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Can Quercetin Help Heal a Leaky Gut?

by Kelsey Kinney, RD

Last updated on

quercetin leaky gut, quercetin histamine
Quercetin, a nutrient found in foods like these apples, is great for healing leaky gut.

Digestive health is a hot topic these days. Problems in the gut not only play a large part in digestive issues like irritable bowel syndrome or reflux, but the gut has an effect on practically every part of our body.

Imbalances in the gut can create rashes, exacerbate joint pain and even cause depression – it’s no wonder we all want to learn how to keep the gut healthy!

One of the most pressing concerns regarding the gut is something called intestinal permeability, often referred to as “leaky gut”. The barrier of the gut plays an important role in maintaining our health by protecting us from the many things we’re exposed to from the outside world. If you think about it, our digestive tract is technically not “in” our body, it’s outside.

Think about your body as a donut and the digestive tract is the donut hole – technically, not “in” the donut. It’s easy to see now that our gut lining is exposed to everything we swallow – food particles, bacteria, dust, etc – and has to decide what to do with all that material! Think of the gut barrier as the decision-maker: some particles are allowed to pass through, while others are told to move on through.

When functioning normally, the gut barrier keeps us healthy by keeping out potentially hazardous materials and letting nutrients and water in. But when it starts to become more permeable (or “leaky”) than normal, we run into problems.

Of course one of the most important things for preventing excessive intestinal permeability is to eat a Paleo diet that works for you (a la Your Personal Paleo Code; The Paleo Cure in paperback). However, there are definitely other nutritional components that can help, quercetin being one of them!

Mast Cells = Leaky Gut?

Researchers have discovered that mast cells play a part in developing leaky gut. While it’s been known for a long time that severe physical stress (i.e. trauma or surgery) causes intestinal permeability, newer research has shown that chronic stress also has this effect. (1) Interestingly, researchers determined that it is the mast cells in the intestine that are responsible for the increase intestinal permeability in these stressful situations. (2)

You may have heard of mast cells before as the cells responsible for allergy symptoms like congestion, runny nose, etc. This is because when mast cells “degranulate” or become “unstabilized”, they release histamine, the chemical that causes allergy symptoms. But you have mast cells in your gut, too and when they “degranulate” or become “unstabilized” there, they cause leaky gut.

Quercetin for Leaky Gut

Quercetin is one of the most abundant flavonoids present in our food supply, found in high amounts in onions, kale and apples. (3) It is well-known for many things, including its anti-allergy properties, anti-cancer effects, and as an antioxidant. But did you know that it can heal leaky gut, too?

Given that intestinal permeability is caused (at least in part) by unstabilized mast cells in the gut, it makes sense that quercetin would have this effect. This is because quercetin stabilizes mast cells and prevents the release of histamine and other chemicals from these cells. (4) When researchers breed rats to have no mast cells in the gut (thus they are unable to have unstabilized mast cells that release histamine), they no longer develop intestinal permeability. (5)

Quercetin has also been shown to enhance gut barrier function by having a “sealing” effect due to its role in the assembly and expression of tight junction proteins. (6) Tight junctions regulate our intestinal permeability by connecting intestinal cells, thus only allowing the nutrients that we need in and keeping everything else out.

In rats given DSS (a substance that causes colon damage), treatment with quercetin restores barrier integrity and partially heals colitis. (7) Rats given another substance to cause colitis and treated with quercetin preserved normal fluid absorption (which is altered by colitis), counteracted glutathione (our “master antioxidant”) depletion and ameliorated colonic damage at two days. (8)

I’d say that’s some pretty good news for those suffering from leaky gut!

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Quercetin in the Diet

Now that we know quercetin is healing substance for a leaky gut, how do we get enough?

Well, the good news is that on a Paleo diet, you should be getting quercetin by eating your fruits and vegetables. Remember that a Paleo diet can, and for most people, should be a diet high in fruits and vegetables, which naturally contain quercetin. But if you’d like to add some extra quercetin to your diet (or you can’t tolerate many fruits and vegetables), a quercetin supplement is also an option.

There is limited data regarding the amount of quercetin in our food, but below are the estimates available. (9) Your best bet is to just eat a wide variety and a lot of plant matter for optimal intake and consider supplementation if needed.

  • Fruits: 2 – 250 mg/kg
  • Vegetables: 0 – 100 mg/kg (onions are especially high at 200 – 600 mg/kg)
  • Tea: 10 – 25 mg/L
  • Fruit juice: 2 – 23 mg/L
  • Red wine: 4 – 16 mg/L
It’s also important to note that other flavonoids such as naringinen seem to have similar healing effects on leaky gut, so including a wide variety of plant matter to increase your intake of many different polyphenols is a great idea. (10) Not to mention that polyphenols improve your gut bacteria, too!

Here’s the take-home message: eat your fruits and veggies for your daily dose of quercetin, or consider a supplement if you can’t tolerate much plant matter or if you’ve got a severely leaky gut. If you’d like to go the supplement route, aim for 800 mg twice a day or 400 mg three times a day for a total of 1,200 – 1600 mg per day. It’s very difficult to get these levels from food, so a supplement is a good choice.

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Chris Kresser in kitchen
Kelsey Marksteiner
Kelsey Kinney, RD

Kelsey Kinney, RD, is devoted to helping the world achieve great digestive health through her blog, private practice, and prebiotic & probiotic drink mix company Gut Power Drinks. Check out her blog, Gut Power Drinks website, or visit her on Facebook for more.

Kelsey is a registered dietitian specializing in digestive and hormonal health. She graduated from New York University with a Bachelor of Science degree in Nutrition and Dietetics and went on to complete her dietetic internship at Milford Regional Medical Center in Milford, Massachusetts. She also has a Master of Science degree in Human Nutrition and Functional Medicine from the University of Western States.

Kelsey loves helping people find their unique, personalized diet that will help them heal, not anyone else. She has always been interested in nutrition and health, and is honored to now help people find a diet that brings them happiness and longevity.

Professional website: https://kelseykinney.com

Gut Power Drinks website: https://gutpowerdrinks.com

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Join the conversation

  1. Chris,
    I was recently diagnosed with a condition called interstitial cystitis aka painful bladder syndrome (IC/PBS) and quercetin was one of the supplements recommended to treat the lining of the bladder. Symptoms of IC/PBS usually include frequency, urgency, pelvic pain, and flares of pain that feel like a uti. A pain flair can be caused by many things, especially diet and stress. The etiology of this condition is complex, but what eventually happens is that the lining of the bladder becomes inflamed and unable to repair itself and has probably been hit with multiple rounds of antibiotics (confused with utis). Irritating foods and drink can inflame the bladder and allow irritating substances and urine to move into/through the damaged bladder tissue, aggravate mast cells in the bladder, and allow stuff to move into the surrounding blood/tissues, thus resulting in a leaky bladder. Like myself, people with IC also have a tendency to have IBS, allergies, sensitivities, and so on. Many people suspect that IC may have an autoimmune aspect to it. What do you think about “leaky bladder,” autoimmunity, and natural treatments for IC?

    • The only human approved condition approved for prescribing DMSO is interstitial cystitis. It’s supposed to do wonders.

  2. Our family suffers from gluten/dairy/egg and banana food allergies (dx by 96 food IgG blood test). Now we notice that eating allergen causes illness. Will Quercetin help heal the gut and eventually resolve our food allergies?

    • Resolve meaning cure, as in they are no more? Probably not, IMO. Resolve as in improve? Possibly? Talk to your medical practitioner before trying it out, then hell, come back and let us know?!

  3. Taking more than 1g of quercetin per day for a long time can be harmful to your kidneys. Probably also want to consider quercetin intake other herbals (Hawthorn has a good amount of it), vitamin C with flavenoid complex bundle-in, and natural diet

    Niacin can be harmful to the liver, but not as much as statins unless you take the time release kind. Statins are evil things. Niacin also increases the odds of suffering from the muscle wasting side effect of statins. Statins also deplete CoQ10. Niacin and fish oil works wonders on your HDL (46 to 65 for me) and triglycerides (185 to 85 for me)

  4. Hi!

    Wow, this sounds really interesting news. I have reflux and ibs both, and foods containing quercetin make me reflux more and worsen my constipation. So would it be a better option for me to reach out for a supplement instead of an apple or an onion? Is it possible to fix my ibs and reflux symptoms at the same time with quercetin, assuming it heals leaky gut?

    • Apples, onions and garlic all cause problems for me, and I recently tried a good brand of quercetin, and it seemed to work the opposite that everyone said it should. It seems that most quercetin is sourced from apple skins, and from onions, so maybe for some of us, it doesn’t work so well? I am currently following a low fodmap diet, and that seems to be helping the most. I’m even looking at my supplements that have quercetin, and some of the plant concentrates in them that hare high on the fodmap list and eliminating until I am symptom free. A good friend once said to me regarding food that one person’s medicine can be another person’s poison!

  5. I take 500mg of quercetin twice a day every day, plus 2000mg of niacin (old fashioned flush kind; use the OTC twinlab niacin capsules that druggies use to try to conceal urine dilution, not the expensive prescription niaspan) twice every day (as well of 4g of fish oil and 4g of flaxseed oil twice a day). No allergies for me this year. For bad flushers like me, sucking up the flushing for two weeks or so (when the body no longer flushes unless you miss more than a day or two) guarantees whole body depletion of histamine. THen add the anti-inflamatory effects of the garlic, olive leaf, fish oil, flaxseed oil, and quercetin. No more allergies, and those weren’t the main intention in taking these, avoiding prescription meds for blood pressure was (which wasn’t successful as only Garlic is effective with my BP but that is probably keeping me off of a 3rd med)

  6. tTG2 Ab and lifelong leaky gut here, Hashi-hypoT, occasional cholinergic urticaria, various skin stuff, gluten-free, etc. … Some 10 yrs ago I experimented with quercetin supps, and the only one that muscle-tested strong on me at that time was Source Naturals liquid quercetin in the dropper bottle fwiw. I suspect potency is an issue with quercetin supplements and may not be well-regulated. … I commonly have a breakfast smoothie that includes the juice of 3 green apples, and eat a red apple for a snack most days. I add raw onions to various dishes. No alcohol. … From my experience of a recent bout of recurring cholinergic urticarial over the last 2 months, I don’t think there’s enough power in these foods and/or the quercetin supp at typical maximum doses on empty stomach to be sufficiently effective, however they’re good on general principles and likely do many other good things. I’ll experiment more with the capers, and with green and black teas, though I dislike the high fluoride content of tea. Being in the high raw subset of paleo, I totally support a diet heavy on the vegetables and fruits. Thanks for a very interesting article, Kelsey.

    • Hey there! I have leaky gut (intestinal inflammation and IgG allergies) since like 3 years. A plethora of other stuff like Hashi´s have showed up in tests but that is non relevant since the last tests show no autoimmunity (I was in strict leaky gut diet this time, no surprise) Since then too, I have chronic eczema and semi chronic cholinergic urticaria. I know the eczema is a no brainer but what about the urticaria? I am pretty sure is related but there is no evidence in google scholar. You are the first leaky gut sufferer that I see states having cholinergic urticaria. BTW after a few months of strict dieting my fucking urticaria disappeared to the point I could exercise.

      What about taking 1500 mg of the Jarrow brand Quercetin per day would that help? I have found that propolis extract has a quick suppresive effect in intestinal inflammation in doses of 6 capsules. Right now I am taking that and Grape Seed Extract, however these last months I have been feasting in whole grain gluten and organic sheep/goat dairy and the effects are very clear today. Keeping up with the diet its been just too much for me, especially regarding the massive weight loss paleo meant for me which made me look even worse.

    • I love examine.com! Such a good resource. They found 1 study on intestinal permeability (http://www.ncbi.nlm.nih.gov/pubmed/21613575), and apparently quercetin actually INCREASED permeability (but it was during exercise under high heat conditions, so we can’t infer the effects under resting conditions). Based on that, I think for now it’s best to wait until further human trials or really good anecdata come out. We can’t really conclude anything from the rat studies. I guess I’ll just stick with eating onions. (I’ve never tried capers, and Wikipedia lists them as the best source. How do people usually eat capers? I thought they were used mostly as a condiment.)

      • Cat,

        Most people use capers as a condiment on/in salad, or flavoring for sauces…

      • capers can be used in many ways. My favourite is to make Italian (non Mexican ) salsa verde with them. put flat leaf parsley, capers, olive oil, vinegar or lemon juice and sea salt into a food processor (if you use the salted capers instead of the ones in vinegar than soak them in hot water for a few mins to wash off the extra salt). I leave out the bread 🙂 puree it to the consistency of pesto. Serve with fish or as a sauce for vegetables. Delicious! easy!

      • Um, pretty sure that says under the conditions, permeability only remained elevated. It doesn’t say it increased permeability, only that under those conditions it didn’t decrease it.

  7. No wonder I healed my RA on the fruit & vegetable only diet. I wonder if hydrogen peroxide and diatomaceous earth can actually kill the bugs…

  8. Leaky gut can be caused by many things: consumption of antibiotics, aspirin, alcohol, processed inorganic foods, stress, flora imbalance, candida overgrowth, unhealthy grain consumption (e.g. wheat), excess sugar, etc. At least in the case of candida, I doubt mast cells play much of a role because it is the candida itself that pokes holes in the gut.

    The greatest source of quercetin is actually capers, then onions. I know that some people dont react well when supplementing quercetin, but you can purchase whole food derived quercetin (e.g. life extension makes a great one). Of course there are many other things that are needed to heal a leaky gut, but quercetin is a great start.

    • Capers and apples are my go-to when I can tell my histamine is too high.

      • I concur Christine. Spice up your daily salad with capers and you’ll be well on your way. However there is another brilliant star on the horizon that Japanese people have known for ages. Newly arrived in Canada, the haskap or honey berry has loganin, outsmarting even quercitin. The research is very new, but pharmaceutical companies are already ordering whatever juice is available to encapsulate it. Concentrated of course. Count on it being the talk for the next decennia

    • I do not react well to quercetin; I had finally stabilized my digestion on a personal paleo diet, then started taking Quercetin supplements during allergy season and my digestion was terrible again!

  9. If one wants to supplement with Quercetin, what is the recommended dosage? Empty stomach versus with food, etc.


  10. I start to understand now my problem could well be leaky gut, highly likely even. With this information I also understand now why I have these histamine issues. Last night I noticed once more I have uticaria factitia. I received histamine pills from the doctor, next to making me sleep better they don’t work at all. Thanks for the post!

    • Have you tried Histamine DAO supplements? I started taking toe before each meal and my life has changed as a result — very litter hyperbole here – Changed. My. Life! Xymogen is the brand I was recommended, but any quality gluten-free DAO enzyme supplement may be worth looking in to.

      • Clarrish – What type of symptoms were you experiencing? For how long before you experienced relief? Are you still doing well?

  11. I’m surprised that anyone would suggest that red wine could be healing with regard to mast cell granulation and high histamine. DAO, the enzyme that breaks down histamine, is rendered useless from red wine. So, it would be completely counter productive to ingest red wine when trying to gain more quercetin in the diet, in my opinion. Many people who have mast cell granulation or have high histamine issues also have very low DAO production. So, doing anything to further destroy DAO seems like a bad idea, in my opinion.

    • I would agree with this. Red wine was the first ‘food’ I had a problem with when I started becoming prone to mast cell degranulation.

    • I have high histamine issues and NOTHING makes me feel worse than red wine. Just sayin’

    • Some foods that give me the most problems: eggplant, wine (grapes), vinegar (grapes), licorice. I noticed most foods that bother me have seeds. Also tea is to be avoided on the high histamine list as well as many fruits/veggies. Healthy for some is not healthy for all.

      • I have to agree. Cutting red wine from my diet was the first time I saw a significant physical difference in my body (my intestinal inflammation is visible in terms of the severity of my psoriasis)

  12. Good article. Information about the sealing effect is intriguing. I have always considered apples helpful for my digestion. Anytime I am feeling a little ‘off’ in the tummy a few bites of an apple can usually settle things down.

  13. Is the quercitin content affected whether the vegetable is eaten cooked? Or is it best raw?

  14. Interesting write up, always looking for new info on healing my gut. I checked PubMed but couldn’t find any human data on quercetin. Are you aware of any?

  15. The Wahls Protocol suggests quercetin as an optional supplement. It is incorporated into the diet for the protocol by suggesting the intake of green tea, onions, and berries. For those with the book, see page 285.


  16. Wonderful piece Kelsey. I’m a wondering though what the effect of cooking (especially with water/steam) has on the presence of quercetin?

    I also recently learned that the mechanism for the effects of GMO’s is that they cause intestinal cell walls to shrink, thus causing ‘leaky gut’.

  17. Kelsey, thanks for this insightful blog. I’ve had digestive issues which I believe come from a leaky gut. The FODMAP diet has helped me. Both onions and apples are not FODMAP safe foods. Would Quercetin supplements be FODMAP compatible?

    • Karen, FODMAPs are types of carbohydrates found in these foods. Quercetin supplements typically would not contain any carbohydrates, so they should generally be safe for FODMAP-sensitive individuals (as long as there are no other ingredients you are sensitive to in the supplement).