Gram Research analysis of 12,749 people found that six dietary nutrients stand out for psoriasis risk: theobromine, lycopene, caffeine, vitamin D, fiber, and vitamin E. A computer model using these nutrients could predict psoriasis risk better than other methods tested, suggesting that eating foods rich in these compounds may help reduce your risk of developing this inflammatory skin condition.
Researchers used artificial intelligence to study how diet affects psoriasis risk in over 12,000 people. They analyzed 45 different nutrients from food and found that six nutrients stand out as especially important: theobromine (found in chocolate), lycopene (in tomatoes), caffeine, vitamin D, fiber, and vitamin E. The study created a computer model that can predict who might be at higher risk for psoriasis based on what they eat. This research suggests that paying attention to these specific nutrients in your diet could be a way to help reduce psoriasis risk, though more research is needed to confirm these findings.
Key Statistics
A 2026 machine learning study of 12,749 participants from the National Health and Nutrition Examination Survey identified six key dietary nutrients that predicted psoriasis risk: theobromine, lycopene, caffeine, vitamin D, dietary fiber, and vitamin E.
According to research reviewed by Gram, the XGBoost computer model outperformed five other machine learning algorithms at predicting psoriasis risk based on analysis of 45 dietary nutrients in over 12,000 U.S. adults.
SHAP analysis in a 2026 study of 12,749 people revealed that dietary nutrients played a dominant role in predicting psoriasis risk, with six nutrients identified as having the strongest influence on prediction accuracy.
The Quick Take
- What they studied: Whether certain nutrients in food can help predict or prevent psoriasis, a skin condition that causes red, itchy patches
- Who participated: 12,749 adults from a large U.S. health survey conducted between 2009 and 2014. The group included people of different ages, backgrounds, and health statuses
- Key finding: Six nutrients emerged as most important for psoriasis risk: theobromine, lycopene, caffeine, vitamin D, dietary fiber, and vitamin E. A computer program using these nutrients could predict psoriasis risk better than other methods tested
- What it means for you: Eating foods rich in these six nutrients may help lower your psoriasis risk, but this is preliminary research. Talk to your doctor before making major diet changes, especially if you already have psoriasis
The Research Details
Scientists used data from the National Health and Nutrition Examination Survey, a large government study that tracks what Americans eat and their health. They collected information from over 12,000 people about their diet, lifestyle, and whether they had psoriasis. The researchers then used artificial intelligence, specifically a type called machine learning, to find patterns between what people ate and whether they developed psoriasis.
The team tested six different computer models to see which one could best predict psoriasis risk based on diet. They used a technique called SHAP analysis to figure out which nutrients were most important in making these predictions. This technique works like asking the computer to explain its reasoning: which foods and nutrients did it rely on most when making its guesses about psoriasis risk?
Because psoriasis is relatively rare compared to other conditions, the researchers used a special technique to balance their data so the computer could learn effectively. This is similar to making sure a classroom has a good mix of students so the teacher can fairly assess learning.
This research approach matters because it can handle complex relationships between many nutrients at once. Instead of studying one nutrient at a time, machine learning can see how multiple nutrients work together. This is important because nutrition is complicated: foods contain dozens of nutrients, and they interact with each other in your body. The SHAP analysis also helps us understand why the computer made its predictions, making the results more trustworthy and useful for real people.
This study has several strengths: it used a large, nationally representative sample of real people rather than a small lab study, and it tested multiple computer models to find the best one. However, the study is observational, meaning researchers watched what people ate and whether they got psoriasis, but couldn’t prove that diet caused the difference. The study also relied on people remembering what they ate, which can be inaccurate. The results need to be confirmed in other groups of people before we can be fully confident in the findings.
What the Results Show
The XGBoost computer model, one of the six tested, performed best at predicting psoriasis risk based on dietary nutrients. This model achieved strong accuracy scores, meaning it correctly identified who was at higher risk more often than the other models tested.
When researchers used SHAP analysis to understand which nutrients mattered most, six stood out clearly: theobromine (a compound in chocolate and tea), lycopene (the red pigment in tomatoes), caffeine, vitamin D, dietary fiber, and vitamin E. These six nutrients had the strongest influence on the model’s predictions about psoriasis risk.
The study found that dietary nutrients played a dominant role in the prediction model, meaning what you eat appears to be an important factor in psoriasis risk. The computer model combined information about 23 different dietary nutrients with 10 other health and lifestyle factors to make its predictions.
The Boruta algorithm, a technique for identifying the most important features, narrowed down 45 nutrients to just 23 that were truly relevant for predicting psoriasis. This suggests that while diet matters, not every nutrient has equal importance. The study also confirmed that combining dietary information with basic health and lifestyle factors created better predictions than using either type of information alone.
Previous research has suggested links between individual nutrients and skin health, but this is one of the first studies to use machine learning to identify which nutrients matter most when considered together. Earlier studies often looked at one nutrient at a time, which doesn’t capture how nutrients work together in real life. This research builds on growing evidence that diet influences inflammatory skin conditions like psoriasis.
This study has important limitations to understand. First, it shows associations between nutrients and psoriasis, not proof that eating these nutrients prevents the disease. Second, the data came from surveys where people reported what they ate from memory, which is often inaccurate. Third, the study was done in the United States, so results may not apply to people in other countries with different diets. Finally, while the computer model performed well in this dataset, it needs testing in new groups of people to prove it works reliably in the real world.
The Bottom Line
Based on this research, consider eating more foods rich in these six nutrients: chocolate and tea (theobromine), tomatoes and tomato products (lycopene), coffee and tea (caffeine), fatty fish and fortified milk (vitamin D), whole grains and vegetables (fiber), and nuts and vegetable oils (vitamin E). However, this is preliminary evidence, so these recommendations have moderate confidence. If you have psoriasis or are at high risk, discuss dietary changes with your doctor or a registered dietitian before making major changes.
This research is most relevant for people with a family history of psoriasis, people with early signs of the condition, and anyone interested in using diet to prevent skin problems. It may be less relevant for people who already have severe psoriasis, as diet alone is unlikely to be a complete treatment. Anyone with existing health conditions or taking medications should consult their doctor before making dietary changes.
If these nutrients do help prevent psoriasis, benefits would likely take weeks to months to appear, not days. Skin conditions develop slowly, so dietary improvements would also work gradually. Consistent eating habits over several months would be necessary to see any potential benefit.
Frequently Asked Questions
Can eating certain foods prevent psoriasis?
Research suggests that six nutrients may influence psoriasis risk: theobromine, lycopene, caffeine, vitamin D, fiber, and vitamin E. However, this study shows association, not proof of prevention. Diet is likely one factor among many, so eating these foods may help but isn’t guaranteed to prevent psoriasis.
What foods have the nutrients that help with psoriasis?
Theobromine is in dark chocolate and tea. Lycopene is in tomatoes and tomato products. Caffeine is in coffee and tea. Vitamin D is in fatty fish, egg yolks, and fortified milk. Fiber is in whole grains, beans, and vegetables. Vitamin E is in nuts, seeds, and vegetable oils.
How much of these nutrients do I need to eat daily?
The study didn’t specify exact amounts needed. Standard recommendations suggest: 25 to 30 grams of fiber daily, 600 to 800 IU of vitamin D daily, and 15 milligrams of vitamin E daily. For theobromine, lycopene, and caffeine, aim for regular consumption of foods containing them rather than specific amounts.
Is this study proof that diet causes psoriasis?
No. This study shows that certain nutrients are associated with psoriasis risk, but it doesn’t prove diet causes the disease. Many factors influence psoriasis, including genetics, stress, and immune function. Diet appears to be one piece of a larger puzzle.
Should I change my diet if I have psoriasis?
Talk to your doctor or registered dietitian before making major dietary changes. While these nutrients may help reduce risk, they’re not a replacement for medical treatment. Your healthcare provider can recommend changes tailored to your specific situation and medications.
Want to Apply This Research?
- Track daily intake of the six key nutrients: theobromine (servings of dark chocolate or tea), lycopene (servings of tomato products), caffeine (cups of coffee or tea), vitamin D (micrograms), dietary fiber (grams), and vitamin E (milligrams). Set a goal to meet recommended daily amounts for each.
- Add one serving daily of a food rich in one of these six nutrients. For example: eat a tomato with lunch (lycopene), drink green tea (theobromine and caffeine), add a handful of almonds as a snack (vitamin E), or choose whole grain bread (fiber). Rotate through different nutrients throughout the week.
- Log your skin condition weekly using a simple rating scale (clear, mild redness, moderate redness, severe). Track which nutrients you consumed each day. After 8 to 12 weeks, review whether weeks with higher nutrient intake corresponded with better skin. Share results with your doctor to discuss whether dietary changes are helping.
This research is preliminary and shows associations between nutrients and psoriasis risk, not proof of cause and effect. The study was observational and relied on self-reported dietary information, which may be inaccurate. Results have not yet been confirmed in other populations. This article is for educational purposes only and should not replace professional medical advice. If you have psoriasis or suspect you may develop it, consult a dermatologist or your primary care doctor before making significant dietary changes. Do not use dietary changes as a substitute for prescribed psoriasis treatments. Individual results may vary based on genetics, overall health, stress levels, and other factors not measured in this study.
This research translation is published by Gram Research, the science division of Gram, an AI-powered nutrition tracking app.