Did you know that nightshade foods can cause bursitis and other joint conditions in some people?
First, what are nightshade foods?
Nightshades are a diverse group of foods, herbs, shrubs, and trees. “Nightshade” is actually the common name used to describe over 2,800 species of plants, many with very different properties and constituents. These plants belong to a scientific order called Polemoniales, and to a scientific family called Solanaceae.
The term “nightshade” may have been coined because some of these plants prefer to grow in shady areas, and some flower at night.
Potatoes, tomatoes, sweet and hot peppers, eggplant, tomatillos, tamarios, pepinos, pimentos, paprika, and cayenne peppers are common nightshade foods.
Ways in which nightshades may affect health
Most of the health research on nightshades has focused on a special group of substances found in all nightshades called alkaloids. In chemical terms, alkaloids are easy to identify because they all have at least one ring-like structure that contains the element nitrogen. Plants produce alkaloids as a regular part of their biochemical activity, and these alkaloids are primarily designed to help protect the plants from insects that would otherwise eat them.
Alkaloids can impact nerve-muscle function and digestive function in animals and humans, and may also be able to compromise joint function. Because the amount of alkaloids is very low in nightshade foods when compared with other nightshade plants, health problems from nightshade foods may only occur in individuals who are especially sensitive to these alkaloid substances. Since cooking only lowers alkaloid content of nightshade foods by about 40-50%, highly sensitive individuals may want to avoid this category of food altogether, while non-sensitive individuals may be able to eat these foods, especially in cooked form, without problem. Green and sprouted spots on potatoes usually reflect high alkaloid content, even though the green itself involves the presence of chlorophyll, not alkaloids. For this reason, sprouted areas should always be thoroughly removed before potato cooking, or the potatoes should be discarded altogether.
There are four basic types of alkaloids found in nightshade plants. These types are: 1) the steroid alkaloids, which contain a fairly complicated fused ring structure and are found in most food nightshades including potato and tomato; 2) the tropane alkaloids, all originating from the simple amino acid ornithine and found in fewer of the overall nightshades, but more extensively researched due to their strong drug-like properties; 3) the pyrrolizidine alkaloid; and 4) the indole alkaloids.
To answer the question whether to eat or not to eat nightshade foods, it is up to the individual whether or not to eliminate nightshade vegetables from your diet, if you have concerns, modifying certain foods in your diet can be a good idea. It just might help identify problem foods of all types, including nightshade vegetables.