Nightshades: Good or Bad?
During the past few years, a certain group of vegetables has started drawing criticism. Nightshades are a family of flowering plants that include more than 2,000 species. Most are not edible, but the edible varieties are commonplace in the typical American diet. Tomatoes, white potatoes, bell peppers, hot peppers, eggplant, okra and paprika are all part of the nightshade family.
Many celebrities and athletes, including famous football quarterback Tom Brady, avoid eating nightshades, believing these vegetables cause inflammation and aggravate arthritic symptoms, such as joint pain. But is this true? Here we’ll take a look at the pros and cons of eating nightshade vegetables.
Nightshades contain a unique alkaloid, which functions as a natural insecticide while the plant is growing. This alkaloid is often called solanine. High doses of solanine can cause inflammation or even be poisonous. However, most of the solanine found in nightshades is concentrated in the leaves and stems, with much less in the edible parts of the plants. There is no evidence that solanine is harmful in typical food amounts that we eat. It’s estimated that a person who weighs 150 pounds would have to consume at least 136 milligrams of solanine to have any effect. An eggplant has just 11 milligrams. Potatoes have the highest count and range from 25 to 275 milligrams of solanine, depending on the variety and cooking methods. Solanine is what causes some potatoes to turn green and sprout. If you were to eat too much solanine, you could get sick.
There is little scientific evidence to support the avoidance of nightshades. The Arthritis Foundation agrees that it is a myth that eating nightshades contributes to inflammation. In fact, this group claims that people with arthritis would benefit from the high nutrient content found in nightshades.
Vegetables of all groups are essential to our health. They provide many vitamins, minerals and antioxidants, as well as fiber. A diet loaded with vegetables helps with weight control, lowering blood pressure and reducing the overall risk of many diseases. Most people do not get enough vegetables in their diets, so eliminating potatoes and tomatoes — the most consumed vegetables in the United States — doesn’t seem like the best idea.
Nightshades provide us with unique and essential nutrients that would be hard to obtain elsewhere. Eggplants contain anthocyanin, which provides a lovely purple color but also numerous health benefits. Anthocyanins have been reported to lower blood pressure, improve visual acuity, reduce cancer cell proliferation, inhibit tumor formation, prevent diabetes and lower the risk of cardiovascular disease. These also are reported to have anti-inflammatory and anti-bacterial activity.
Tomatoes are an excellent source of lycopene, a powerful antioxidant with many health benefits, including sun protection, improved heart health and a lower risk of certain types of cancer.
Potatoes are an excellent source of potassium and vitamin C. If you are concerned about solanine in potatoes, removing the skin before cooking will eliminate 70% of your concerns. Store potatoes in a cool, dry place to prevent sprouting, and cut off any green-tinged areas.
Peppers are an excellent source of vitamin A and vitamin C. They also contain the chemical compound capsaicin, which is known to help decrease inflammation and even help with pain relief.
There is no need to eliminate or limit the consumption of nightshade vegetables for the vast majority of people. Of course, when it comes to diet, no one size fits all. If you think you might be sensitive to solanine or nightshades in general, try a diet elimination to see if it makes a difference.
1 1/3 cups all-purpose flour
!/2 cup cornmeal
2 tsp baking powder
2 ½ Tbsp unsalted butter, softened
1 cup reduced-fat plain Greek yogurt, divided
1 large egg
1 cup shredded Cheddar cheese
½ cup olive oil mayonnaise
2 tsp sugar
½ tsp grated lemon zest
1 tsp ground pepper, divided
1 pound tomatoes
¼ tsp flaky sea salt
Fresh basil leaves
Preheat oven to 400 degrees. Place flour, cornmeal and baking powder in a stand mixer fitted with the paddle attachment. Beat on low speed just until combined. Add butter and ½ cup yogurt. Beat until mixed, 2-3 minutes. Press the dough into the bottom and up the sides of a 9” tart pan with removal bottom. Top with parchment and pie weight.
Bake the crust for 15 minutes. Remove the parchment and weights, and continue baking until the crust is golden brown and the bottom is set, about 10 minutes more. Let cool completely on a wire rack.
Mix the remaining ½ cup yogurt, egg, cheddar, mayo, sugar, lemon zest and ½ tsp pepper in a medium bowl until smooth. Spread evenly over the crust. Slice tomatoes, and pat dry with paper towels. Arrange on top of the filling. Bake until filling is set, 25-30 minutes.
Turn on the broiler, and broil until the top is lightly browned, 2-3 minutes. Let cool on a wire rack for 10 minutes. Remove the pan sides. Sprinkle the top with the salt and remaining pepper. Garnish with basil. Cut into 6 wedges.
Nutrition Information: 443 calories, 27 g fat, 36 g carbs, 14 g protein, 3 g fiber, 515 mg sodium
Anita Marlay, R.D., L.D., is a dietitian in the Cardiopulmonary Rehab department at Lake Regional Health System in Osage Beach, Missouri.