Image Credit: Jojo / Wikimedia Commons. This image has been modified.

Plant-Based Diets for Rheumatoid Arthritis

Plant-based diets may help rheumatoid arthritis by decreasing exposure to an inflammatory “Trojan horse” compound found in animal products called Neu5Gc. In How Tumors Use Meat to Grow I talked about the inflammatory role Neu5Gc may play in stimulating breast cancer growth, but what about inflammation in our joints?

For those of you who have been following my work since the beginning, you’ll remember back in 2003 I covered a landmark paper in the Proceedings of the National Academy of Sciences entitled “Human intake and incorporation of an immunogenic nonhuman dietary sialic acid.” They took autopsy samples and discovered proof of Neu5Gc in human tumors. In my video The Inflammatory Meat Molecule Neu5Gc you can see it stained brown in human breast cancer, melanoma, brain tumors, and ovarian cancer.

The presence of Neu5Gc in human tumors mystified researchers, because human beings are genetically unable to produce this substance. But other animals can. Maybe, the researchers proposed, human beings absorbed it from eating these other animals? So they put it to the test.

Because Neu5Gc is found in animals and animal products, the researchers had to first eat vegan for a few days to clear their system (including no animal-derived ingredients in foods or drugs or shampoo), and then they basically drank a glass of diluted pig mucous. Within days this invading meat molecule could be found oozing from their bodies, in their saliva, urine—even their hair clippings. They concluded: “Because NeuGc-type compounds are not found in plants, and Neu5Gc is not synthesized by microbes, the dietary source of Neu5Gc must be foods of animal origin.” They proposed that the metabolic incorporation of this molecular “Trojan horse” from animal products may be contributing to the higher rates of cancer and heart disease in those that eat meat and dairy.

Why heart disease too? If you check out my 3-min video Nonhuman Molecules Lining Our Arteries, you’ll see that this foreign meat molecule tends to accumulate not only in the lining of hollow organs (where carcinomas like breast cancer develop inside your glands), but also in the lining of blood vessels. This may be contributing to the hardening of our arteries, the #1 killer of men and women in the United States.

Inflammation is one of the three steps en route to fatal heart disease. See:

Antioxidants found predominantly in plants may also decrease inflammation within the body. Nuts may be particularly useful in this regard.

The absorption of the inflammatory molecule Neu5Gc from animal foods may also explain why vegetarian diets seem to improve rheumatoid arthritis. Maybe the incorporation of this reactive alien molecule into inflamed tissue such as arthritic joints could be aggravating arthritis. That could explain why rheumatoid arthritis is not present in most other great apes. What we do know is that if you take animal products away, rheumatoid sufferers can feel better within weeks–see Diet & Rheumatoid Arthritis and Preventing Arthritis.

Bacterial endotoxins are another reason animal products may trigger an inflammatory immune reaction. See:

Beyond the putative role of nonhuman Neu5GC as a potential molecular link between diet, autoreactive antibodies, and the progression of human cancer and heart disease, I close out the Neu5Gc story with a 3-min. video entitled Meat May Exceed Daily Allowance of Irony. It turns out that consuming Neu5GC may set children up for life-threatening reactions to E. coli toxins originating in the same animal products. The researchers ask if this is “poetic justice” for meat eaters. Not when it’s a major cause of acute life-threatening kidney failure in children. For more on E. coli, see Fecal Bacteria Survey and Chicken Out of UTIs.

My exploration into Neu5GC spanned a seven video series (starting with Cancer as an Autoimmune Disease). If you’d rather these more extensive probes than my one-off videos, I’ve done similar in-depth series on reversing cancer cell growth, why animal products cause inflammation, changing vitamin D recommendationsarugula athleticism, why nuts don’t appear to cause expected weight gain, as well as the latest dietary guidelines.

Michael Greger, M.D.

PS: If you haven’t yet, you can subscribe to my videos for free by clicking here and watch my full 2012 – 2015 presentations Uprooting the Leading Causes of Death, More than an Apple a Day, From Table to Able, and Food as Medicine.


Michael Greger M.D., FACLM

Michael Greger, M.D. FACLM, is a physician, New York Times bestselling author, and internationally recognized professional speaker on a number of important public health issues. Dr. Greger has lectured at the Conference on World Affairs, the National Institutes of Health, and the International Bird Flu Summit, testified before Congress, appeared on The Dr. Oz Show and The Colbert Report, and was invited as an expert witness in defense of Oprah Winfrey at the infamous "meat defamation" trial.

29 responses to “Plant-Based Diets for Rheumatoid Arthritis

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  1. Why does the research you present discourage meat consumption yet there are numerous advocates for eating meat backed by research? It’s very confusing for me as I try to better my diet. (Btw I do enjoy your video they’re excellent).

    1. What HemoDynamic said :)

      1. Granted it can be really tough to look at sources of funding. Even if you can get access to the primary journal article, and it appears that it came out of a university, you still have to check affiliations of all authors. Plenty of university researchers get funding from big beef, big dairy, etc. You always want to get research from people who research for the sake of research, NOT for pleasing their industry benefactors.

      On the other hand for someone to have gotten funding from NIH or NSF for example, a) they would have had to prove that their research will benefit the public, and b) they will not have to deal with any bias from the funding source. NIH and NSF want good science, and they want results, whatever they may be. Not so with industry funding sources.

      Dr. Greger does occasionally present research funded by some group like The New Zealand Kiwi Association for example, but he always discloses it. Also it’s important to note that the funding source does not automatically dictate whether it’s good or bad science. But let’s say we have hundreds and hundreds of studies detailing the harmful effects of beef and then a few saying it’s beneficial, and those few studies are funded by the beef industry, well, you make that judgement call as to the quality and integrity of those studies. A thorough reading of the actual study will typically reveal its flaws.

      2. Context and balance of evidence are key. If someone can produce even a dozen sources that they claim imply that a meat based diet is beneficial, that is nothing, NOTHING, compared to the mountain of evidence in favor of a plant based diet. And of course that is assuming their sources are valid. Often bloggers will use a legitimate journal article to try to make a point, even though the source does not in fact support it. They count on people not reading the original literature themselves. They also count on people not being able to. Frankly, it takes someone with a scientific-journal-article-reading background to read scientific journal articles and most bloggers are not equipped. Heck a scientist from one field will have trouble reading an article from another field. Biochemistry journal article is basically my second language. But can I read a computational chemistry journal article? Heck no. Should I go forming grand opinions on the field of computational chemistry based on my interpretation and present them as fact? Definitely no.

  2. There are two questions that should always be asked in the scientific world when reading or listening to the results of research: 1. Who funded the study? 2. What do they have to gain from the study?
    I know it’s tough to mire through the details to get that information but that is where comes in: Dr. Greger scours the details to bring you the most unbiased information possible. Why, because he truly cares about the human population and wants you to have the most unbiased information so you can make the best choice for keeping yourself healthy.

    I have treated thousands of patients and never have I seen one patient prevent, arrest or reverse their chronic diseases (eg. Coronary disease, Vascular disease, Diabetes, Hypertension, Autoimmune disorders like, Lupus, RA, Crohns, Ulcerative colitis, Thyroiditis) on a meat based lifestyle. The only ones that can change the coarse of their chronic diseases are those that change their lifestyle to a Whole food, plant based lifestyle rich in complex carbohydrates (eg Potatoes, Rice, Beans, Corn etc) and beautifully colored vegetables.

    1. It is difficult to know who to trust especially when you have a limited understanding of health and diet matters. I talk to my family about this sites information and they think its absolute BS…we’ve always had meat eaters in this family/ extended family. I have cut back meat consumption considerably because of this site but going vegan I don’t think I could ever do.

      1. Simon, if you think you can’t then you won’t. Start out small, slowly. A day or two a week. I live with a meat eater. I won’t change him and he won’t change my vegan ways.

        1. I have personal trainer and that whole industry seems to push paleo diets and this is where a lot of my confusion is coming from (as well as the fact my natruropath and doctor recommend eating meat)I need to read more
          and watch more of these videos.

          1. Good for you for thinking critically and deciding to watch more videos!

            If you haven’t already, I suggest checking out: Forks Over Knives. That one, in addition to Dr. Gregers, Uprooting the Leading Causes of Death (available free on this site) should be of great help.

      2. Simon, if you don’t think you can you won’t. Try eating a plant based diet one or two days a week. It really is a personal choice. Have fun on your journey.

      3. Simon: Best of luck to you. I can imagine how hard it would be to be surrounded by such a culture and try to do something different.

        I have two thoughts for you which you might find helpful:

        1) You can find all sorts of stories of world class athletes and body builders who eat vegan. Most report improved performance after going vegan. I would think that reading about such athletes and how they got where they are would both be inspirational to you and would provide something for you to say to personal trainers, etc. I found a site the other day that is dedicated to famous vegan athletes. I also get the Meatless Monday e-mails. I’ve seen several stories about people getting in shape and running marathons as seniors because they switched to a plant based diet. I think there was one such story in the last issue. So, Meatless Mondays might be another source of inspiration for you.

        2) You would be surprised how your views of what is possible will change over time – especially as you educate yourself more and more. I personally thought I would never go vegan. But here I am. Both of my parents told me that while they support my decisions, they would never go vegan. Then they started eating some vegan meals. Then they ate vegan only at home, but not necessarily when out of the house. Then, as they saw more and more concrete, measurable health benefits, they eventually decided to go all the way.

        Here’s my point: for some people, going cold turkey is the right approach. For other people, it is something that they gradually find themselves doing. Even though you can not see yourself as going all the way at this moment, maybe you could continually ask yourself: Now that I’m comfortable with what I am doing, what is the next baby step I could take to improve my diet? Walk enough baby steps and you may find you have traveled quite far.

        Hope these ideas are helpful to you.

      4. Simon, I was just wondering if you have looked into all the new vegan products on the market today. While I am not advocating veganism is about diet, it’s not, I do think that for many non-vegans interested in learning more about veganism, it may be beneficial to consider trying these products. Many of the comfort foods you enjoyed a non-vegan have been recreated by many vegan food companies. And they are available at many major grocery store and online. You want chicken, beef, fish, try Then there, And Man I could go on all day. The point is, your transition into veganism can be easy. And while your trying some of these delicious choices I would suggest reading, The World Peace Diet by Dr Will Tuttle. It will amaze you. Google anything you want to know about veganism. And don’t let people you know sway you from wanting to change your life style; it’s your life. And I think they will see a new you and become curious and you can help them understand. I would take the advice you got from these other post seriously. They have no reason to lie. Vegans have nothing personally to gain from being vegan. That’s what makes it altruistic. I wish today you where looking back at this moment as if it happened many years ago. You will smile and know you did the right thing. We’re all here to help. Just ask. Namaste.

        1. YES there are MANY ‘Vegan’ products on shelves these days, but almos ALL are ‘processed’ food and simply only marginally better than long time processed things! THINk Whole Food, Plant Based w’little or No Oil (WFPBNO) as where it’s at!

      5. I used to think I couldn’t either. Never ever. I did. It took me 4 years of elimination (first mammals, then poultry, then seafood, then finally dairy 8/2017) but now it is easy. Read “How Not to Die” (which is full of research) and it will make sense. The meat and dairy industries lobby Congress which is why our government pushes those poisons. Have you ever heard of a fruit or veggie lobbiest? Nope. Meat and dairy get to write the nutritional recommendations for our country because they give big bucks to our politicians. It is shameful.

  3. I was diagnosed with hallux limitus, a type of degenerative arthritis of the big toe. Since going plant based a couple months ago, my range of motion and pain has improved greatly. Thank you for all the work you do in providing these videos.

  4. Great info, again. Grateful I am vegan and have been for 13 years. I do wonder how those researchers were able to drink pig mucous. Beer back?

  5. I want to know how the researchers drank the diluted pig mucous. Beer chaser??
    Thank you again Dr, G for the awesome info.

  6. I was vegetarian for 20 years and had to start eating meat again. My energy really improved. Now, I have a very healthy diet of mostly raw vegetables, fruit, nuts, seeds and sprouts. I also occasionally eat my own hen’s eggs and organic meat. Once I figure out how to replicate how I feel when I eat some meat as a vegan, I will try it again. My iron and B12 status fine. so it is something else. My sister has RA and I have done a lot of research on it. It is not just a vegetarian diet that helps but a grain-free raw vegan diet that helps. Wheat can cause SIBO, just as undigested meat can. Leaky gut and dysbiosis are really prominent in folks with autoimmune diseases. In the study with Neu5GC, did they control for already existing pro-inflammatory cytokines? What about omega-6 to omega-3 fatty acids?

    1. Hello Brenda. My dad has severe RA – has had it for 13 years…he was on humira untli they found he developed b-cell lymphoma. At this point, we don’t know if the drug caused it, or the inflammation itself. We have been juicing for him every day….as well as try to get him as gluten/meat/dairy free as possible. But he’s just in so much pain all the time….and sometimes will have chicken or fish. I see you said “grain-free raw vegan diet” but does your sister ENJOY it? My dad LOVES food and gets very depressed in the thought of not eating what he wants…..this diet is hard enough for him. There’s just no relief for him. If you could give me ANY information that could possibly help….I’d so appreciate it. Thank you!

  7. McDougall’s study from 2002 is hardly impressive. Non significant changes in inflammatory markers, and only signficant improvement in subjective findings of pain, and joint scores. And it lacked a control group.

      1. Rather than read the whole 56 pages of that Cochrane Review, the author’s conclusions sum it up “The effects of dietary manipulation, including vegetarian, Mediterranean, elemental and elimination diets, on rheumatoid arthritis are
        still uncertain due to the included studies being small, single trials with moderate to high risk of bias. Higher drop-out rates and weight loss in the groups with dietary manipulation indicate that potential adverse effects should not be ignored.”

  8. No mention of oxalates and other anti-nutrients in plant foods especially nuts, which contribute to pain associated with arthritis. Lots of plants including nuts are toxic and shouldn’t be in our diets because of these antinutrients. Check out Susan Owens Low Oxalate website and try the low oxalate diet if you are suffering.

    1. There is zero scientific evidence showing that oxalates demote health. Yes they are antinutrients but this is really a non issue and does not cause trouble in a normal healthy person. If someone is having severe kidney issues then in this case oxalates would be advised by a doctor to be restricted.

  9. Hi! I have so called chronic Lyme disease. I didn´t know until recently so I didn´t get treatment for a long time. Do you have advice, on this? Research on what foods can be helpful, anything. My going very very vegan, even raw for a while, and paying a lot of attention to nutrition. I know there is this controversy about the late stages of Lyme. All I know is that neuroboreolosis certainly does exist, unfortunately. Well, I´m interested to know any and every piece of info n advice that you would be able to share… Thank you for inspiration and tons of useful info.

  10. Hi Dr Greger,
    I recently came across someone who took cherry juice concentrate for Gout. When I looked up the benefits of tart cherry juice, it is touted as a. powerful antioxidant as well as anti-inflammatory. What are your thought on it? It seems an ounce of this a day could be meaningful for many inflammatory conditions.


  11. Dr Gregor, Thanx for all the great videos!

    I was diagnosed with RA in July of 2012. I had been a lacto/ovo vegetarian for 35 years. After reading that animal proteins might be a cause, I began eating Vegan, 6 months ago. It doesn’t seem to be helping. Nodules continue to appear all over my bones and my fingers are all getting swan necks. I am also on an anti-inflammatory diet:

    NO gluten, corn, peanuts, sweeteners, condiments, chocolate, oranges, eggs, dairy, meat. Any ideas or input would be most appreciated. Thank you!

    1. RA is likely more than one disease. There are many who significantly improve on a plant-based diet but as a physician I have also met suffers of RA who have not improved adequately on a plant-based diet. Nevertheless, it is still a much healthier way to live. I would encourage you to keep searching for the cause. Something is irritating your joints.

      1. Thank for your kind reply.
        I am doing much better.
        I’ve add many anti-inflammatory herbs and I believe they are making a difference.

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