The WHYs behind the Autoimmune Protocol: Nightshades

August 22, 2012 in Categories: by

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Tomatoes, potatoes, eggplants, sweet and hot peppers (but not black pepper), and chili-based spices (including paprika) all come from plants which are members of the nightshade family. Nightshades can be problematic for many people due to their lectin, saponin and/or capsaicin content. They tend to be even more problematic for those with autoimmune disease and of all the foods restricted in the autoimmune protocol, are probably the least likely to be successfully reintroduced, especially tomatoes and chilies.

There are over 2000 plant species in the nightshade family, the vast majority of which are inedible and many are highly poisonous (like deadly nightshade and jimsomweed). Tobacco is also a nightshade, and is known to cause heart, lung, and circulatory problems as well as cancer and other health problems (clearly some of this has to do with the other toxins in tobacco products derived from the processing). Of the edible species in the nightshade family, poisoning can actually occur with excessive consumption and it is possible that the low-level toxic properties of the nightshade vegetables contribute to a variety of health issues as they progress over time 1. So, let’s talk about two (okay, three) key compounds in nightshades that make them such a common food sensitivity and a problematic food for those with autoimmune disease.

Nightshades contain lectins. Actually, all plants (and even animals) contain some lectins, a class of sugar-binding proteins with many biological roles, including protecting plants (especially the seeds of the plant) against predation.Not all lectins are problematic (I have an entire post in the works explaining why the lectins in wheat can be such an issue but the lectins in blueberries aren’t). The lectins which we avoid in the paleo diet are the ones with the ability to increase intestinal permeability (see this post on how lectins do this). These are lectins which resist digestion (typically due to high proline content), are relatively heat-stable (so there are still sufficient quantities to cause an issue after cooking), and have the ability to strongly interact with proteins in the membrane of the cells that line the intestine (and some can even bind to receptors in those membranes and be transported intact across the intestinal barrier). There is huge variability the effect of different dietary lectins, from proinflammatory and promoting a leaky gut on one end of the spectrum to completely harmless and even potentially therapeutic on the other. Until a systematic analysis is performed of all plant lectins and their physiological effects, the foods advocated and restricted on a paleo diet really only represents our best guess based on what is known so far. So, what do we know about nightshade lectins? Tomato lectin is known to enter the blood stream relatively quickly in humans, which suggests that tomato lectin can contribute to the development of a leaky gut 2This information has led me to recommend that tomatoes should be eaten in moderation for most people. People with autoimmune disease are more likely have a leaky gut and have more challenges to healing a leaky gut once it has developed. For these sensitive individuals, tomato lectin should be avoided.

Nightshades contain saponins. The flowers, fruit, and foliage of the nightshade family contain a type of saponin called glycoalkaloids (e.g.the α-solanine and α-chaconine in potato, α-solanine in eggplant, and the α-tomatine in tomato) and contain steroidal drugs (e.g. the stimulating capsaicin in peppers, the tranquilizing nicotine in tobacco)3I explained in detail how saponins can contribute to a leaky gut in this post (also see reference 4). Very importantly for those with autoimmune conditions, saponins, such as α-tomatine, have adjuvant activity. An adjuvant is a chemical that stimulates and exaggerates an immune response. The glycoalkaloid α-tomatine is such a potent adjuvant that it is used in vaccines to ensure that the recipient develops immunity against the virus they are being inoculated against. This is critical in the discussion of autoimmune disease because dietary saponins are believed to rev up the immune response to proteins leaking out of the gut 5. When antibodies are formed against proteins (like gluten) that have amino acid sequences that look very similar to sequences of other normal proteins (like transglutaminase) in the human body, the chances of developing an antibody against one’s self increases. When this happens, the immune system attacks normal healthy proteins/cells in your own body and this is the development of autoimmunity. Beyond these actions of saponins, glycoalkaloids inhibit a key enzyme, acetyl cholinesterase, which is required for nerve impulse conduction. There is also evidence that diets high in potatoes, in particular, result in increased markers of inflammation (this could also be due to the carbohydrate load that potatoes provide and not an effect of the glycoalkaloids themselves). Glycoalkaloid poisoning can occur with excessive consumption of nightshade vegetables, and many researchers have hypothesized that the low level toxic exposure from more moderate consumption of nightshades can contribute to a variety of health conditions 1Another problematic substance is capsaicin, a steroidal stimulant found in chili peppers (it is one of the substances in peppers that give them heat). While a variety of health benefits have been attributed to capsaicin, it is also a potent irritant to a variety of tissues, including skin, eyes and mucous membranes. Very importantly, there is evidence that capsaicin can increase intestinal permeability 6.

Of all the foods restricted on the paleo diet autoimmune protocol, nightshades are the least likely to be reintroduced successfully. In fact, many people are sensitive to nightshades independent of illness or autoimmune issues.In my own experiences, two meals (on two consecutive days) containing a small amount of tomatoes nearly two months ago resulted in a massive lichen planus flare (it was also timed with some stressful life events, which I’m sure didn’t help). Two meals of tomatoes set me back months in my recovery. I am only in the last week or two starting to see some improvement to the new lesions that formed nearly overnight. While frustrating, I try and focus on the positive: I now know that tomatoes are not good for me. And avoiding them is worth it.

1 Childers N.F., and Margoles M.S. “An Apparent Relation of Nightshades (Solanaceae) to Arthritis” Journal of Neurological and Orthopedic Medical Surgery (1993) 12:227-231

2 Carreno-Gómez B et al. “Studies on the uptake of tomato lectin nanoparticles in everted gut sacs.” Int J Pharm. 1999 Jun 10;183(1):7-11.

3 Gee JM, et al “Effects of saponins and glycoalkaloids on the permeability and viability of mammalian intestinal cells and on the integrity of tissue preparations in vitro.” Toxicol In Vitro. 1996 Apr;10(2):117-28.

4 Francis G et al.“The biological action of saponins in animal systems: a review.” Br J Nutr. 2002 Dec;88(6):587-605.


6 Jensen-Jarolim E et al. “Hot spices influence permeability of human intestinal epithelial monolayers.” J Nutr. 1998 Mar;128(3):577-81.


Do you find that raw tomatoes or cherry tomatoes are worse than cooked ones? I believe that tomatoes are behind the one last major bit of inflammation that is still affecting me. My recent overindulgence in a bunch of fresh vine-ripened cherry tomatoes seems to have verified it for me. In my case it’s causing wrist pain and tendonitis. All my other inflammatory issues went away when I quit eating gluten and dairy which helped me to figure out that I have celiac disease. If I were waiting on my GI doc to diagnose it I’m sure I’d still be waiting. Thanks heavens for my family practice doc; she was much more open minded than my GI.

Hi Anon!
I am a lot more sensitive to fresh tomatoes then things like tomato paste. Sometimes I can’t have anything that maybe once sat next to a tomato (overacting, maybe ^_^), but I can usually tolerate a little tomato paste every now and then.

Thank you for the uncomplicated explanation for how these affect those of us with autoimmune disease. I’m so sorry you are only now seeing some improvement in your symptoms after your consumption of tomatoes, but I’m impressed by your positive outlook! It’s hard when you are suffering to remember what the experience taught you, but I have found it to be the best outlook. I’m looking forward to listening to your recent podcast on autoimmune as well 🙂 PS I bought Practical Paleo, and you were right. It’s an amazing resource!!

Thank you for posting this. I have known that I have an auto immune disease for a year now and have done a whole30, and changed to a mostly strict paleo diet but have not just made the jump to the AIP… You finally put things in perspective for me – its not worth the set back!! Thanks Paleo Mom 🙂

Good information! I was doing pretty well on a health program treating immune issues, until one day I had terrible stomach pain with every meal. I was already on a very clean diet to heal leaky gut, so my doc was baffled. After a while, I realized I had recently started three new supplements and all three had cayenne! Stopped the supplements, no more pain. That’s when I started looking at nightshades as a problem for me. Or at least cayenne!

I once tried a cleanse that included cayenne in pill form. I had such bad stomach pain. It was so intense the muscles in my back literally spasmed. I quit after three days. I am not sure I could ban tomatoes from my life though. I love, love, love tomatoes.

I also wonder about sweet peppers. I’m sure that I’m reacting to raw tomatoes but I seem to do okay with sweet peppers. I also do not eat white potatoes as they always cause digestive problems, but it’s really more like a gluten cross reaction. Can you react to one nightshade and be fine with another??

It’s very individual. Many people find that they can eat nightshades as long as they steer clear of tomatoes and/or hot peppers. So, yes, you can react to one nightshade an not another. And the substances in tomatoes seem to be the most problematic for people.

Wow! I have done a lot of research on things to help my autoimmune disease and this is the first i have heard of avoiding nightshades. I had suspected for a while now that I suffered from a sensitivity to them so i had been avoiding the delicious homegrown tomatoes from my garden but last night I had some homemade spaghetti sauce on zucchini noodles. Today one of my hands is swollen and terrbily sore. I am going to lay off of the tomatoes (and other nightshades) starting today.
Thank you!

I was diagnosed with Celiac 3 years ago. I am confident that I’ve eliminated all gluten; my home is entirely gluten free; and I never eat out. However, I continue to test positive. Is it possible nightshade consumption is causing this?

It is possible that dietary saponins from nightshades, legumes (like soy), and pseudograins (like quinoa) are stimulating your immune system to continue to produce antibodies. The other possibility is some very small gluten exposure in something that you are unaware contains gluten.

Since this is so individual for food sensitivities, why spend a life time trying to eliminate foods. Test, don’t guess! Food allergy testing (IgG) or better yet food sensitivity testing to inflammatory foods with the MRT test? I tried rotating, eliminating, and re-introducing foods for 25 years. Yes, some foods were easy to detect what was causing issues, but others not so much or combo of foods that were causing inflammation. I tested with both tests, but was astonished with the MRT as I was reacting to Paleo foods like lettuce and broccoli!! Of course the nightshades and lectins were an issue too but it went much further than just those foods. Test…don’t guess!!

I eliminated night shades from my diet several years ago. I have been pain free up until a few months ago when
I started taking ashwagandha. I began having terrible pain in my neck and shoulder. After doing research on the
internet and finding out that ashwagandha was a nightshade, I stopped taking it as of Oct. 20, 2012. I still am in
pain and was wondering how long it will take for everything to clear out. I am also wondering if other supplements
could be culprits too. None of my supplements have cayenne pepper in them. I quit taking vitamin C, because I
don’t know what the ascorbic acid is derived from. Do you have any idea what n-acetyl cysteine and alpha lipoic
acid are derived from? I just found your website and greatly appreciate it.

Quite a long time, depending on your sleep, stress levels and diet. I had tomatoes in July and am still struggling to control the inflammation. Ascorbic acid is made by fermenting glucose (I think the glucose is typically isolated from sugar cane or corn). Amino acids are typically manufactured by a series of ferments with different microorganisms so the starting ingredients are similar, sugar and enzymes or bacteria. I don’t think those supplements would be the problem.

I have Hashimoto’s and I seem to tolerate tomatoes fine. I only have an issue with them if I eat them too frequently, like in the summer when the garden is full of them. But I can no longer eat eggplants. I gave up nightshades for a couple of years but tried reintroducing them and eggplant made me ill. Is that possible to be ok with one nightshade and not the other?

This is interesting! I found out I was pregnant in May 2011 and shortly thereafter took a trip to Italy. I’d never been so sick in my life. I had sadly just developed a droopy eyelid that I attribute to Myesthenia Gravis and a leaky gut (with wheat, egg and dairy allergy), but after eating pasta, pizza, tomotoes, gelato etc for two weeks, I thought I was going to die from the nausea and intestinal pain. We thought it might be morning sickness but it quickly resolved when I came back to the states and quit the wheat. I hadn’t learned about my allergies yet but I also developed an aversion to eggs that summer. I am going to do the Paleo AIP as the droopy eyelid persists.
My 3 year old son loves all nightshades (especially peppers and tomatoes), but I think it might be wise to stop buying them for his sake.

I am taking Plaquenil (hydroxychloroquine) for my autoimmunity problems. I feel that this drug is impairing my gut, could it be a triggering factor, like nightshades or AINS are?

It’s a double edged sword, similar to corticosteroids or other DMARDs. It is likely perpetuating a leaky gut but it is also directly modulating your immune system. You can’t fully heal your gut while you’re on it, but going off will likely cause a flare. I’m not sure if you can do this, but you might ask your doctor is you can gradually wean off of it. And I wouldn’t even attempt to wean off of it until you’ve been on the autoimmune protocol for a few weeks and feel like you’ve got that down (and the being super strict while you wean off and for the month or so afterward will be very important). Transitioning off the drugs is very tricky and should definitely be done under doctor’s supervision.

Thank you so much for this post. My husband has a skin issue that erupted around his eyes 7 months ago. We tried so many things, and finally have treated him for Candidiasis. But we now know that the skin issue is also related to tomatoes, so we are searching out information about healing a leaky gut, the body’s reaction to nightshades and how we can heal his system. I just wanted to send you a big thank you for the information you are sharing and a huge thumbs up for the work you are doing, it will be so helpful in our journey toward health!

Wow, that might explain the massive headaches I got when I tried ashwagandha. I had no idea. I do know I can’t tolerate tomatoes, eggplant or hot peppers, so this looks like another one.

Wow! My mind is boggled! Just as I think I have made positives changes, I learn even more! I have first hand experience with the tomatoes. I have near finished a massive inflammation flair and extreme fatigue from about a weeks worth of new recipes all having some sort of tomato product. Ugh!

Question: what do you use as a supplement for tomato paste, sauce, etc in soups, etc?

Another question: I am taking ashwagandha coupled with a few more items to boost my low thyroid function and extreme fatigue. Any recommendations for another product?

Well, I would definitely avoid ashwagandha, but I’m not sure what a good alternative would be other than to make sure you’re taking selenium and magnesium, getting enough iodine and sleeping as much as possible.

For soups, I mostly just live without. Pumpkin puree, coconut cream, avocado, and red wine do make appearances in my soups, and I guess those are the replacements.

Did you check tyrosine (l-tyrosine) ?

I have some dried herbs bought long ago, mostly powdered and I powder those that aren’t. The list includes ashwagandha. For morning use I have:

1)Muira Puama
2)Nettle Root
3)Club Moss
12)Horse Chestnut
13)Butcher’s Broom

For evening use I have:

6)Gotu Kola
12)White Peony Root
13)Horse Chestnut
14)Butcher’s Broom

And I have a mix for morning and a mix for evening with ashwagandha that may last 3-5 months I think. I know nightshades cause me joint pain but I do not feel pain from using that small amount of ashwagandha I get from the evening mix about as much as I can heap on a teaspoon. I think this herb mix is beneficial to me rather than harmful so I’ll go on using it till it ends and next time I’ll do it without ashwagandha, and later I may try ashwagandha or not.

If I’m wrong about something it will be nice to know.

I’m not super familiar with all of these… some are immune stimulators, some are very beneficial, some I just don’t know… but if you think it’s helping you, you should continue.

The juice from fermented / cultured red cabbage has some acid and colour to help as a tomato sub. Pureed carrot, beet, parsnip can do a tomato paste sub.

Dr.Loren Cordain says here:
”Besides grains, grain leaves and alfalfa sprouts, other elements in the typical western diet can also increase intestinal permeability including all legumes (peanuts are legumes as are all beans), potatoes, tomatoes and other and nightshade plants. In my most recent book, The Paleo Answer, I have outlined the scientific evidence with hundreds of citations, showing how these foods increase intestinal permeability and act as immunological adjuvants to impair normal immune system functioning. Green tomatoes, cherry tomatoes and yellow tomatoes contain high concentrations of the compound alpha tomatine which increases intestinal permeability. Ripe red tomatoes are almost devoid of this compound, so unless you have an autoimmune disease you dont have to forgo this delicious food.”
Do you agree with him about the types of tomatoes which are bad?
Thank you.

Do, you mean for people with autoimmune disease? Unfortunately, alpha-tomatine is not the only problematic substance in tomatoes. They also contain lycopersicon esculentum agglutinin (more colloquially called tomato lectin) which also increases intestinal permeability and acts as an adjuvant and is present in the ripe fruit.

I can’t seem to find out if sweet potatoes are allowed on the AI Paleo….? Also, are there recipes on the other pages of your website that are also AI frindly? or are all the AI recipes listed here? I was hoping to get more… (so hungry)… just started 2 days ago. 🙁

After eating paleo (probably 80& most of the time, with a few periods of screw-it-all-I’m-going-to-eat-whatever thrown in there) for the past 3 years or so, I’ve recently been much more strict with it, and finding a lot of improvement in general health. However, I’ve not been able to completely get rid of my significant osteoarthritis symptoms (diagnosed in both knees, and I’m only 32), nor my occasional migraines (though these are much improved in frequency), nor my heartburn/acid reflux (which has actually gotten more severe). I’d never looked into the AIP and only today found your website with this information. Your explanations make COMPLETE sense though. Although I’m a little horrified at the thought of giving up almonds (especially almond butter!), eggs, and especially coffee(!!!!), I think I’m going to have to try it! So basically this is just a comment to thank you for putting this together and being so descriptive and clear in your explanations!

My husband does not eat paelo but, has had inflammation and painful irritation associated with bowel movements for years. This conditions worsens extremely if he eats red bell peppers. Do you think he may have a sensitivity just to nightshades? He is reluctant to go completely paleo and cut out grains, legumes, dairy AND nightshades. Do you have a suggestion where to start? Thank you! (p.s. his doctors told him to eat more fiber… of course this didn’t help)

Sounds like my husband. He now knows he can’t eat capsicum (bell peppers) and I have persuaded him to reduce his grain intake heavily, but can’t get him to go all the way!

I just want to say thanks so much for this wealth of information. I am having many issues and am in the midst of a multitude of testing. One thing we are fairly sure of, is that I do have an autoimmune disorder of some sort.Last year, I did a juice cleanse. While doing it, I was making a lot of juices using tomato as my base. I felt like my joints were going to explode, I was in soooo much pain! Of course, I thought that it was because my body was releasing toxins. Once I switched over to fruit juices (because I couldn’t take anymore of the vegetable juices), my symptoms started to subside, and I was so proud of the fact that I had worked through the detox. When I started eating solids again, I was living off of whole grains, low fat proteins, raw veggies (a lot of tomatoes, peppers, etc.), and fruit. I could not for the life of me figure out WHY I was just feeling worse and worse. This week I took my children to the fair, and the last 2 days I’ve been barely able to walk because of it. My entire body is in pain, my muscles are fatigued, my joints are inflamed. I did nothing but walk around the fair. That’s when I started researching dietary ways to fight off autoimmune disorders. This completely makes sense with all the other intestinal issues I have had as well. I have had many surgeries for intestinal issues and pelvic abscesses that rotted out several feet of my intestines. The drs seemed puzzled by all of these issues. I’m thinking we probably have our answers right here. I hope we have the answers because I can do without all of these things if it means I will feel better!

I definitely think you are in the right place! And my book should be very helpful in opening up a dialogue with your doctor about the role of diet changes in autoimmune disease. Autoimmune diseases can be very difficult to diagnose, but no matter which disease you have, my recommendations are the same. Good luck!

I purchased The Autoimmune Paleo Cookbook. What is the name of your book? Sorry I’m still learning to navigate the site. It has already been a wealth of info to me!

I have a question about ashwagandha. I am currently following the auto immune protocol because I have some risk factors and early signs. However, I have also been take ashwagandha for many years now. I have cut out all other nightshades, but I am reluctant to give up ashwagandha. This herb is actually supposed to help the immune system! It has a very long history of usage as a remedy for many ailments related to this. I won’t pretend to know exact details, but I have read that there are scientific studies showing it’s immune boosting effects.

Do you think it’s one of those things that should be avoided during flare ups, but is ok to take when your condition is reasonably stable? It has been so helpful for me for dealing with stress and fatigue.

I recommend avoiding everything that “boosts” the immune system if you have autoimmune disease. Autoimmune disease is in part caused by an overactive immune system, so boosting the immune system even further can be a big problem. Instead, I recommend things that are immune regulators, which support the immune system balancing itself (these are things like zinc, vitamin A & D).

That being said, many people who can’t tolerate nightshades seem to do okay with ashwagandha. So, if you feel like it’s working for you, then you should continue taking it.

Hello, I am new to your website and I am so excited I found it. I have Hashimoto and Psoriasis and I am looking forward to reading your book. I am reading all the information that you provide online and there is just something that I can’t grasp. The autoimmune protocol advise to eliminate gluten, dairy, eggs, nuts,nightshades,…. Gluten seems to be banned forever while the rest can be reintroduced. What I don’t understand is this…if these foods don’t seem to cause me problems when I eat them, does that mean I can eat them? For example, eating potato doesn’t seem to cause any problem. How can I tell if I can eat them or if behind the scene they are actually causing inflammation or increasing gut permeability. Actually I have the same issue with gluten. It doesn’t seem to create any symptoms. Basically I would like to understand how can I tell if a certain food is causing a problem or not, if I don’t have any obvious symptoms. Thank you so much.

Part of the autoimmune protocol is increasing nutrient density and another huge part of it is eliminating all foods that either stimulate the immune system or cause increased intestinal permeability (leaky gut). These things are chronic, so it can be tough to tell without doing a full elimination diet whether or not they are a problem for you. I recommend eliminating all of these foods for at least 4-6 weeks (until your psoriasis is gone would be best) and then reintroduce. That should make is abundantly clear whether or not these foods are contributing or if they’re okay for you.

You are my hero! I went to a nutritionist a couple of weeks ago to get advice (I was told by my endo that she specializes in nutrition for thyroid conditions like Hashimoto) and she could not answer any of the probing questions I was asking. As someone trained in research (albeit, social science) I am constantly looking for a deeper dive to understand the CAUSES and the reasons why foods should be avoided. Thank you for the truly scientific explanation!

I LOVE potatoes..but 6 hours after I eat them or too much potatoe starch (think baking)..I get a migraine…It really sucks because I can’t have gluten, wheat, diary and corn…along with alot of fruit and some veggie 🙁

Paul Jaminet (The Perfect Health Diet) claims that following his diet / supplement protocol should help heal a leaky gut (among other things) and should, for many / most people allow the re-introduction of some foods (sensitivities, not allergies).

I seriously can’t wait for your book! The past few weeks I’ve been diving into the research around autoimmune diseases & diet because of a few clients with autoimmune diseases. Your site is one of the only resources I guide clients to because I know you’ve read the actual research studies (vs a blogpost) and know the science, so thank you! On another note, I need to find a way to convince my boyfriend to test out going nightshade free for a month or so – he always complains about knee and back pain…and his favorite foods include tomatoes, peppers, potatoes, and the spiciest spices ever.

It is so heartening to see someone with lichen planus who’s dealt with it so bravely. The medical community doesn’t seem to care much for it since its not a ‘serious’ condition and I’ve spent the last 8 months trying my best to find info on it. My dermatologist gave me steroids and said we’d stay in touch if it flared up again. That didn’t sound convincing, so I’ve been going to an Ayurveda practitioner. I’ve stayed away from alcohol, coffee and spices in my diet for the past one month and apply a mix of sandalwood, manjista powder and orange peel powder on the lesions. They seem to be somewhat under control but new lesions continue to pop up once in awhile. I’m going to get an MRT test done soon to eliminate potentially harmful foods.

How did you deal with the lesions? I suppose its going to be years before they become unnoticeable :/

When I’m stressed and not getting enough sleep, I still get new ones even when my diet is super clean. I use a moisturizer made with grass-fed tallow and olive oil, which helps. If it’s really itchy/painful, I use a topical arnica montana gel. I haven’t resorted to topical steroids in about 2 years.

I am from Indian decent. Tomatoes are staple for me. All the curries and cooking is around that. You recommend to no reintroduce night shades after AIP for 30 days. I have hashimotos and I am on AIP for 6 weeks and will start re-introducing foods.
If tomatoes are totally cooked, even then its a problematic.

Thanks and love your blog.

WOW. I know that wheat causes my body to hurt. If I eat anything with wheat, I pay for it for about 3-5 days. I’m not sure about these other things. I don’t eat a lot of dairy, but I do cook with a lot of peppers and some tomato. I guess I’m just not in tune with my body, or I’m just so used to being in pain that I don’t really notice it when it occurs. I have dealt with this all over body pain for about 7 years now. I say it’s Fibro, as I have all of the symptoms, but I was referred to a rheumatologist who says arthritis. His dx explanation is that the pain in my muscles is caused by strain on the muscles by compensation for joint pain. This after he checked the tender spots for fibro and I had pain in all of them, plus 4 others. I say he’s crazy because I have no joint pain. I think he’s one of those that think fibro is all in your head. So, anyway, I read a book on wheat and learned how it causes an inflammatory response, so I took it out and it helps a great deal. HOWEVER, I am not completely pain free, though most days I am really good. I suspect, after reading this, that it’s the nightshades. I made chili last night and am having some low level pain this morning. I guess I will have to start with taking out the peppers for a bit and pay more attention to how I’m feeling. I am also planning to do a candidiasis treatment this month to see if that helps. Then, sadly, I may have to say farewell to those garden fresh tomatoes.We keep a garden and grow a lot of tomatoes, and honestly, that is the best part of the year! There’s nothing like a big juicy tomato running down your chin!

I don’t have any kind of stomach issues; no IBS symptoms, no regurgitation or indigestion, I’m not usually gassy and am regular. Do you think there may still be some leaky gut issues occurring?

There may be or gut dysbiosis, which just means you don’t have the right variety of the right microorganisms in the right locations in your gut. There haven’t been studies investigating leaky gut and gut dysbiosis in all immune and autoimmune diseases, but it’s been there in every disease in which they’ve looked.

I’ll do some studying up on that. THANKS! I guess that would be easy enough to address with the use of probiotics.

I was on Eat Right For Your Type and it said that for a type O blood type fresh tomatoes and any other tomatoe goes nill in a Type O system an I believe it as tomatoes do not bother me at all. Also red potatoes do not seem to bother me either but nothing to do with Eat Right For Your Type. I am watching your site as my body seems to be changing again and will see if this Palio is any good or stay as a Gluten Free person. Thank you for all the info it is real interesting.


[…] •    Joint pain •    Stiffness upon waking, or stiffness after sitting for longs periods of time •    Muscle pain and tension •    Muscle tremors •    Sensitivity to weather changes •    Poor healing •    Insomnia •    Skin rashes •    Heartburn •    Stomach discomfort •    Digestive difficulties •    Headaches •    Mood swings •    Depression   How Do I Learn If I’m Sensitive?   The only real way to know if you have a sensitivity to Night Shades is to ELIMINATE them from your diet.  When eliminating anything from your diet you should give at least 30 days. WITHOUT CHEATING. Then, REINTRODUCE them into your diet as a test:  Introduce only one at a time for at least 3 days. Stop eating them, for 2 days and monitor your symptoms for a least 72 hours.  Now during this 30 days and reintroduction phase you want to LISTEN to the body responses. Did you notice any improvement during the 30 days?  Did you have a negative/positive reaction when you ate them again?   Were there any noticeable changes in your life, refer to the list above.   What are Nightshades?   Night Shades are not harmful to everyone, but they contain enough toxins to cause inflammation in some people, particularly those with leaky gut or autoimmune disease. There are as many as 80 different type of autoimmune diseases affecting millions of people, including myself.  If you have any inflammation in your body, perhaps seeing if eliminating “Night Shades” will help decrease it.   Often, we don’t realize just how much, until we stop eating them.    Here’s the list:   •    Tomatoes •    Tomatillos •    Potatoes •    Eggplants •    Peppers (bell peppers, banana peppers, chili peppers, etc.) •    Pimentos •    Goji berries •    Ground cherries •    Ashwagandha (an ayurvedic herb) •    Tobacco •    And red pepper seasonings (paprika, chili powder, cayenne, curry, etc.) •    Read labels: terms like “spices” and “natural flavors” often contain the above seasonings. •    Similar sounding foods that are not nightshades: Sweet Potatoes and Peppercorns (black, white and pink)   some useful resources […]

In a March 5, 2014 post, the book Eat Right For Your Type was mentioned. When I read it, I had already stopped eating nightshades (except for the ones I didn’t know about like ashwagandha. I have type A blood and found it quite interesting that every food that is a nightshade was listed as an “AVOID”. I would love to know what percentage of those who have discovered themselves to be nightshade intolerant are type A. I know there are many exceptions – especially those who have autoimmune diseases – but….. just wondering! Recently I found out that a “healthy” turkey bacon I was eating was a problem. Watch out for foods that list “spices” as one of the ingredients. One of the spices in the bacon was paprika.

The blood type diet is not supported in the scientific literature, and nightshade intolerance is common among all autoimmune patients regardless of blood type. – Christina, Sarah’s assistant

I have a autoimmune problem and as a lot of people some problems with nightshades. For me the eggplant totally the bell peppers i can take a certain ammount and than stop eating them for a while. With tomatoes it is funny, i can eat one species of tomato with no problem while the other one after eating a small bit i will leave them allone. Potatoes are no problem if i do not eat them every day. But my body will NOT accept sweet potatoes it makes me trow up and feeling sick. Is there something else i can put in place of the sweet potatoes

Hi Sarah! I am soo thankful for your book and other resources. I have restarted the auto immune elimination diet and am trying to be strict to see better results with my Hidradenitis suppurativa. A have a couple questions:

-Fermented foods…is sauerkraut, komboocha, and Kimchi allowed during elimination phase?
– Fruits- What fruits are to be eliminated in elimination? I am trying to limit my fruit sugar/intake. Think I may need to take berries out?
-Gut and Body flora- Since I am trying to heal sores from inside out should I avoid swim pools, lake water (bad bacteria), bleach baths, and all topical creams. I use coconut oil and sometimes manuka honey on skin but don’t want them to heal faster without disrupting the good bacteria. The same with the water…may provide temporary good effects for skin with the bleach but will it disrupt the good bacteria?
-Is yucca bad or a nightshade? and tapioca products? Are those not supposed to be used?
– I haven’t made coconut yogurt yet but the Soso brand I buy contains Carrageenan. Should I avoid this product as well?

Thank you sooo much! I have been doing everything else recommended and I’m really trying to focus in so that I see progress in my healing and discover triggers.

Fermented foods, fruit, and yucca/tapioca are fine. Carrageenan is not. I would avoid using any harsh chemicals on your skin (or even in your home), but swimming and moisturizers like coconut oil are fine. – Christina, Sarah’s assistant

Thank You for writing this – I found the article helpful and many of the comments interesting. I just wanted to leave a comment because I noticed the statements that tomatoes and potatoes seem to be the most problematic – if you mean for people with autoimmune problems, then maybe that is why it is different for me, because I have been tested and I do not have an autoimmune problem. I have Osteoarthritis and injuries – with resulting pain. But I have been eating a lot of peppers – both Hot and Sweet – in my cooking for years now on a daily basis – also using Tapatio Hot Sauce and Cayenne and Paprika in my cooking. I had rarely been eating tomatoes and potatoes, though. But I decided to try the nightshade elimination — and it helped immediately – I mean to some extent the same day and it has continued to help, though it is only a few days so far. When out walking, I am doing much better. I guess you could say I was in the group of people who were overdoing it on the nightshade peppers and related spices – but it looks to me like I do have a nightshade sensitivity. I am going to continue eliminating all nightshade foods for a number of weeks and see how it all improves – and what if any I can re-introduce without having such pain. I’m a little amazed at all the info and testimonial statements online on this issue – and it is interesting to see what works for different people!

Is there a preparation method or food/supplement that can be taken with a nightshade (tomato, specifically) to counteract or minimize its effect on intestinal permeability and immune response?

[…] The WHYs behind the Autoimmune Protocol: Nightshades. Tomatoes, potatoes, eggplants, sweet and hot peppers (but not black pepper), and chili-based spices (including paprika) all come from plants which are members of the nightshade family. […]

I have been dealing with inflammation-based pain and stiffness in my neck and shoulders for about a year and a half and have recently been diagnosed with early-stage Hashimoto’s. I did an elimination diet for food sensitivities during the winter and it did wonders to improve the pain/inflammation. I found that I am extremely sensitive to all peppers, among other things, so I had to quit the Garden of Life multivitamin I was taking (contains bell pepper juice). The MegaFood multi was recommended to me, but it contains ashwagandha root, which I recently learned is also a nightshade. I am planning on trying the AIP to see if I can get the autoimmune reaction stopped before it damages my thyroid. Is there a good nightshade-free multivitamin you would recommend?

i am desperately looking for a good, nightshade-free women’s multivitamin as well, so anyone who knows of them, please let us know!

I was just diagnosed with thyroid disease, hashimotos/thyroiditis. Do you suggest having an allergy test done? I consume lentils still and in between meals almonds or pistachios. I had tomatoes in an avacado salad. I honestly don’t know the first thing about immune protocol. I am underweight and cutting all this out makes me feel hungry already! Any recommendations how to deal
With this? Not to mention, although I do have support, many people react badly to a thin girl taking everything out of her diet!

Sarah recommends following the autoimmune protocol for at least 30-90 days before adding foods back in, regardless of whether or not those foods tested positive for allergies/sensitivities (because false positives are fairly common). – Christina, Sarah’s assistant

While IgG allergy tests can be very helpful, and I would recommend getting one (that tests for total IgG – like the one from The Great Plains Laboratory), they will not reveal if you have a lectin-based problem with nightshades, as I do. Nightshades don’t even register on my IgG test, because it’s not an antibody issue with the nightshades, but believe me…I have a serious problem with nightshades.

I have always believed sweet potato, Japanese sweet potato or yams were allowed on the AIP. Sarah commented that a sweet potato was a “cheat.” In this post she only referred to “potato.” I’m confussed. What is okay for an autoimmune patient that is trying follow the complete AIP?

Would you mind pointing me in the direction of a few peer-reviewed journal article references that are more recent? The articles referenced are from 1993 – 2002. Many thanks.

Sweet potatoes are not nightshades. They are in a different botanical family. All other potatoes, like russet, red, yukon etc. are nightshades.

Would drinking tea that contains some seeds/nightshades still be harmful? I love chai tea and the blend I have contains cardamom pods. Thank you!

[…] Back to the WHY: “Nightshades can be problematic for many people due to their lectin, saponin and/or capsaicin content.”  The lectins, saponin and capsaicin can cause increase of intestinal permeability, can contribute to leaky gut and so much more. To read a more in depth detail of how the nightshades can cause harm to our insides, click here. […]

[…] Back to the WHY: “Nightshades can be problematic for many people due to their lectin, saponin and/or capsaicin content.”  The lectins, saponin and capsaicin can cause increase of intestinal permeability, can contribute to leaky gut and so much more. To read a more in depth detail of how the nightshades can cause harm to our insides, click here. […]

I have had chronic heartburn since I was in Kindergarten. I probably have myriad disorders and permanent issues as a result; I keep Tums and Ranitidine nearby daily because my heartburn is unpredictable and insufferable, such that I have to induce burping just to clear bursts of acid burn in my stomach frequently throughout the day.

Over the years, I have learned–though had an impossible time ridding myself of these things–that cereal grains, super high fat foods (though usually in conjunction with other culprits on the list, therefore making the determination if I have a gall bladder issue difficult to assess), tomatoes, sugary foods all aggravate my heartburn.

It’s so bad that I can have intense bile proliferation that regurgitates through my throat just from sipping on water–a condition that is new to me later in life. I always felt these issues after eating tomato-based pasta sauces, salsas, conventional cheeses (read: cheddar/American over Parmesan), chocolate milk, pasta, rice…

I got it bad. But now I am 34, and I suffer ALL THE TIME to the point that I figure I am screwed. I figure I am going to die from the wear-and-tear that my bile mechanics have waged against me over the years (even more unfair because a lot of my childhood and adult indigestion I have linked to stress).

But when I cut high fats, wheats, sugars, tomatoes out of my diet, I suffer less–if at all. What you say makes sense. However… I am an experience-based person. I want the indulgences and none of the penalties. Life is but once, and the least I can do is enjoy a steaming bowl of Chicken Gypsy Style or related to comfort me.

How do you replace tomatoes, grains, and related in your diet when these are the only foods you’ve known and they bring an immediate comfort, even if they also bring the sulfur and brimstone promised in the Bible?

If there is a Hell, I can only hope that my inflamed-bowel existence on earth has served as some sort of penance over the years. God knows I’ve suffered enough.

Hi Joel,
Like you, I suffer from heartburn and other digestion-related issues-which is what brought me to the post about nightshades. I used to think like you, too, about the joys of certain foods. Then one day I started trying different recipes with foods way outside my comfort zone. And I was AMAZED at the flavors and textures and how good some (although not all) of these are. It now feels like a win-win to not be woken out of a sound sleep by a run of acid bile up my throat and to have loads of new go-to choices. I started at because of the issues with bile and liver and now enjoy the AIP info at Paleomom and fascinating insights at bulletproof nutrition.

Your site is amazing and so packed with good info and easy to understand.
I would like to know if you think there is a connection between mercury poisoning from amalgam and the autoimmune leaky gut syndrome. such that the mercury is causing problems in the gut leading to all the rest.
thanks, hope you can reply to my email.

my daughter who is now 22 years old, suffers from asthma and Excema. She has had Excema since she was about 7 months old. She would get rashes all over her tummy, back and in creases of elbows and knees. Sometimes it would get so bad it would bleed. Today it’s not as bad, but she still has break outs and is so itchy for days and nothing seems to work. She has tried to eliminate eggs and milk for two weeks at a time. Do you think night shades could be the culprit? She has been to many doctors and the only thing they recommend are steroids and drugs, so frustrating!

So I have been having issues after eating these foods, but mine are more in the realm of anxiety, and a fuzzy feeling head. Barbecue sauce, and other red sauces just mess up my mind so much I want to hide in the corner for two days. I am actually developing a fear of eating for I just did not know what was causing it. This actually looks like it could be a good explanation, yet I do not see anyone having the issues I have from it.

I was wondering if it was possible to eat white sushi rice in the AIP diet. I have Hashimoto hypothyroidism and I’m a college student. I’m on a budget of “what ever my parents give me” + minimum wage. I used to eat white rice everyday because it is cheap and I have had no problems. However I noticed that since I have started college, every year there would be a period (one warmer month out of the year) that I would suffer adrenal fatigue. Last week my hair started to fall out ALOT and I scrambled the internet and came across the AIP diet. I have read articles that argue for rice and others that argue against it. I would like your advice on this topic. (I also am going to see an Doc too >.< ) Any advice much appreciated!!!

I cannot comment specifically as to rice, but just the other day I read an article about elimination diets, and it said that we should not eat the same item for more than 4 days in a row. Even a “safe” item eaten every day can start to build up unhealthy levels of a supposedly healthy vitamin or mineral. You might just need to take a break from rice.

[…] A diabetic may wish to reduce the number of tomatoes as shown in the analysis below which reduces the net carbs to a much more ideal 12g per 500 calorie serving.    With the reduction in tomatoes we get a small drop in the nutrient score from 80 to 73, although the amino acid score increases from 125 to 129.  Tomatoes can also be something to watch out for if you have autoimmune issues. […]

Hi, I have been on the AIP protocol for about 6 weeks now with my 4 year daughter who was diagnosed with Lichen Sclerosus. 6 months ago, she broke out in hives after eating a bag of potato chips. And yesterday someone gave her mashed potatoes! so she had nightshades and milk, maybe even gluten. She has swollen lymph nodes in her neck now. (No other symptoms of illness.) Can this be a nightshade reaction?

Hi, I’m 56, diagnosed with RA at 18. Been Paleo lifestyle for 6 years. Have been in “remission” since then. Had a hip replacement 3 years ago. I’ve been in a flair for about 3 months and need to get it under control. I have 2 Aleeve daily. Seemed to be ok through very stressful last 3 years, but recently started divorce proceedings . Is it possible my body protected me through the 3 years and then finally gave in? Will you please offer me details on what to do immediately, AIP, and supplements, to end this ASAP. I started Whole30 Oct 1. Thank you so much!

I just discovered that Yerba Mate’s a no-no. I’ve been drinking it with no ill effects, and just read that it’s full of saponins. Big bummer, I had said goodbye to coffee and was watching my oxalate intake, so tea had to go as well.

Does maca fall into this category? I had been using it and love it for all its superfood qualities and did not notice any ill effect but stopped it because I read the plant is similar to potatoes. Is it a nightshade, or does it contain any of the similar properties?? I would like to introduce it back if ok…

I need to begin a low vitamin d diet as I am starting The Marshall Protocol for sarcoidosis. Is the AIP diet suitable for that? I see some of the restricted foods are the same as on the MP but I’m not sure if this is the same type of diet.

I have a question for the Paleomom or her assistant. I do sincerely hope I get an answer 🙂 that would be great.

Do you know if an IgG test is reliable? I have developed a persistent case of Alopecia Areata when I moved from Europe to Hong Kong (the food is completely different here). However, IgG test shows no sensitivities at all.
I am willing to start the autoimmune diet, but I wonder if it is helpful if the IgG test doesn’t show anything.

I have recently been thought to have an autoimmune issue which has caused a flare in acne and boils on my body. When I changed my diet to take out all sugar, processed foods, nightshades, gluten, and taking curcumminoids, along with a nice hot bath several times a week and antibacterial soaps, my skin clears, I have less GI problems, and my overall mental health as well seems more stable. I have not stuck with that diet recently and all of my symptoms have returned. Additionally, I have noticed a decrease in memory ability and my language has suffered recently as well-quite noticeably in verbal expression. I had done some online research of acetyl cholinesterase awhile back in relation to the development of Alzheimer’s, so this post is very relevant to me, especially with a familial history of Alzheimer’s. Food for thought….thanks for the info. I’m currently gaining strength to get back on the diet; the boils alone are so painful and not worth eating certain foods. Initially, my autoimmune response, I concluded was from taking antibiotics for several years, contributing to leaky gut which has now caused an autoimmune response. I’m tempted to go back to the antibiotics because it takes a few weeks to get my body back in good health after eating badly for a few days, but I know it’s not the true answer and will only subside my symptoms and in turn, potentially make my leaky gut worse in the long run.

I’m so sorry that you’re having such awful symptoms, but that’s pretty incredible that you’ve been able to find relief through your dietary changes, as well as the hot baths. I’m glad you found the post helpful. If you do decide that the antibiotics have become necessary, Sarah has a great post on recovering from anitbiotics. -Kiersten

When you say that tobacco causes “heart, lung and circulatory problems as well as cancer” are you talking about eating it?
About the nightshades… I LOVE spicy foods. Red, yellow, orange peppers, jalapeños, etc. Potatoes are like their own food group in my mind. What are the chances that if I enjoy eating them so much (and I don’t really enjoy eating at all) that they are bad for me? I have no noticible reaction.

It is impossible to say whether nightshades are bad for you personally. However, if you have an autoimmune condition or joint pain, it may be worth removing them from your diet for at least 30 days and then retesting them. Sometimes we don’t notice that we are reacting to something until we remove it and add it back in. -Kiersten

My son is three and a half years old and has autism. Recently we took gluten and dairy out of our son’s diet but I was shocked to discover that nightshades are as bad for you. My son has a leaky gut and digestion problems as we can tell by his nappy. My son is a fussy eater but he wasn’t to begin with. I’ am aware that fussy eating due to autism is mostly down to sensory and reflux problems that begins early on. He will only eat his lunch/dinner if it has tomato pasta sauce on it. The brand he likes only has 6% tomato puree and 14% tomatoes, then herbs and sugar etc. I thought that the sugar would be bad for him but now because of your posts I can see that it is the tomato that is the problem. Do you think that eating this amount of tomato for about 2 odd years could be the reasons to my son’s problems and any ideas how I can replace the tomato taste he likes but with a heathier alternative? He has reflux problems so prefers to eat with a sauce base.

It’s impossible for me to say whether or not the tomato sauce is the cause, and likely there isn’t just one cause, but a combination of things. But nightshades definitely do pose issues for a lot of people (as does sugar). Sarah has a recipe for nightshade free bolognese sauce on page 226 of The Paleo Approach Cookbook. -Kiersten

For anyone reading this consider that the sources cited range from 16 to 23 years ago. I am not invalidating anyone who has an autoimmune disorder or allergies to the saponins or lectins in “nightshades”. Though you cannot attribute correlative disorders and diseases as causation in normal individuals or even affected individuals. Everyone’s genetics and metabolism are different. Making generalizations about the metabolism and biochemistry of these compounds is disinformation. YOU MADE YOUR OWN LITERATURE REVIEW TO SERVE AS A CONFIRMATION BIAS FOR YOUR OWN HYPOTHESIS. YOU CANNOT CHERRY PICK OUTDATED STUDIES AND GIVE NUTRITIONAL OR MEDICAL ADVICE TO THE PUBLIC. I am an MD choose your words carefully and do your research before dissuading and causing mass hypochondria.

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