Nightshade vegetables belong to the Solanaceae family of plants. Due to the belief that nightshades promote inflammation, many people eliminate them from their diets.
The vegetables are highly nutritious, however, and little to no evidence supports the claim that they cause inflammation, though some people do notice beneficial changes in their health when they avoid nightshades.
While many people associate the name nightshade with extremely poisonous plants, such as belladonna, most nightshade vegetables are generally safe for consumption. Like most fruits and vegetables, nightshades are rich sources of many nutrients. However, all types do contain alkaloids that are toxic in large quantities.
Much of the stigma surrounding nightshade vegetables stems from them containing alkaloids. Of these, the most dangerous is solanine, which exists in the leaves, fruits, and tubers of Solanaceae plants.
Ingesting high levels of solanine can cause gastrointestinal issues like diarrhea and vomiting, as well as headaches and hallucinations. Despite this, the vast majority of nightshade vegetables are not capable of delivering enough alkaloids to cause any harm.
While there are not enough alkaloids to harm someone in normal servings of nightshade vegetables, many people believe that alkaloids promote the culprit behind many health problems: inflammation.
As a result, other rumors developed stating that nightshade vegetables worsen arthritis and similar conditions. No large-scale studies have confirmed any inflammation-promoting properties of the alkaloids in nightshade vegetables.
Despite nightshade vegetables not promoting inflammation, many people do feel worse after eating them. This is likely due to a sensitivity or allergy to common nightshade vegetables. Food sensitivities are person-specific and may be symptomatic of another issue rather than a permanent problem with a specific food.
Experts advise people who feel they might be intolerant to nightshade vegetables to cut the foods out of their diets for several weeks. If symptoms such as skin rashes, hives, itching, swelling, or difficulty breathing develop after eating nightshades, seek medical care immediately.
Small studies on rats have discovered a few possible interactions between nightshade vegetable alkaloids and certain diseases. Several research groups found that alkaloids increased intestinal inflammation in rats with inflammatory bowel disease. Nightshades may also aggravate symptoms of conditions of celiac disease, rheumatoid arthritis, and multiple sclerosis.
Keep in mind, however, that these studies often use far higher doses of alkaloids than are present in the vegetables themselves, and these findings have not been confirmed in humans.
In general, the evidence does not point towards a need to avoid nightshade vegetables. However, experts recommend taking things on a case-by-case basis. If a certain food seems to worsen symptoms, cut that food out and speak with a doctor.
If avoiding nightshades improves symptoms, it is possible to determine the cause of inflammation and then improve nightshade tolerance over time.
Because there are over 2000 nightshade plants, it is often difficult to keep track of what is or is not a nightshade vegetable. It is an extremely widespread belief that onions are nightshades, but they do not belong to the Solanaceae family. Other vegetables and fruits that are not nightshades include:
Many of the edible nightshades are common sights in most diets. Additionally, though people tend to refer to them as vegetables, some nightshades are fruits.
Some of the most widespread nightshade vegetables and fruits are tomatoes, eggplants, potatoes, bell peppers, and the spices that come from these foods, such as paprika and cayenne.
Like most vegetables and fruits, nightshades are bursting with nutrients. Peppers, such as bell peppers and chili peppers, are low in calories and contain fiber, B vitamins, vitamin C, and vitamin K. Potatoes are excellent sources of fiber while also providing vitamin C, vitamin B6, niacin, and manganese. Technically a fruit, tomatoes contain all four carotenoid antioxidants, as well as a wide range of vitamins. Evidence shows that many of these nightshades actually help fight inflammation, despite common myths.
Because nightshade vegetables contain so many nutrients, eliminating them entirely can lead to dietary deficiencies. Experts recommend using alternative vegetables in their place. Sweet potatoes are also rich in fiber and vitamin A. Pesto or beet sauces can easily replace most tomato sauces. Citrus fruits are overflowing with vitamin C and make excellent alternatives to nightshades.
This site offers information designed for educational purposes only. You should not rely on any information on this site as a substitute for professional medical advice, diagnosis, treatment, or as a substitute for, professional counseling care, advice, diagnosis, or treatment. If you have any concerns or questions about your health, you should always consult with a physician or other healthcare professional.