Fruits and vegetables from the nightshade family are staple foods for many people. Nightshades are nutritious, healthful foods and the idea that they cause inflammation is not supported by evidence.

Nightshade foods contain solanine, a chemical which some people believe may aggravate arthritis pain or inflammation. The Arthritis Foundation say that this is not true. However, if a person feels that certain foods trigger their arthritis symptoms, including nightshades, they should avoid these foods.

In this article, we discuss the effects that nightshade vegetables might have on inflammation and arthritis symptoms, the health benefits of nightshades, and which other foods may have anti-inflammatory effects.

What are nightshade vegetables?

Nightshade vegetables including bell pepper, tomatoes, and eggplant.
Nightshade vegetables include bell peppers, tomatoes, and eggplants.

Nightshade vegetables are part of the plant family Solanaceae. Some species are toxic, including the belladonna plant, which is also called deadly nightshade. Other species are commonly cultivated and eaten by humans.

Common nightshade vegetables that we eat include:

  • white potatoes
  • tomatoes
  • eggplant
  • bell peppers
  • cayenne pepper
  • paprika

Nightshades contain an alkaloid called solanine, which is toxic in high concentrations.

Solanine is found in trace amounts in potatoes and is normally safe, though the leafy stalks of the potato plant and green potatoes are toxic, and solanine poisoning has been reported from eating green potatoes.

Do nightshade vegetables cause inflammation?

Some people believe that the solanine contained in nightshade vegetables may cause inflammation, or make inflammation related to arthritis worse.

While some people may report a worsening of symptoms when eating nightshades that contain solanine, there is no research to support that solanine has a direct effect on inflammation or arthritis pain. Instead, these symptoms may be caused by or related to a food sensitivity to the nightshade family.

A 2010 study suggests that eating purple or yellow potatoes may, in fact, reduce inflammation and DNA damage. These species contain high levels of antioxidants, including carotenoids, which the authors suggest may prevent cell damage.

Despite this, if a person believes that they may have a food intolerance or food allergy to nightshades, they can remove them from their diet and make a note of any effects that this has to their symptoms.

If a person wishes to eliminate nightshades from the diet, they can replace them with other non-nightshade vegetables, such as:

  • sweet potatoes
  • yams
  • cauliflower
  • mushrooms

Health benefits of nightshades

White potatoes in wooden bowl.
Potato skins are rich in vitamin C.

Certain nightshade vegetables can be excellent sources of nutrients, including vitamins, protein, and fiber.

Eating a varied diet rich in vitamins and minerals can have a powerful effect on a person’s health and improve the symptoms of chronic conditions, such as rheumatoid arthritis.

Nutritious nightshades include the following:

Eggplant

Eggplant is an ingredient used in many diets, including the Mediterranean diet and is stocked in most grocery stores.

Eggplant is a good source of fiber, potassium, and vitamin B-1, B-6, and K.

Tomatoes

Tomatoes are an excellent source of vitamins and minerals, including biotin, potassium, iron, and zinc. They also contain the antioxidant lycopene, which may improve inflammation.

Potatoes

Purple, white, and yellow potatoes all offer nutritional value that includes fiber, vitamin C and vitamin B-6.

Peppers

Bell peppers are great sources of vitamin A and C, potassium, and folic acid.

Anti-inflammatory foods

According to the Arthritis Foundation, there is no specific diet that a person with rheumatoid arthritis should follow, but there are some foods that can help to control inflammation. Many of these foods are found in the Mediterranean diet.

Anti-inflammatory foods recommended by the Arthritis Foundation include:

  • Oily fish: These have a high Omega-3 content that may reduce inflammation. Good sources include salmon, tuna, and anchovies.
  • Colorful fruits and vegetables: Examples include blueberries, cherries, kale, and broccoli that are full of antioxidants to support the immune system.
  • Nuts and seeds: These include walnuts, pine nuts, and almonds with monounsaturated fats, which may help with inflammation. Olive oil can have a similar effect.
  • Beans: Examples are black beans, pinto beans, and kidney beans, which contain anti-inflammatory and antioxidant compounds.

Incorporating these foods into recipes and daily meals is easy with a wide range of recipes available online and in cookbooks.

Am I allergic to nightshade vegetables?

woman coughing
Symptoms of a nightshade vegetable allergy may include coughing or wheezing.

A person may be allergic to one or more nightshade vegetables if they experience the following symptoms shortly after eating them:

  • hives or a skin rash
  • shortness of breath
  • wheezing
  • coughing
  • tightness of the throat
  • pale skin
  • anaphylaxis

Anaphylaxis is a life-threatening reaction and a medical emergency.

If a person experiences a severe allergic reaction such as anaphylaxis after eating any food, they should seek emergency medical attention and use an EpiPen, if one is available.

Outlook

Nightshade vegetables are excellent sources of nutrition, and no research to date has linked them specifically to increased inflammation or other symptoms of arthritis.

However, there are some people with sensitivities or food allergies that involve the nightshade family. Eliminating these foods may help those with a sensitivity find relief from their symptoms.

A person should speak with a dietitian if they are concerned about the effects of a particular food on their health.