And while there’s no scientific evidence that says eating a certain diet can have a significant and direct impact on psoriatic arthritis, some people have reported experiencing improvement in symptoms when they make some dietary changes. But regardless of how much your diet can impact your psoriatic arthritis, the fact is that eating a healthy diet can affect your overall health and reduce your risk of developing health problems that are related to psoriatic disease such as obesity, cardiovascular disease, and diabetes, according to the National Psoriasis Foundation (NPF). Given this important possible connection, which diets are best for people who have psoriatic arthritis?

Mediterranean Diet

What it is:

While there isn’t any one set definition of what constitutes a so-called Mediterranean diet, it’s generally considered to be one that features fruits and vegetables, healthy fats (like olive oil), seafood, nuts, seeds, and legumes, and less red meat and carbohydrates than a typical American diet, according to the U.S. National Library of Medicine. (The name comes from the fact that countries in the Mediterranean region such as Italy, Spain, and Greece have followed this type of eating style for centuries.) There are also fewer sweets and desserts and butter in the Mediterranean diet.

Why might it be good for psoriatic arthritis?

The Mediterranean diet is rich in omega-3 fatty acids, which are found in fish (especially cold-water fish that are high in fat such as salmon, mackerel, tuna, and sardines), nuts, and seeds (such as flaxseeds and chia seeds). Omega-3 fatty acids may help reduce inflammation and joint stiffness, says Nilanjana Bose, MD, rheumatologist at the Rheumatology Center of Houston in Texas. And olive oil may also help arthritis: An October 2017 study published in the journal Nutrients found that olives and their derivatives (such as olive oil) have anti-inflammatory properties and may prevent cartilage damage due to osteoarthritis. And red meats and refined sugars, which are both considered inflammatory foods, are limited in this diet, says Shailendra Singh, MD, FACP, director of Rheumatology at White River Medical Center in Batesville, Arkansas. Generally speaking, the Mediterranean diet is a well-balanced diet, says Laura Gibofsky, MS, RD, CSP, CDN,  clinical nutritionist at Hospital for Special Surgery in New York City. In contrast to the American diet, which is often loaded with fast foods and trans fats, the Mediterranean diet contains more fresh, whole foods. “The more a food is processed, the less we know about what in that food might trigger inflammation and the less we are able to control an inflammatory condition [such as psoriatic arthritis],” says Gibofsky.

Precautions for people with psoriatic arthritis:

While the Mediterranean diet is very healthy, there isn’t a set amount of recommended fat or calories. “The use of fat is not in a regulated amount, so it’s important to watch how much you eat,” says Gibofsky. “The Mediterranean diet is not just a diet but also a lifestyle.” Other aspects of the Mediterranean diet involves sharing meals with friends and family and being more physically active, which is a way of eating that is less likely to contribute to obesity.

Why might it be good for psoriatic arthritis?

“It encourages food in its original form and not processed, and those who follow this diet tend to cook more,” says Gibofsky. This diet, like the Mediterranean diet, is high in anti-inflammatory foods such as fish, nuts, seeds, fruits, and vegetables, and restricts foods thought to cause inflammation such as refined sugars, processed foods, and high-fat meat.

Precautions for people with psoriatic arthritis:

“It lacks grains, dairy, and legumes so there’s a lack of fiber, which keeps you regular and lowers your risk of cholesterol and diabetes,” says Gibofsky. “Constipation and bone health can be a concern.” Lack of dairy may especially be problematic since psoriatic disease may increase your risk of osteoporosis, according to the NPF. “We need dairy to protect our bones,” says Bose. While some people with psoriatic arthritis report that eliminating dairy from their diet improves gastrointestinal symptoms (and there is a connection between inflammatory bowel disease and psoriatic arthritis, according to NPF), if you don’t have trouble with dairy, eliminating it may not be beneficial and could risk bone health, says Bose. And while you may experience weight loss on the paleo diet — which is a good thing for psoriatic arthritis management — it may be due to the fact that whole categories of foods have been eliminated from the diet. “There’s a difference between removing a food that may cause symptoms and removing an entire food group,” says Gibofsky.

Vegetarian or Vegan Diet

What it is:

Eating a vegetarian diet means eating a diet that focuses on plants (nuts, seeds, grains, fruits, vegetables) and occasionally includes dairy, says Gibofsky. A strictly vegetarian diet does not include meat or fish but some variations of a plant-based diet can include fish (pescatarian) or occasionally meat or poultry (semi-vegetarians). A vegan diet is one that excludes meat, poultry, fish, eggs, and dairy as well as anything that could be considered an animal product such as gelatin or honey.

Why might it be good for psoriatic arthritis?

In a meta-analysis of 18 studies that evaluated effects of any type of vegetarian diet compared with omnivore diets on circulating levels of inflammatory biomarkers, which was published in 2017 in the journal Public Nutrition, researchers found evidence that following a vegetarian diet for at least two years was associated with lower levels of C-reactive protein, a key marker for inflammation in the body.

Precautions for people with psoriatic arthritis:

The concern with a vegetarian or vegan diet is whether or not someone is getting enough essential nutrients like protein, calcium, vitamin B12, and iron, says Bose. When your body is lacking key nutrients, it requires a lot of work to make up for it, says Gibofsky, and that can be a problem when you have a chronic condition such as psoriatic arthritis. “You should maximize your diet to make sure your body always has good nutrition so that you can put all your energy to being healthy and managing your condition,” says Gibofsky.

Gluten-Free Diet

What it is:

A gluten-free diet is one that cuts out foods that contain the protein gluten, which includes grains such as wheat, barley, and rye. While a gluten-free diet is essential for people with conditions like celiac disease or a wheat allergy, there’s been little solid medical evidence for removing gluten from the diet if you don’t have a gluten sensitivity. Nevertheless, a gluten-free diet is one that’s gained some popularity in recent years among people who do not have a diagnosed gluten intolerance. According to the Mayo Clinic, some claimed benefits of a gluten-free diet are increased energy, weight loss, and improved overall health. “There’s a large discrepancy between what’s reported and who actually cannot tolerate gluten,” says Gibofsky. “The reports of gluten intolerance are probably overinflated.”

Why might it be good for psoriatic arthritis?

Having an autoimmune condition like psoriatic arthritis increases the odds of having another autoimmune condition, according to the Arthritis Foundation, which notes that some studies have linked psoriatic arthritis to an increased likelihood of developing celiac disease. And according to the NPF, there is a connection between psoriasis, psoriatic arthritis, and inflammatory bowel disease. One Danish nationwide 20-year study published in the Journal of Investigative Dermatology in February 2019 found that having psoriasis was associated with an increased risk of having Crohn’s disease or ulcerative colitis. While we don’t yet have a clear understanding of this possible link, some people with psoriatic arthritis have reported having less joint pain after eliminating gluten from their diets, says Bose.

Precautions for people with psoriatic arthritis:

If you have symptoms like diarrhea and constipation, you may want to talk to your doctor about trying out a gluten-free diet, says Singh. But removing gluten from your diet requires working with a nutritionist or a doctor trained in nutrition to make sure you get adequate amounts of fiber and other nutrients, cautions Gibofsky. And, she notes, if it isn’t something you need for a medical reason, it can be hard to stick to when you’re on vacation, at work, or at school. “You want a diet you can stick to for life,” says Gibofsky.

Pagano Diet

This diet, created by a chiropractor named John O. A. Pagano, DC, is based upon the premise that all types of psoriasis are caused by a buildup of toxins in the intestines. The Pagano diet is mostly made up of fresh, organic fruits and vegetables and smaller amounts of wild meats and organic greens. It eliminates all red meat except lamb, all sweeteners, anything processed with preservatives or additives, and fried foods. It also eliminates white potatoes, chocolate, yeast, eggs, shellfish, citrus, and any nightshades (such as tomatoes, eggplant, and peppers).

Why might it be good for psoriatic arthritis?

According to the NPF, a survey from researchers at the University of California-San Francisco School of Medicine’s Department of Dermatology published in the journal Dermatologic Therapy in June 2017 found that people with psoriatic disease reported that following certain diets, including the Pagano diet, was helpful for their symptoms. The researchers asked 1,200 NPF members about the influence of diet on their psoriasis symptoms and found that more than half of the study participants reported that they cut back on foods like alcohol, gluten, and nightshades and saw noticeable improvement of their symptoms. In addition to the Pagano diet, members reported other diets like the Mediterranean, gluten-free, and vegetarian diets to be helpful in managing their symptoms. While there isn’t solid evidence on whether any specific diet is most effective for psoriasis, the NPF says one thing that has been shown to be beneficial is weight loss. While a certain diet might be worth trying with a doctor’s supervision, losing weight has been shown to be effective for reducing stress on joints and decreasing inflammation.

Precautions for people with psoriatic arthritis:

As with any diet, it’s essential that you work with a nutritionist to make sure that you aren’t missing any key nutrients that you need for your body and mind to function properly. If you think you have an issue with a particular food, talk to your doctor or nutritionist about how to best eliminate it, says Singh.

Things to Keep in Mind for Any Psoriatic Arthritis Diet

Regardless of which diet you choose, steer clear of inflammatory foods, says Bose. As a general rule, stay away from sugars, processed foods, and red meat and add beneficial foods such as fish, nuts, and seeds that are high in omega-3 fatty acids.While weight loss is beneficial for psoriatic arthritis, losing too much might be a sign that you’re missing something in your diet, says Singh.Try to avoid switching eating patterns too much and too often. “Drastic change to metabolism could be stressful to the body and could exacerbate inflammation,” says Gibofsky.There is no one diet that’s right for everyone with psoriatic arthritis. “Every person is different,” says Gibofsky. Someone may have a gluten intolerance while another might benefit from removing nightshades.What you eat is only part of your psoriatic arthritis management. Making healthy lifestyle changes like exercising and talking to your doctor about other treatments is also part of disease management. “Diet is a way to help symptoms and manage your condition; it’s not a cure,” says Gibofsky.No matter which eating plan you and your doctor decide might be right for you, remember that you want a healthy, balanced diet to help your body work at its best. “Your body needs protein, carbs, and fat to function properly,” says Singh. Your body, says Singh, needs a balanced diet, not one type of diet. “It might be helpful for short-term weight loss but it might not be a long-term solution.”Bottom line: “If a diet can help you manage your psoriatic arthritis with less medication, that’s a good thing,” says Bose.