD is related to food intake (see Mood Cure by Julia Ross) and if the PB can help. Thanks for the ears.

  13. Dave, I know there are stubborn people out there! I’m an acupuncturist so I get them AFTER they have gone through everything (good and bad) that you see. Of course, I do have the luxury of getting those who may feel powerless but at least they are motivated to try something new.

    I think the only you can do is keep talking to them and letting them know. I remember a sales seminar saying people have to hear something five times or more before “they buy”. If they aren’t really listening, that may mean speaking even more often! I know my husband doesn’t want to give up certain things. When he does, it’s not after I’ve told or the naturopath that I’ve sent him tells him, but after he reads it online as well… He’s getting better but it is a slow frustrating process.

    Some of it is not trying to push those people–they have a vested interest in having no power and suggesting they do (have power) is very scary. Again, I’m getting people who are more motivated but if they haven’t come to me for diet issues, I do have to go very slowly. Increasing water… making sure they are getting SOME good protein and minimizing sugar are a good way to start (and notice it’s not ELIMINATING sugar but MINIMIZING it)… Making the steps small enough that they can be successful with minimal effort is a good way to start them on a path. Many of my patients are too fatigued and overwhelmed by life to consider many of the changes to a Primal. It involves cooking and they see no way to have the energy to do it and they aren’t convinced they’ll see results (nothing else has worked). Often times baby steps allow them to have some confidence in being successful but also brings their energy up so that they can envision a time when they CAN make those bigger changes–then they’ll be asking YOU what else they can do. At least that’s how I’ve found that I can work around the “Yes but’s…” of my chronic illness patients to diet.

  14. Great post and interesting comments, all. Looking forward to the fermented subject being tackled here. I drink GT’s kombucha daily (4 oz only since it’s expensive) and enjoy wonderful lacto-fermented raw sauerkraut & carrots from my farmers market. I don’t know if it helps but it sure is delicious. My veggie hubby enjoys his tempeh reubens with homemade ketchup, mayo and the aforementioned kraut on ezekiel bread. Not quite primal but it’s as close as I can get him- at least it is good for him (and tasty)

  15. I wonder if, once you have removed the main objects of harm in your personal environment – that is, most starches (especially the ones containing gluten and lectins) and refined sugars in the diet, and overt amounts of stress – your body might be able to handle the other environmental toxins present. And if you can’t, well, what can one do about it anyway? Other than buying grass-fed meat and organic produce and avoiding large cities, I don’t know that you CAN do all that much. Is a city-bound mother to avoid breathing in while outside so her baby doesn’t get asthma in the future?

    I do agree with the solutions posed to these problems, with some reservations. Regarding supplements, I’m only convinced of the necessity of magnesium and, of course, vitamin D3. Interesting post regardless.

  16. Great post! As you stated in the article, this information is out there and it’s about self empowerment and understanding where to draw the line. I really appreciate all the links etc. It seems to really complement much of the research done by Bruce Lipton and the like, as well as some of the new findings in quantum physics.


  17. Your article brings to mind a study I recall reading in a book called Lights Out. Researchers were experimenting with known carcinogens by administering them to rats. In this study there were two groups of rats. One group was exposed to light almost all the time. The other group enjoyed normal cycles of light and complete darkness.

    The results? The rats over-exposed to light got cancer and died so quick the researchers couldn’t tell what exactly was causing it. The second group which lived in accordance with natural light/dark cycles barely got cancer, if at all, despite their exposure to known cancer causing chemicals.

    There is more research just like this suggesting that living in harmony with nature results in the greatest survival ability. So I would add reducing chronic light toxicity by enjoying a good amount of complete darkness each night to your list of ways to offset the influence of modern environmental toxins.