Red Meat & Cancer—Again! Will It Ever Stop?
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Red Meat & Cancer—Again! Will It Ever Stop?

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The media and blogosphere are abuzz with the latest report from the WHO, which classified cured and processed meats as carcinogens and put them in the same category as asbestos, alcohol, arsenic, and tobacco. But what does the research really tell us about the link between red meat and cancer?

meat causes cancer myth
Red meat is associated with many things, but cancer isn't one of them. istock.com/LauriPatterson

Well, here we go again. Each year, like clockwork, the conventional medical establishment mounts an attack against red meat.

For decades, we were told not to eat it because of the cholesterol and saturated fat it contains. When that argument became less convincing, a new one was offered: we shouldn’t eat red meat because it increases production of a compound called TMAO, which causes heart attacks.

Now we’re being told not to eat red meat—and especially cured and processed meat—because it will give us cancer. In a recent report, the World Health Organization (WHO) ranked bacon, sausage, and other cured and processed meats as “group 1 carcinogens,” which puts them in the same category as tobacco, asbestos, alcohol, and arsenic. It also placed fresh red meat in the “group 2A” category, which suggests that it is “probably carcinogenic” to humans.

Of course, this isn’t a new argument; it’s been around for at least 40 years. As far back as 1975, scientists speculated that the consumption of animal products was linked to cancer. (1)

How Strong Is the Evidence Linking Red Meat to Cancer?

However, the evidence supporting this claim has never been as strong as its proponents suggest. I have critically reviewed this evidence on several occasions in the past, as have many of my colleagues. Here’s a list of a few articles and podcasts I recommend reading and/or listening to if you’d like to go deep on this topic:

I realize that many of you don’t have the time to sift through all of that material, so I’ll do my best to summarize the salient points here.

Is eating bacon the same as smoking cigarettes when it comes to cancer?

Let’s start with a critical review of the evidence linking red meat to cancer that was published in one of the most prestigious scientific journals in the world (Obesity Reviews) in 2010. (2) The authors looked at 35 studies that claimed to find an association between red meat and cancer and found numerous problems. Here are some key passages from this paper, with my commentary.

Collectively, associations between red meat consumption and colorectal cancer are generally weak in magnitude, with most relative risks below 1.50 and not statistically significant, and there is a lack of a clear dose–response trend.

Translation: the association between red meat and cancer is not strong (i.e. comparing bacon to cigarettes is absurd), and in fact is often not distinguishable from chance. If red meat really did cause cancer, you’d expect to see a linear (continuous) increase in cancer rates as red meat consumption increased. But that’s not what we see in many cases. In fact, in some studies you actually see a decrease in cancer rates in the people who ate the most red meat. (3)

Results are variable by anatomic tumour site (colon vs. rectum) and by gender, as the epidemiologic data are not indicative of a positive association among women while most associations are weakly elevated among men.

Translation: the studies claim that red meat causes different rates of cancer in different parts of the intestinal tract, and different rates in men and women. For example, in the study I just referenced above (#3), there was an inverse relationship between red meat intake and colon cancer (meaning people who ate more red meat had less colon cancer), but a positive relationship between red meat and rectal cancer. And in an analysis of data from the Women’s Health Study, researchers found a strong (and linear) inverse relationship between red meat consumption and colon cancer. (4) Without a clear explanation of why red meat would be prevent some types of intestinal cancer while contributing to others, and have different effects in men and women, the likelihood of a causal relationship between red meat and cancer is reduced.

Colinearity between red meat intake and other dietary factors (e.g. Western lifestyle, high intake of refined sugars and alcohol, low intake of fruits, vegetables and fibre) and behavioural factors (e.g. low physical activity, high smoking prevalence, high body mass index) limit the ability to analytically isolate the independent effects of red meat consumption.

Translation: the studies linking red meat and cancer are plagued by “healthy user bias.” This is a fancy way of saying that people who engage in one behavior perceived as healthy are likely to engage in other behaviors they perceive to be healthy. On the flip side, people who engage in one behavior perceived to be unhealthy are likely to engage in other behaviors perceived to be unhealthy.

In an ideal world, we would be able to conduct a randomized, controlled trial to determine whether red meat causes cancer. We’d create two groups of people that are relatively similar in age and other characteristics. Then we’d isolate them in a medical ward, strictly control their diet, exercise, and other lifestyle factors, and then feed one group more red meat and the other group less.

Unfortunately, this will never happen. Cancer can take decades to develop, so these poor souls would be living in a ward for at least 20 years. Even if we could find people to volunteer for such a study, it would be astronomically (and prohibitively) expensive.

As a result, we’re left to rely on observational studies to shed light on the question of whether red meat causes cancer. The problem with this is that observational studies do not prove causality—they just demonstrate an association, or relationship, between different variables. Sometimes the association is causal, and sometimes it’s not.

Let’s consider red meat. Regardless of whether consuming fresh and/or processed red meat is unhealthy, it has certainly been perceived that way for the past half-century in the industrialized world. What this means is that people in observational studies that eat more red meat also have a tendency to smoke and drink more, eat fewer fresh fruits and vegetables, exercise less, and engage in other unhealthy behaviors that could influence cancer risk. This isn’t just speculation; it has been shown in numerous studies. (4, 5)

For example, most Americans that eat red meat eat it with a huge bun made of white flour, with a serving or more of other refined carbohydrates (chips, fries, soda) cooked in rancid, industrially processed vegetable or seed oils. How do we know that it’s the red meat—and not these other foods—that is causing the increase in cancer?

The better observational studies attempt to eliminate the influence of these other factors, but in practice that is difficult if not impossible.

You Can’t See What You’re Not Looking For

What’s more, there are certain factors that are likely to play a significant role in the relationship between any food that we eat and cancer, but to my knowledge, have never been adequately controlled for in any study.

One of these is the gut microbiome. Previous work has shown that the composition of the gut microbiota may directly affect the influence of dietary factors on cancer risk. (6)

For example, Streptococcus bovis, Bacteroides, Fusobacterium, Clostridia, and Helicobacter pylori have been implicated in tumor development, whereas Lactobacillus acidophilus, L. plantarum, and Bifidobacterium longum have been shown to inhibit colon carcinogenesis. (7) Other studies have found that certain species of bacteria were higher in populations with high colon cancer risk, while other species were higher in populations with low colon cancer risk. (8) Finally, a recent paper compared the gut microbiota of 60 patients with colorectal cancer with that of 119 normal controls. The patients with cancer had significant elevations of Bacteroides/Prevotella (both species that are recognized as potentially harmful) when compared to the control group, and the difference was not affected by general patient characteristics (e.g., age, body mass index, family history of cancer), tumor size or location, or disease stage. (9)

We still have a lot to learn about the influence of the microbiome on health and disease, but we know enough already to conclude that it is significant. It is possible—and I would argue likely—then, that the variability we see in studies showing an association between red meat consumption and cancer may be in part due to the status of the patient’s microbiome.

In other words, a patient with a dysbiotic (i.e., compromised) microbiome may be at increased risk for cancer if he or she consumes high amounts of either fresh or processed red meat. But a patient with a normal, healthy microbiome may not be.

There is, in fact, some research that hints at this possibility—though it wasn’t what the study authors intended. A couple of years ago, scientists from the Cleveland Clinic published a paper linking red meat consumption with the production of a compound called TMAO, which has been associated with cardiovascular disease.

That paper was riddled with problems (which I outlined in this critique), including the most glaring one—that several foods, including seafood, increase TMAO production by a much greater margin than red meat. However, there was one section of the paper that I found to be very interesting.

It showed that omnivores who eat red meat produce TMAO, whereas vegans and vegetarians who hadn’t eaten meat for at least a year do not. The researchers claimed that this means eating red meat must alter the gut flora in a way that predisposes toward TMAO production.

However, there’s another explanation that I believe is much more plausible: the red meat eaters are engaging in unhealthy behaviors that lead to gut dysbiosis. This could include eating fewer fruits and vegetables and less fermentable fiber, while eating more processed and refined flour, sugar, and seed oils. All of these behaviors have been shown to be more common in the “average” red meat eater, and all of them have been associated with undesirable changes in the gut microbiota. (10, 11, 12)

Apples and Oranges (Or, Paleo vs. Standard American Diet)

Observational studies are useful for generating hypotheses and identifying general trends. But another limitation they suffer from, in addition to those I’ve described above, is that they aren’t able to detect the effects of crucial differences between study participants.

Consider two different people. One follows a standard American diet, doesn’t exercise much, and has a compromised gut microbiome. The other follows a Paleo-type diet, exercises regularly, and has a healthy gut microbiome. In an observational study looking at the relationship between red meat and cancer, at least 95 percent (if not more) of the red meat eaters in typical studies will fall into the former category. If the study concludes that there is a link between red meat and cancer, the 5 percent of the participants that eat a healthy diet, exercise, and have a healthy gut—and are thus highly unlikely to experience the same impact from eating red meat—will be lumped together with the other 95 percent.

Put a different way, it should be fairly obvious, given what we already know about the influence of diet, lifestyle, and the microbiome on cancer risk, that someone following a Paleo-type diet and lifestyle will not share the same cancer risk as someone following a Standard American Diet and lifestyle, even if they are eating an equivalent amount of red meat. Yet these two groups of people are always lumped together in the studies and media reports. This is a huge problem in research, and it has not been adequately addressed.

What’s the Bottom Line?

Even if you ignore everything I’ve written in this article and accept the WHO report at face value, just how much would your risk of cancer increase if you eat cured and processed meats?

About three extra cases of bowel cancer per 100,000 adults. That means you have about a 1 in 33,000 chance of developing bowel cancer from eating cured and processed meats.

This is a far cry from how much smoking cigarettes, which the WHO now classifies in the same category as eating bacon and salami, increases your risk.

As Professor Ian Johnson of The Institute of Food Research said in an interview with The Guardian:

It is certainly very inappropriate to suggest that any adverse effect of bacon and sausages on the risk of bowel cancer is comparable to the dangers of tobacco smoke, which is loaded with known chemical carcinogens and increases the risk of lung cancer in cigarette smokers by around twentyfold.

What’s more, the report from the WHO classified 940 other agents, along with red meat, as potential carcinogens. In the Guardian article above, Betsy Booren, the vice-president of scientific affairs for the North American Meat Institute, put it in perspective:

The IARC says you can enjoy your yoga class, but don’t breathe air (class 1 carcinogen), sit near a sun-filled window (class 1), apply aloe vera (class 2B) if you get a sunburn, drink wine or coffee (class 1 and class 2B), or eat grilled food (class 2A). And if you are a hairdresser or do shift work (both class 2A), you should seek a new career.

At this point, given what the research indicates, I do not feel that modest consumption of cured or processed meat is likely to pose a significant health risk, provided you are doing other things right (i.e., nurturing your gut microbiome, eating nutrient-dense, real foods, exercising, etc.). I think there is even less evidence suggesting that we should limit consumption of fresh red meat, especially when it is cooked using gentle methods (rather than charring it) and when you eat “from nose to tail.”

Okay, that’s it for this year’s installment of “red meat won’t kill you.” See you next year!

265 Comments

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  1. I’ve been trying to incorporate more omega-3 rich foods, and I like smoked herring. Does smoked fish have too much lipid rancidity to be healthy?

  2. Ooops. Sorry Chris, I arrived at your site via Ben and wrote the wrong name in my post.

    My bad.

    I will have to eat a large steak (rare) in penance.

    Regards

    Craig.

  3. We in the UK are constantly told that a Mediterranean diet is best for longevity.

    Well, having lived in Italy and experienced very healthy old people, who eat Salami, Prosciutto di Parma (Parma Ham for those who don’t know) and similar meats – I beg to differ when it comes to so called experts advice. Prove it. Eat some yourself and we can experiment on you.

    I am also interested to seek an opinion on why I have canine teeth, if I should not eat ANY type of meat.

    It is all complete drivel, and as long as you cook your food in the correct way, and balance your diet (I eat a large amount of veg and salad too) then you will be fine.

    Besides, you are more likely to be in a car accident that could be fatal than get Cancer.

    Smoking does indeed not help, I restarted after an 18 year lay off – but a divorce forced me back into it rather than drink myself to death.

    I noticed what effect it had, now down to less than 10 per day – and will stop again.

    That (as mentioned before by Ben) is very obviously going to kill me – and I will stop.

    So, given Ben’s advice and what I have already said – eat meat, but balance your diet.

    Stay healthy.

    Now where’s my bacon sandwich 🙂

    • The people in Mediterranean have some very important differences: the size frequency and raising of these foods is very different than American habits and meat available.

      And equally importantly their staples of whole grains ,legumes ,vegetables and fruits are eaten in very high volumes and all, including beans and whole grains, are very protective for avoiding colon and other cancers.

    • Well, the Med diet does not refer to the general Italian diet, but to the diet of rural and sea-coastal Mediterranean towns. In these regions, they eat red meat the least of all other foods.

    • Gregor and Campbell have sacrificed their whole lives for their cause. I especially love Campbell’s story,…. growing up in the golden age of “animal protein”, researching how to get more animal protein to market to save the undernourished third worl, and coming full circle without any ax to grind.
      Both men… Heroes

  4. I too am very worried about Chris’s opinion on this. I know he is a Paleo pusher but when he does not draw a firm line under processed meats I start to wonder. I will not say more than that for fear of getting banned. As far as meat is concerned when you look at the Blue Zone’s one common factor seems to be low consumption or in some cases no consumption of meat. This leaves me with a choice, try to mimick the blue zones and hope that it is dietary and not simply something in the water or pitch in with a bunch of possibles, maybes or perhaps meat with etc etc will be OK. I only get one role of the dice.

    • I love red meat.
      If my body didn’t react to it I would go get a McDonald’s hamburger right now.
      In 2000 I went to Mayo’s because of a condition that caused my joints to ache severely, and though I didn’t recognize it for seven years, it also affected my thinking.
      In 2007 after a 35 day fast I realized that something in my diet was causing it. It took me three months to figure out it was red meat.
      Today if I accidentally eat any mammal meat in about 4 hours I will feel very tired and want to go to bed. I will wake up with severe joint pain. In a day or two my body will expell it and within 15 seconds my blood pressure will drop 40 points and I will feel better.
      As a sidenote I get the same symptoms if I get a cut on my body that becomes infected. It seems as though anytime my body has to metabolize redmeat even my own it causes the problem.
      My advise. Try not eating red meat. If it helps, don’t eat any. If it doesn’t help, go buy a baconator at Wendy’s and enjoy.

      • Gary , you mention the issue or why your body rejects red meat: you are eating ‘cooked’ meat. Cooked meat is damaged protein – the nutrients have been destroyed. Meat is meant to be eaten raw. And most people can’t rap their mind around that, but its true. Raw red meat tastes great in my opinion.

      • Mc’Donalds? are you kidding me?. What’s that? like 1/3 lb of extremely processed meat COVERED in processed bread and processed sauce (hint: everything here has high fructose corn syrup).

        And you call that red meat? if this is what people refer to “red meat causing cancer” well no shit. You don’t have to be a scholar to realize food made out of a chem lab will give you cancer.

  5. Dear Chris,

    The hyperbole, fallacy and misinterpretation of data in this and other articles written on critical health topics on this site are very disconcerting considering the influence that you supposedly have over people’s health decisions. I will go so far as saying what you are doing is irresponsible. I recognize that the media you produce probably does have a positive impact to some in certain ways. But please be careful not to misuse data to disguise opinion as fact.

    In comment to your article, the WHO explicitly mentions in its report that processed meat and red meat are not equivalent cancer risks compared with cigarette smoking. The WHO also explicitly states in its report that red meat and other meats have health benefits, and should not necessarily be avoided altogether (as opposed to their view on cigarette smoking). The point is reduction and moderation of red meat consumption, especially processed meat.

    Your assessment that saturated fat in foods such as red meat does not lead to high cholesterol did not make the prevailing clinical guidelines of healthcare professionals “less convincing.” Your argument is based on an article that evaluated only the effects of saturated fat on HDL (“good cholesterol”) levels. The same article validates the highly vetted studies that have determined serum LDL (“bad cholesterol”) is about as strongly associated with dietary saturated fat as can be. It is LDL that is of concern when we’re discussing causes of atherosclerosis and other forms of heart disease.

    There is fallacy in your argument that there is no “likelihood of a causal relationship between red meat and cancer” because it is supposedly protective of some GI cancer and contributory to others. First of all, don’t forget there is no such thing as a causal relationship, only correlations. We’ll never know for certain, but we can be pretty sure about the data by controlling variables, objective peer reviews, and analyzing statistical information. There are different mechanisms likely involved in the effects of red meat on different GI cancers. If red meat is supposedly protective against one cancer, that doesn’t diminish the body of knowledge that points to it being contributory to another type.

    You seem to have gained popularity by speaking against conventional medical wisdom. In many cases this is called for. But when doing this, please for the sake of health, take more responsibility to publish accurate and unbiased information.

    -Paul (medical student)

    • Hello Chris,

      I’d like to say I agree (a bit) with Paul… while I appreciate that you tackle topics that are of importance to the general public (and that you are, in fact, writing for them- not professionals) sometimes a little more attention to the nuances of the data and details might be needed.
      For example, up above you wrote “The patients with cancer had significant elevations of Bacteroides/Prevotella (both species that are recognized as potentially harmful) when compared to the control group,” but a little more attention to detail here would have improved your statement and your sentiment. Bacteriodes and Prevotella are NOT SPECIES, but in fact GENERA, and as such have many members with different characteristics. A genus that is familiar, Felis, includes domestic cats but also jungle cats reaching weights of 35lbs. One might be able to kill you, one might make you feel happy… same Genus.
      You wrote, “composition of the gut microbiota may directly affect the influence of dietary factors on cancer risk,” then went on to make this statement about Bacteroides and Prevotella levels… it doesn’t mean these genera are protective. And even though these genera have many members, each of which might contribute or detract to the microbiome, these level changes could be DUE to chemotherapy, changing only AFTER cancer occurred. The the same arguments many paleo lovers are familiar with apply here, “correlation does not mean causation,” and as Taubes has said, “Do NOT over interpret your data.” Furthermore, Prevotella was found to be reduced in children with Autism (plosone.org, July 2013, Vol. 8, Issue 7). So, is it protective or detrimental? It’s a group, right? With different individuals with different characteristics. Or maybe, it’s vulnerable to changing levels drastically in different situations. The point is that this data is AT BEST a starting point for a good hypothesis for experimental research.
      That said, I’m a microbiology professor and I’m holding your words to a high level. I’d probably not correct any of my undergrads more than in passing. You DO put forth more effort than some other people I’ve seen. I applaud your intent. Just, perhaps, try a little harder to keep your statements a bit more moderate? Thanks.

      • One other problem with meat is that research shows that in conjunction with carbs such as white rice or potatoes you get a much bigger insulin spike than you would with the carb’s alone. this may explain the recent rise in diabetes rates in places like China who until recent increased meat consumption had low rates despite very high rates of white rice consumption

        • One could say:
          the problem with rice and other high carbs is that research shows that in conjunction with red meat that you get a much bigger insulin spike.

          So, whats your point?

      • Thanks Aurora, I enjoyed reading this and Paul’s response.

        Before I arrived at this article I had been reading about the WHO report on the cancer research site and it is interesting to see the difference between what they say and how the media have interpreted it. Cancer Research are happy for people to eat 70g red or processed meat per day, whereas most media simple say ‘red meat is bad like smoking’.

        It’s an interesting conversation!

  6. What I would like to see is a study on red meat that only uses organic meat, in other words, meat from pasture-raised cattle, not the current factory-farmed and gmo-fed meat typically seen in the grocery store. Sick meat makes sick people, and gmo-fed animals are sick.

    • I agree, I would love to see this– I would hypothesize a big difference in outcomes when comparing grass-fed organic beef consumption to factory farmed beef and/or the pink slime version of beef. It would be no surprise to find THAT to be carcinogenic!

    • Thank you for bringing some sense to the analysis of this article. How can a valid judgement be made when the meat eaten is already toxic from the massive metabolic ravages of industrialised farming.

      Also the industrialisation of the various fraudulent oils that the UE and FDA sanction as edible is of huge concern.

      Most people will actually be cooking their meat in toxic, highly processed oils, of dubious origin.

      The carcinogens occurring in heated seed oils could be as much of a long term danger as the meat itself.

      As for plastic containers for the oils, well the list of carcinogens goes on, way beyond the meat itself.

  7. @CHRIS KRESSER

    Every one of these articles coursing on FB about meat and malignancy are making me insane! Only a little learning about history and a tiny bit of judgement skills goes far. Anyway, I posted your article on my FB page and as a reaction to everybody’s inquiries and different articles saying meat causes disease.

    regards
    rakhi

  8. I loved this article, but I still feel so confused.

    My father was recently diagnosed with kidney cancer, that has spread to his lymphatic system. We are opting to treat it naturally.
    My question is if a person already has cancer, should they remove it from their diet? Every natural cancer sight says “yes.” And to eat legumes, such an lentils instead.
    I have been a devoted paleo and westen A. price follower for years and now am radically rethinking everything I know?

    Would you eat meat if you already had cancer?

    Help, please!

    • Hello Aubrey- I realize your comment was meant for Chris, so I don’t want to tell you what to do- (so you can take this with a grain of salt). But I got cancer 6 years ago, after eating a plant-based diet for many years prior- (no red meat at all, only very occasional fish and eggs). I, too, had to rethink everything I thought I “knew” about diet. I think it’s a total fallacy that a vegan diet will save you from cancer- (or that “meat causes cancer”)- because I obviously got cancer from eating no meat. I think there’s a very strong anti-meat bias in our culture right now, which colors people’s view- (the media certainly doesn’t help with this). After being diagnosed, I had a bit of a “devil-may-care” attitude; I immediately started eating meat again (as well as other foods, like fat)- because it was clear to me that the diet that I thought would protect me didn’t actually do that. Once I switched to eating meat, I started feeling much healthier; which got me researching; eventually I discovered the Primal diet…..and well, the rest is history. (I’ve been cancer free for 6 years now). Also, keep in mind that cancer was extremely rare in hunter gatherer cultures. For instance, apparently there were many centenarians among the Sioux Indians; they were a mostly meat eating group of people, and cancer was essentially non-existent among them.

      Bottom line is, I don’t think we really *know* what causes cancer. There are many theories, and of course people loudly vocalize what they believe. If you are interested, let me direct you to the work of Dr. Seyfried. He has a theory that cancer is a metabolic disease, caused by damaged mitochondria. (You can google him, and find some information). This idea seems to be the best explanation for my own experience, anyway. I hope this helps……

      • The problem with stating that one is plant based is that it hides the possibility that numerous other bad dietary habits may have been adopted. I get loads of emails from my local Veggie society inviting me to meals out and when I look at the menu its full of stuff I would not dream of eating. Many people are veggies or vegans for ethical reasons not health reasons and when you drill down their diet is pretty bad, full of sugar, grains etc.

        • Mark- yes, that’s a good point! And true, when I was mostly vegan, I did eat grains- (lots of them; but when you’re plant based, there isn’t much else to eat). I ate some sugar- (much of it without even realizing it at the time. I ate a lot of vegetarian sushi rolls, thinking they were “healthy”; they looked and tasted “natural”; I didn’t realize sushi has sugar and other additives). I also ate a lot of legumes, which made me sick to my stomach. (Legumes was something Aubrey was asking about). The problem is, Mark, in order for people to know what’s “healthy”, they have to study nutrition pretty extensively- (I do that now; most people don’t). You also have to know enough to disregard what the media says (including the WHO!) I didn’t do that before; I assumed people in positions of power knew what they were talking about. I’m sure many people make this mistake.

          I’ve since stopped eating grains and sugar, and I personally feel better for it. I’ve also discovered I can’t tolerate soy, so I don’t eat that. Most legumes make me sick, and there are very many vegetables I can’t eat either, as i get digestive issues. So, that doesn’t leave me much in the way of vegan food. I feel really great eating eggs, fish, cheese, meat, and some vegetables (the ones I tolerate). My own personal theory is that the diet that is best for each of us is the one we can digest the best. Good digestion is essential; when you don’t digest your food properly, you can’t assimilate the nutrients. So, the optimal diet for one person may not be the optimal diet for another.

          • Have you tried blending veggies into a predominantly veg smoothie, this may make them easier to digest. Every day I have a beetroot, spinach, apple and chia seed smoothie

            • Mark- yes, I have tried juicing. That’s actually quite terrible for me: too many FODMAPS and sugars, all at once in the system! I think that plant foods have fiber as a natural insurance that you don’t eat too many of them in one sitting- (at least, for people like me). In any case, the problem is not that I need to add more vegetables to my diet; I eat plenty of vegetables. The problem is that I don’t want to go vegan (been there, done that!) partly because I would not be able to eat a variety of different foods to give me enough nutrients and calories. Next reason: I have read that some people are able to extract the nutrients better from plant foods than others- (there are various conversions that need to happen within the body; not like with animal foods, where the nutrients are in an easily bio-available form). If you’re one of the people that can extract enough nutrients and calories, and be healthy on a plant based diet, great! But I don’t seem to be one of those people. And since others like me exist, this is the reason why I don’t think it’s a good idea to give people advice, even if it works well for you. As I said, where I live I have access to good quality and affordable wild meat and poultry (and wild fish). I am perfectly happy eating this way, so I will stick with that.

        • There is now significant evidence that increased blood glucose levels increases the incidence and the rate of growth of cancer. The physiological explanation of why this might be is that cancer cells are restricted to and require glucose directly as fuel to grow and multiply due to their defective mitochondria. This presents an opportunity to disadvantage cancer cells in comparison to normal cells. Eating a daily diet restricted to around 30 carbohydrate calories would provide this advantage. This translates into meat and above-ground vegetables, limited fruits, typically small berries and severely limits grains and starches. No wonder diabetics and obese individuals are in a significantly higher risk category for cancer.

          • I now question everything I know. I always limited my fruit/carb intake. My father went on the NORI diet (high fruit) and the tumor in his neck has started to go down and He feels great. He is eating a low-fat, high fruit!

            It goes against everything I thought I knew. I have a paleo blog, and yet have seen result from doing the opposite.
            I now know there is not one way to eat.

            • I thought it was accepted fact that cancer cells metabolize glucose (sugar) as their main source of fuel. Doctors have used 1/2 bar of Herseys chocolate (eaten by the patient) to “light up” the cancerous areas in the human body during the body scan. I personally don’t eat sugar (for over a year now). I also restrict my carb intake because the human body turns carbs into sugar. My body has been using good oils (fats), protein and ketones for over a year now. I’ve had numerous blood work ups that show that everything is great!! Cancer cells can not metabolize Ketones. To make Ketosis even more inviting….Ketones help reduce inflammation in the human body, just like eating Blueberries reduces inflammation (Blueberries contain Ketones). I’ve written before that reducing inflammation in the body should also reduce the risk of cancer formation (less cell damage). If you do happen to get cancer while in Ketosis the cancer should starve to death or remain dormant.

              Treblig

            • Aubrey- I’m glad you returned to this discussion. My personal opinion is that there are different ways to combat (or starve) cancer, not just one way. That sounds wonderful that your father is doing so well; maybe this is the answer then! In my opinion, this doesn’t necessarily counter all that you believe in. The Paleo diet is also a healthy diet- (Paleo people did eat fruit too, after all). Also, a point to remember, is that a “curative” diet for someone who’s ill may be a temporary diet, and not necessarily the diet that everyone else should eat all the time. In any case, we are all constantly learning about nutrition, and it’s best to just keep researching, and to keep an open mind.

          • Dave Boothman- thanks for your comment. This is exactly the route that I’ve decided upon for myself. I don’t have cancer now, but I’ve been eating low carb, no sugar (i.e. no refined sugar, I do eat some fruits and vegetables), to prevent recurrence. So far it’s been working. I also do intermittent fasting and try to keep some ketones roaming around in my body- (apparently, this keeps the mitochondria healthy). I can definitely say that I have much more energy eating this way. Back when I ate the high carb, mostly vegan, “government guideline” diet I felt “burned out” so much of the time! Maybe that was a sign of unhealthy mitochondria.

      • Going to throw another side of the story out there. Yes red meat can be good for you but its the quality. I would not be surprised if our basic non organic red meat causes cancer specifically based on the fact that it is pumped up with hormones which ARE cancer causing. Extra estrogen intake is the cause for many diseases and cancers like breast cancer ovarian cysts and ovarian cancer and endometriosis just to name a few. Wild animals that eat what God intended and are free range and killed properly would never be cancer causing but sadly to say these are not the same meats easily available to us in our grocery stores. I have endometriosis and have stopped eating meat for a month now to see if it had any effect and it has my pain has decresed significantly. Blessings on your health journeys everyone!

        • Hello Marie- Yes, this is so true! Unfortunately it’s a huge problem in America. Thankfully hormones have not been a problem for us in Europe so far, though I fear that may be coming. In any case, I prefer to eat wild meat. Not only does it taste way better, but I’m sure it’s healthier.

      • You were not a vegan, and you were not plant based. You ate fish and eggs. Of course vegans can get cancer too we live in a carcinogenic world! that doesnt mean becoming a murderous corpse eater is the way to go!

      • Deciding that meat doesn’t give you cancer because you got cancer on a plant-based diet ignores the fact that you could have gotten cancer for a million other reasons such as asbestos exposure.

        • Or more likely his cancer developed decades before the six years he was on a better diet.

          Appears that many do not want science, they instead want opinions of unqualified people like on this site.

      • You need to do some research on cancer and also on the low rates among vegans who eat a whole plant-based diet not fries and ketchup!
        Cancer takes many decades to develop and the fact that you might have been on a good diet for six years is proof of nothing…except there is evidence of cancer being reversed by changing the diet.

    • Why would you?, no one seems to be saying that plant based diets are associated with Cancer so even if the meat = higher risk of cancer crowd are wrong going plant based is not going to have an adverse effect especially if you supplement with vitamin Bs to compensate for the achilles heels of pure plant based diets.

      • Mark- I’m afraid you’re wrong about that. A little known fact- (even in the mainstream media)- is that the kind of cancer I had is, in fact, associated with vegetarian and vegan diets. (Of course, “correlation doesn’t equal causation”, so it’s not clear that they cause this cancer either; just like, I may hasten to add, it’s not clear that “meat causes cancer”!) Seventh Day Adventists (who are vegan or vegetarian, I can’t remember which)- have a much higher rate of this particular cancer than the general population. But that’s not my only reason for eating the way I do now; this whole cancer experience has taught me that quality of life is equally important. When I ate a high carb, plant based diet I felt totally rotten; eating a primal diet, I feel healthier than I have in my life. I would rather feel good during the rest of my years on this earth. So you may as well save your energy; I’m not going to eat vegan again, just forget about it.

        • You give almost no facts….I have to guess that you are citing one study in 2009 that contradicted many other studies and said colorectal cancer was more common about vegetarians and vegans, at least in the UK.
          Sorry, I do not buy it. I would rather use the modern diet of many Africans today that is very similar or worse than that of the US, yet they have almost no colon cancer.
          They consume less fiber and more processed foods but very little meat. How do you explain the near absence of colon cancer?

  9. Hi Chris –
    I couldn’t believe it when I saw that red meat was being compared to cigarettes. There is a huge difference and I was pleased to see that the correlation wasn’t as strong after doing a little bit of reading. I think that is the key here – doing more research than just accepting a headline and moving along. Have you encountered a lot of people that are 100% accepting of that claim?

    • I certainly believe it! Is it your addiction to meat or cigarettes that makes it so unbelievable? It certainly is not science or the evidence presented by the five Blue Zones of long-living populations.

  10. Eating meat is not essential to health, and the WHO is NOT lying. They’re not attacking you.
    There is no reason to eat meat other than taste, culture, and convenience. Stop spreading misinformation and shut down this blog.

    • You really omitted the strongest reason to consume large quantities of meat. It is addiction and can be shown in studies of the brain.

  11. Lots of interesting comments and I’m glad to see comments on the reserch and not just peoples’ opinions. Haven’t seen any relationships made to blood type. I see that type O’s eat a high meat diet more successfully than type A’s who do better on low protein. Our digestive systems have evolved differently. Interesting that a lot (but by no means all) of macrobiotics are type A by natural choices of what is best for them.

  12. I tried the paleo diet for awhile and felt miserable. I don’t think it’s actually a healthy diet. I don’t think anyone really even knows for sure what an actual “paleolithic” diet was like. And I didn’t like not being able to eat black beans, but being encouraged to eat bacon. It was ridiculous. There’s just no way you’re going to convince me that eating meat at every meal and not eating black beans is healthy. And do we really think Paleolithic people actually ate beef all the time? Why do no paleo diet books ever talk about eating grubs and insects? Or fish? Nuts? Who says that they didn’t eat grains?

    https://www.drmcdougall.com/misc/2012nl/jun/paleo2.htm

    Research here demonstrates people ate grains and legumes as early as 44,000 years ago.

    http://www.ncbi.nlm.nih.gov/pubmed/21187393

    And why should we be Paleolithic? The whole concept is absurd. Why can’t we just look at more recent eras of our history where rates of cancer and heart disease were lower? Like say, the 1940s? Or at least at a time before we had processed foods. At least at a time where we have more data to look at what and how people ate as well as their lifestyles. It’s impossible to mimic a diet based on a time frame we know little about, and at the earliest point of our history.

    Whatever. It’s a silly fad and a silly diet. I’ll be happy to hear this trendy diet leaving mainstream discussion and I will gladly go back to a diet that makes sense to me.

    • I do not believe that we can use one particular book as a bible to tell us how to eat. I do believe that all of the processed crap that has been shoved at us and the distorted genetically modified wheat that we are fed is doing us no good. I personally do not believe that we should not eat legumes either. I have also read that the paleo diet was different for peoples living in different parts of the world. Inuits live on as much as 95% protein diets (look at where they live) while other peoples subsisted on 85% vegetarian diets. I have not read the Paleo Book by Cordain (I am glad I have not). I have personally cut back on breads and potatoes because diabetes runs in my family and that helps me maintain my sugar levels. I think the point of the Paleo diet is as you wisely pointed out. Avoid the processed crap, eat locally and as naturally as possible. It looks like McDougall has chosen sides in this argument. I do believe that white rice is a good starch to eat and that eating different potatoes than the normal varieties that most of us eat is probably fine also. Cordain is advocating one form of extreme eating and the dude that wrote the book on the starch diet is advocating another extreme. Lets educate ourselves and then use our common sense to decide what to eat and what best works for ourselves. Thank you for posting McDougall’s letter. I found it interesting.

    • In order for prehistoric man/woman to survive the long cold winters they had to have had to eat meat as their main source of food. There are no vegetables of fruits during 4-6 months of the winter cycle. This is why the human body is capable of surviving on meat/fat without fruits and vegetables. In fact you can survive without any sugar at all and little to no carbs. The human body automatically goes into Ketosis in the absence of sugar and carbs. This is an accepted fact. If you eat fat (good oils) and meat your body will burn the fat and also use the meat for energy and bone development. Why Oh why would the human body develop this adaptation??…..Because early man had to survive on meat and fat for a good number of months every year. The Eskimos (Inuit) still survive this way and they’ve survived in sub zero weather longer than everyone in the US.
      Ketosis is an interesting state to be in!! During Ketosis your body produces Ketones (lots and lots of Ketones). Ketones reduce inflammation, this is why your supposed to eat blueberries (for the Ketones). On the other hand sugar increases inflammation, imagine that??/ The human body converts carbohydrates into sugar, imagine that??
      The icing on the “sugar free” cake is this…..Cancer cells can not metabolize Ketones, cancer thrives (and multiples) on sugar, imagine that??.

      PS – Black beans are actually good for you and are low in carbs (like most beans). I’ve been on a super low carb/low sugar, high fat (good oils), meat diet for over a year. My blood shows an increase in good Cholesterol and decrease in the bad. I have plenty of energy, feel great and my allergies have disappeared for the first time in 50 years!!!

      Treblig

  13. I’d like to see a study where these processed meats are sourced from healthy, appropriately fed, clean animals, managed in a sustainable environment and “processed” in traditional ways. Then look at the rates of cancer and compare. Seems to me we are still lumping all red meat together, as if it makes no difference how those animals were raised or how the meat was processed.

    • That’s the way junk science works. In diet science it’s almost a favorite. For example lump trans fat with saturated fat then when you get caught out pretend saturated fat is still dangerous despite solid scientific data sowing it isn’t. I’m waiting for the water with Warfarin lumped together test, they they both begin with W. When that one crashes they’ll rationalize that yes, water is less harmful than Warfarin. Think I’m cynical then look up the rationalization of all trans fats being harmful . Now its changed to naturally occurring ones are less harmful. Let’s see how long it takes for it to get out that all trans fats are not equal; there’s a left hand and a right hand and only the manufactured one is toxic, the other one is naturally occurring in food.

    • Yes, this is so true, and a big reason why these so-called “studies” aren’t very credible. In addition, I’d be interested in seeing a study where they measure how many people eat processed meat and DON’T get cancer. If it were really scientifically done, shouldn’t we see the other side of the coin, so to speak? If a large proportion of people eat processed meat but don’t have any health problems- (which I suspect would be the case: I live in Germany, where many people eat processed meat, but people aren’t dying right and left of colon cancer)- wouldn’t their “association” all blow up in smoke?

  14. I’m just going to state the obvious. Darwinian evolution insists that, it is the nature of the human primate to eat meat, inclusive of red meat. For millennia, human lived as foragers, hunting meat, and gathering fruits, vegetables, nuts, and seeds. Our species is defined by meat-eating. To claim that there is some toxic carcinogen waiting to poison us inside meat is about as incredible as to suggest that, next, we should stop feeding our dogs and cats meat as well.

    Do I detect the vegetarian agenda rearing its head again? They’ll not just leap to the wrong conclusion, they’ll leap over mountains to convert someone to their way of thinking. As a paleodieter, I had been shamed by a vegetarian on “moral grounds” –pointing to the violence of killing animals. Yet, is a tiger morally bankrupt by just following what nature intended for it. First things first. Until we solve the overriding problem of Man’s Inhumanity to Man, we shouldn’t even begin to worry about eating animal meat. To malign the goodness of all hunters over this, is wrong-headed. I usually respond to their argument that I object to the eating of grain on moral grounds —as, it was the advent of agriculture spawned by grains spawned interpersonal violence more than any other single factor (read Pandora’s Seed by Spencer Wells, and many other books that look at Evolutionary Psychology). I shame them for eating grain in support of the millennia of war, greed, and violence spawned by grain.

    But back to the main argument, Human Evolution would be perverse to design an animal who cannot eat the foods it was designed to eat (as ludicrous as it sounds!) In fact, meat is the ONLY food group that can sustain us if no other food existed. The Inuits prove this, undeniably. They live in a place where fruits and vegetables often don’t even exist. All they eat is fish, seals and walruses, and red polar bear meat (I don’t claim to have made a precise inventory here). Basically, they just eat meat —and they live a full, healthy life, often into their 70s, as do most of us in the Occident.

    So again, how is it possible that the important part of our diet across the millennia, now, is somehow poisonous If the claim is about some chemical called haem that gives red meat its color. I assure you that they’ll, eventually, discover that (whoops!), the haem is only problematic nowadays because it conflicts with this other modern chemical addition to our diet (the X-factor!) that we didn’t properly consider. It is “X-factor” that has to be removed from our diet; the red meat is fine as Nature made it. I predict that will be true; because, otherwise, the theory of Darwinian evolution is basically trash. Yet, if that claim were true, than all of biology goes with it. And that is astoundingly unlikely. I predict WHO will find it’s not yet even on first base yet (WHO’s on first??) It will find itself in the embarrassing position of comedienne Gilda when she was forced to whine, “Nevermind!”

    • I am repeating myself but its needed. The meat we have at our disposal in local supermarkets available to the masses does not really resemble the meat our ancestors were living on, in fact it does not really resemble the meat eaten by much more recent cousins. For me the argument pivots on the idea that if you cannot access quality meats or perhaps afford them then you would be better of going veggie from a health perspective.

      • Nutrient density and nutrient diversity as well as what is considered a choice cut are two problems. What others do you have?

      • I think you are forgetting that we did not just go from “hunter-gatherer” to “consumer” in one fell swoop. We have also been herders, traditionally, for a very long time. Domesticated meat has been the mainstay of many native diets, even longer than many of our more modern plant foods. So again, this argument doesn’t really hold up. And as was mentioned in the article, “processed” meat- in the form of hanging, drying, salting, fermenting, etc., has also been around a long time. There is no logical reason why there should be anything inherently wrong with red meat.

        • I am not suggesting we have jumped from individually running around hunting meat to buying it in a supermarket. What I am saying is that confined feeding and rearing plus grain fed meats plus injecting them with anti biotics is a recent thing and is the reason we should avoid this TYPE of meat

          • Mark- I’m glad you clarified that, because it seemed to me that all this time you were advising people to cut out meat and eat vegetables instead; I’m pretty sure this is what you said. It’s important to remember also that when you write comments on the internet, your audience is going to be international, not just American. In many countries around the world, meat in the supermarket is not “bad” meat. I realize it can be harder for Americans, but it’s still not impossible. Some supermarkets sell Amish meat, which is probably not a bad choice. Many people have access to farmer’s markets, and buying meat from the “small farmer” is probably your best bet- (as opposed to Whole Foods, where the meat might be expensive. However, sometimes it may go on sale, and since meat is so easy to freeze, you can take advantage of sales). Some cuts of meat are generally cheaper, like ground beef or stewing meat- (which you have to cook slowly; but it can be really delicious in a stew!) For those who have access to high quality liver and other offal, that is often very reasonable too. And if you have trouble finding good quality meat where you live, the Weston Price Foundation has information for where you can order it.

            Finally, I always remind myself that meat is a very satiating, nutrient dense food. I feel it is worth a few extra dollars; especially since I’m not buying the packaged cookies, pastries, cereals, and other crap that many others buy. I suspect the price probably all evens out in the end……

            • Both messages ie include meat full stop and exclude meat full stop are both incorrect but the latter, in the current climate, is the least damaging, in fact not damaging at all. When I speak to people about food it is very difficult to get them to take ideas on board let alone stick with them. So if I was addressing a room of people with limited funds and limited interest I would advise veggie. Why?, because its healthy compared to the undiscerning route they would take with meat. My concern with Chris is that has not made it clear about the caveats with regard to meat.

              • Mark- I ate vegetarian (actually, mostly vegan)- for many years, and I became massively ill from that diet. I’m not saying it’s wrong for everyone, but many people DON’T thrive on that diet! So I don’t believe it should be recommended “for the masses”. Let people decide what diet is best for them.

                • I get regular emails from my local veggie society regarding get togethers and the like. What strikes me is how awful their eating seems to be despite the veggie baseline. Lots of pasta, sugar and any old crap as long as its not harming animals which seems to be their primary concern. Veggie does not always equal healthy. Personally I am closer to Pescarian than anything

        • There are very logical reasons why the meat, chickens and fish are very different than 100 years ago, so talking about what people consumed 100,000 years ago is folly.

    • Dale Bach- great comment! You’ve expressed my own opinion very well. The idea that red meat should be “unhealthy” just does not make logical sense to me at all. Partly from an evolutionary perspective, of course, but also it’s clear to me that I feel really healthy when I eat it.

      Also, that book you recommended sounds interesting….thanks for that, I’ll have to check it out.

    • Another interesting book written by a retired Anthropologist considers the evidence regarding the demise of the Neanderthals and the survival of Homo Sapiens. Neanderthals were quite similar to us, probably even had bigger brains, so what happened? The single stark archaeological contrast now Neanderthal sites are being seriously excavated is that human sites of the period always have dog remains, sometimes buried together with humans, so they were highly valued. Neanderthal sites have no evidence of dogs. At the time of the demise the climate became cold and challenging and the theory suggests that hunting dogs made the difference between eating and starvation. I’ve hunted in Georgia with a hound pack, feral hogs and bear, and can confirm that men and dogs make a far superior predator to man alone. Dogs bring the prey to bey after several hours but being smart hold back to avoid injury. Man then moves in and kills the prey from a safe distance, because we are tool users. The result is that men and dogs would eat where separate neither would most times. If dogs made all the difference why did the Neanderthals not have dogs? Here the theory is entirely speculative. Most animals do not have whites to their eyes but both dogs and humans do and they use the whites to communicate. A dog will watch your eyes intently looking for signals because they communicate with each other with eye movement. So this aspect of human and dog phenotype is matched and would make inter-species cooperation easier. The speculative suggestion is that maybe Neanderthals didn’t have whites to their eyes and so did not have the advantage in attracting dogs into their camps. Humans and Neanderthals did cohabit from time to time the evidence is in our DNA so why were they unable to adopt and work together with our dogs? And if dogs made the difference it wasn’t in finding more cabbages; dogs hunt meat. No wonder dogs have become so valued in our culture and are virtually a part of our phenotype, with millions of them living the life of Rile at our expense because of what heir ancestors did for us and is now burred unconsciously in our psyche.
      “The Invaders” by Pat Shipman

      • That’s also fascinating! I sort of like the theory that the Neanderthals mated with Homo Sapiens and became incorporated in us- (maybe because I “feel” sort of like a Neanderthal myself, and so I relate to them): but this theory could fit together with that. If whites of the eyes are, from an evolutionary standpoint, a trait that helped hominids survive, maybe it makes sense that this trait was a slow adaptation, until all humans had white eyes?

  15. Chris,
    What is Your opinion about the Significance of Neu5gc when It comes to hashimotos? (the podcast you referred in the comments does not mention auto immunity) Should one with hashimotos limit red meats?

    • I don’t believe the evidence is sufficient to discourage red meat consumption in people with autoimmunity because of Neu5gc.

  16. Those with a type 4 APOE gene are supposed to be less tolerable of meat and animal fat. It is conjecture on my part but I wonder whether the likes of Esseltyn and Ornish do well with their patients on meat free diets because being already patients of heart disease they are more likely to have more than a random number of APOE type 4 meat eaters. It would be interesting to know what the split is amongst there patients

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