Nightshades are a group of vegetables belonging to the nightshade family. More than 3,000 species of plants belong to this group. Common varieties are eggplants, tomatoes, potatoes and peppers.
Some people have an intolerance or allergy to nightshade vegetables. There are limited data to indicate how many people are affected, but reaction to nightshades is thought to be rare.
Learn about nightshade vegetables, intolerance and allergy symptoms, nightshade alternatives, and tips for eating out.
Intolerance or allergy to nightshade?
A nightshade allergy is not the same as a nightshade intolerance. Indeed, food allergies and food intolerances are two different conditions.
While intolerances and allergies both cause uncomfortable symptoms, an allergy is much more serious. Allergies can even lead to anaphylaxis, a life-threatening reaction.
Food intolerances affect the digestive system. This occurs when the body is unable to digest or break down nightshades. This can happen for a number of reasons, including:
- Sensitivity to food additives
- Having a reaction to chemicals that occur naturally in certain foods
- Have an enzyme deficiency (lack of enzymes that produce the primary bile acids needed to digest food)
In many cases of food intolerance, a person may be able to eat a small amount of the food they are intolerant to (such as nightshades) without causing significant problems.
Having a food allergy involves the immune system. It is the part of the body responsible for defending it against invaders like germs and toxins. If the immune system identifies a food like nightshades as a threat, it will initiate an immune response.
This involves the production of an antibody called immunoglobulin E (IgE). This antibody then tells the cells to release chemicals that cause an allergic reaction.
Allergies can be life threatening
Unlike a food intolerance, an allergic reaction to nightshades can be life-threatening and can occur from even eating the smallest amount of food.
Only a health care provider can diagnose a food allergy. If you think you may be allergic to nightshades, make an appointment with your primary care provider or an allergist.
There are a number of foods that belong to the nightshade category. Popular varieties include:
- white potatoes
- Spices like paprika and cayenne pepper
Many vegetables from the nightshade family are a good source of nutrients and antioxidants. They even fight inflammation. This includes:
- Aubergine: Eggplant is a good source of fiber and potassium, as well as an excellent source of magnesium, which helps with nerve function.
- peppers: Peppers are antioxidants and a good source of vitamin C. Studies suggest that the spicier peppers may also boost metabolism.
- Potatoes: Potatoes are high in fiber and also high in potassium, which helps lower blood pressure. They also contain other minerals as well as B vitamins.
- Tomatoes: Tomatoes are an antioxidant and a good source of vitamins like vitamins C and K.
Nightshade Intolerance Symptoms
Those who are nightshade intolerant may experience digestive issues. Symptoms can appear within half an hour of eating food, but in some cases they can take up to 48 hours to appear.
Possible symptoms of a food intolerance include:
- Abdominal pain
Nightshade Allergy Warning Signs
Unlike an intolerance, the symptoms of a food allergy will likely appear seconds or minutes after ingesting a food.
Food allergy symptoms, including:
- facial swelling
- Swelling in the throat and mouth
- Itchy mouth
- Tingling in the mouth
- Difficulty swallowing
- Pain in the abdomen
- Feel dizzy
- Shortness of breath
- Itchy eyes
- To sneeze
In severe cases of an allergic reaction, a person may experience anaphylaxis. This is a medical emergency and can be life threatening.
Anaphylaxis can occur suddenly with the same symptoms as above. Additionally, people with anaphylaxis may collapse or experience the following:
- Difficulty breathing
- Difficulty speaking
- Difficulty swallowing
- Swelling in the tongue
- feeling of weakness
- Tightness in the chest
If a primary health care provider suspects an allergy, they will refer to an allergist, a specialist who diagnoses allergies.
Screening for food allergies can involve a number of approaches. These include:
- A skin test: This involves placing a small amount of a suspected food allergen on the skin of the arm or back. The skin is then pricked to allow food to move under the skin. The bite site is then examined and if a red or itchy bump appears, allergies may be likely.
- Blood test: This will check for the presence of IgE antibodies produced by the immune system.
- Oral provocation test: In this test, an allergist will administer a small amount of a food that may be causing your allergy and observe and treat any allergic reactions. If the initial amount is tolerated, increasing doses will be given until a person consumes a full serving or until a reaction occurs and is treated.
Nightshades and Health Conditions
Some claim that nightshade vegetables contribute to inflammation and therefore are not suitable for people with conditions such as arthritis, lupus and cancer.
However, there is no evidence backed by scientific research that shows an association between normal levels of nightshade consumption and inflammation.
In fact, some ingredients in nightshades may actually benefit inflammation.
Carotenoids are a nutrient in tomatoes and peppers, and anthocyanins are a nutrient found in eggplant. Both of these are antioxidants and actually protect cells against inflammation in the body.
The Arthritis Foundation says that nightshades can be a valuable part of the diet for people with arthritis. However, people who experience pain from nightshades should eliminate them from their diet, then reintroduce them and monitor for symptoms.
List of Nightshade alternatives
Those who are sensitive or allergic to nightshades may want to try alternatives. These include:
- Substitute cauliflower and sweet potatoes for white potatoes
- Replace eggplant with mushrooms
- Replace peppers with radishes, zucchini or celery
- Replace carrots or beets with tomatoes
- Replace ground white pepper or black pepper with spices like cayenne pepper, paprika and red pepper flakes
Adjusting to a Nightshade-Free Diet
Adjusting to a new diet can be difficult, but there are ways to make dining out and grocery shopping a little easier.
When eating out, people with food allergies can take certain steps to ensure they are safe.
- Call ahead to ask about dish ingredients
- Look at the menu in advance
- Upon arrival, identify yourself to the manager and explain your allergy
- Ask about cross-contamination
- Inform your server of your needs or ask to speak directly to the chef
- Always carry an EpiPen
- Have a back-up plan in case restaurants can’t meet your needs
- Consider returning to restaurants that have been understanding and helpful in the past
When grocery shopping, people with allergies or intolerances should avoid nightshade foods to which they react.
Know that there are many varieties of nightshades. For example, peppers are part of the nightshade family. Those who must avoid all nightshades should not eat bell peppers, chili peppers, or banana peppers.
People with intolerance or allergies should also be aware of nightshades in seasonings like paprika, chili powder, cayenne pepper, and curry powder.
It is important to read labels carefully. Nightshades can be hidden in certain ingredients such as “spices” or “natural flavors”. Potatoes can also be found in foods that contain “starch” as an ingredient.
Nightshades are a group of vegetables. Commonly eaten vegetables in the nightshade family include tomatoes, eggplant, white potatoes, and bell peppers. Some people may experience an intolerance or allergy to nightshades, but these are thought to be rare. Those who suspect they have a nightshade allergy should see an allergist for testing. Alternatives are available for those intolerant of nightshades.
A word from Verywell
Dealing with a food intolerance or allergy can be distressing. But you are not alone. If you experience uncomfortable symptoms, consider contacting a medical professional. If you suspect an allergy, it is important to get tested.
Frequently Asked Questions
Does nightshade tenderness cause stomach pain?
A nightshade sensitivity or intolerance, like other food intolerances, can cause a number of symptoms, including stomach pain, diarrhea, and nausea.
What are good substitutes for a tomato allergy?
People with a tomato allergy may want to try other vegetables in their meals. Possible choices are beets and carrots.
What effect do nightshades have on autoimmune diseases?
Some people believe that nightshades can cause inflammation in the body and are not suitable for people with conditions such as lupus or arthritis. However, there is no scientific evidence to support this claim.
When should you stop eating nightshades?
If you suspect you have nightshade intolerance, you can try eliminating them from your diet completely before reintroducing them one at a time to check for symptoms.
However, if you think you are allergic to nightshades, you should stop eating them. Make an appointment with your health care provider as soon as possible.