Human Interference Factor

Have you ever had wagyu beef? Wagyu is the breed of cattle from which the infamous kobe beef is derived: highly marbled, impossibly tender. I mean, this stuff is ridiculous. I’ve had wagyu steak that you could cut with your fork, no knife required. It can actually be too melt-in-your-mouth tender for me. I’m not saying I like meat tough and stringy, but I like to know I’m actually eating something’s muscle tissue. At PrimalCon 2011, the wagyu steaks were grass-fed, grilled perfectly, and not overly tender or excessively marbled. Just great. I suspect they were a wagyu-angus crossbreed, which is true for most wagyu raised in the US. I can get behind wagyu like that.

So why am I talking about wagyu beef (why not?) and what does all have to do with “human interference factor”? Well, last week I happened across an interesting science story in a newspaper. It was your typical science reporting – kind of vague and prone to make broad proclamations based on limited evidence – but the study being referenced got my attention. In it, Australian researchers compared the postprandial inflammatory markers of patients after eating either 100 grams of wild kangaroo meat or 100 grams of Australian wagyu beef.

C-reactive protein and interleukin-6 were the main markers studied. CRP is a general assessment of systemic inflammation, and chronically elevated CRP is strongly linked with metabolic syndrome, heart disease, cancer, obesity, and lots of other fun stuff. You basically want your CRP as low as possible. IL-6 is an inflammatory cytokine that the body makes during the inflammatory response using tissue omega-6 fat. It can be useful in the right quantities, but harmful in excess (like, in folks with too much omega-6 in their diet and body tissues). After eating wild kangaroo meat, CRP and IL-6 levels were unchanged in subjects, while eating the wagyu spiked both IL-6 and CRP levels. One hour after eating wagyu, CRP was “significantly” spiked, and after two hours it had dropped to an “insignificant” elevation. The researchers called this evidence of a “low-grade, systemic, immune reaction” to “new” or “modern” meat. In other words, the meat with a high “human interference factor” was more inflammatory than the wild food.

Human interference factor refers to the amount and type of artifice used in the raising of an animal for food. Was the animal raised in a manner closely congruent with its wild nature, or did a human tinker with the feed ratios and living conditions in a way that conflicted with the animal’s nature? Obviously, there are varying degrees of HIF, some of which are necessary if we want regular access to animal products without having to hunt, fish, or forage. Domestication of livestock is the most basic interference we can run, and it can be done well. Joel Salatin is a proponent of rotational grazing, which involves moving the herd of cattle to a new patch of pasture every day. This attempts to mimic the nomadic nature of wild ruminants by giving them access to fresh vegetation each day and preventing overgrazing in a single area. It’s a type of HIF, but a gentle type that pretty closely resembles nature and produces healthy animal fat and protein. Now, what about Australian wagyu? What kind of HIF is involved with wagyu production? Quite a bit.

First, the feed. All Australian cattle get a good amount of pasture time, but the wagyu are shifted onto intensive grain-feeding for the last 200-500 days of their lives. They typically receive a mix of corn, wheat, alfalfa, and barley grains, whereas many standard Australian cattle finish out their lives on grass. So the meat in the study was certainly grain-finished, and intensively so. Grain is a pretty unnatural diet for cattle. A diet of cultivated corn and wheat is highly unnatural and only possible with human interference.

Second, the genetic stock. Wagyu is a selectively bred strain of cattle, genetically predisposed to develop greater marbling with higher amounts of unsaturated fatty acids (both monounsaturated and polyunsaturated) and lower levels of saturated fat. These traits were no accident; they were cultivated over centuries. Most other cows (even feedlot cows) have higher levels of saturated and monounsaturated fat, with very little polyunsaturated fat.

Third, the living conditions. Australian wagyu live the latter part of their lives in the feedlot, which isn’t the traditional norm for ruminants.

Overall, wagyu is a breed with some novel nutritional characteristics that you won’t encounter much in the wild. But you know what? This isn’t just about the wagyu. It’s about the human intervention, and it’s about whether animal products raised with a high level of HIF deserve greater scrutiny.

Human interference was a problem, this time, but what about with other animal products, like eggs? Researchers from Tel Aviv looked at the fatty acid composition of conventional eggs from hens fed typical hen stuff: soy, corn (and its oil), sunflower, and safflower. In other words, hens that lived on omega-6 and whose tissues were imbued with the stuff. They then gathered a group of new hens, yet to lay eggs. These innocent, feathered maidens hadn’t eaten the typical omega-6 fare growing up, so their tissues were largely free of omega-6 fatty acids. Instead of corn and soy feed, these hens ate wheat, barley, and sorghum, plus an antioxidant blend. Eggs from both groups were fed to human subjects at a rate of two eggs a day per person for several weeks. At the end, people eating the conventional eggs had 40% more oxidized LDL than people eating the eggs low in omega-6. Oxidized serum LDL is strongly associated with atherosclerosis (and it’s probably a causative relationship).

HIF mattered with eggs, but in a different way. Both groups of hens experienced HIF. For the conventional group, human interference did what you’d expect: crammed the birds full of grains and fats they’d never encounter in a wild setting, resulting in nutritionally poor, downright unhealthy eggs that you’d be better off avoiding altogether. For the experimental group, however, HIF was mild, gentle. It maintained and supported the animal’s nature, rather than stifled and perverted it. Selectively using modern grains and antioxidant supplementation, it promoted and enabled an “ancestral” level of omega-6  in the animals’ tissue and in the eggs themselves. Both rearing methods were “unnatural” and only possible with human ingenuity, but the experimental method was a perfect example of positive human interference. It was interference designed to achieve the natural, ancestral endpoint, and it worked. Pastured and wild chickens eat wild plants, seeds, bugs, and grain (most of which contain various antioxidant phytochemicals and low levels of omega-6); the experimental hen diet recognized this and got to a similar place using slightly contrived methods.

I don’t think eating is supposed to be a stressful, inflammatory experience that induces a systemic immune response. I don’t think eating two eggs a day for a couple weeks is supposed to oxidize your LDL. That the wagyu meal was stressful on a clinical level and that the omega-6 enriched eggs negatively affected blood lipids both suggest that human interference factor is a valuable tool for making good food choices. Meaning, how we raise food, even if we mean well but especially when we try to circumvent or ignore the realities of that animal’s evolutionary past, can negatively affect how that food interacts with our metabolism. But, as grass-fed beef, pastured eggs, and this whole Primal Blueprint thing have all shown, when an animal is raised in a manner congruent with its nature, good things generally happen. Health, fatty acid profile, flavor (have you tasted a longterm Primal eater? tender and delicious!), micronutrient density (we’re also fairly high in selenium), and plenty of parameters that we have yet to even understand or identify, all improve.

And that’s the crux of this stuff: there’s a lot we don’t know. We’re still learning – we’ll always be learning, if we’re doing it right – and we need tools to which we can refer in times of uncertainty. I mean, you gotta eat something today. What’s it gonna be? How are you going to decide? Are those pastured eggs worth a couple extra bucks a dozen? To me, yeah. I defer to nature and prefer foods with a low human interference factor. It’s worked well so far. But you have to decide for yourself.

Human interference factor appears to be a budding area of study, so this is a topic I’ll be revisiting as I become aware of more research.

What do you folks think? Is human interference factor a good heuristic for determining the safety and suitability of animal foods? If I’ve missed an example that shows something different, let me know! 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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146 thoughts on “Human Interference Factor”

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  1. Very interesting. Can I still be primal if I’d like to at least TASTE a wagyu steak in my lift, despite the high HIF?

    You had me at Joel Salatin. But I wonder if a higher HIF actually makes for healthier, more natural meat in some cases–like those where previous human interference has wrecked the natural land (or sea)scape that’s the animals’ habitat. But a low HIF does seem to make more sense–for the animals and for us–in most instances.

  2. It seems as if the diet of the animals we eat is DRASTICALLY important. This is what I understand from this article.

    I have actually always thought this to be honest. I have not said much on the quality of food on my blog but will have to do so sooner rather than later.

    I personally only buy grass-fed beef myself (4 lbs of ground beef yesterday at Trader Joes!), pastured eggs but am ok buying non pastured chicken breasts.

    I feel as if a meat is pure protein then it will not harm me. I am not a fan of how we raise non pastured chickens but I am simply doing the best I can with what I have from where I am.

    Soon… all the food I buy will be grass-fed, pastured, etc. I may even raise my own chickens!

    I’ll do what I can to spread the word about eating healthy animals as much as possible!

    1. This article also shows that us humans are going to thrive on our natural diet.

      It’s inconclusive that grains, legumes and dairy are NOT included!

      Experiment on your own body folks. That is the best science for YOU!

  3. this goes a long way to explaining why eating 2+ eggs a day can be bad (conventional supermarket eggs) and good (free-ranging, bug eating) for your health. It is no surprise that conventional wisdom is so flawed, when the source of their data is buried under a century of animal mismanagement.

    1. So damn true. A century of animal mismanagement. Thankfully I see it turning around exponentially over the next decade or 2… or 3?

      1. I hope you are right. The food system is getting so out of control. I always buy only free range chicken, beef and eggs. I live for the day where conventional farming will become illegal and free range farming will be the only way to go.

        1. Sadly, I suspect the opposite, that those who lose money when we grow our own food and buy local straight from the farmer will start to clamp down harder and harder in order to force compliance and keep profits high. With the recent raid in California on the raw milk folks, I’m afraid we may already be seeing it.

          That said, this all comes down to one all too common trait we humans seem to possess in industrial quantities: hubris. We know better than nature, we can engineer anything we want. Just do it, just get it done. Don’t think about what might happen, don’t worry, just go.

        2. The opposite is going to happen.
          More and more little laws pop up here and there every year to rob people of their freedom.
          I’ve watched enough conspiracy FACTS to clearly see the future, as far as climate, land, population, water and food goes.
          This is an empire, not a democracy. The wrong kind of people are behind everything that’s being done in this country. Some people have been in charge (their hands in the politics of money) for over 60 years. Some of them are in their 90’s and senile…and voting. /scary

          I would’nt put it past them if one day a law came out where personal gardens are illegal. Growing your own food will be illegal. Just look at the baby formulas. They put substances in them to induce type 1 diabetes. So as soon as the baby gets off mothers milk and onto formula, the baby is diagnosed with Type1 diabetes, ironic eh. Lifelong dependencies on pharmaceutically produced meds is what they want. And they’re working on producing as many seedless plants as possible, or genetically modified to where they don’t reproduce from the seeds they may grow.

          Sure wish I could ride my horse to the store and back home, but NO, that right has been taken away,too. No ‘farm’ animals within town district.

  4. That was really interesting Mark. Thanks for pointing out those studies. I found this particularly poignant: ” At the end, people eating the conventional eggs had 40% more oxidized LDL than people eating the eggs low in omega-6″

    In a way the media is right. Meat and eggs (from the wrong sources of course) are bad, maybe even just as bad as the high carbs which they typically choose to ignore.

    It’s great that we have the power to raise animals for food in a way which is congruent with nature. Theoretically, we can maintain our modern lifestyles and eat domesticated food that mimics wild foods.

  5. HIF seems a qualitative rather than quantitave measure, so the decision still comes down to whether you’re buying industrial, CAFO-raised meat, eggs, and dairy, or buying pastured, sustainable, traditional products. While there may be some differences between a rotational grazing/managed intensive grazing and farms that do not rotate their cattle and poultry between paddocks, the differences IMO would be far more scant than the difference to CAFO products.

    Incidentally, I just got a quarter beef last Friday and 3 dozen pastured eggs, so I’m a happy camper. Looking to add a half pig and a half lamb this fall to the freezer.

  6. This is one reason I love that I grew up in a family that hunted and fished! And that I live in a family that continues to do that. I grew up and still eat wild venison meat (assuming we are lucky enough to get deer each fall) I also really enjoy fishing, and my dad was an avid duck hunter (in fact I hate eating duck in a restaurant cause it tastes nasty to me). For me growing up I learned that wild game actually tasted so much better to me and I am thankful that my folks raised me that way, and I plan to raise my kids that way!

    That being sad, we all have to do the best we can when choosing meat at the market! I try very hard to shop at a local meat market who gets meat from local farms, lots of grass feed and free range stuff to choose from, but honestly sometimes the cheaper chickens just have to do, and we don’t often get to buy grass fed steaks, since $8-10 a pound is a pretty hefty price for a young family of 4 soon to be 5!

    We all just have to do the best we can. And thank you Mark once again with the good education we get here at Mark’s Daily Apple!

    1. Joanne, if you have the space to add a freezer (cube or chest), it would be a good investment. If you buy direct from farms (quarter/half cow) you can realize big savings. is a great resource for grass-fed products.

      I found a farm selling beef for $2.50 per pound hanging weight; once you factor in butchering waste and packaging fees, my average price per pound for ground, roasts, steaks, livers, etc. is about $4.75.

    2. “assuming we are lucky enough to get a deer each fall…”

      Are you losing faith in my hunting abilities? 🙂

      Great article Mark!

  7. More studies that encourage clean food. I’m for it. Always progressing, but this highlights the importance of food quality!

    1. There are studies that show organic, permaculture fruits and veggies are more nutrient dense, which makes sense since industrial farming strips the soil of micronutrients and any microbial culture or mycelium. So while the nice red giant tomatoes made of styrofoam in the grocery store may be nutritionally vacuous, they are not necessarily harmful (until one adds up pesticide and herbicide effects). The difference in meat, dairy and eggs is that industrial methodology makes them immediately harmful (inflammatory). The danger from industrial meat is more pronounced, in other words.

      1. Not all organic is created equal. I can’t help but smile to myself at the store when folks buy mass-produced organic produce at regular grocery stores. Twice the price and most certainly not twice the quality!

        1. I agree, and was over-generalizing. That’s why I try to source fruits and veggies the same way I do meat, dairy and eggs: by being familiar with the farmer and the farm as much as possible, knowing their methods of raising crops, etc. IMO, industrial-organic from the supermarket is something to be considered for the most pesticide-heavy crops ONLY when the better sourced options are not available.

        2. I was one of them.
          I ate Organic EVERYTHING and still in joint pain and digestive distress.
          Organic sunflower bread,organic margarine, made from ‘organic’ soyspread, organic (ultra-heated and homogenized) milk, organic pot pies, organic burritos, organic spelt noodles, organic chicken fed ‘organic vegetarian’ diet (soy), grassfed buffalo (that was fattened for 6 months on grains after taken off pasture but nowhere labelled), ‘wild caught’ fish (farm raised and released and captured down the stream).
          Now I eat ALL the things that was said to cause inflammation (meat, dairy, eggs) EVERY DAY, but from grass/finished, truly wild caught, pastured, bug-eating animals and ALL of my problems have disappeared.

  8. Overtime our food supply will get better as we understand more. The big food companies will come around, eventually! When they see how much money co-ops make per square foot, good food pays!

  9. That egg study is enlightening. But just try to find eggs whose chicken isn’t fed corn and soy. Even pastured hens are fed the stuff. And my understanding is that eggs that claim to have more Omega-3s include flax seed in the chicken’s meal, but what isn’t told is how that affects their 6-3 ratio.

    Makes you wanna raise your own, doesn’t it?

    1. Agreed. I get eggs from a guy at my farmer’s market who pastures them, and the yolks are almost red, they’re so saturated with beta-carotene. But I’m sure he also feeds them laying ration. It’s impossible to tell what’s in that stuff: it’s little gray pellets. A lot of chicken owners also feed “scratch” which is a mixture of corn and wheat.

      1. Those little gray pellets are soy.

        I’ve been raising chickens for years now, and I’ve found they simply do better with grain feeds to supplement their free range foraging.

        I feed my chickens 3-way scratch – cracked corn, wheat, and milo. But I also mix in barley, whole oats and flax seeds.

        This is in addition to all food scraps generated from cooking daily meals, as well as allowing them to free range in the yard to eat bugs, worms & grass. Broccoli, onions, tomato, garlic, asparagus, apples, and all kinds of meat (just not chicken or turkey, they’ll eat it too, but I have a visceral distaste for cannibalism…). Chickens are literally pigs with wings.

        Some people seem to think that because wheat, corn, etc. are bad for humans, that you should avoid feeding grains to chickens. This is ludicrous. Chickens, unlike humans, were designed to eat grains as a part of their omnivorous diet. If you watch chickens free ranging on a pasture, they love to go for grain-bearing stalks of grass. That being said, I do oppose soy feed that is ubiquitous in CAFO and even free range chicken farmers.

        The very reason why I started raising my own egg laying hens was to get soy-free eggs. WAPF found that Soy isoflavones are be present in eggs from soy fed hens.

        Farmers love the soy feed because it promotes much higher egg production. My chickens produce about one egg a day a piece, while I have a neighbor who exclusively feeds his chickens soy feed. He produces a much higher yield of eggs, but they are thin shelled, dull yellow etc. They don’t feed them scraps nor let them free range. They are permanently confined and only eat the ‘egg producer’ soy feed.

        In terms of quantity, he’s got me beat…but certainly not quality.

        1. I used to love it when my ladies would daintily peck off the seeds from the tip of a stalk of grass. ^_^ And you are so right about them being pigs with wings. We had to make sure and bury our dead chickens deep enough that they wouldn’t find them by accident and dig them up. XP

        2. Great post, thanks for the info. Good to hear this stuff straight from the real deal.

    2. Funny you ask – I have a friend who just started raising chickens and hens and they just got their first batch of eggs. So happy!

    3. If the chicken are outdoors, and have access to bugs, dirt, weeds and grass, but are also fed grains that contain soy…the chicken have the option to pick what they want to eat and usually leave the things, that they feel make them ill, behind.
      The place where I buy my chicken eggs does taht, they say that when spring hits, and the bugs start coming out, most of the grain feed is left on the ground.
      The yolks are very orange during that time, and turn into a pale yellow during winter IF they even lay eggs. Most of the time when late fall hits, the egg production stops.

    4. In Western Washington, there are at least a couple of options for buying food for our pastured hens that contain no corn or soy. Just about every breed of chicken – whether used for eggs and/or meat – needs extra inputs and is not able to live off of pasture alone. It’s not a bad idea to contact your egg supplier to ask what is in the feed – then you will know and be able to make wiser decisions about purchasing.

  10. Nice stuff. This is why you’re the king, Mark. I have already read the egg one but this new meat study puts some things into context. If I eat grain-fed meat from the local supermarket (try not to but it happens) I usually get a few pimples, but if I stick to completely grass-fed meat my skin is flawless. Same goes for pasture-products eggs and conventional ones. It’s quite the difference.

    I have made my choice but I don’t want to be alarmist about grain-fed meat. The difference between grainfed and grassfed meat in my CRP is 0.3 and 0.1, so it’s not like if your diet is generally good then eating meat that has seen grains is a dealbreaker, I think most of our response to pro-inflammatory foods is ultimately determined by our bodies’ innate regulatory systems. How’s your PUFA ratio? How’s your gut flora? Vitamin d, glutathione, etc.

  11. I was so disappointed at Trader Joes yesterday. Went to purchase some beef only to find that not a single package of meat (of any kind) was from the US. Everything is shipped in from Australia, Canada, etc. I just couldn’t buy the ground beef from Australia, even if it was grass-fed, because I thought about the resources that it took for that beef to get to my little Hollywood Trader Joes. I’m starting to notice that there are so many other factors in buying meat, and location & sustainability are 2 important ones that shouldn’t be ignored.

    Can anyone provide some good places near Los Angeles to purchase meat (in bulk or not) that has been grown in CA?

    To health!

    1. Whole Foods usually carries locally-raised options, at least in Atlanta. It’s right on the label with the price. I think it’s part of their philosophy to go local whenever possible.

    2. I would also tell the folks at your TJ’s. Folks from my CF box kept asking for grass-fed meats and local produce, and it did start showing up this summer. Our store is small, and I live in ruralish Ohio, so it couldn’t have been that hard. You may also want to search for local butchers. I found a great one who knows a ton about how the animals are raised and can go down the case and tell you the name of the farm that raised it. Might take a few phone calls to find grass fed, but worth the time.

    3. The Mar Vista farmers market on Sundays has a vendor, Dey-Dey’s, who sells CA-raised, grass-fed meat– it’s really good. Here is their website:

      The Mar Vista farmers market is at the intersection of Venice Blvd. and Grandview, 90066 zip code.

      I’m not sure if they go to other farmers markets in the area– worth asking!

    4. While I admire the localvore ethos, this is probably cutting off your nose to spite your face.

      The reason why it’s so difficult to find grass fed beef in CA, is because most cattle ranchers simply have to sell their stock to the CAFO’s to stay in business. The CAFO’s are simply too huge in the market.

      If more and more people continue to buy Australian grass fed beef, you will create more market demand for your local area ranchers to begin selling part of their herds to grass fed suppliers.

      And the resources argument is a little bit ridiculous. Global trade is not going away anytime soon. Every single day, ships depart from both US and AU with cargo holds full of produce and products for sale in both markets.

      It is what it is.

      Refusing to eat 100% grass fed beef because it’s from AU is not going to stop those ships from doing their trade routes. Shipping has been going on for centuries.

      You should worry more about what your eating rather than the supposed “resources” used to get it to your local market.

      Yes, support your local farmers where ever possible, but if you can’t find grass fed beef anywhere but at TJ’s or WF’s and it’s from AU, than do what’s best for your diet!

    5. I think we are very fortunate to live in California (I live in Ventura Co.), where we have excellent year round farmer’s markets. For the grass fed beef, you might try Novy Ranches. It is available at many of the farmer’s markets, (including the Sunday morning one in Brentwood), raised in California, based in Simi Valley. They have a website, too: I have been very happy with it!

  12. I also can’t afford to go 100% organic/grass-fed/pastured, unless I am out to eat I will not compromise on beef, eggs, butter and sour cream…these foods are just too high in fat to eat conventional. I agree with Primal Toad…boneless, skinless chicken breast is simply pure protein for the most part so I save my $$$ to buy the good beef, eggs and on occasion sock-eye salmon.

    1. What do you mean ‘these foods are just too high in fat to eat convention’? Just curious…

      1. I think he means that all of the nasties are harbored in the fat….so foods with a high fat content must come from an impeccable source (ie. non-conventional) whereas lean chicken doesn’t pose quite the same risk.)

    2. Keep in mind, though, that conventional chickens are fed arsenic, and it ends up in the meat.

      @Oily-I suspect they’re thinking that since the toxins usually end up stored in the fat, it’s good to avoid fatty conventional foods. Which is probably true.

      1. “Keep in mind, though, that conventional chickens are fed arsenic”

        Citation, please

        1. It was widely reported in the news within the past couple of months. A google search will turn up articles from everything from Huffington Post to New York Times to Science Daily. And that’s just on the first page of hits.


          Fact is that all poultry (commercially grown) are fed arsenic.

      2. Conventional chickens also receive medicated feed to help them survive until slaughter – it seems to me that the antibiotics have got to show up in the meat, which seems like a good reason to avoid conventional chicken.

  13. I’m working my way more and more into the “eat foods that were raised well” camp. I’m very close to the point where I’m willing to pay extra for the “good stuff” so to speak, but it’s very hard to navigate what is and isn’t good and there’s no real accountability here.

    Companies (YES even companies that sell foods at all the new-age, hug the earth, “good food” type stores) can slap labels on stuff that don’t mean anything. How do I know that those $7.99/dozen eggs are REALLY the good ones? Seriously, how do I know for sure? The answer is I don’t! Sad fact of the matter is that people LIE and companies LIE — and if I’ve learned nothing else from the Primal experience…it’s not like I can trust the government (or any other type of regulatory agent) to make a difference here.

    And that’s frustrating!

    1. Agree with you (SO much food industry trickery and deception)! do you know REALLY helps to purchase it direct from the farmers as much as possible (the site helps you locate them). Also, I joined a CSA this year for eggs and veg, I know/trust that farmer as well, and a big time saver over farmers markets.

    2. That’s a great point. We’re struggling with the same thing in our household, and here’s what we’ve done to shift into the “eat foods that were raised well” camp.

      1. Meat purchased directly from the farm. We only have a 2 person household and do not have a huge meat freezer, so we don’t have enough room for a whole cow or anything. We started small – we buy 1/2 lambs from a local farm and then visit the farmer’s market to buy our beef and pork. You can also find local farms that are willing to ship direct to you if you don’t have a farmer’s market. We are also fortunate that we have friends and neighbors with chickens, so we take “extra” eggs and then subsidize with grocery store organic eggs as little as possible. With the exception of the shipping option, you get great accountability because you get to physically see the environment your food was raised in.

      2. Whole Foods meat – I know you may have had them in mind when writing your comment. But, they do have a very detailed pamphlet about what exactly constitutes “stage 4” v “stage 5” chicken, pork, beef, and so on. You can find it here:

      And yes, the farm and the company could be lying, but maybe I’m a little more naive. Seems like a lot of trouble to go through with specific standards when they could just slap a “vegetarian diet” or “natural” sticker on it and call it a day.

    3. also, what if you just can’t afford it? I try to buy organic/soy free, etc. but I agree with you.. sometimes companies just put an organic sticker on their stuff and its all bullcrap. Hard to know who to trust..

  14. great article, thanks Mark. Its interesting about the Wagyu breed, I was actually planning on raising a couple on my in laws property completely pastured. Perhaps I’ll save some money and go with a hybrid wagyu/angus.

  15. Another key difference between the two meats: calories. If I understood correctly, both groups were given 100g of meat, but the kangaroo meat only contained 4% fat while the wagyu meat contained 30-40% fat (presumably by weight). That means the wagyu group ate more than twice the number of calories. I think a small increase in inflammatory markers following a meal may not necessarily be abnormal– it’s observed in many studies. I don’t know, it remains to be determined. But the more food you eat, the more of a spike you get.

    Mark, nice to see you at AHS.

    1. One thing to note about this study in general is that by comparing two completely different animals, you are introducing an incredible amount of variability making it hard to pin down what it was that caused the different responses. It could vary well have been the “human interference factor”, or it could be the differences in nutritional profile as Stephan pointed out, or something completely different.

      I am just saying that these results need to be taken with a grain of salt until it can be shown in a much more controlled study that isolates these various factors.

    2. If you subscribe to the idea that a calorie is a calorie is a calorie, then yeah, that might be a problem. But if you do more reading around the site, you’ll discover that saturated fat calories aren’t harmful the way sugar calories are.

    3. @Stephan, I can always trust you to drill down a little deeper. Great point and worth noting and further researching. Re:AHS, I was hoping we’d get a chance to talk further, but it was nice spending the time we did. Next time, maybe.

  16. Makes perfect sense that the quality of an animal’s meat reflects the quality of what they’re fed on…and predicates our bodies reaction to eating it.

    Unfortunately, in the UK we don’t always have all the options you lot in the US have (I don’t really understand what ‘Trader Joe’s’ is). I went into our only local butcher’s shop (us:’store’) the other day. It’s been established for many decades and I’m lucky to find one at all now they’ve all but been ousted by the supermarket. I asked if they had any ‘grass-fed beef’. They just looked at me as if I’d asked for a Martian kebab. No idea what it was…not a clue!

    1. Hmm… Oily… maybe you know… whenever I’m in the UK I’m more likely to order lamb in restaurants because I see so many lambs out grazing in the fields that it’s hard to imagine that there is factory farmed lamb out there. Do you have any idea if that’s true? I figure there’s a greater chance of me getting grass-fed animal that way.

      1. That’s true. Lamb in the US is grassfed/finished. But, it could be fed dried hay only if confined and supplemented with peas/corn.
        Regardless, the animals are still outdoors and get plenty of sunshine, and usually do get a lot of pasture time.
        Lamb is THE BEST option on meat to buy in restaurants (aside from whole fish or a salad).

    2. @Olly

      Trader Joe’s is the name of a grocery store chain in the US that prides itself in innovative, hard-to-find, great-tasting foods. They’ve become very popular here as their veggie/fresh food selection is top notch. But they do seem to have unusual items we can’t find in conventional grocery stores at reasonable prices.

      Personally, what I like about them is that they are willing to carry stuff that the conventional stores won’t carry. Obviously, if it doesn’t sell they won’t carry it anymore, but at least they are willing to try new stuff.

      Google “Trader Joe’s” and you’ll see what I mean. And, no, I’m not related to anyone at TJ’s but I do frequent their stores whenever I can as does all of my family. Some of the stuff is Primal friendly and some is not – so pick and choose.

      1. So far, I’ve been somewhat disappointed with Trader Joes. It mostly seems like a hang out for the vegetarian/vegan/eat lots of “healthy grains”/granola crowd.

        There’s a few items that I’ve found at my local store that intrigue me, but honestly other than the wine (which I had been going there to get for some time…but no get much less — limiting alcohol since going on Primal) I don’t really see the attraction to them if you are going strictly Primal.

        There’s a *lot* of products aimed directly at the CW approach to “health” crowd.

      1. but have you seen the price greensleeves.Ok for you rich guys but us ordinary people just cannot afford it.Same with organic.
        You may well say what price health but there is a line you cannot cross.

        1. Same boat! Don’t get me wrong. I’d love nothing more than to buy grass fed pastured everything, but the truth of the matter is that I’d have to live in a tent in my Mom’s back yard to do it. I’m trying to save some dough for part of a nice cow and an adopt-a-chicken program that a local grower has, but that’s a ways off. For now it’s conventional meats AND eggs most of the time.

    3. Hi Oliver,

      there are ressources in UK! Thanks to the Weston A Proce Foundation. Check out the “Natural Food Finder UK”.

      I got my Green Pastures High Vitamin Col Liver Oil from them. It is impossible to get it in Germany where I live.

      Her’s the page about Meat, Poultry and Seafood:

      Btw: I like your website.
      Good luck for “hunting” your grassfed beef. Ireland is good for grassfed too (think Kerrygold Butter).

  17. It would appear that Human interference factor would be a useful measuring tool with the confound of humans being able to re-interfere with their own interference to undo or mitigate the negatives.

    EG. Temple Grandin working to reduce stress and injuries of cattle before slaughter positive HIF.
    increase profit as a result of increased animal well being(less bruising ).

    Feeding chickens the cheapest feed available regardless of their natural diet or resulting egg quality to increase profit negative HIF.

    If the interference is to increase profit at the expense of the animal or consumer yeah it’s bad.

  18. I think there are levels of everything. It’s a fact of life that real people’s budgets won’t always include enough wiggle room for totally grass-fed, antibiotic and chemical free meats and certified organic local dairy.

    To me, I’d rather at least try to avoid the harmful chemicals put in meat, eggs and dairy by men, and then worry about the diet that was eaten by that animal.

    In my area of the US, it’s fairly easy to find local, antibiotic free meats and eggs that are in a price range only a touch above what conventional meats are. Adding total grassfed to the local, no AB roster spikes the price quite a bit, and availability becomes an issue.

    In the long run, I’d love to find a cowshare program that was fully grassfed, AB free. But in the meantime, I’d rather eat a grainfed cow that was at least lower in the way of chemicals.

    1. When I eat organic store food I dish out about $120 for myself in 1 week.
      During the farmer’s market season I pay $50-60 for 1 week.

      I save a ton of money in 1 month buying farm fresh, local, grassfed/finished products.

      1. well for the UK,your $120 is well over half my weekly income and bear in mind organic and pasture fed are far more expensive here.We just don’t have the room

  19. I buy all of my animal products from a local buying club. They’re all grass-fed and pastured. I’d encourage people who can only buy corn-fed from the supermarket to look into local farms. They’re usually not too much more expensive.

    1. I wish folks would say where they are from and where exactly they are buying in their posts on here. I’ve scoured and while it has helped I’m certain the site, while good, is not definitive.

  20. The whole egg thing is really confusing me, can somebody help?

    I’ve been eating tons of these local “pastured” eggs that I found at Whole Foods:

    They say that their hens remain on pasture and graze on bugs and greens. However, “in addition, they are fed a 100% vegetarian feed consisting of soybean, canola, corn, wheat, oyster shells, minerals, feed free of antibiotics and hormones.”

    Is this an issue? Should I try to find a different source for eggs that doesn’t supplement their hens’ diets?

    1. No. If the hens have acess to bugs, worms, grass and weeds they’ll pick through the stuff they want to eat.
      Remember that some grains are normal for birds since they can produce an enzyme to break down phytates and other plant substances toxic to us humans.
      They can’t however deal with the hormone disruptors in soy, but if they have the option to not eat it, they won’t.
      My eggs come from a similar place, outdoors, pastured, eating bugs, etc…and get grains thrown onto the ground. The difference in the egg yolk color is great between the time of weather being too cold for bugs to be out or not. Spring, summer and early fall the yolks are orange, late fall they start to turn to yellow and production stops when winter hits.

  21. I just have one problem:

    “Oxidized serum LDL is strongly associated with atherosclerosis (and it’s probably a causative relationship).”

    If this is supposed to be a “science” article quotes like the previous one have no place. References to where the information was obtained (Oxidized serum LDL is strongly associated with atherosclerosis) would be nice.


    1. Oh and ignore the multitude of grammatical errors .. I know, I know… It is that stream of consciousness habit!

  22. Definitely interesting, but not really a new concept, just a new way of approaching the big issue – that we consume animal products from animals that are factory farmed.

    Chickens get their beaks chopped off so they don’t peck the hell out of the other chickens they are crammed on top of. They are fed grain when they really should be picking through the cow crap left by the cows the day before. Cows are fed grain laced with ethanol and injected with hormones and antibiotics.

    The movement is working though. I see more and more farms producing 100% grass fed animal products. In fact, I went from having to buy it online or at a local health food store to buying it from a few local farmers.

    It’s happening, it’s just slow…….

  23. Hi there,
    I just went halves with my brother-in-law in a fully grass fed hereford. He is a beef farmer and the beast was slaughtered on his farm, (they roam freely over his the hills and on the plains !)No grains at all and boy are my 2 freezers full of great tasting beef. Oh I live in Australia.
    One obserxation, the meat from peters farm has more blood in it.

    1. Does he dry-age or wet-age his meat?

      Just curious.

      My grass-fed is dry-aged, but it’s still got plenty of blood; I suppose the moisture reduction from dry-aging just condenses it?

  24. This article has got me worried… it seems I’m going to be a preferential meal for any health-conscious predators out there.

    If I spot any lions wearing Vibrams, I’m really going to start panicking!

  25. I understand that feeding cattle grain – an unnatural diet – is a prime reason why livestock producers need to over-use/mis-use antibiotics. The stomach upset cows experience from digesting grain, rather than grass, leads to problems with the natural balance of their digestive and immune systems, and the antibiotics are used to counteract that. By “solving” one problem – or, by seeking more profit – you create a more serious problem.

    Dennis Blair

  26. The egs we have in our supermarket are
    -organic (whatever that means) $6 per dozen
    -free range $4.50 per dozen
    -omega 3 enriched $3.50 per dozen
    normal $2 per dozen

    the mark up is significant, but I have no idea if it is worth it to pay the 2x mark-up for free-range, providing I cannot afford paying $12 a week for organic.

    1. Hunt up a farmers market. Maybe I am just in a chicken friendly area, but the big market in town has folks selling good pasture-raised eggs for between $3 and $4 per dozen. If you talk to people and are willing to go to the farms yourself it can be less.

    2. Free-range could mean they’re not in cages but still in the barn, without day light, completely in the dark, in a 50×50 square foot building. It could also mean that the barn isn’t cleaned the entire time the chicken are alive and eat and poop.
      There is literally 2-3 foot high chicken crap in the barn which the chicken live on, until removed for slaughter. THAT is the USA’s definition of free-range: cramped up, living indoors on their own feces without light.
      Also some pastured chicken usually have the label vegetarian fed and it means they have acess to the outdoors where there is usually NO pasture at all but just hard dirt with feeders installed for grains and beans. These ‘pastured’ chicken are allowed to see day light outdoors.

      It’s always best to go and look at the chicken personally by driving to the farmer directly and taking a look at the situation.

      If you buy your eggs from a store other than a Co-op, local indoor farmers market, etc…chances are the chicken were abused.

  27. I LOOOOVE THIS PAGE AND ALL THE INFO THAT COMES HERE..Well the info is great…some of the threads get twisted into pretty weird places..but humans go to pretty weird places…LOL..I LOVE MY AUSTRALIAN FREE RANGE BEEF THAT I GET FOR A GREAT PRICE..”Natures Reserve”…I love the lamb too…The fact that I can get better meat for a better price than American Standard is what makes this PAPA GROK a very happy GROK…I just bought whole beef Tenderloins for $5.99 per pound..I bought 2….I have many friends from all over the world now due to this way of life…and my Australian ones are some of the best and they can Raise some MIGHTY good Beef…

  28. Mark, in Italy there is a farmer who supplies milk goat to chickens,(Leghorn chickens galline Livornesi) it is natural to give milk to the chickens?…. know you that the chickens have the breast?

  29. Awesome, I’ve always paid attention to HIF whenever I choose my food, but it’s mainly just a rule of thumb. If a clinical study shows that a particular human-tainted food is healthier, so be it. Nonetheless, looking at HIF is a great place to start one’s hypothesis for a food study 🙂

  30. My takeaway from this is a little different. Mark touched on it with his Joel Salatin (vis a vis Michael Pollen?) reference. To me, it says without foraging and hunting for truly wild things, we have to eat domesticated animals. A modern chicken which cannot survive without its human partnership is inevitably a product of HIF. The wild chicken ancestor living in evolutionary conditions is lost in time. So we can either seek to replicate evolutionary conditions as best we can, to varying success, or not. Whether one agrees with this argument or not, I believe the logic extends to why we might choose to supplement. I.e. a probiotic because we don’t eat dirt anymore.

  31. Hi Finnegans wake,
    He just has it slaughtered and as I understand it , it is hung for a few days and then cut up. The butcher does it all at Peters farm.

    1. Gotcha. Dry-aging involves hanging larger pieces for 14-21 days, and letting the flavor devlop through moisture evaporation and natural enzymatic processes. Sounds like yours it wet-aged, i.e., butchered and packaged right away (under a week). That could explain the juiciness. There is a difference in flavor to dry-aged, though.

    1. jack just didn’t know about moving frequently at a slow pace…to much stress. universe rest your tired soul.

  32. As soon as I read that wagyu beef was finished in a feedlot, I was in no hurry to try it out; not a big fan of “factory farming” and what I perceive as the inhumane treatment of animals in such places, and I think for the cost of Wagyu I could get a huge chunk of grass finished steak that is nutritionally dense and delicious.

  33. I live in Japan and not all the wagyu here has so much marbled fat (the term “wa gyu” just means “Japanese cow”); I regularly eat local wagyu rump steak. It is normal steak: tender, full of flavour and has a high proportion of meat to fat. The cows are allowed to roam free and eat grass during the summer (fed on dried rice shoots during the winter due to snow). This is a lot better than the other offerings you can find in Japanese supermarkets and in the difficult quest of being primal in Japan it’s the best we can get.

    1. Hi JPGrok,
      I too live in Japan and there are a lot of great choices in beef. Every supermarket I go to has Australian and/or New Zealand beef, and they’re all grassfed. One expensive delicatessen actually had a sign saying: this beef is grain-fed! It was from Australia, and I guess it was so rare that they put up a sign for it.

      1. Hi garymar, interesting stuff. How do you know the Australian beef is grass fed? There are no labels on the stuff we get up in Hokkaido other than “Australian Beef”. It would save me a good chunk of cash if I knew the Aussie stuff was good.

        Whereabouts are you based?

        1. South part of Tokyo. I assumed that all Australian beef was grassfed unless otherwise indicated! Because I’ve read remarks from Aussies saying why would they feed their cows expensive corn when they have all the grass they need.

          I’m pretty sure all NZ lamb is grassfed.

        2. Spoke too soon! I’ve been looking at Australian beef websites. The website had this to say:

          “In 2007-08, 26 per cent of adult cattle in Australia were finished on grain, with the remaining 74 per cent pasture fed.”

          The proportions look good, but there’s no way to tell which we’re getting here in Japan.

        3. I think Aussie beef is probably the best we are going to get here. I called a meat supplier this morning to ask whether they stock any organic or grass fed beef and they said, “No organic meat whatsoever but we can source grass fed Aussie beef”. They also told me that most wagyu was finished on grain and feed from America. He said that more than likely they use hormones and antibiotics too (sigh). I think I might go Aussie from now on! He said 1,300 yen per kg of grass fed Aussie. Might put in a big order after Obon.

        4. Standard Australian Beef is grass fed. The grain finished stuff is more expensive.

  34. Great post, Mark!

    Eating sustainably-raised meat, eggs and dairy also supports the local economy. is a great resource for sourcing locally-raised grass-fed beef, lamb, goats, bison, poultry, pork, dairy…and other wild edibles.

    Check out your local farmers market as well. I rarely shop at Trader Joe’s or Whole Foods because I prefer to buy direct from the producer whenever possible.

  35. Yes I just found this Waguye study too. Makes total sense to me. HIF is a useful concept. Dr. Cate Shanahan in her book “Deep Nutrition- Your Genes need traditional food” says the same. Great book btw. She writes that the quality of the soil and the way plants are grown has an impact on their quality and the information they give to our genes. Same goes for the animals that eat the grass and are eaten by us. I always thought: Food Indstry animals and plants are produced in a perverted way. This can’t be healthy for me. That is why I don’t ever eat conventional meat.

  36. I discovered “Pasture to Plate,” a company in the Vancouver, BC area that sells pastured meat from BC ranchers. There’s also a restaurant (they also have a store) called Ethical Kitchen in North Vancouver that uses pastured meat and poultry. I wrote a blog post about some other local sources, too, for such things as certified organic coconut oil, fermented cod liver oil, x-factor butter oil, etc.

    1. Just a note that apparently farmed oysters are no different from wild oysters. Yay! Farmed fish, however, are definitely to be avoided.

  37. Would be great to have access to the full text article for the meat study. I want to know if they corrected for the fat content between the kangaroo meal and the wagyu. Wagyu always seemed a little suspect because beef just does not become this marbled in normal circumstances.

  38. In reply to Olly about grass fed beef in the UK – If you buy beef around September time you can be fairly sure it will be grass fed for its final “finishing”. Farmers keep stock indoors over the Winter and feed supplements, but from late Spring onwards they are on grazing. We don’t have the US type intensive feed lots in western Europe. There are also lots of suppliers of guaranteed grass fed and organic beef on the internet, you just pay more.So stock up the freezer next month.

  39. Thanks Mark. Interesting and informative as always.
    Love to try the wagyu though, bit like a beef version of streaky bacon; wonder if there’s any available in the UK?

    Conclusion – what’s good for us (ie genetically appropriate) is good for our food sources.

  40. Foie gras—the ultimate in grain driven Human Interference Factor!!

    1. Then I must thank with all my heart the human interference factor because Foie Gras is absolutely amazing ….

  41. Another great post Mark, HIF is interesting but what your post points out more importantly is how “science” continues to fail to control for all of the variables and then reaches spurious conclusions.

    As far as Wagyu and HIF I would like to give a shout out to Torm Siverson at Pasture Prime Wagyu (I’m not spamming so google if you are interested) They are a very nice family in central Florida that Raises Pigs and Cows the way they are supposed to be raised. They love the animals and love what they do. In addition to 100% pure Wagyu stock, they are also bringing back traditional meats like Berkshire pigs and forgotten meats like Mangalitsa (wooly pig)pigs.

    If you have the means to purchase super quality food it is worth checking out.

    Now I’m off to have your latest “pate” recipe and some homemade Kimchi!


  42. Mark, does this mean you would recommend not eating eggs if one can not afford/obtain eggs from pasteurized chickens?

    1. Eating eggs is still 500% better than eating the grain directly yourself.

  43. You know, it stands to reason that what our “food” eats affects us. Look at what happens when animals higher up on the food chain eat animals that are contaminated with toxins – eagles lay eggs with shells too thin to support the chick inside, etc. Heck, if I had my way we’d have a chicken or two running around in the yard and have fresh eggs every day (I’m sure my two Labs would love that one).

  44. The problem I have with all this navel-gazing is that it assumes that we can actually trust the labeling on the foods we buy. Grass fed? Really? Is it? Who knows. Unless you are driving to the ranch, pointing at your cow, and reading a magazine while it’s butchered up for you, you don’t know.

    Also, the US regulations for chickens to be considered “free range” is FIFTEEN MINUTES A DAY outside the cage. Does anyone really think fifteen minutes a day on a patch of grass is going to significantly affect the quality of the eggs or the meat? I don’t.

    I find that making excruciating scientific explorations into every single aspect of things that, in the end, most of us have no control over is defeating on this diet.

    I have a limited number of grocery stores that I can shop at. I have an extremely limited budget, and cannot afford to mail-order beef that may or may not actually be grass fed.

    I choose to just make the best choices I can with what is available to me at the grocery store. Regular old chicken, regular old beef, regular old vegetables.

    I’m eating much healthier than I was before, and I’ve lost thirty pounds and counting. If I’m going to get exhausted, it will be at the gym… not looking through a mental microscope at my food.

  45. I have to admit as an Aussie, I’ve tried both Roo and Wagyu and I would pick the roo any day. It is my primary red meat of choice. Very lean so you have to cook it slow with the lid on the pot so it doesn’t dry out but SO TASTY!!

  46. There is a lot to this. I found out in my own way last December when I went on a trip to Egypt (yes we were there when the revolt started- good timing). My girlfriend, who has serious gluten and fodd sensitivity problems (she normally cannot eat grains, eggs, soy, apples, and a host of other common things), wnet with me on the trip. Much to our surprise her problems with food vanished completely. Mind you we went everywhere in Egypt, and in some places nobody is really allowed to go. but the one common thread was that we ate LOCAL food that came straight from their farms. Nothing really altered by people. We realized that her food allergies and sensitivities were caused by all the crap they do to our food over here. It’s genetically modified, innoculated, the animals eat all sorts of garbage that they shouldn’t (I mean marigold pollen fed to chickens so the agg yolks are yellower – give me a break). Of course her food problems came back when we returned, but armed with this knowledge we can find food that works. For instance in my town (Tucson) you can readily get venison, quail, alligator, rattlesnake, and even the occasional python. There are lots of organic and non- altered grocery stores too.
    My basic rule is this: if you don’t feel good, what are you exposed to? It’s either something you eat, something you drink, or what you breathe. These 3 are basically 100% of your exposure vectors.

  47. So, the people that have been eating more eggs (from a commercial source) as part of the Paleo lifestyle are essentially killing themselves with atherosclerosis? Did I understand this correctly? Are eggs not worth eating at all unless they’re pasture-raised?

    1. +1 to this.

      And even after searching and contacting several different farms in Oregon, most of them said that their pastured hens are still supplemented with wheat, and sometimes corn and soy.

  48. t’s always best to go and look at the chicken personally by driving to the farmer directly and taking a look at the situation.

  49. LOVE this site! Mark, your articles are fantastic.

    We eat pastured or wild meats, wild fish, and free-roaming organic poultry WE raise. I love knowing that the beef I buy directly from the source, came from beef gazed on “salad bar” pastures. I have been to the MN ranch many times, and know the people. I also buy lamb from them. We can taste the difference even when compared to other grass-fed meats. This man actually seeds his pastures to enrich the wild diversity of pasture grasses and pl

    1. Oops… and plants.

      The eggs from our chickens have orange yolks. And yes, they too taste better given the natural diet we give them.

      1. You wouldn’t happen to be talking about Kelly O’Neill’s farm, near Winona, MN, would you?

  50. David Katz’s article in last month’s Huffington post got me thinking about the best sources of meat and supports the evidence for low HIF. As an Australian I’m in the fortunate position of having access to plenty of wild Kangaroo. Apart the health benefits, culling Kangaroo’s (which appear to be considered a pest in many areas) saves on greenhouse gas emissions and the environmental degradation associated with cattle farming.