Perhaps you avoid nightshades yourself, or have noticed a lot of people do? Is there any reason for avoiding them?
Nightshades are in the Solanaceae family, which comprises 2,800 types of plant. The common nightshades include potatoes (which aren't consumed on a Paleo regime, so I won’t be talking about them), tomatoes, all types of peppers/ capsicum, eggplant, tomatillos, tamarios, paprika and cayenne. Sweet potatoes are related, but belong to the Convolvulaceae family, so aren't classed as a nightshade. Similarly black pepper is not classed as a nightshade as it belongs to the Piperaceae family.
Nightshades contain alkaloids, which the plant produces as a defence mechanism. Some alkaloids have been shown to interact with nerve activity and inflammation, which may impact conditions such as arthritis and gout, as well as gut irritation. Many people have no sensitivities to Nightshades, but those that do may find avoidance very beneficial. Cooking decreases the alkaloid content by up to 50%, so for those with borderline sensitivity, this can be a good option.
If you think you may have a sensitivity, eliminating nightshades for 30 days before reintroducing should give a clear indication as to the effect these plant have on you. If you find you do have a sensitivity, you might chose to avoid them on a more permanent basis.
Hidden Sources of Nightshades You Might Be Overlooking
If you’ve eliminated the obvious nightshades — like tomatoes, capsicum and eggplant — but still experience symptoms associated with intolerance, it’s worth checking your pantry and fridge for hidden sources. Nightshade derivatives are commonly used in spice blends, sauces, seasonings and even processed meats.
Watch for these often-overlooked ingredients:
- Chilli powder and cayenne pepper: Found in many spice blends, rubs and marinades.
- Paprika (including smoked): A standard addition to many BBQ rubs, sausages and dips.
- Tomato paste and powders: Used in stock cubes, sauces, and as flavour enhancers in snacks.
- Capsicum extract: Sometimes labelled as “natural flavouring” in chips or dressings.
Many nightshade-sensitive people report marked improvements in joint pain, skin clarity and digestive health only after removing these hidden triggers. Reading ingredient labels and cooking from scratch makes a huge difference if you’re conducting a proper elimination.
Nightshades and Autoimmune Protocols (AIP)
The Autoimmune Paleo Protocol (AIP) is a stricter elimination plan designed to reduce inflammation and support healing in those with autoimmune conditions. Nightshades are completely excluded during the elimination phase of AIP due to their potential to exacerbate systemic inflammation, increase intestinal permeability and trigger immune reactions.
For individuals with conditions such as Hashimoto’s thyroiditis, rheumatoid arthritis, lupus, psoriasis, or Crohn’s disease, removing nightshades can sometimes lead to a dramatic reduction in flares and symptoms. Once the body has stabilised, some people choose to reintroduce certain cooked nightshades (like peeled, pressure-cooked tomatoes) in small amounts, monitoring for any return of symptoms.
How Alkaloids Affect the Gut and Joints
There are several alkaloids of concern when it comes to nightshade intolerance:
- Solanine: Primarily found in potatoes and green tomatoes, solanine can disrupt digestive enzymes and irritate the intestinal lining.
- Capsaicin: The compound responsible for the heat in chillies, capsaicin can be an irritant to sensitive stomachs and may contribute to GERD or gastritis in some individuals.
- Nicotinoid alkaloids: Found in low levels in all nightshades, these compounds are chemically similar to nicotine and can influence nerve function and stress responses.
These compounds may be harmless in moderate amounts for most people, but for those with underlying gut permeability (“leaky gut”) or chronic inflammation, they can exacerbate symptoms and hinder healing. Since Paleo focuses so heavily on healing the gut and restoring balance, nightshade avoidance can be a valuable short- or long-term strategy for some.
Common Symptoms of Nightshade Sensitivity
If you’re unsure whether nightshades are affecting you, here are some signs that may indicate a sensitivity:
- Persistent joint pain or stiffness, particularly in the morning
- Digestive discomfort, bloating or cramping after meals
- Skin flare-ups, such as eczema or acne
- Fatigue or brain fog that’s hard to explain
- Heartburn or reflux following spicy or tomato-rich meals
Tracking symptoms and keeping a food journal during your elimination phase can be incredibly helpful. Symptoms may not appear immediately after consumption, so observing patterns over several days is key to identifying correlations.
Substituting Nightshades in Paleo Cooking
One of the biggest challenges for people avoiding nightshades is reworking their favourite recipes. Fortunately, many Paleo dishes can be adapted with a little creativity. Here are some substitutions to consider:
- Instead of tomato-based sauces: Try pureed roasted beetroot or carrot with a splash of apple cider vinegar and herbs for acidity and depth.
- Replace paprika or chilli powder: Use dried herbs like thyme, oregano or turmeric for flavour without the heat. A small amount of ginger can mimic spice in some dishes.
- Swap capsicum in salads: Use thin slices of fennel or cucumber for crunch and freshness.
- Use sweet potato instead of white potato: In many cases, sweet potato provides a similar texture and is nutrient-dense without the problematic compounds.
Many AIP and nightshade-free recipes have been developed in recent years, and it's becoming easier to find inspiration from cookbooks and blogs that specifically cater to these dietary needs.
Reintroducing Nightshades Safely
If you've eliminated nightshades for at least 30 days and noticed improvements, reintroduction should be done slowly and methodically. Introduce one nightshade at a time, ideally cooked and peeled (to reduce alkaloid exposure), and wait 72 hours before trying the next. Watch closely for any return of symptoms such as joint discomfort, digestive changes, or mood shifts.
Some people find they can tolerate certain nightshades better than others — for instance, they may handle small amounts of cooked tomato but not raw capsicum. Others may do fine with chillies in moderation but react to eggplant. The goal is to find your personal threshold, not necessarily to eliminate an entire food group permanently unless needed.
Listen to Your Body
As with every element of the Paleo lifestyle, the key is tuning in to how you feel and using food as a tool for health. While nightshades may be nutrient-rich and fine for many, they’re simply not right for everyone — and that’s okay. Honouring your individual response to foods is a huge part of building a sustainable, nourishing routine.
If you’re experiencing unexplained inflammation, skin issues, or digestive discomfort, it might be time to trial a nightshade elimination. The effort is minimal compared to the potential relief it can bring, and your meals can remain flavourful, satisfying and deeply nourishing — even without tomatoes and peppers on the plate.
Do you eat Nightshades? Do you have a sensitivity to them?
