Certain foods can worsen psoriasis by fueling the chronic inflammation that drives the disease. Psoriasis involves an overactive immune response where inflammatory signaling molecules ramp up skin-cell turnover, and what you eat influences those same signaling pathways. While no single food “causes” psoriasis, research has identified several dietary categories that consistently aggravate flares or blunt the effectiveness of treatment. Here are nine worth limiting or avoiding, along with what the evidence actually shows about each one.
Alcohol
Alcohol is one of the most consistently linked dietary triggers for psoriasis flares. A study that tracked how lifestyle habits influenced treatment response found that alcohol consumption was one of the factors that hampered patients’ ability to achieve meaningful improvement with conventional therapy.1PubMed Central. Psoriasis and alcohol And the relationship is dose-dependent: as the amount and frequency of drinking increased, disease severity scores rose significantly and quality of life dropped.2PubMed Central. Impact of Alcohol Consumption, Smoking, and Diet on the Severity of Plaque Psoriasis: A Comprehensive Assessment using Clinical Scales and Quality of Life Measures
The mechanisms are not subtle. Alcohol promotes inflammation through several routes at once: it disrupts gut-barrier integrity, shifts the balance of gut bacteria toward pro-inflammatory species, and increases oxidative stress. Beer may be particularly problematic because it contains gluten in addition to alcohol, potentially doubling the inflammatory hit for people with gluten sensitivity. If you have psoriasis and drink regularly, reducing or eliminating alcohol is one of the clearest evidence-backed changes you can make.
Red Meat
Red meat, particularly fatty cuts of beef, pork, and lamb, is rich in saturated fat and arachidonic acid. Arachidonic acid is an omega-6 fatty acid that your body converts into pro-inflammatory compounds. Research has identified red meat as one of the dietary factors that can worsen psoriasis by activating key inflammatory pathways and promoting the release of molecules like TNF-α and IL-17 that drive skin-cell overproduction.3PubMed Central. Nutrition and Psoriasis You do not necessarily need to go vegetarian, but swapping some red meat meals for fish, poultry, or plant-based proteins reduces the supply of arachidonic acid your body has to work with.
Processed Meats
Bacon, sausage, hot dogs, and deli meats deserve their own mention beyond red meat because they bring additional problems. Processing introduces high levels of sodium, nitrates, and advanced glycation end products, all of which independently promote inflammation. Processed meats are also a major source of saturated fatty acids, which can activate toll-like receptor 4 signaling and amplify the immune response.4PubMed Central. Obesity, Inflammation, Toll-Like Receptor 4 and Fatty Acids In practical terms, a breakfast of bacon and sausage delivers a concentrated package of saturated fat, salt, and chemical additives that hits multiple inflammatory triggers simultaneously.
Sugary Foods and Drinks
Simple sugars found in soda, candy, baked goods, and sweetened cereals have been identified as a dietary factor that exacerbates psoriasis through several overlapping routes, including the promotion of reactive oxygen species and gut dysbiosis.5PubMed Central. Nutrition and Psoriasis High-sugar diets also tend to spike blood glucose rapidly, which promotes insulin resistance over time. Insulin resistance is closely tied to visceral fat accumulation, and visceral fat is itself an active source of inflammatory signaling molecules that worsen psoriasis.
A large prospective study using UK Biobank data examined the relationship between carbohydrate intake and psoriasis risk, adding to the body of evidence linking high-glycemic diets to the disease.6PubMed Central. Association between carbohydrate intake and the risk of psoriasis: a prospective cohort study based on UK Biobank The practical takeaway is straightforward: cutting back on sugary drinks and snacks lowers the overall inflammatory burden. This does not mean avoiding all carbohydrates. Whole grains, fruits, and legumes provide carbohydrates alongside fiber and anti-inflammatory compounds, which is a very different metabolic package from a can of soda.
Fried Foods and Foods High in Saturated Fat
French fries, doughnuts, fried chicken, and similar foods cooked in large amounts of oil deliver a heavy dose of saturated and, in some cases, trans fats. Saturated fatty acids activate inflammatory signaling through the toll-like receptor 4 pathway, which is one of the body’s frontline alarm systems for detecting harmful substances.7PubMed Central. Obesity, Inflammation, Toll-Like Receptor 4 and Fatty Acids When that pathway stays chronically activated, as it can with a diet heavy in fried food, the resulting inflammation compounds what psoriasis is already doing.
Trans fats, which still appear in some commercially fried foods and shelf-stable baked goods, are particularly harmful because the body processes them even less efficiently than saturated fat. Reading labels for partially hydrogenated oils and choosing baking or grilling over deep-frying are small shifts that reduce this inflammatory input.
Ultra-Processed Foods
Ultra-processed foods are products that have been industrially formulated with synthetic additives, emulsifiers, artificial colors, and preservatives. Think packaged snack cakes, instant noodles, frozen pizza, and many fast-food items. These products tend to be low in fiber and high in the inflammatory ingredients already mentioned: sugar, salt, saturated fat, and chemical additives. But the combination may be worse than the sum of its parts.
Research has found that ultra-processed foods are associated with reduced microbial diversity in the gut, lower levels of beneficial bacteria, and an increase in pro-inflammatory microorganisms. These microbial shifts contribute to persistent inflammation linked to a range of chronic conditions.8PubMed Central. The Detrimental Impact of Ultra-Processed Foods on the Human Gut Microbiome and Gut Barrier For someone with psoriasis, where the gut-skin connection is already disrupted, adding more gut-barrier damage through ultra-processed food is like pouring fuel on a fire that is already burning.
High-Sodium Foods
Salty snacks, canned soups, fast food, and pickled or cured items can deliver far more sodium than most people realize. Research suggests that excessive sodium intake can trigger systemic IL-17-mediated inflammation, which is directly relevant because the IL-23/IL-17 axis is one of the central drivers of psoriasis.9PubMed. Association of dietary sodium intake with IL-17-mediated diseases in the UK biobank In lab studies, high salt concentrations push certain immune cells toward a more aggressive inflammatory profile, the very type of immune behavior that worsens psoriatic plaques.
Reducing sodium is easier when you cook from scratch, since about three-quarters of dietary sodium in a typical Western diet comes from packaged and restaurant foods rather than the salt shaker on your table. Swapping canned vegetables for frozen or fresh versions, rinsing canned beans, and checking labels for sodium content can meaningfully reduce your daily intake without making food taste bland.
Gluten-Containing Foods (for Some People)
This one comes with a significant caveat: gluten is not a universal psoriasis trigger. The evidence points to a specific subset of patients who benefit from avoiding it. A study of psoriasis patients found that about 14% had elevated antibodies to gliadin (a component of gluten), compared to just 2% of controls. When those antibody-positive patients went on a strict gluten-free diet without changing their other treatments, all of them showed improvement. The patients with the highest antibody levels saw the most dramatic drops in disease severity and were even able to scale back their medications.10PubMed Central. Prevalence of antigliadin IgA antibodies in psoriasis vulgaris and response of seropositive patients to a gluten-free diet
If you do not have those antibodies, eliminating gluten is unlikely to help and could unnecessarily limit your diet. The practical approach is to ask your doctor for a simple blood test for antigliadin IgA antibodies before committing to a gluten-free lifestyle. If the result is positive, a trial of strict gluten avoidance is worth considering. If it is negative, your effort is better spent on other dietary changes.
Omega-6-Heavy Cooking Oils
Corn oil, soybean oil, sunflower oil, and safflower oil are staples in many kitchens and virtually all processed foods. They are rich in omega-6 fatty acids, which are not inherently harmful but become problematic when they overwhelm the omega-3 fatty acids in your diet. The ratio between these two types of fat matters for inflammatory skin diseases. Research indicates that a combined approach of boosting omega-3 intake while reducing omega-6 consumption offers the strongest potential for dialing down the inflammatory processes involved in psoriasis.11PubMed Central. Omega-3 Versus Omega-6 Polyunsaturated Fatty Acids in the Prevention and Treatment of Inflammatory Skin Diseases
In a typical Western diet, the ratio of omega-6 to omega-3 fats can be as high as 20-to-1, when something closer to 4-to-1 or lower is thought to be healthier. Swapping soybean or corn oil for olive oil or avocado oil in cooking, and eating fatty fish a couple of times per week, shifts this balance in a favorable direction. You will never fully eliminate omega-6 fats, nor should you, because your body needs some. The goal is simply to stop drowning out the anti-inflammatory omega-3s.
Why Your Gut Matters as Much as Your Plate
Several of the foods on this list share a common downstream effect: they damage the gut microbiome. This matters because the gut and the skin are more connected than most people assume. Psoriasis patients tend to show specific alterations in gut bacteria, including an imbalance between major bacterial groups that compromises the gut lining. When the gut barrier weakens, bacterial byproducts leak into the bloodstream and activate immune responses that reach the skin.12PubMed Central. The role of gut microbiome in inflammatory skin disorders: A systematic review
The gut microbiome also produces short-chain fatty acids, particularly butyrate, which have anti-inflammatory effects. The bacterial imbalances seen in psoriasis patients tend to shift production away from butyrate and toward other compounds that promote inflammation.13PubMed Central. The role of gut microbiome in inflammatory skin disorders: A systematic review Dietary components like omega-3 fatty acids, polyphenols (found in colorful fruits and vegetables), and fiber-derived short-chain fatty acids can help restore a healthier balance by supporting beneficial gut bacteria and reducing inflammatory signaling.14PubMed Central. Targeting Cytokine Dysregulation in Psoriasis: The Role of Dietary Interventions in Modulating the Immune Response
Modulating the gut microbiome through diet and potentially through probiotics and prebiotics is being explored as a therapeutic approach for psoriasis, though the field is still young.15PubMed Central. Gut Microbiota in Psoriasis The takeaway is that avoiding the inflammatory foods above is only half the equation. Replacing them with gut-friendly alternatives amplifies the benefit.
What to Eat Instead
The strongest positive dietary evidence for psoriasis comes from the Mediterranean diet, which emphasizes fruits, vegetables, whole grains, legumes, nuts, olive oil, and fish while limiting red meat, sugar, and processed food. A recent randomized clinical trial tested this directly. Participants with mild-to-moderate psoriasis who followed a Mediterranean diet for 16 weeks saw a meaningful drop in disease severity scores, with close to half achieving a 75% or greater reduction in their symptoms. Participants in the control group, who made no dietary changes, saw essentially no improvement.16PubMed Central. Mediterranean Diet and Patients With Psoriasis: The MEDIPSO Randomized Clinical Trial
Clinical guidance now recognizes the Mediterranean diet as a reasonable complementary approach for psoriasis patients, given both its anti-inflammatory profile and its cardiovascular benefits.17PubMed Central. Nutrition and Psoriasis: The Latest Evidence and How to Approach Nutrition in Clinical Practice This matters because psoriasis is not just a skin disease. It comes with elevated cardiovascular risk, and a diet that addresses both the skin inflammation and the metabolic complications is more valuable than one that targets only the plaques.
The Mediterranean pattern is also practical because it does not require eliminating entire food groups. It is not a restrictive elimination diet. You are replacing fried foods with olive oil, swapping processed snacks for nuts and fresh fruit, and eating fish more often. These are sustainable changes that most people can maintain long-term without risking nutritional gaps.
When Elimination Goes Too Far
The internet is full of aggressive psoriasis elimination diets that cut out dairy, nightshades, all grains, legumes, and more. Some of these have essentially no research behind them. Nightshade avoidance (cutting tomatoes, peppers, eggplant, and potatoes) is one of the most commonly repeated pieces of dietary advice for psoriasis, yet no controlled studies support it. Wholesale dairy elimination is similarly lacking in strong evidence for most psoriasis patients, even though individual sensitivity is always possible.
Cutting too many food groups at once creates real risks. Eliminating dairy without adequate replacement removes a major source of calcium and vitamin D, both of which are already commonly low in psoriasis patients. Dropping all grains eliminates fiber that feeds the beneficial gut bacteria your skin needs. And the psychological burden of an extremely restrictive diet can increase stress, which is itself a well-documented psoriasis trigger.
A more measured approach is to focus on the changes that have the strongest evidence behind them: cut back on alcohol, reduce sugar and processed food, shift your fat balance toward omega-3s, and build your meals around the Mediterranean template. If you suspect a specific food is triggering your flares, try eliminating it for a few weeks and then reintroducing it while tracking symptoms, rather than overhauling your entire diet at once. And if gluten is on your radar, get the antibody test first rather than guessing.
Body Weight and the Inflammatory Feedback Loop
The relationship between excess body fat and psoriasis runs in both directions. Fat tissue, particularly the visceral fat around your organs, is not just inert storage. It actively secretes inflammatory signaling molecules that worsen psoriasis, and dysregulated fat-derived hormones have been identified as an important link between the skin inflammation and the metabolic complications of the disease.18Springer Link. Adipokines in psoriasis: An important link between skin inflammation and metabolic alterations At the same time, some psoriasis medications work less effectively in people who carry excess weight, and the systemic inflammation from psoriasis can make weight loss harder.
Many of the nine foods above contribute to weight gain independently of their inflammatory effects. Alcohol adds empty calories, sugary drinks spike blood sugar without satiety, ultra-processed foods are engineered to encourage overeating, and fried foods are calorie-dense. Reducing these foods often leads to some weight loss as a side effect, which in turn lowers the inflammatory output of fat tissue and can make psoriasis treatments work better. The dietary changes are not just about removing inflammatory ingredients from the equation; they also help break the cycle between excess body fat and worsening skin disease.