Doctor's Note

For more on anti-inflammatory foods, see Garden Variety Anti-Inflammation and Anti-Inflammatory Antioxidants. For more on choosing the foods with the most antioxidant power, check out Antioxidant Power of Plant Foods Versus Animal Foods. Then for other foods that may help tame high blood pressure, Hearts Shouldn’t Skip a Beet and Fill in the Blank. What about the Toxins in Cooked Potatoes? Or the Toxins in Sweet Potatoes?, which are are indeed better, and purple sweet potatoes are the best of the best. These are the only ones I’ve tried, but they are fantastic. See my other videos on purple sweets.

We know plant-based diets decrease markers of inflammation, but do all these anti-inflammatory plant foods actually have an impact on inflammatory disease mortality? Check out Fighting Inflammation in a Nut Shell.

For further context, check out my associated blog posts: How Does Meat Cause Inflammation?Treating Crohn’s Disease With DietLead Poisoning Risk From Venison, and Mushrooms and Immunity.

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  • Michael Greger M.D.

    For more on anti-inflammatory foods, see Garden Variety Anti-Inflammation and Anti-Inflammatory Antioxidants. For more on choosing the foods with the most antioxidant power, check out Antioxidant Power of Plant Foods Versus Animal Foods. Then for other foods that may help tame high blood pressure, Hearts Shouldn’t Skip a Beet and Fill in the Blank. What about the Toxins in Cooked Potatoes? Sweet potatoes are indeed better, and purple sweet potatoes are the best of the best. These are the only ones I’ve tried, but they are fantastic. I have some videos on purple sweets coming up, but in the meanwhile feel free to browse the hundreds of other videos on more than a thousand subjects.
    We know plant-based diets decrease markers of inflammation, but do all these anti-inflammatory plant foods actually have an impact on inflammatory disease mortality? Stay tuned for Monday’s video-of-the-day Fighting Inflammation in a Nut Shell.

    • HemoDynamic, M.D.

      On the ‘darker’ side of things:

      Purple potatoes, purple cabbage, Purple onions, purple corn, purple carrots, Beets, Dark green leafies, and lest us not forget Yellow Watermelon.

      Whom ever said ‘white is right’ disn’t see the science.

      Color me Purple baby! :-}

    • HemoDynamic, M.D.

      Purple potatoes (Purple Vodka?), Purple Wine, both antiinflammatory.  When are they going to make Purple Beer. 

      Oh, already done, Prickly Pear Pale Ale.  Check out this link:

      This begs the question, Is it antiinflammatory?

      Inquiring minds want to know.  Hmmmm.  :}

  • Beth Genly, RN, CNM

    On the topic of decreased inflammatory markers,also see

    • HemoDynamic, M.D.

      Interesting.  But what happened to the fiber? :-}

      • Beth Genly, RN, CNM

         Well, fresh ripe veggies and fruits beat concentrates every time, of course.

  • Thea

    But what about the two varieties of Sweet Potatoes? (white flesh and orange flesh – often referred to as yams)  Did they not study that?  I tend to like the white flesh sweet potatoes and had been under the impression that they were a lot healthier than the regular white potatoes.  I’m pretty sure Dr. Greger has a video about this somewhere, but I wonder how the sweet potatoes would fit into this study/question on inflammation?

    • carfree

      There is also a purple-fleshed sweet potato called Okinawa sweet potato. It is so delicious and very common here in Hawaii.

      • Thea

         carfree:  Thanks for that interesting bit of info.  Sounds delicious.  I don’t think I can get that in this area, but I’m going to keep an eye out at my local farmer’s market.

        • carfree

          You’re welcome! They are gray/white on the outside, and look a bit more gnarly than other sweet potatoes. I like to think they’re partly responsible for the long life expectency of the Okinawan people!

  • carfree

    I’m a little confused about inflammation and its effects on our hearts. Is this just referring to generalized inflammation, or does localized inflammation also affect our health so negatively?  I’ve heard that poor teeth hurt us because of the inflammation; what about something like a sprained ankle? Are these two different animals, or separate arms of the same animal? Or no difference at all?

    • Gale

      Inflammation is a response to an injury. When you have a sprained ankle the inflammation is part of the healing process and is not bad for the body. It is a necessary part of healing.

      When we talk about the vascular system it is the same animal. The arteries become inflamed as they become diseased. Poor teeth health is bad because of the bacteria that are associated.

      Both autoinflammatory and autoimmune diseases share an inflammatory response. In both the body attacks itself. Neither are a good thing.

      • carfree

        Thank you, Gale.

  • traffic safety lady

    What to do if you react with asthmatic or allergy symptoms when eating purple, blue or yellow potatoes? Any other good foods to eat?  I even react to walnuts, kiwi and eggplant…the swollen airways are not fun!

  • Melanie

    There is so much great information in these studies. I am going to looking at the links to see if there is something I can offer my patients. I am not allowed to prescribe (advise) on anything people can ingest, as it isn’t in my scope of practice, but I have lots of allied health information in my waiting area.

  • Ren Mendoza, PT, DPT

    Great information Dr. Greger! I just want to clarify if other types of rhizomes with pigmentation (i.e. purple yams, etc) would bring the same effect on inflammation? Thank you!!!

  • Reid


    Thank you for your work

    I really wish you would
    address targets and balance relative to your advice.

    By targets I mean, what
    should we be shooting for with anti-inflammatory food choices? Should we eat no
    bananas? When we eat potatoes, should they only be purple? Is the normal
    plant-based whole-foods diet anti-inflammatory? How anti-inflammatory should it
    be? Is there a target, that if we meet it we are fine? Is there a point of
    diminishing returns relative to continuing to pay more attention to this issue?

    I would like you to say
    “If you do X, you will be doing fine according to Michael Greger
    M.D.” Or, “If your diet looks like Y, that seems like it will be

    Also, to be safe, should we
    take a baby aspirin a day?

    In conclusion, I find this information to be relatively useless without the
    fuller context needed to understand that it in a useful way.  It would be useful to me if I could answer
    the questions in the large paragraph in this comment. 

    • Thea

       Reid:  I can’t speak for Dr. Greger, but I have some thoughts for you.

      1) We/humans may not know the answers as precisely as you would like.  We may know from studies that it is best to say “reduce inflammation”, but we may not always be to the point that we know all of the details such as exactly how much for each type of person…  Thus, it would be up to each of us to take the information in these videos/from the studies and apply the science to our own bodies the best way we can.  If we don’t know the answer, I think it would be irresponsible for Dr. Greger to make a recommendation–unless it comes with enough qualifications that a wise person would know just how to take it…

      2) Dr. Greger *does* make both general dietary recommendations and (sometimes) very specific recommendations in the videos.  For an example of a specific recommendation, check out Dr. Greger’s video series on Vitamin D.  He explains why it is hard to come up with a one-size-fits all recommendation for every person.  And then he does just that, explaining how he came up with the number.

      Dr. Greger does have a blog post on this site which has his over-all dietary guidelines that I would say fit the bill of “If your diet looks like Y, that seems like it will be good.”  However, I think that blog post is a bit out of date.  I know you can get the very latest recommendations by purchasing Dr. Greger’s Volume DVD 9.  Dr. Greger includes a printed paper with his overall dietary guidelines inside the video.  I keep hoping Dr. Greger will put that information in a link at the top of this website, right after “blog”.  But at least it is available somehow.

      Hope you find this helpful.

  • Merry

    I was wondering whether the study used conventional or organic potatoes. Seems reasonable that purple potatoes have higher antioxidants in either case. But it seems that since conventional potatoes are on the dirty dozen list, it may be that the chemical residue on them is contributing to the oxidant activity and not the white or yellow potatoes themselves. Any way to find out which type of potatoes were tested? 

  • Tom

    This information while appreciated also confuses me. Dr McDougall’s entire plan is starch based and he is a HUGE proponent of all types of potatoes.  I do love russet potatoes with black beans, corn, green onion and salsa on them.  Is this just ONE study about pro inflammatory effects of white potatoes and maybe theres HOPE to still eat russets a few times a week?  :)  I do eat orange sweets and have tried purple sweets as well. Very tasty.

    • Thea

       Tom:  I think you will be very interested in the following video.  Based on the title, it seems like the video is just about white bread, but watch it through.  I don’t want to give away the suspense, but it directly addresses your question about the health of white potatoes.

    • Thea

       I forgot to say:  I also find these studies very sad.  I love white potatoes…  But I have changed my diet to severely limit them.  One thing I am no certain of, however, is the health effects of white sweet potatoes.  Are those different?  I hope so, because they are not as strong as the orange potatoes and often go better in certain dishes.

      I also had a thought for perspective: even if white potatoes are not the healthiest food to be eating, it seems to me that the science points to white potatoes being far, far better than animal products.  So, if you found yourself with a choice between mashed white potatoes and say yogurt – go with the potatoes!

      • Jane’s Addiction

        Hi Thea, do you (or anyone else reading this) happen to know if red potatoes, the ones with the red skin and white flesh, fall into the dreaded “white potatoes” category? I’ve started eating them daily because of their huge loads of potassium but if they’re causing inflammation and all of that I need to find a better potassium source…
        When I first got into them, I was hopeful that the word “red” in their name exempted them from all of the white potato trouble, but I’m starting to wonder if they’re just as bad as russet potatoes.

        • Thea

          Jane: I’m sorry, I just don’t know. I like to think positive. But I really don’t know. :-(

          • Jane’s Addiction

            Thanks all the same, very kind of you to take the time to respond. As a bit of an update of my own, I can report that I switched from red potatoes to blue/purple potatoes yesterday. This is hardly scientific and could be placebo, but I felt an immediate improvement on the blue potatoes. After eating them, it was like my body was expecting a blood sugar spike (since I’ve been gorging on red potatoes for a couple of weeks now), and when it didn’t come it was like, “Hey, this feels pretty good!” The feeling, real or imaginary, was so strong that it has me feeling pretty averse to the idea of ever eating another white potato, even if they are called “red,” again.

          • Thea

            Jane: Wow. That’s really interesting. And I like how you understand that it may be placebo, but who cares, because your experience is your reality. Good analysis. Enjoy your purples!

  • lynn

    What about the peel? Toxic?  I grow small knobby very purple potatoes & have been just scrubbing & steaming & mashing them or making grated potato pancakes. Yummy & a beautiful color.  It wouldn’t be worth trying to peel them.

  • Doctor Greger, I have been an omnivore (with heavy leaning toward
    carnivore) most of my life. Due to friendships with more health
    conscious individuals (vegetarians with leanings toward vegan) I am
    gradually changing my eating habits.

    In laying out my future dietary patterns I have found your research very
    helpful overall. For this I thank you.

    At the same time I find myself questioning things. Although the overall
    health benefits of a vegetarian vs. a omnivore lifestyle are statistically
    indisputable, the cost/benefits of individual elements and mechanisms are less clear.

    “Animal protein is bad”… “well, it is actually the saturated animal fat”, “well,
    really the worst part is the systemic inflammation caused by the bacterial
    toxins unavoidable in animal products that the saturated fats help permeate
    the intestinal wall that does the killing”. But “cooking temperatures and methods greatly impact the negative consequences of eating animal
    products”. “And nuts and purple fleshed potatoes seem to do an amazing
    job of mitigating the overall negative effect of inflammatory toxins on
    our bodies”.

    What I am actually looking for is a “Unified Theory on Health”, where elements can be weighted (both individually and combined with
    enhancing/mitigating factors) and evaluated for individual choice and application.

    “Must you eat meat? Fine, looking at the unified theory you might decide to
    slow cook skinned free range antibiotic free chicken thighs. Skim off
    the fat and mix in a moderate amount of olive oil during last 20 minutes
    of cooking. Eat early in the day with purple fleshed potatoes. Have a
    dessert high in both whole grain oats an tree nuts, and engage in at
    least thirty minutes of moderately high intensity physical activity 3 to
    5 hours after your meal…”.

    “It has to be beef? Fine, you look at the theory and start with lean, organically raised beef. Cook at low temperature…”

    And “help cleanse your system the next day by going totally high fiber
    vegan. Start with a whole fruit breakfast, accompanied if you must with
    a small amount of home made low sugar low wheat breakfast cereal in
    almond milk. Vegetarian chili and beans makes a wonderfully filling
    lunch. Add a lentil soup and salad for dinner and you are ready for a
    good nights sleep”.

    You get the idea.

    At this stage of the science can this be done with any degree of


  • lovestobevegan

    Lose Your Mustache Mash

    – 4 cups organic* purple potatoes, peeled and cubed
    – 7 whole cloves garlic, peeled
    – 1 tbsp sage
    – ½ tbsp rosemary
    – 1 tsp thyme

    Boil potatoes and garlic until mashable. Place herbs in the bottom of a
    large bowl and top with freshly boiled potatoes and garlic. Mash everything together and add some of the boiling water to achieve a creamier mash. Season to taste with sea salt.

    *Potatoes rank 10th (up from 12th last year) in the “dirty dozen: 12 foods to eat organic” so choose organic.

    Bookmark my new Plant-Based Emporium Facebook page for all my latest recipes.

    ~Complements of lovestobevegan

  • Catherine

    Dr. Greger, thank you for being you. Please write a cookbook or at least compile your favorite recipes. It would be a best seller!

  • Mscopeman

    Second person asking…. While it’s clear that purple potatoes are healthier than white potatoes based on the studies above. The question is, do they cause the same insulin spike that eating white potatoes does? We haven’t eaten a white potato in years but used to grow and enjoy purple potatoes. We’d grow them again if they don’t cause an insulin spike, if not we’ll continue to stick to sweet potatoes.

  • One Single Act

    Did you see the movie Interstellar? The earth is a dust-bowl (cows?) the last remaining crop that can grow is corn, so humans have to leave the planet to find a new place to live. How come potatoes weren’t the last crop to survive. Water efficient, they grow under ground, almost a complete food for humans (just a little greens needed). We could have held out a lot longer. And where did those beers Mathew McConaughey had come from?

  • PegasusWing

    My friend lectured me about not eating potatoes on a diet. I found that a med potato, @ 100 calories satisfied my appetite between meals.
    I stopped eating potatoes and started gaining weight, even when keeping to my weight loss diet!
    I know that I have an enlarged thyroid, but tests said I was ok, but I still suspected that something was off.
    Finally I looked up iodine in vegetables. Seaweed is the best, but I can not choke it down for love nor money.
    Fish and shell food is also great, but I have acute allergic reactions.
    Potatoes is the vegetable highest in iodine. I still can not find information which potato has the highest levels of iodine.

  • john tiffany

    so purple potatoes are healthy; but does this mean blue corn is better than yellow corn?

  • john tiffany

    so purple potatoes are healthy; but does this mean blue corn is better than yellow corn?

  • Ryan Graber

    With the darker (often purple) varieties of veggies and fruits often being healthier (cabbage, potatoes, etc), does the same go for purple tomatoes? Not just the pseudo-purple tomatoes like “Black Krim,” but what about the new true-purple varieties like “Indigo Rose” from Oregon State University (see link below) which claim to be the first with anthocyanins? If these have higher levels of nutrition, I might start growing some in the home garden.

  • dougdelt

    Hi Dr. Greger. I love your informative articles. On August 26, 2015, Science News summarized recent studies that purple pototoes appear to be a primary and second means of fighting colon cancer, as it apparently kills stem cells — the root cause of colon cancer growth. Here is a link: The headline is :”Compounds found in purple potatoes may help kill colon cancer stem cells and limit the spread of the cancer, according to a team of researchers.” So you were 3 years ahead of the curve endorsing these potatoes in 2012! Keep up your great work. Much appreciated!

  • “Pigmented potato consumption reduced inflammation and DNA damage in healthy adult males. this offers consumers an improved nutritional choice in potato consumption.” the study concluded. They say in healthy adult males – what about already sick people. ;-)

  • Regina

    When I have nightshade veggies it causes inflammation. Do you think purple potatoes would cause me inflammation?

    • Hi Regina,
      I am a volunteer moderator for Dr. Greger and am happy to help. Potatoes (excluding sweet potatoes) can sometimes worsen inflammatory conditions, so it is often excluded from an anti-inflammatory diet (along with nightshades, mushrooms and tomatoes). I hope this helps!

  • Cathy Katin-Grazzini

    Am perplexed by the beneficial impact of extra virgin olive oil, compared to corn or non virgin? Other tests like the brachial artery tourniquet test suggested strong inflammatory effects of this and other oils on arterial function. Any explanation?