There is no specific diet that causes or treats psoriasis or PsA.
Foods to eat
A healthful diet including vegetables, fruit, legumes, and seeds is recommended for people with PsA.
The foods that are good for treating PsA are the same foods that reduce the risk of heart disease, diabetes, and cancer by decreasing inflammation.
The base of a person's diet should involve:
- vegetables and fruits in a range of colors
- nuts and seeds
It is best to cook with healthful fats, such as extra virgin olive oil, unrefined coconut oil, or avocado oil.
Foods high in dietary antioxidants are the main focus of an anti-inflammatory diet.
People with PsA may want to include these inflammation fighters in their diets:
Green tea or matcha
Tea contains catechins, powerful antioxidants known for having beneficial anti-inflammatory and anticancer properties. Green tea may also have an anti-arthritic effect by protecting against inflammation.
Matcha is a form a powdered green tea that may have even more health benefits. Unlike traditional tea, matcha leaves are physically eaten instead of just being steeped in water.
However, matcha has become fashionable and is being added to cakes, cookies, and even donuts. Consequently, just because the food has matcha in it does not mean it is healthful.
Avocado is the only fruit that provides healthful, beneficial fat. Avocados have upward of 20 different vitamins and minerals and are especially high in potassium, lutein, beta-carotene, and vitamins C, E, and K.
Leafy greens like kale, spinach, Swiss chard, beet greens, and collard greens are the best for people who are looking to add more vitamins, minerals, and antioxidants.
Just half a cup of collard greens provides around 662 percent of daily-recommended vitamin K intake.
Sprouts and the seedlings of vegetables and herbs, otherwise known as microgreens, often contain an even higher concentration of nutrients when compared with the fully-grown species.
The healthy fat in salmon, trout, and herring is good for heart health. It also provides anti-inflammatory omega-3 fatty acids
Ginger is high in antioxidants and contains at least 14 healthy bioactive compounds, enhancing its anti-inflammatory powers.
Three of these particular compounds are gingerol, shogaol, and paradol.
Foods to avoid
Cookies and cakes that can contribute to weight gain should be avoided by people with PsA.
There are also foods that can cause inflammation, as well as worsen or increase the risk of inflammatory conditions. These include saturated fats from processed foods, simple carbs, sugar, and alcohol.
Weight loss through diet and exercise has been shown to decrease overall inflammation as well as psoriasis and PsA symptoms. However, a recent review suggests that overall evidence to support this is limited.
Foods to avoid for people with PsA include:
- sugary drinks and soda
- white bread, white rice, and other processed or enriched bread products
- packaged cookies, cakes, and snack foods
- processed meats such as bacon, sausages, and hot dogs
- fried foods
- alcohol, especially drinks with sugar
Maintaining a healthy gut
The health of the gut plays a huge role in overall health, including the immune system, metabolism, and weight. The bacteria in the gut play a vital part in making sure the body works as it should.
There are huge numbers of bacterial cells inside the human body. Diet directly impacts this important community of cells.
A study published in Arthritis & Rheumatology compared the gut bacteria of healthy people to those with PsA. The authors found that people with psoriasis and PsA had less diverse gut bacteria than healthy people.
Several types of healthful bacteria that were identified to be lower in people with PsA have also been found to be low in people with inflammatory bowel diseases such as Crohn's disease.
When people eat foods such as white bread and other simple carbohydrates, these are quickly digested. This means that they don't even make it to the end of the digestive system where the beneficial bacteria live. If someone is eating a low-fiber diet, they are essentially starving those healthful bacteria.
Constipation or diarrhea may be signs that a person has unhealthy gut bacteria.
Signs that someone may have unhealthy or unbalanced gut bacteria:
- chronic constipation or diarrhea
- being sick multiple times a year or prolonged symptoms
- recent use of antibiotics
- autoimmune conditions
Foods to eat to improve gut health include the following:
- Vegetables and fruits: Getting fiber from a variety of plant foods helps to maintain and feed the diversity of bacteria in the gut.
- Fermented foods: Kimchi, kefir, kombucha, sauerkraut, and miso contain beneficial bacteria.
- Beans and legumes: High in fiber, beans and legumes also feed the healthful gut bacteria.
People with PsA may also want to start taking a probiotic to help boost their gut bacteria. Different strains of bacteria have different jobs, so people should find a probiotic that contains many different strains.
A person may also want to find a probiotic that has strains particular to their needs. People with PsA should speak to their doctor or a registered dietitian to find a probiotic that is appropriate.
There is no specific prescribed diet for PsA. However, eating an anti-inflammatory diet high in plant-based foods may decrease symptoms and reduce the risk of further complications.
Plant-based foods include vegetables, fruits, legumes, seeds, and unrefined oils.