It happens every August. A patient (often the same patients as last time) will come in for their regular wellness adjustment and have a concern. The conversation usually goes like this, “Doc, I don’t know what’s going on. I haven’t hurt myself or pushed myself but I woke up this morning feeling achy all over. My knees, back and shoulders hurt like crazy! I feel like an old person.” After some discussion, we’ll uncover that indeed there was no strain, injury or unusual repetitious event. Finally, I’ll ask if they have eaten tomatoes or potatoes lately. The look I’m given is skeptical and confused. The response goes like this, “Well, yes! My tomatoes are overflowing my garden. I’ve been eating them like apples!”
Hmmmm. So here I am a chiropractor. First of all, our patients know we don’t treat their symptoms. We help their spine align so the body can heal itself. Patients value regular adjustments to help their body be balanced and healing optimally. Care is about overall wellness. Yet, they have an odd moment of discomfort. They are asking me to fix them. And then here I go asking about tomatoes?
I first read about nightshades (the class of “vegetables” containing tomatoes, white potatoes, red and green peppers and eggplant) over 12 years ago in the the book Food and Healing by Annemarie Colbin. I found it interesting that this group of “vegetables” (they are actually fruits and potato is a tuber) could cause inflammation and achiness in the body. The nightshades contain solanine which is a glycoalkaloid poison that can cause a toxic effect in susceptible people. Symptoms can include arthritis, calcium depletion, stiff joints and painful knees, ankles and wrists. It can even cause GERD symptoms (heartburn.)
Like most nutritional information I come across, I decided to test it for myself before educating patients. I did an old fashioned “elimination diet” to test how my body reacted to nightshades. This meant that I ate absolutely no nightshades for two weeks (even ketchup!) After two weeks, I took one day where I ate a large amount (think eggplant parmesan for lunch and tomato pizza for dinner.) And then I went to bed. Now remember, I was only 25 years old. I rarely had any pain in my body, and certainly no arthritis so I expected no obvious signs of nightshade sensitivity.
I woke up the next morning feeling like a 95 year old woman! Every joint in my body seemed to ache. Lying in bed, I was amazed at the ache in my fingers. My neck, shoulders, back and knees all felt like I had done a triathlon the previous day. I slowly got up and showered. By later that morning, I felt near normal again. I was so surprised, that I retested again the next month. The same thing happened!
It’s not that I no longer eat nightshades. I just make sure that I don’t have too much in one day. If I happen to wake up achy and stiff I review what I ate the day before. I can always pin it on tomatoes or potatoes. Over the years, I tend to go with the non-nightshade choice. It’s not worth it.
Leading nutritional cleanses in the office, I have patients test nightshades the same way. Not everyone has a reaction like I did, but several people in each group find that nightshades make them achy and stiff. For some people, It’s quite depressing to know their favorite food hurts their body. For others, it’s a huge blessing to finally find a reason for their unexplained pain.
In a study published in the Journal of the International Academy of Preventive Medicine, out of 5000 arthritis sufferers who eliminated nightshades, seventy percent reported relief from aches, pains and disfigurement.
And yet, how many people with arthritis are taking medication to ease the pain! They have likely never been educated about nightshades. I very rarely have a patient who has heard of the symptomatic effect of foods they eat. Nutrition is way more important than most people realize!
Don’t get me wrong, there are definite nutritional benefits to potatoes and tomatoes (and the rest of the nightshades.) They are very high in potassium and go well with animal foods because they aid in the digestion of fatty proteins.
My best recommendation is to test this for yourself. Eliminate nightshades for a minimum of two weeks (by the way, tobacco and Motrin are also nightshades.) Then take a day to eat a considerable amount (good part of each meal.) Wait and monitor how you feel. It may take until the next day (likely the morning) to feel the effects. For many of you, you’ll feel the same and have no worries. For others, it may explain a lot. Then it’s up to you to decide how much to have nightshades in your diet.
For me? Ketchup… sure! A few breakfast potatoes next to my omelette…probably! Gnocci (potato pasta) in a tomato sauce? No way!

August 27, 2010 at 4:16 am |
Wow. I never knew. There are days that I wake up really stiff. I wonder if mine is connected to nightshades as well.
September 3, 2010 at 2:16 am |
I heard anecdotally that it was generations after tomatoes were first discovered before they first started being consumed regularly since they were known to be related to nightshade and were thought to be poisonous. I guess they weren’t so far off, at least for some people.
I’d be devastated if I had that kind of sensitivity! This house goes through a ton of tomatoes. I’ve put up 10 quarts of tomato sauce so far this season with no end to the harvest in sight!
September 9, 2010 at 1:24 pm |
Very interesting! I don’t eat an abundance of either of these, but my Mom does, and she has a lot of stiffness and achy-ness. She eats tomatoes like they’re going out of style. I’m going to tell her about this and see if she can go without them long enough to try the ‘test’. I wish she lived here so she could get chiropractic care from you & Dr. David. I just know you could help her. Thanks for the post!!
September 10, 2010 at 3:57 pm |
I never cease to learn from you
Thank you for sharing, I too will pass it on to my many achy friends!
September 16, 2010 at 11:42 pm |
I had heard that nightshades can also cause more skin symptoms like eczema. This was very interesting. I am not a big tomato or potato fan overall so I already limit them, but I LOVE learning new things!!
September 17, 2010 at 12:11 pm |
Wow! I never knew this. I need to test myself on this. Just thinking about the salad I make with dinner most nights…this could be why I wake up achy in the morning. Thank you!
September 18, 2010 at 12:29 pm |
Wow, I knew nightshades were poisonous, and that tomatoes, eggplants and potatoes were all nightshades, but I really hadn’t realized how much of an impact high quantities of them could have! I know you said that they are really helpful in the digestion of fatty proteins, which leads me to ask the following question:
Is there a way to eat them (either particular methods of preparation, or combinations of other foods to eat them with, etc.) that neutralize the toxins, or at least significantly ameliorate the toxic effects of nightshades?
Thanks!
September 19, 2010 at 2:14 am |
Steering away from tomatoes wouldn’t be so tuff but potatoes are another story. Is there anything in the method of preparation that would minimize the toxicity?
September 20, 2010 at 7:51 pm |
This was very interesting to me, because some of my favorite dishes were mentioned in here (gnocchi for starters). I think with everything it’s moderation, and you have to eat different things every day so no one “poisonous” alkaloid can build up. I’ve been reading “Green Smoothie Revolution”, and the author notes that when she first started she made her smoothies exclusively with kale. After 3 months of this she and her family started noticing their face was numb! I’m being careful to use different greens, and I imagine a similar system would be recommended with the nightshades and all veggies and fruits really. Eat different ones, keep it a rainbow, and all will be good in your body!
September 21, 2010 at 4:07 pm |
Amazing! I remember many late August days in my childhood when Mom was grumbling over steaming pots of tomatoes and canning jars. (We knew to stay FAR away from the kitchen on those days!) I always thought she was just hot and tired, but now I wonder if all those tomatoes she ate during those days were also affecting her mood!
Which makes me wonder – can the toxins of nightshades be transmitted via the steam/gasses released when cooking them? If so, the workers at the Prince Spaghetti Sauce factory must be real grouches!
September 22, 2010 at 1:08 am |
Fascinating! I will definitely ponder what I have recently eaten when I am achy. Thanks, Jennifer.
September 22, 2010 at 2:23 am |
Well, I made this great Gluten Free fried eggplant, fresh tomato and asiago cheese “club” tonight so we’ll see how we feel in the morning.
I’d realy like not to have yet another food thing that I can’t eat!
September 23, 2010 at 2:39 am |
How interesting! You never cease to amaze me how knowledgeable you are on so many levels!
Well, just a week or so ago I mentioned to Jewelie that I was feeling especially achy that day, all over! I wish I could remember now what I had eaten prior!
I could almost bet it was a tomato or two; love those garden-fresh tomatoes!!
I’ll have to take the ‘test!’
Thanks for sharing!
September 23, 2010 at 6:07 pm |
See! I knew vegatables were bad for you. I’m sticking to my healthy diet of steak and M&Ms!
September 30, 2010 at 10:36 pm |
I tried the 2 week nightshade test following the cleanse. Eliminating nightshades made a difference, especially in smaller joints like my fingers. I’m really missing tomato products. Hopefully I will be able to tolerate small amounts. (A little ketchup?)