What Are Nightshades?

Nightshades are a group of plants from the Solanaceae family. These nightshade vegetables are staples in many diets due to their nutritional benefits and versatility in cooking. However, the term "nightshades" often sparks questions such as, "Are nightshade vegetables bad for you?" or "What foods are considered nightshades?"

The reason for concern is that nightshades contain natural chemicals called alkaloids, which in large amounts can be harmful. While nightshade vegetables are safe for most people, those with conditions like ME/CFS or fibromyalgia may experience nightshade sensitivity. Nightshade vegetables are not inherently inflammatory, but they can be inflammatory for individuals with certain sensitivities or chronic inflammation, both common in ME/CFS.

Foods That Are Considered Nightshades

Nightshade vegetables are common in many diets. Here’s a list of the most common nightshade foods:

1. Tomatoes – This includes fresh tomatoes, tomato sauces, and other tomato-based products.

2. Potatoes – White potatoes are nightshades, but sweet potatoes are not.

3. Eggplants – Also known as aubergines.

4. Bell Peppers – This includes all colors of bell peppers, as well as hot peppers like chili peppers, jalapeños, and cayenne.

5. Paprika – A spice made from ground red peppers.

6. Goji Berries – These small red berries are often used in health foods and supplements.

7. Tomatillos – These are similar to green tomatoes and are used in many Latin American dishes.

Nightshade Sensitivity

Nightshade sensitivity involves an adverse reaction to certain compounds found in nightshades, particularly alkaloids. Alkaloids are natural chemicals that help protect plants from pests and pathogens. While nightshade sensitivity is not the same as a food allergy, it can cause uncomfortable symptoms, especially in people with conditions like arthritis or autoimmune diseases.

Common symptoms of nightshade sensitivity include:

• Joint pain – Many people with arthritis or inflammatory conditions report that eating nightshade foods worsens their joint pain or stiffness.

• Digestive issues – Some individuals experience bloating, gas, or stomach discomfort after consuming nightshades.

• Inflammation – For people with chronic inflammation, nightshades may trigger or worsen inflammatory responses, leading to fatigue or flare-ups of pain.

Types of Alkaloids in Nightshades

Solanine is often considered the main culprit for people with nightshade sensitivity. It’s a natural compound found in several nightshade vegetables, particularly in potatoes and tomatoes. Solanine belongs to a group of chemical compounds called glycoalkaloids, which can be toxic in high amounts.

While solanine levels in commonly consumed nightshade vegetables are usually low, they can become more concentrated in certain situations. For example, potatoes that are green or have sprouted often contain higher levels of solanine. Eating large amounts of these potatoes can lead to symptoms like nausea, headaches, or even neurological issues in rare cases.

Other alkaloids like tomatine in tomatoes have been studied for their potential to increase inflammation in animal models of arthritis. Similarly, capsaicin, found in peppers, has been linked to both anti-inflammatory and pro-inflammatory effects. Capsaicin is commonly used in topical creams to relieve pain, but some people experience irritation when consuming spicy nightshade foods.

Cooking potatoes and tomatoes can reduce their alkaloid content slightly, but it's still important to avoid eating green or sprouted potatoes.

Nightshade Sensitivity and Autoimmune Disease

If you told me about nightshade sensitivity 10 years ago I would have laughed it off. Then I started working with patients. There is limited direct research linking nightshade vegetables to autoimmune disease symptoms or other conditions, but many people report sensitivity to these foods. For example, some ME/CFS patients with autoimmune diseases often experience worsened symptoms after consuming nightshade vegetables.

Even for those without autoimmunity, trialing an elimination diet to avoid nightshade foods can be worthwhile. For individuals with severe ME/CFS or high levels of inflammation, this dietary change could bring significant relief. An elimination diet involves removing all nightshades from the diet for a period of time, then slowly reintroducing them to see if symptoms worsen.

Are Nightshades a Problem for You?