A Functional Medicine Guide To Nightshades + Inflammation


Trying to achieve your optimal health is a daunting task that takes many things into consideration. It’s hard to know exactly which diet works the best for you and even when you think you found “the one”, inflammation can sometimes still occur. The truth is, eating healthy isn’t always black and white; and what helps one person can hurt another.

One of the food groups that can be extra tricky is nightshades. A lot of people have never even heard of nightshades before and might think these sound dangerous – and to some they are! We’ll get into that soon, but let’s talk about the basics first.


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What Are They

Nightshades are a group of botanical plants from the Solanaceae family with over 2,000 species. This group is composed of fruits, vegetables, herbs, flowers, and even trees. Some of these are edible fruits and vegetables, and some are highly poisonous to the human body. Here’s a list of nightshades that are edible and commonly consumed:

  • White Potatoes
  • Tomatoes
  • Peppers
  • Eggplant
  • Goji Berries
  • Okra
  • Tomatillos
  • Paprika
  • Cayenne Pepper
  • Ashwagandha

Although the safe nightshades list is short, there is a large list of nightshades that are highly poisonous. A nightshade’s poisonous factor comes from the alkaloids that are present in all nightshades of varying levels. These alkaloids act as a natural pesticide to keep insects and mold away from the plants. Of all the substances created by plants, alkaloids are some of the most potent. The poisonous members of the nightshade family cause many people to question the safety of eating the fruits and vegetables. But the edible nightshades are harmless to the majority of people. In these, the toxins are large enough to kill a bug or bit of mold, but when compared to the much bigger size of the human body it doesn’t usually cause any harm.

Aside from that, the majority of this poison lies in the stems and leaves which are not normally eaten. There are a few different types of alkaloids present in nightshades and, while not poisonous, it’s these compounds that can contribute to symptom flare-ups in those struggling with autoimmune conditions.

If you have ever taken a bite of food and experienced pain from the spiciness, you know more about capsaicin than you probably thought. You also probably noticed that the next few bites weren’t as hot. You aren’t imagining this; this is another effect the alkaloid has on your body. Capsaicin, which is only present in peppers, is what makes spicy peppers hot and it causes a weakened or numbing effect on the body immediately following. Any effect that comes from eating a spicy food is from the capsaicin in the peppers. It can cause irritation to eyes and skin, and can also affect gut and digestive issues as well.

Solanine and tomatine are types of alkaloids that are produced by potato and tomato plants that can be stored in the body and released during stressful or traumatic times. Although the solanine and tomatine levels in these nightshades are usually at a safe level, there are a few times that they can be especially high. The first thing that can vary the alkaloid level is the ripeness of the vegetable. Unripe tomatoes, also known as green tomatoes, have a very high level that can affect almost everyone and cause temporary stress on the body. The same goes for when potatoes have green areas or are sprouting. Although it is not common at all, solanine poisoning can occur when large amounts are ingested.

Saponins, another molecule that is found in nightshades, can create an exaggerated response from the immune system. Although having a healthy immune system is a good thing, when it becomes overactive it can start attacking more than just the toxins and cause an autoimmune disorder. This can happen by the saponins creating small openings in cell membranes that allow food and other matter that doesn’t belong into the body to get through the gut lining.

What are the symptoms of nightshade intolerance?

Most people do not show any long term effects from nightshades. However, every person reacts to food differently and it is possible to have a nightshade sensitivity. Most people who do have this sensitivity suffer from autoimmune disorders (especially rheumatoid arthritis), leaky gut syndrome, or chronic pain. When suffering from an autoimmune disorder or other issue, your body and digestive tract is already compromised and can’t handle even small irritants. Nausea, vomiting, inflammation, brain fog, migraines, acne, rashes, hives, and achy joints after eating nightshades are all signs and symptoms of a sensitivity.

Because nightshades and inflammation are closely linked, If you think a nightshade sensitivity is responsible for your inflammation the best way to handle it is an elimination diet.  This diet is usually 60 days that will bring your body to a healthy state of knowing what is beneficial to it. After those 60 days you can slowly and carefully bring back in different foods to see if it causes any inflammation. You can learn more about how to correctly follow an elimination diet in my video course.

The good news is that most nightshades can be substituted with another fruit or vegetable to still be able to enjoy your favorite foods and meals. You can also look for nightshade free ketchup, BBQ, deli meats, and snacks as some companies do make compliant versions.

Substitutes and Alternatives

  • For potatoes: Sweet potatoes can be prepared in any way that a white potato can be: baked, mashed, roasted, or as chips or fries. Plantain chips are also a great alternative to potato chips.
  • For tomatoes: Fruit – like strawberries, blueberries, and pineapple – can be added to salads and salsas to provide the refreshing flavor that tomatoes provide. When thinking about a tomato sauce, butternut squash can be pureed to provide the same marinara consistency.
  • Peppers: Cucumber, radishes, and carrots all provide the same crunchy texture that raw peppers do.
  • Eggplant: Portobello mushrooms and zucchini have a similar texture allowing them to be used in place of eggplant in many recipes.
  • Paprika and Cayenne Spices: In order to get the spicy flavor without using nightshades, the best options are white and black pepper, ginger, turmeric, mustard powder, horseradish, garlic, and onion.

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Dr. Will Cole, DNM, IFMCP, DC is a leading functional medicine expert who consults people around the globe, starting one of the first functional medicine telehealth centers in the world. Named one of the top 50 functional and integrative doctors in the nation, Dr. Will Cole provides a functional medicine approach for thyroid issues, autoimmune conditions, hormonal imbalances, digestive disorders, and brain problems. He is the host of the popular The Art Of Being Well podcast and the New York Times bestselling author of Intuitive Fasting, Ketotarian, The Inflammation Spectrum and the brand new book Gut Feelings: Healing the Shame-Fueled Relationship Between What You Eat and How You Feel.

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Gut Feelings

Healing The Shame-Fueled Relationship
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