About Nightshades

I was having a conversation with a member the other day about her likes and dislikes, and I mentioned a random little fact I'd picked up somewhere: technically, eggplants are berries. In exchange, she gave me a random fact: eggplants are a member of the nightshade family, along with potatoes and tomatoes.

That got me looking into nightshades, a strange family of produce that include potatoes (a tuber), tomatoes (fruit), peppers (fruit), paprika (spice), cayenne (spice), and tobacco. The Solanaceae plant family may have been called “nightshades” because some of these plants prefer to grow in shady areas and some flower at night.

The nightshade family is known, whether directly or indirectly, by the alkaloids that are common in the majority of the different species that make up the family. These alkaloids are incredibly interesting as they can be healthy and beneficial, undesirable, or even toxic and lethal depending on the specific kind of alkaloid. One of these types of alkaloids, called tropane, is found commonly throughout members of this family, and is the infamous and lethal ingredient in deadly nightshade and mandrake. But this same alkaloid is also incredibly beneficial in small quantities and is used extensively in medicinal practice to reduce allergic reactions and reduce the affects of motion sickness and chemotherapy among other things.

Some people have alleged that nightshade vegetables contain a toxic alkaloid compound called solanine, a defence mechanism in some Solanaceae plants that protects against natural threats such as insects. It’s true that solanine may develop in potatoes, which turn green when they are exposed to light during growth. The greenish hue is actually caused by chlorophyll, but its presence indicates that concentrations of solanine are present. Eggplant, peppers, and tomatoes - even the green ones - do not produce solanine and are perfectly safe to eat. As a general rule, people should avoid consuming the leaves, stems, and flowers of members of the nightshade family.

Nightshade vegetables confer a number of health benefits because they are often rich in vitamins, minerals, and other useful compounds. For many people, they are an important part of eating a colourful diet, which has been linked to getting a variety of mirconutritents. They are also usually high in potassium, known to help balance sodium intake. Tomatoes, in particular, contain lycopene, which, it has been shown, helps prevent osteoporosis and cancer. Whether mild or fiery, peppers are one of the richest sources of vitamins A and C. Eggplants are high in fibre. Research has found that the skin of eggplant may contain more fiber that the actual eggplant itself, so eat that colourful skin!