Most people can enjoy nightshade vegetables without any issues. However, people with certain sensitivities or health conditions may want to eliminate them from their diet. Read on to see if you’re at risk and learn what delicious alternatives are still on the menu.
Nightshades are flowering plants that belong to the Solanaceae family. There are more than 2,700 species of them, ranging from crops to spices to weeds to medicinal herbs.
When you hear the word nightshade, you might think deadly. You wouldn’t be totally wrong. Atropa belladonna, deadly nightshade, is indeed the edgy goth black sheep of the Solanaceae clan. But this family also contains wholesome, beloved vegetables like peppers, eggplants, and even the mighty potato.
Here’s everything you need to know about nightshade vegetables, including who should avoid them and what alternatives reign supreme.
There’s a huge amount of variety among nightshades, particularly those that grow in South and Central America. Some of the most commonly eaten in the U.S. include:
- Ground cherries
- Pepino melons
- Chili peppers
- White potatoes
- Winter cherries (ashwagandhas)
That’s an impressive assortment! It doesn’t even include nightshades like tobacco and Datura, which aren’t eaten but still get ingested or used medicinally.
Alkaloids are organic compounds with medicinal and psychoactive properties. Morphine, codeine, caffeine, mescaline, and cocaine are all derived from alkaloid-rich plants. Nightshades contain alkaloids including solanine, capsaicin, and nicotine.
Keep in mind, the exact alkaloid levels are dependent on the plant.
Solanine. This alkaloid shows up in particularly high quantities in potatoes. It’s used in traditional medicine, but too much of it can be poisonous. Thankfully, you’d have to eat a lot of unpeeled green potatoes to reach a harmful dose.
Capsaicin. This is the active ingredient in chili peppers. It’s responsible for that delicious spiciness, but it’s technically classed as a neurotoxic irritant. We don’t need to spend ages exploring what too much spicy food might do to the digestive system. If you know, you know.
Nicotine. Smoking nicotine has nothing to do with eating vegetables. The nicotine in nightshades isn’t harmful and may actually have beneficial effects.
Scientists broadly accept that nightshades have medicinal properties which help them fight conditions like:
- Oxidative stress
- High cholesterol
- Liver disease
However, there’s still wide debate on how well your body absorbs the beneficial nutrients from some nightshades. Others are far safer bets in terms of getting the good stuff into your cells. Some of the most nutritious nightshades are:
- Capsicums (aka bell peppers). High in vitamin C, which is important for normal immune function.
- Chili peppers. A good source of antioxidants.
- Eggplants. A decent amount of dietary fiber gives your gut a helping hand, as well as being good for heart health.
- Potatoes. A great source of potassium, vitamins C and B6, and manganese. A potato a day is good for most people’s digestive and immune systems.
- Tomatoes. A cornerstone of the mega-healthy Mediterranean diet, tomatoes are packed with vitamins A and C. They’re also rich in lycopene, which is amazing for your heart.
As a family containing both deadly poisons and daily food staples, nightshades have a somewhat complex reputation. Everyday foods like potatoes and peppers are scrutinized for negative health impacts, maybe unfairly when we look at the evidence.
Studies linking everyday nightshades to health problems are mostly either old, inconclusive, or old and inconclusive. There is, however, a reasonable amount of anecdotal evidence worth hearing out.
For example, we spoke about calcitriol’s potential to flood the blood with too much calcium if you ingest too much. This has been linked to arthritis when calcium gathers around the joints, but no study has proved it.
Can nightshades worsen autoimmune disease?
The presence of so many nitrogen-rich alkaloids in nightshades has some questioning their impact on the immune system.
Some studies mention solanine, a glycoalkaloid found in tomatoes, eggplant, and potatoes. Solanine is suggested to increase intestinal permeability and may worsen arthritogenic conditions.
Another study found that patients with psoriasis – an autoimmune disease – found their psoriasis symptoms improved after eliminating alcohol, gluten, nightshade plants, and other foods from their diet. This makes it hard to say if nightshades on their own are associated with psoriasis.
Does inflammatory bowel disease get worse when you eat nightshades?
Inflammatory bowel disease (IBD) is a growing issue around the world. Inflammation in the gut results in conditions like Crohn’s. There are questions about whether all those alkaloids in nightshades could make those conditions worse.
Several elimination diets that are used to treat IBD include the avoidance of nightshades. But, we still don’t know if nightshades on their own will remedy all symptoms, or if other foods are to blame.
It’s safe to assume that spicy nightshades like chili peppers won’t help matters. But scientific evidence is rare, with few studies done on humans.
Can you be sensitive or allergic to nightshades?
Eight foods account for 90 percent of all food allergies: cow’s milk, eggs, tree nuts, peanuts, shellfish, wheat, soy, and fish. So if you’re experiencing allergy symptoms and you’ve already ruled out those eight, it’s easy to get stuck.
Allergies to nightshades like eggplants and tomatoes are rare, but they’re not unheard of. Try dropping them from your diet for a while to see if it eases symptoms like:
- skin rashes
- shortness of breath
- a sore, irritated throat
- swelling around your joints
Right now, the evidence doesn’t support any urgent need for us to ditch potatoes and tomatoes after thousands of years. Not en masse, at least. In fact, lots of nightshade vegetables are associated with some pretty dope health benefits.
If you feel like you’re sensitive to nightshades, try an elimination diet and find out for sure. Ditch the nightshades for 5-6 weeks before reintroducing them into your diet, one at a time every week. If your symptoms reappear, you’ve likely found your culprit.
PSA: Talk to a healthcare provider or registered dietician for guidance before you start an elimination diet. They can also help make the reintroduction phase a lot easier.
Swapping nightshades out of your diet means losing out on some easy sources of vitamins and dietary fiber. But it’s a big world, there’s a lot of food out there. Consider alternatives like:
- Citrus fruits. Oranges and grapefruits can replace the hit of vitamin C you’d otherwise get from tomatoes and peppers
- Greens. Collard greens, kale, spinach, and similarly leafy greens will net you plenty of fiber, vitamins, and minerals
- Pestos. Green pesto is a good replacement for tomatoes in pasta dishes or on pizzas. Red pesto is likely to contain tomatoes, which kinda defeats the point
- Spuds. Sweet potatoes, or yams if you prefer, pack more vitamin A than their pale brethren and can be cooked the same. Plus… they’re sweet!
They’ve got an emo name and it’s hard to describe them in a few words, but nightshades are enjoyed worldwide. There’s no reason most people can’t aspire to eat more fresh vegetables, just because they’re distant second cousins of tobacco.
But of course, we can’t make any sweeping generalizations. Nobody knows your body better than you do. And if you don’t want to eat something, don’t eat it. More potatoes for the rest of us!