Nightshade Allergy 101
Plants produce a number of chemical compounds for their own use, and it just so happens many of those compounds benefit us, too. Some plant chemicals, though, can be toxic, especially for those with allergies or sensitivities. Nightshades such as tomatoes, potatoes, and peppers are packed with fiber, antioxidants, and other nutrients, but if you have a nightshade allergy or intolerance, you may need to eliminate them from your diet. In this article we’ll look at what nightshades are, why they can be problematic, and how to find out if you are allergic or sensitive to them.
What Are Nightshades?
Nightshades, members of the family Solanaceae, are flowering plants high in solanine, a naturally occurring alkaloid compound. Alkaloids are bitter nitrogen-containing compounds that are thought to be produced by plants (and a few animals) as natural pesticides.
Alkaloids are stored in varying amounts in each part of a plant, with the leaves, seeds, roots, and bark tending to have the highest concentrations. Some alkaloids, such as morphine, caffeine, and nicotine, can have biological effects, such as alertness and decreased sensation of pain, when we consume them. (Source, Source)
Alkaloids can have biological effects on the circulatory system and the gastrointestinal tract. Some alkaloids include:
- Solanine: Found in potatoes, tomatoes, and eggplants. Solanine poisoning can occur when high levels are consumed, most commonly in the form of green potatoes. Milder symptoms may occur with low-level exposure or consumption. Neurological symptoms of solanine poisoning such as headache and even hallucinations have been reported, but most common are gastrointestinal symptoms such as vomiting, cramping, and diarrhea. (Source)
- Nicotine: Found in tobacco leaves, nicotine was once used as an insecticide in the United States. Nicotine is known to be highly addictive when consumed through tobacco products. This kind of relatively low-level exposure can cause an increase in blood pressure, heart rate, and alertness. Nicotine is extremely toxic in larger amounts, and severe exposure can lead to abnormal heart rhythm, involuntary twitching, paralysis of the muscles that control breathing, and death. (Source)
- Capsaicin: Found in peppers, capsaicin is the compound that gives spicy peppers their heat. Capsaicin may increase intestinal permeability, which means both that it may enhance delivery of oral medication and that it may play a role in leaky gut. Capsaicin may also alter the composition of the gut microbiota, and has been studied for possible use in the treatment of obesity. (Source)
Is It Safe to Eat Nightshades?
Some nightshades are toxic to humans, but many are not. Common examples of edible nightshades include:
- potato (red and white potatoes)
- eggplant and aubergine
- bell peppers, hot peppers, chili peppers, pimiento
- goji berries
- ground cherries (similar to tomatillos)
- spices sourced from pepper, such as cayenne powder, chili powder, and paprika
There a quite a few foods that are commonly mistaken for nightshades. However, the following list of foods are not part of the nightshade family and thus would not need to be avoided if you have a nightshade allergy or sensitivity. This includes:
- sweet potato
- black pepper
What Is Nightshade Allergy?
Nightshade allergies are rare, but do sometimes occur. Like other kinds of allergies, food allergies involve an inappropriate immune response to something that is not otherwise harmful. Allergy symptoms can range from mild to life-threatening.
Symptoms of a nightshade allergy include:
- rashes and itching
- achy muscles or joints
- swelling of the face or other parts of the body
- excessive mucus production
- trouble breathing, nasal congestion, or wheezing
- constriction or tightening of the airway
What Is Nightshade Intolerance?
Slightly more common than nightshade allergy is nightshade intolerance or sensitivity, where you have trouble digesting nightshades. A food sensitivity is generally caused by a deficiency of enzymes that normally break food down a particular food.
Symptoms of food intolerance may include the gastrointestinal tract, but other parts of the body may also be affected. Often you may be able to tolerate small portions of a food that causes symptoms in larger amounts.
Symptoms of nightshade intolerance or sensitivity may include:
- bloating and gas
- joint pain
- brain fog