A nightshade allergy, like any other allergy, needs to be taken seriously. Even for mild, non-fatal allergies, the more the body is taxed with the task of filtering out allergens or dealing with substances that cause irritation, the more your health, wellness, and general quality of life suffers. This article runs down which plants and spices are in the nightshade family, what this allergy entails, and how you can diagnose and treat a nightshade sensitivity.
What Are Nightshades?
Part of the Solanaceae plant family, nightshade plants are most famously linked with nightshade belladonna, aka the “deadly nightshade.” The very name is associated with a fatal poison, and yet most people can eat foods like tomatoes all day long and not keel over dead. In fact many of the nightshade plants are highly nutritious and full of health benefits…for most people.
Nightshade vegetables are well-known even if they’re not always thought of as nightshades. Tomatoes, eggplants, and peppers are in just about every grocery store in North America. Edible nightshade plants include:
- White potatoes
- Bell peppers
- Chili peppers
- Cayenne pepper
- Red pepper
- Goji berries
Blueberries, huckleberries, and goji berries are not technically nightshades but they do contain some of the same alkaloids that cause allergic reaction to nightshade veggies, so they are included here in the interest of helping you avoid food sensitivities.
White potatoes can be replaced with sweet potatoes, yams, or cauliflower. White pepper can replace cayenne or chili pepper, and other dark berries can easily and nutritionally stand in for the problematic berries on this list. For more specific food replacements, read on to the end of this article.
What Is a Nightshade Allergy?
People with a nightshade allergy could have issues with rashes, eczema, or breathing problems after eating these foods.
A nightshade intolerance or nightshade sensitivity is often present without being noticed by sufferers. Without going on an elimination diet or seeking medical advice, people may assume their digestive issues are associated with some other food or just a coincidence.
Not only can nightshades affect your health, but they can also have an impact on other underlying medical conditions. How does this happen?
Nightshades contain alkaloids, compounds that are toxic and present to prevent damage from pests and mold for the cycle of the plant’s life. These compounds include substances like nicotine, solanine, and capsaicin, and while human allergy to these compounds is rare, it nevertheless affects some people. These alkaloids are highest in unripe tubers and fruits like green potatoes and tomatoes. Concentration of the compounds are also high in the stems and leaves of these plants, which humans should not eat at all.
What Are the Symptoms of a Nightshade Allergy or Intolerance?
The adverse effects of consuming nightshade plants and their alkaloids for those who are allergic include:
- Itchy skin
- Skin rashes and hives
- Aching joints and muscles
- Bloating and gas
- Excessive mucus
A food intolerance to nightshade can wreak havoc on your digestive system and hinder your quality of life, so how can you know if that’s what is causing your issues? Read on to find out.
Nightshade Allergy Diagnosis
If you suspect that you have a nightshade allergy, you can start by keeping a food diary. If you feel ill after certain meals, start seeking out common ingredients or spices and see if you can’t discover the culprit on your own.
An elimination diet is also a great way to identify a food allergy of any sort: stop eating the suspected foods for 4 weeks, and then begin adding them back one by one to see which causes you pain or discomfort.
However, severe cases of nightshade allergy could cause the symptoms of anaphylaxis, so if you have ever experienced any trouble breathing, it’s recommended you seek professional medical advice to make sure you’re never in a position that compromises your ability to breathe.
Your doctor may diagnose you by administering:
- A skin prick test: This will involve the doctor marking small areas of your skin and pricking them with certain allergens to see if there is an adverse reaction.
- A blood test: Blood tests for the antibodies that are produced by allergic reactions can help doctors quickly zero in on what you’re allergic to.
Nightshades and Pre-Existing Conditions
Even if you’re not exactly allergic to nightshade, there are some pre-existing conditions that are adversely influenced by nightshade consumption. Here is a list of medical conditions that may be worsened by the various alkaloids in nightshade.
1. Digestive Disorders
Nightshade veggies have the potential to aggravate certain digestive disorders, including irritable bowel syndrome (IBS), bloating issues, and heartburn. While there are no studies confirming this link conclusively, anecdotal reports from patients keeping food diaries reveal a connection on a personal level, and if you notice such a correlation you may want to point it out to your doctor and ask for further advice.
Adjacent to this topic is this 2017 study on an autoimmune protocol (AIP) diet given to patients with inflammatory bowel disease (IBD). It showed that eliminating nightshades (along with legumes, alcohol, and other substances thought or known to irritate the gut) helped improve the symptoms of those with ulcerative colitis and Crohn’s disease. While it’s not 100% inclusive, it does lend support to the personal findings of many people with digestive disorders who find that eliminating nightshades from their diet helps.
Similarly lectins, which are proteins thought to damage the intestinal barrier and cause leaky gut syndrome, are also contained in nightshade and could exacerbate the condition.
2. Joint Pain
The solanine in nightshade foods can cause inflammation, and any increase of inflammation may adversely affect inflammatory disorders like rheumatoid arthritis. Again, scientific evidence is unfortunately skimpy in this area: it may be on you to be your own diagnostician and talk to your personal physician about the connections you notice. While science is invaluably precise, it is still a slow process that isn’t always up to the speed we need.
3. Other Autoimmune Diseases
We’ve already addressed a couple of autoimmune diseases with rheumatoid arthritis and IBD, but other autoimmune and digestive disorders like celiac disease may be harmed by the consumption of nightshade too. Because nightshade plants and compounds can trigger an allergic immune system response, they could be exacerbating these types of conditions.
How to Substitute for Nightshade Plants
If you suspect or already know for sure that you have a nightshade allergy, the best and safest thing you can do is to avoid eating them. A nightshade-free or anti-inflammatory diet doesn’t hurt, and it doesn’t mean you have to feel deprived either, because there are a few convenient replacements and stand-ins for nightshade plants, and we’ve outlined them here.
- Bell peppers can be replaced with radishes, celery, or Swiss chard.
- White potatoes can be substituted with yams, sweet potatoes, or blended cauliflower.
- Eggplants can be done away with in favor of mushrooms like shiitake or portabello.
- Cayenne and red pepper can be replaced by black pepper, cumin, turmeric, or white pepper.
- Tomato sauces be left behind in favor of Alfredo, pesto, and olive oil-based pasta sauces, and tomato coloring can be replaced with beets.
- Huckleberries, blueberries, and goji berries can be swapped out with raisins, raspberries, and cranberries.
Whether your need is for taste, texture, or cooking versatility, there are plenty of ways to creatively side-step nightshade ingredients in your kitchen.
Fortunately nightshade allergies are very rare, and their side effects, while painful and potentially dangerous, often come in mild forms of discomfort (they’re not as severe as, say, a peanut allergy can be). The best diagnosis is still the trial-by-error method with the elimination diet, but once you’re sure that nightshades are what cause your digestive problems, you can quickly sub in other foods and not miss out on any valuable nutrients. Be your own researcher and diagnostician here, and feel better knowing that you have the ability to heal yourself.