Despite what their ominous name suggests, these common veggies may very well be nothing to fear. 

By Briana Riddock 
April 27, 2018
Getty Images/Jamie Marshall

Plenty of us consume nightshade plants on a daily basis without a second thought, but recently, we’ve witnessed a growing concern that they might be harmful.

...So, what exactly are nightshades?

Nightshades are botanical plants from the Solanaceae family ranging from shrubs to small trees. This family consists of over 2,500 species of plants—some of which are edible, while others are poisonous for consumption. The most well recognized domesticated nightshade plants are potatoes (but not sweet potatoes), tomatoes, eggplants, and peppers. Tobacco also falls into this family of plants.

There are several myths that surround the name "nightshades"— which allegedly comes from the idea that some plants prefer to grow in the shade, and also that some bloom at night. Since many of these plants are, in fact, poisonous, there are also rumors that they were used in practicing witchcraft. However, this is largely speculative.

Witchcraft myths aside, here’s where nightshades get their foul reputation today: Certain nightshade plants contain alkaloids, a naturally occurring chemical compound that causes psychological and poisonous effects in the body. More specifically, many people are concerned about the alkaloid compound solanine, which is present in edible plants such as tomatoes, eggplants, and potatoes.

As Carolyn Williams, PHD, RD said in the August 2017 issue of Cooking Light magazine, many believe solanine is “often to blame for arthritis inflammation. However, there is no conclusive research that proves this link.”

Inflammation is the immune system's defense process against foreign organisms that invade the body. This can occur if you suffer from certain diseases like arthritis, cut your knee, or have a cold. But certain foods can also cause an inflammatory response in the body, and over time, it can cause serious health problems.

For years, people who were diagnosed with arthritis were advised to avoid nightshade vegetables to reduce and/or eliminate pain and stiffness in their joints. And while there are cases when those with arthritis eliminated nightshades from their diet and experienced signs of reduced inflammation, this is not the case for everyone.

The vegetables that do contain solanine, all contain varying amounts of it. You could be sensitive to just one specific nightshade, and not all of them. Williams says, “Nightshades are packed full of anti-inflammatory nutrients, such as lycopene and beta-carotene.” If nightshade plants do not trigger any symptoms, you could be missing out on healthy nutrients if you avoid them.

If you do struggle with inflammation or otherwise believe you have a sensitivity to nightshade plants, it is recommended that you alter your diet slightly under the advice and supervision your medical doctor. The elimination diet consists of you removing the suspect food items for approximately two to three weeks, or a recommended time frame from your doctor or nutritionist, to help pinpoint if you have a sensitivity or not. Take notes in a food diary in order to track observations. And when you reintroduce the food back into your diet, continue tracking to see if there are any noticeable changes in your body.