This family of produce has gotten a lot of, well, shade. But what does the science really say? Read on to see how nightshades impact health and our list of nightshade vegetables.

Julie Stewart

Pictured: Grilled Eggplant & Tomato Pasta

Many familiar produce picks are nightshade vegetables. Like other fruits and veggies, they pack plenty of beneficial nutrients like the cholesterol-­reducing lycopene in tomatoes and potatoes' blood-pressure-lowering potassium. So why is this plant family getting the booth from some diets?

What are Nightshades?

Nightshades include:

  • Tomatoes
  • Eggplants
  • Okra
  • Potatoes
  • Peppers (bell and most all varieties)
  • Tomatillos

Nightshades contain compounds (such as glycoalkaloids and tropane alkaloids) that nightshade opponents claim can increase inflammation in the body, leading to health issues. Some nightshades, particularly white potatoes, contain a compound called solanine. This chemical helps protect the plants from insects as they grow, and are in very small concentrations. However, as white potatoes go bad and turn green, their solanine levels increase, which is why it is advised to compost potatoes that turn green.

"In high concentrations, these compounds are quite toxic," says Gaurav Moghe, Ph.D., an assistant professor of plant biology at Cornell University. (They're what make ornamental nightshades like petunias unfit to eat.) While edible nightshades also have some of these same compounds, he says the levels are so teeny that they're harmless for the majority of healthy individuals, and no solid research suggests otherwise.

Nightshades and Health

But are nightshades bad for you health? Short answer, no. Some folks with inflammatory conditions, such as eczema, psoriasis, fibromyalgia and inflammatory bowel disease, report feeling better after nixing nightshades, but the research is far from definitive. In some of the studies, participants eliminated multiple food groups-so, was it the nightshades or something else? Plus, some improvements were self-­reported (not measured by a doctor). Additionally, there are many anecdotes of people finding some relief from arthritis after cutting out solanine. However, research is not conclusive and actually has found solanine may have some anti-inflammatory properties.

Bottom Line

If you have an inflammatory condition, talk to your doctor to see if it's worth trying a nightshade-­elimination diet. Otherwise, as long as you feel fine when you eat grilled eggplant or a tomato sandwich, keep enjoying these nutritious plants.

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