Why Nightshade Foods Can Be Problematic

Written by Sheridan

November 21, 2017

Did you know that some nightshade foods may actually be causing inflammation in your body? This group of foods baffled me for a long time. How could something natural—like tomatoes or eggplants—that have been around for countless years and which people have not tampered with or changed in any way, be causing inflammation?

Nightshade foods are otherwise known as the Solanaceae family. This family of plants includes roughly 2,700 species, a small number of which are edible with the rest being highly poisonous. In fact, there is even a species known as the deadly nightshade, which, as it sounds, is fatal. Not everyone has an issue with nightshade foods, but some people may have an underlying problem with them and may need to eliminate a few of them or all types completely.

The most common nightshade foods include:

  • Tomatoes
  • White potatoes
  • Eggplants
  • Capsicums
  • Chillis/peppers (excluding black and white pepper)
  • Tobacco
  • Okra
  • Goji berries
  • Paprika
  • Cayenne pepper
  • Sorrel
  • Gooseberries
  • Ground cherries
  • Pepino melons

So why are they a problem?

Nightshade foods contain potent alkaloids which can be highly toxic in varying amounts. These alkaloids include solanine, capsaicin, tomatine, nicotine and tropane (not typically found in common nightshade vegetables, mostly just the family of plants). It is sometimes advised for people to avoid nightshade vegetables completely when experiencing liver problems, as they have been shown to be hepatotoxic (damaging or destructive to liver cells). It is also advisable to avoid them if you have an inflammatory condition which includes all autoimmune diseases, irritable bowel syndrome or other digestive distress.

Let’s use the potato as an example. Potatoes contain small amounts of glycoalkaloids, one being solanine, and when people and livestock are exposed to this alkaloid in high amounts it can be incredibly toxic. Potato leaves, stems and shoots are highly concentrated in toxic glycoalkaloids, and when the potato turns green through light exposure, the toxin level increases drastically and it should be avoided, or peeled, removing the green part. The glycoalkaloids are generally much higher in the peel than the flesh of the potato due to this process however, if you find you are sensitive to these toxins, it should be noted that the glycoalkaloids are still found in the flesh.

Symptoms that may be linked with nightshade sensitivity:

  • Inability to lose weight
  • Irritable bowel syndrome 
  • Diarrhea
  • Constipation
  • Headaches
  • Joint pain
  • Muscle pain
  • Skin problems
  • Foggy mind
  • Liver problems

People have very individual and varying sensitivities to nightshade foods. Whilst one person may react to tomato, another may be fine with tomato but react to eggplant. Therefore, if you are sensitive to these foods, it is wise to include nightshade elimination as part of your elimination protocol, either with your practitioner or via something like the Hunter Gatherer Elimination Protocol.

Common nightshade vegetables have been consumed for thousands of years, and therefore do not need to be avoided if you aren’t sensitive to them. Think of tomatoes in Italy, which are so widely consumed with no perceived side effects. The alkaloid types and levels vary in each plant, so find your tolerance level, though it is wise not to overindulge, ensuring that they are not the predominant source of vegetables in your diet. You may be able to have tomatoes a couple of times a week, though every day may become an issue for you. Some people believe that cooking the nightshade foods reduces their alkaloid content, though I am unable to find solid evidence of this so it cannot be guaranteed.

Have you had any experience with removing nightshades from your diet? Have you discovered a sensitivity?

Sheridan Austin

Changing Habits Nutritionist and GAPs Practitioner

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  1. Liz

    Hi where r u based ?

    • Changing Habits

      Hi Liz, we are based on the Sunshine Coast in Queensland, however we are an online business that offers delivery of foods, phone and Skype consults and so on. Was there anything in particular you were after?

  2. Ellen Henderson

    I had recurring health problems that became almost constant. My dr ordered lots of tests but the results were al the same. “We can see you have a problem but we don’t know what is causing it so can’t treat it. “. I was desperate. Migraines are almost constant, as were gut problems, sleeping patten was nonexistent and anxiety level sky high for no reason. I was recommended to try Chinese medicine. I was diagnosed as suffering poisoning by nightshade plant foods. After the first acupuncture treatment and going off all nightshade foods I had instant relief. We have since discovered that potatoes are deadly! Tomoatoes I can hVe very little of, capsicums I. can eat in small lots. It

    • Jordan Pie

      Hi Ellen, Wow thank you so much for sharing your story. Hopefully, it can help someone else out there suffering from similar symptoms.

  3. Barbara

    Hi Jordan, I’m just starting Round 2 P2D1 – Whilst my first round was very successful it was, for the most part very painful; particularly in my back. Towards the end of P2 a friend recommended that I stop eating tomatoes for a few days and voila the pain reduced over a period of the following week! I had never been a great lover of tomatoes but being a free salad food I was eating them twice a day, daily!! I am looking forward to much more freedom from pain in this 2nd round! Cheers

  4. Barbara

    Hi Jordan, I am just starting Round 2 P2D1. Whilst my first round was very successful I experienced high levels of pain during P2. Towards the end of P2 a friend recommended that I stop eating tomatoes which I did and the pain (mainly in my back and shoulders) ebbed away. I have never been a great lover of tomatoes (particular in salads) but as they were a free food I was eating them twice daily every day! I now, occasionally, have a couple of cherry tomatoes roasted and I look forward to more freedom from pain in R2!

    • Jordan Pie

      Thanks for sharing this Barbara! Isn’t the body so intelligent 🙂

  5. Katherie

    Not another food people are now sensitive too? Humans will run out of foods to eat at this rate!!!!

    • Changing Habits

      Hi Katherie, I know, it does sound all a bit crazy. Nightshades are something you would touch on once the person is on a 100% real food diet and may still be having issues. However, as we tend to not eat seasonally these days, and have an abundance of nightshade foods available, we can easily overdo them. Eating seasonally and a wide variety is crucial and can ensure one avoids gaining a toxic level of the nightshade food chemicals. I hope this helps :)! Sheridan.

  6. Leesa

    Hello. I have eliminated eggplant and capsicum, I rarely eat white potato. I have tried to eliminate tomato, but find it really hard ! I will now do it as my fingers ( full of Osteo Arthritis ) are really sore. Is it true, that Roma tomatoes are better if your going to eat tomatoes at all ? Thanks

    • Jordan Pie

      Hi Leesa,
      It would be best to avoid ALL tomatoes completely if you have issues with nightshades, otherwise, you may not see any improvements.


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