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9 Common Food Triggers for Psoriasis

By Kelly Bryant
Reviewed by Allison Truong, M.D.
September 30, 2022

Whether you’ve been living with psoriasis for years or have been recently diagnosed, you may be constantly learning what makes this condition tick. It may seem like your psoriasis symptoms have a mind of their own, when, in fact, they are being triggered.

Potential psoriasis triggers include stress, weather, infection, and skin injury. Food is commonly discussed as a potential trigger, too, possibly because what we eat is something we can control. But it’s difficult to prove a connection between food and psoriasis symptoms, namely because scientists are still trying to uncover the mechanisms of how the skin reacts to certain foods.

“There is not a definitive link between any one food and psoriasis,” says Elizabeth DeRobertis, a registered dietitian in Scarsdale, New York. “For each of these foods, there are studies that find they may trigger psoriasis flares and there are studies that show they have no impact.” More research needs to be done, so we can have more answers regarding specific foods’ impact on the skin. In general, it’s difficult to do research on diet since there are so many foods, and it’s hard to get people to adhere to specific diets.

Plus, everyone’s different. Some people may react to certain foods and others don’t. If you think a certain food may be triggering your psoriasis flares, the best way to find out is to do a temporary elimination diet.

“If you suspect a food is causing a flare-up, eliminate it from your diet until things clear up,” explains DeRobertis. “It is thought that foods may be able to be reintroduced, eventually, and tolerated better in the future. Some recommend reintroducing foods in as little as 30 days. Others recommend eliminating them for two to three months so the gut has time to heal.”

If you’re unsure how to do this kind of diet, work with your doctor or a dietitian to create a personalized plan for discovering any food triggers you may have.

Here are nine foods commonly said to trigger psoriatic flare-ups.

Red Meat

If you’re a steak lover, this one might really bum you out, but red meat contains a polyunsaturated fat called arachidonic acid that can convert into an inflammatory compound, which can cause a flare-up for some people. The good news is, you can swap out meat for fish with a meaty consistency, like swordfish or ahi tuna.

Dairy Products

DeRobertis says that dairy, like red meat, contains arachidonic acid. Plus, the protein casein found in milk may also cause inflammation for people who have a sensitivity to it. Fortunately, there is a plethora of dairy substitutes that can replace the real stuff if you find it’s exacerbating your symptoms. From oat milk to vegan cheeses, there are plenty of great-tasting options.

Gluten-Containing Foods

Gluten is said to trigger psoriasis symptoms only in people with gluten antibodies; and, it turns out, that may be more common than you think. A study in the Journal of the American Academy of Dermatology reported that among 33 people with psoriasis who had high gluten antibodies, 73 percent experienced an improvement in their skin symptoms after going gluten-free. To know if you have gluten antibodies, your doctor can do a blood test.

While gluten is in many common foods—bread, pasta, desserts, and crackers, for example—there are also many gluten-free alternatives on the market.

Processed Food

Those foods in the middle grocery aisles—such as canned foods and frozen and boxed meals and the tasty takeout meals that are so easy to grab—are also often high in saturated fat, possibly trans fats, salt, and refined sugars. This is a trifecta thought to trigger inflammation.

“High-sodium and high-sugar foods may cause the most inflammation because the body tries to combat the change in environment, which can cause inflammation through increased water retention or changes in blood sugar,” explains Morgyn Clair, a registered dietitian in Tampa, Florida.

Clair suggests swapping high-sugar foods for more natural choices that still satisfy a sweet tooth, like apples with oats for extra fiber, or a blueberry-and-yogurt parfait for some added protein. It’s often recommended that people make their own homemade meals, too, which then allows you to control the fat, salt, and sugar in your foods.

Alcohol

There’s scientific research that suggests alcohol may play a role in psoriasis outbreaks by increasing the body’s susceptibility to infection, stimulating the production of more immune cells (lymphocytes) and more skin cells (keratinocytes), and by producing more proinflammatory cytokines, which will produce further inflammation in the body.

Also, alcoholic beverages and cocktails can be packed full of calories and added sugars, which can contribute to weight gain, which can also make psoriasis worse. People with psoriasis are at higher risk of fatty liver disease, and so are people who drink excess alcohol. To limit these risks, you might consider trying to abstain from alcohol completely to see if your psoriasis symptoms improve.

Nightshade Vegetables

Eggplant, potatoes, peppers, and tomatoes are among the nightshade category of plants. They contain an alkaloid called solanine which is thought to trigger inflammation in people with inflammatory conditions like psoriasis and psoriatic arthritis. Still, doctors say nightshades are linked to psoriasis flares only in people who are intolerant to these veggies, and that for everyone else, they’re reasonably nutritious dietary choices.

Citrus Fruits

Lemons, limes, grapefruits, and oranges may look bright and cheery in a fruit bowl, but DeRobertis says citrus fruits are a common allergen thought to trigger psoriasis flare-ups in people who have an allergy to them. “However, they are also high in vitamins and antioxidants, which can boost the immune system,” she explains. “So, if they’re not an allergen to you, it’s likely best to keep them in your diet.”

Condiments and Spices

This one can be tricky. Common kitchen staples such as pimento, curry, cinnamon, vinegar, paprika, Tabasco, Worcestershire sauce, and ketchup, may cause inflammation in some people. Thankfully, you don’t have to wipe out your entire condiment shelf or spice rack. But it might really pay off to look closely at food packaging labels and maybe even keep a food journal. That way, you may begin to find patterns between your flares and eating a certain type of food. This could lead you to tracing your symptoms back to one particular spice or condiment.

Soybeans and Soy Products

Soy has high levels of omega-6 fatty acids which are thought to create inflammation in people with a sensitivity or allergy to soy. If you find that that’s you, make sure to read labels, since soy is an additive in many foods.

“Some of the hidden names for soy are soybean oil miso, soy lecithin tofu, soy protein tempe, and soya,” says Clair. “People should make sure these aren't on the ingredient list if they’re trying to avoid them.”

The bottom line? More studies need to be done to understand how food interacts with skin inflammation. If you know that you’re sensitive, intolerant, or have allergies to specific foods listed above, then try eliminating them from your diet to see if your psoriasis improves. It’s always a good idea to discuss these dietary changes with your doctor to be sure they’re safe, and so your physician is aware of its impact on any treatments they’ve prescribed to you.

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