Nightshades & Psoriasis: Do They Really Trigger Flare-Ups?
If you've spent time in psoriasis forums or spoken to others managing the condition, chances are you've come across the idea that nightshade vegetables could be making things worse. Tomatoes, potatoes, aubergine, peppers — the suggestion is that these common foods might be fuelling inflammation and contributing to flare-ups.
But is there anything behind this claim? And should you actually be cutting these foods out?
Here's what the evidence says — and what it doesn't.
What are nightshade vegetables?
Nightshades are a group of plants that include:
tomatoes
potatoes
aubergine (eggplant)
peppers
paprika
They contain natural compounds like alkaloids, which are sometimes linked to inflammation.
These foods are nutritionally valuable — they're rich in vitamins, antioxidants, and fibre. The reason they come up in conversations about psoriasis is because of a group of natural compounds they contain called alkaloids, particularly solanine, capsaicin, and glycoalkaloids.
The concern is that these alkaloids may, in some people, contribute to intestinal permeability or trigger localised inflammatory responses. But this is where things get nuanced.
Do nightshade vegetables make psoriasis worse?
Nightshades are often blamed for triggering psoriasis—but there’s no strong scientific evidence they affect everyone.
In short:
Not proven to trigger psoriasis universally
Some people report flare-ups
Highly individual response
No need to avoid unless you notice a reaction
Why nightshades are linked to psoriasis
The idea comes from the fact that:
psoriasis is an inflammatory condition
some people believe nightshades increase inflammation
elimination diets sometimes remove them
However, this link is mostly based on anecdotal reports—not strong clinical evidence.
Does science support the link?
This is the most important question — and the honest answer is: the evidence is limited.
There are no large, well-controlled clinical trials demonstrating that nightshades trigger or worsen psoriasis in the general population. Most of what circulates online is based on anecdotal reports, small observational studies, or broader research into inflammatory gut conditions rather than psoriasis specifically.
What research does tell us is that psoriasis is an immune-mediated inflammatory condition influenced by a complex mix of genetic, environmental, and lifestyle factors. Diet is one piece of that puzzle — but it's rarely a single food group that makes the difference.
That said, dismissing the nightshade question entirely would also be too simplistic. Individual responses to food vary significantly. Some people with psoriasis do report a noticeable improvement when they remove nightshades from their diet. The experience is real — it's just not universal, and it isn't well explained by the current scientific literature.
What research shows:
No strong evidence that nightshades trigger psoriasis
Dietary triggers vary widely between individuals
Overall diet quality matters more than specific foods
Major health sources don’t recommend avoiding nightshades unless you personally react to them.
Why the nightshade theory persists
There are a few reasons this idea has staying power even without strong evidence behind it.
The gut-skin connection is real. There's growing research into the relationship between gut health and skin conditions including psoriasis. If certain foods affect gut permeability in susceptible individuals, it's plausible — though not proven — that this could influence systemic inflammation. Nightshades have been studied in this context, particularly in relation to conditions like inflammatory bowel disease.
Elimination diets do help some people. When people undertake structured elimination diets — removing multiple food groups at once — they often report improvements. Nightshades are commonly removed as part of these protocols, which makes it difficult to isolate their specific effect. The improvement could be down to removing nightshades, or processed foods, or gluten, or simply eating more whole foods overall.
Personal experience carries weight. Living with psoriasis is exhausting. When someone finds relief by cutting out a particular food, that matters — even if the mechanism isn't fully understood. This is worth respecting rather than dismissing.
Why some people feel better without nightshades
Even without strong evidence, some people do notice improvements.
Possible reasons include:
1. Food sensitivities
You may have a personal sensitivity to certain foods.
2. Reduced overall inflammation
Removing processed foods alongside nightshades may be the real factor.
3. Placebo or behavioural changes
Improved diet awareness can lead to better choices overall.
The key point: results are individual—not universal.
Should you avoid nightshades?
For most people:
No need to eliminate them
They contain valuable nutrients
Only avoid if they clearly trigger symptoms
Blanket restriction isn’t necessary.
How to test if nightshades affect you
If you've noticed that specific foods — including nightshades — seem to correlate with flare-ups, it's worth investigating. The most structured way to do this is an elimination and reintroduction approach:
Step 1 — Remove. Eliminate all nightshade vegetables from your diet for 3–4 weeks. Be thorough: this includes paprika in spice blends, potato starch in processed foods, and tomato-based sauces.
Step 2 — Track. Keep a simple symptom diary throughout. Note the state of your skin, any flare-ups, and any other variables (stress, sleep, alcohol) that might be relevant.
Step 3 — Reintroduce. After the elimination period, reintroduce nightshades one at a time, with a few days between each. This helps you identify whether it's nightshades as a category, or a specific food within the group, that's causing a reaction.
This approach takes time and patience — but it's far more useful than either blanket avoidance or ignoring the question entirely.
One caveat: nightshades contain important nutrients including vitamin C, potassium, and antioxidants like lycopene. Eliminating them permanently without a clear personal reason isn't recommended. If you do find they affect you, a registered dietitian can help you ensure you're getting those nutrients from other sources.
Diet is part of the picture — not all of it
Even when dietary changes help, most people with psoriasis find that managing the condition requires more than food adjustments alone.
Psoriasis is driven by immune system dysregulation, and multiple systems in the body influence how the skin responds — including stress responses, sleep quality, nutrient status, and skin barrier integrity. Diet affects several of these, but it rarely addresses all of them.
This is why many people find that layering approaches — dietary awareness alongside targeted nutritional support and lifestyle management — tends to produce better results than any single change on its own.
Supporting your skin nutritionally from within
One aspect of skin management that's often underexplored is targeted nutritional supplementation — not as a replacement for medical treatment or a healthy diet, but as a way to ensure your skin has the building blocks it needs to function as well as possible.
Specific nutrients play documented roles in skin barrier function, immune regulation, and cellular repair — all of which are relevant for psoriasis-prone skin. These include zinc, vitamin D, vitamin C, magnesium, and CoQ10, among others.
For people whose skin is consistently reactive, dry, or slow to recover, addressing nutritional gaps may be a useful part of a longer-term approach.
Drought's Skin Support Formula is designed specifically for this — a daily supplement containing 14 nutrients selected for their role in supporting normal skin function. It's manufactured in the UK, suitable for vegetarians, and designed to be taken consistently over time as part of a broader skin health approach.
It won't replace the work of understanding your dietary triggers — but for many people, it's a useful addition to the toolkit.
What the evidence does say about diet and psoriasis
While the nightshade link remains inconclusive, there is stronger evidence for the role of diet more broadly in managing psoriasis.
Research consistently points to the following as beneficial for people with the condition:
An anti-inflammatory dietary pattern. A Mediterranean-style diet — high in vegetables, oily fish, olive oil, wholegrains, and legumes — has the most evidence behind it for reducing systemic inflammation. Several studies have found associations between adherence to a Mediterranean diet and reduced psoriasis severity.
Healthy body weight. Excess weight is a well-established risk factor for more severe psoriasis and is linked to reduced response to treatment. Dietary changes that support a healthy weight are consistently beneficial.
Reduced alcohol. Alcohol is one of the most reliably documented dietary triggers for psoriasis flare-ups. Reducing or eliminating alcohol tends to have a more measurable effect than removing specific food groups.
Omega-3 fatty acids. Found in oily fish, walnuts, and flaxseed, omega-3s have anti-inflammatory properties and are associated with improved skin barrier function.
These changes have more consistent evidence behind them than nightshade avoidance — which doesn't mean nightshades are never relevant, but it does suggest where to prioritise.
FAQs: Nightshades & psoriasis
Do nightshades cause psoriasis?
No — nightshades do not cause psoriasis. The condition is driven by immune system activity, genetic factors, and a range of environmental triggers. While some people report that nightshades worsen their symptoms, there's no scientific evidence to support this as a universal trigger.
Should I avoid tomatoes with psoriasis?
Only if you have noticed a consistent personal reaction. Tomatoes contain beneficial nutrients including lycopene and vitamin C, so removing them without good reason isn't advisable. If you suspect tomatoes are affecting your skin, try a structured elimination protocol to test it properly.
Are nightshades inflammatory?
Not categorically. Nightshades contain alkaloids that are sometimes linked to inflammation in susceptible individuals, but for most people they are a nutritious part of a balanced diet. The evidence for nightshades as a systemic inflammatory trigger is not strong.
What diet is best for psoriasis?
The Mediterranean diet has the most consistent evidence for reducing inflammation in people with psoriasis. This means prioritising oily fish, vegetables, wholegrains, legumes, and olive oil, while reducing processed foods, red meat, and alcohol.
How long should I do an elimination diet?
Most practitioners recommend eliminating suspect foods for 3–4 weeks before reintroducing them one at a time. Shorter periods may not give the skin enough time to respond.
Final thoughts
Nightshades are not proven to trigger psoriasis — but for some people, they may be a personal trigger worth investigating.
The most sensible approach is to avoid blanket restrictions based on anecdote, and instead use a structured elimination protocol if you have genuine reason to suspect a food sensitivity. Meanwhile, the dietary changes with the strongest evidence — an anti-inflammatory eating pattern, reducing alcohol, supporting a healthy weight — are worth prioritising regardless.
And if you're looking for additional nutritional support beyond diet alone, targeted supplementation designed with skin health in mind is worth considering.
Nightshades are often blamed for psoriasis—but the reality is more nuanced.
For some people, they may be a trigger. For others, they have no effect at all.
The key is identifying what works for your body—not following blanket restrictions.
Supporting your skin from within can help reduce flare-ups and improve long-term stability.
