How Does Meat Cause Inflammation?

How Does Meat Cause Inflammation?

The anti-inflammatory effect of plant-based diets is about more than just the power of plants. It’s also the avoidance of animal foods. In my blog last week, Treating Crohn’s Disease With Diet, I profiled the extraordinary power of even a semi-vegetarian diet to calm inflammatory bowel disease. We’ve known for 14 years that a single meal of meat, dairy, and eggs triggers an inflammatory reaction inside the body within hours of consumption. This results in a stiffening of our arteries (you can see the arterial response curve in my 4-min. video The Leaky Gut Theory of Why Animal Products Cause Inflammation). Within 5 or 6 hours, the inflammation starts to cool down, but then what happens? Lunchtime! At that point we can whack our arteries with another load of animal products for lunch. In this routine, we may be stuck in a chronic low-grade inflammation danger zone for most of our lives. This can set us up for inflammatory diseases such as heart disease, diabetes, and certain cancers one meal at a time.

What exactly is causing the meat-induced inflammation? Inflammation is an immune response to a perceived threat, but what’s the body attacking? At first, scientists thought it might be the animal protein, which is thought to be the culprit in certain types of arthritis. However, similar inflammatory reactions were triggered by whipped cream, which is mostly just animal fat. After digging deeper, investigators discovered that after a meal of animal products one’s bloodstream becomes soiled with bacterial toxins known as endotoxins. No wonder there’s so much inflammation! But where are the endotoxins coming from?

Endotoxins come from bacteria. Where are there lots of bacteria? In our gut. Thus, researchers figured that maybe the saturated animal fat was causing our gut lining to become leaky, allowing our own bacteria to slip into our blood stream. Experiments on mice showed that indeed saturated fat made their guts leaky, so for years this was the prevailing theory as to why animal products caused inflammation within hours of consumption. Only recently did researchers realize this didn’t make any sense.

In my 2-min. video The Exogenous Endotoxin Theory, I illustrate the critical flaw to the leaky gut theory: the time scale. The rise in inflammation after a meal of meat, dairy, and eggs starts within just an hour of ingestion, but our gut flora aren’t in our small intestine–rather, twenty feet farther down in our large intestine. It can take food hours to get down there, so what was going on? If the bacterial endotoxins were not coming from our gut, maybe they were coming from the food.

For the first time ever, 27 common foodstuffs were tested and they found endotoxin equivalents in foods such as pork, poultry, dairy, and egg products, as well as certain fermented foods. Can endotoxins be cooked out of the meat? Find out in the final wrap-up video in the series, Dead Meat Bacteria Endotoxemia.

Saturated fat also appears to have other deleterious effects such as increasing the risk of heart disease (see Blocking the First Step of Heart Disease and Tolerable Upper Intake of Zero) and shortening the lives of breast cancer survivors (Breast Cancer Survival, Butterfat, and Chicken). For more on foods that fight inflammation, see my videos Fighting Inflammation in a Nut Shell and Anti-Inflammatory Effects of Purple Potatoes.

-Michael Greger, M.D.

Image credit: woodleywonderworks / flickr

  • Thea

    I love how these blogs pull information together in such a way that add so much value to the videos.

    In this case, I have a question about the saturated fat paragraph.  It seems like every time someone mentions the problems with saturated fat, someone else starts talking about medium vs long chains, etc.  They throw out a lot of technical jargon for which I am not familiar.  What I want to know is, what is the response to someone who says that some saturated fats (for example, maybe from coconut oil) has been shown to be good for one? 

    I would guess that the response might be: “you can throw out all the jargon and theories that you want, but when tested, all saturated fats come out having the same effects on the body when it comes to negative health impacts.”  But is that true?  Or did I just make that up?  I can’t tell from Dr. Greger’s videos whether he is addressing the issue of medium vs long chains in fats.

    • Thea

       I’ll just add in response to my own comment: “…some saturated fats (for example, maybe from coconut oil) has been shown to be good for one? ”  I have read Toxin’s reply specifically about studies on coconut oil.  If I understood Toxin’s reply, he (she?) is saying that the studies really do not support coconut oil as being good for one.  But is that a direct answer to when people start talking about length of fat chains?  I just want to know if there is really an answer to this or not.

      • Toxins, why classify coconut oil as a junk food. Then you would have to classify most if not all oils as junk food. People are not normally eating oil as a food, but are using it to cook food. Comparing it to other oils and not food, it is head and shoulders above other oils. Its lauric acid is antiviral, antifungal and aids the immune system. Its medium chains fatty acids are better than the long chain fatty acids of other oils because it is metabolized much more quickly and are used for quick energy, rather than being stored as triglycerides in fat cells as do much of the oil from other veggie oils do.

        • Toxins

          All oils are junk food based on the definition of a junk food. Why would you consume something on the basis that it is antiviral and fungal? should we begin consuming alcohol based on this presumption? Where is your evidence for your claims or do you follow the bandwagon and recite what an appealing article has stated?

          • AqiylHenry

            Yes you can classify coconut oil as having empty calories but I wouldn’t classify it as a junk food. Being realistic about coconut oil consumption, it is not consumed as a food like hotdogs and hamburgers, that replace meals that are healthier and are higher in nutritional value. Coconut oil is an additive used to either cook are season foods, and most people are not drinking a gallon of coconut oil in a sitting to satisfy their food needs. I study everything I write about and you can look at my articles on I would tell people to stay away from junk foods, but I wouldn’t tell people to stay away from coconut oil, because it has many health/nutrition benefits. If you are really interested in finding out about the benefits of coconut oil you can easily find scholarly articles on the web.

          • Toxins

            I believe you are missing the point entirely, the evidence used for coconut oil is quite scant and I have not seen any concrete studies that have supported coconut oil to the degree of making the claim that it is a healthful “condiment”, in ones diet.

            The link you posted to natural life energy leads me to this article which is purely anecdotal, and I am missing the studies. Anecdotal evidence is the least reliable form of evidence.

            Here are some of the most common studies I have seen used to support the use of coconut oil.

            Forty obese women cut their food intake by 200 calories a day and exercised four days a week. Half of them used two tablespoons of coconut oil (about 240 calories’ worth) every day in their cooking and the other half used soybean oil.

            After three months, both groups had lost the same amount of weight, about two pounds. To me this is not at all significant, and it could very well be attributed to the loss of calories as well as the exercise, not the oil.

            Placebo and coconut fat takers scored no different on a cognitive impairment test when the subjects were randomized. If they weren’t randomized (which could represent stacking up the placebo group with very sick patients) then the coconut fat consumers scored slightly better after 45 days. After 90 days though everyone pretty much evened out. This is
            not something I would use as evidence to support the notion that coconut oil can help with Alzheimers.


            In the only study done in people in the last 17 years, Malaysian researchers last year found that when they fed young men and women 20 percent of their calories from coconut oil for five weeks, LDL cholesterol was 8 percent higher and HDL cholesterol was 7 percent higher than when the participants were fed 20 percent of their calories from olive oil.

            Just because both bad cholesterol and good cholesterol went up does not mean that coconut oil is protective against heart disease. This
            doesn’t make good sense.


            Even using coconut oil as a condiment in the fashion that you are claiming, a mere tablespoon has 120 empty calories and 12 grams of saturated fat. 8 grams of this saturated fat is medium chain fatty acids which we have very limited evidence to claim is completely negligible as well as 3.7 grams of saturated fat for which to which we know to be unhealthful. A tablespoon is easy to add to food and people likely add much more throughout the day leading to excess calories and saturated fat, needlessly. The national academy of science notes that any incremental increase in saturated fat increases the risk of heart disease incrementally. Using this advise, we should consume whole plant foods and if we choose to include nuts in our diet, choose the healthiest variety with the best omega 6:3 ratios.

            So I ask you again to show me the evidence for your claims.

          • That is a nice plant based website AqiylHenry btw, thanks. Esselstyn says if you have heart disease stay away from all refined oils and oily plants; Campbell in his new book Whole says that isolated nutrients are rarely as healthy as the whole plant source (unless you are treating a deficiency) and often less healthy. So I don’t try to micromanage my nutrient levels anymore, I just eat a varied diet and stay away from anything refined (like oils), extracted or isolated and stick with whole foods – no supps other than B12. Coconut oil is quite good topically btw

          • AqiylHenry

            Thanks Dan. I totally understand about eating “a varied diet and stay away from anything refined (like oils), extracted or isolated and stick with whole foods.” As you can see I eat a plant based diet, which consists mostly of wholefoods, and mostly raw. I use coconut oil and olive oil minimally. I oil pull with coconut oil which has greatly helped my oral hygiene and I used to drink a tablespoon of coconut oil before strenuous workouts like my 50 mile bicycle, for quick energy. I am moving towards more carbs, lots of fruits, for energy while reducing my fat intake, so I have cut down on the coconut oil, but it has been good for quick energy. I also ate lot of nuts, but I am going the way of carbs, (fruits).

    • Toxins

       Coconut oil does indeed contain medium chain fatty acids and this may be metabolized differently but there are very few studies to make the conclusion that coconut oil is “ok” or that medium chain saturated fats are negligible. A tablespoon of coconut oil has about 11.7 grams of saturated fat. about 8 grams of this is medium chain saturated fat and about 3.7 grams of this is long chain saturated fat. We have an abundance of evidence concluding that that long chain saturated fats are harmful so we cannot consider this oil a healthy option based on that alone.

      As far as minerals and vitamins go, there is not one significant vitamin or mineral in coconut oil. The only vitamin present in a tablespoon of coconut oil is .1 micrograms of vitamin k which does not even register as a percentage of daily value. Its also absent of any omega 3 fats. Just looking at coconut oils nutritional profile we see that it is clearly a junk food. Junk food is by definition empty calories.

      • Thea

         Thank you Toxins!  That is a clear and extremely helpful answer.  Now I know what to say to people.

      • nianbo

        nonsense coconut oil is nbo junk food seriously why are u even promoting this bogus science GO LOOK AT THE MOVIE FAT HEAD U F**KING MORON

      • nianbo

        coz seriously people like u make me sick

      • Plus: only 50% of the saturated fats are medium chain – the rest is normal longchain…

    • Waveboy

      What I’d like to know is, why don’t these so called Endo toxins which cause systemic inflammation of the body including the arteries have any negative effect on animals when ‘they’ consume animal flesh?

  • Robert Clements

    I think Dr. Gregor deserves the Nobel prize in medicine

    • nianbo

      in my opinion no he dosen’t that’s just my opinion don’t have to agree with me

      • Toxins

        Nianbo, I saw your rather unprofessional and quite ridiculous comment in my email that you deleted below and I urge you to raise your standard for evidence. Using a movie as the base of your argument is simply bad science.

        • nianbo

          hey dude it’s my opinion

        • nianbo

          hello mr lowfat now lot’s of expert’s disagree with the lipid hypothesis coz when the expert’s did studys to prove saturated fat causes heart disease they found there is no link between sat fats and disease not only that u have to look at the kind of study coz almost all observational studys don’t prove anything coz they don’t find a link but a clinical study actually is well controlled and does find a link i’m done

          • Thats a dilema. By seperating the observed objekt in Clinical studys you construkt a unnatural envirement. And by just looking at oberservational studys you dont get to the detail. We are stuck :(

  • Roger

    Thanks for this excellent explanation!

  • DJ Burnett, MS, RD

    Could you please start listing references to your posts so those of who are interested in learning where you get your information can also review the sources?

    • I do! Below each video there’s a Sources Cited section with all the papers–with links!

      • AqiylHenry

        Thanks Dr. Greger

      • Paleo Huntress

        This doesn’t appear to be a video and I don’t find any sources cited. Can you point me to them please.

  • Sassy

    Dr. Greger — This is really informative.  Thank you.  Can you please share where we may find the 27 foods that were tested, which include fermented foods?  We aren’t talking tempeh or sauerkraut here, are we?  Gulp.  :-/

  • Bill

    I obtained a shower gel containing coconut oil. It appears to cause jock itch which came after using the gel, failed to respond to doctor prescribed treatments and almost completely departed when gel use was discontinued. Was the condition feeding on the coconut oil?

    • nianbo

      probraby other factors

  • nianbo

    this article is total BULLSHIT IT’S JUST BULLSHIT michael greger u just don’t try to post ur propaganda on us it’s totally unscientific geddit and btw it’s refined carbs that cause inflammation and also carbs increase insulin and make u store fat just look at weson a price and the movie fat head they will tear apart this shitty propaganda

  • nianbo

    whoever wrote this i’m betting he is either a paid liar or a quack. coz saturated fat dosen’t oxidize if at all and talk about oxidized fats and omega 6 they are even more pro inflammatory saturated fats are’nt inflammatory coz they are heat stable

  • e

    which were the fermented foods that had endotoxins–I eat a lot of them for the health benefits–so I guess these endotoxins mean not to eat the particular fermented foods carrying them–therefore, important to know which ones to eliminate. thank you

  • e

    oh, just realized that endotoxins can have beneficial effect, so clearly the fermented foods are beneficial, no need to eliminate.

  • Connie Kuramoto

    Has anyone tested the reaction in organic grass fed meat in comparison to factory farm meat?

  • Bo

    Those academics think they are smart. They can´t blame seafood to be bad because it contains DHA, DPA, and EPA in a good ratio to ARA. All this crap meat they sell is not healthy, poultry, and pig is the worst. Grassfed beef contains at least a decent amount of DHA, DPA and EPA and less ARA than this crap. Less fat, a lot of CLA AND VA can´t be that bad. Fowl is also bad. So if you eat meat eat grass fed beef and wild meat except fowl is a good choice. Don´t be afraid of dairy, soured milk, youghurt, medium fat cheese is a good choice. Many people say milk is not natural it is for babies or calves but they eat a lot of high fat dairies like butter, fat french cheese and cream. Enjoy your grass fed steak and treat it gently. Eat some seafood sometimes and a lot of fruit and vegitables and let the suckers eat poultry and pig. I am a former ovo lacto vegitarian and now I am a pescetarian.

  • Rodrigo Cardoso
  • Abby

    Very intetesting info but I was wondering if the tests were done by using factory farming produce or products produced in organic environments. I think tests of such varying diets should be examined.