Diet and psoriatic arthritis: What's worth trying?

Can healthy eating ease psoriatic arthritis pain and stiffness? No diet can treat psoriatic arthritis. But some foods can help fight pain and swelling, also known as inflammation.

Allergies and other reactions to certain foods can cause symptoms that might make tiredness, pain and skin issues worse. And certain foods can set off the body's immune response. That, too, can affect psoriatic arthritis symptoms.

A diet rich in whole foods is great for everyone's health and can help ease arthritis symptoms. The Arthritis Foundation recommends the Mediterranean diet, which focuses on the following:

• Fruits and vegetables. Enjoy all the colors of both. Eat at least nine servings a day. Be sure to include citrus fruits, such as oranges and grapefruit. They have a lot of vitamin C. Some research shows that vitamin C helps keep joints healthy.

  Other research shows that eating foods with vitamin K, such as spinach, kale and broccoli, can reduce inflammation. But people who take the blood thinner warfarin need to talk to their health care providers before eating more vitamin K-rich foods.

• Whole grains, such as whole-wheat bread, oatmeal and brown rice. These fiber-rich foods can help you feel full and control weight.
• Fish. The omega-3 fatty acids in fatty fish help fight inflammation and ease arthritis symptoms. Fatty fish include salmon, tuna, sardines, scallops and anchovies. Try a fish oil supplement if you don't like fish.
• Plant proteins, such as beans, soy and nuts. These are full of nutrients and help fight inflammation.
• Plant-based oils such as olive oil. Use instead of butter.

• Processed foods. Foods such as frozen meals, deli meats, bacon, and cookies, chips and other snacks can be high in salt and unhealthy fats. Both are linked to health problems.
• Nightshade vegetables. These include eggplant, tomatoes, peppers and potatoes. Although these vegetables are full of nutrients, some people think they cause arthritis flares. There's little scientific support for this. But if you think nightshade vegetables make your symptoms worse, try not eating any for two weeks to see if your symptoms get better.

• Gluten. This is a protein found in wheat and other grains. Not eating gluten is helpful for people who have celiac disease or react to gluten, known as a sensitivity or an allergy. Gluten sensitivity might be more common in people with psoriatic arthritis. For those who react to gluten, eating it could make arthritis symptoms worse.

  Talk to your health care provider about cutting out gluten to see if your psoriatic arthritis symptoms get better. If you don't have a gluten allergy or sensitivity, cutting out gluten likely won't help. And a gluten-free diet might not have important vitamins and nutrients.

To see if any foods make your symptoms worse, cut out one food or food group at a time. This will help you understand which one affects your psoriatic arthritis. For example, don't cut out gluten and nightshades at the same time. And don't make your diet so strict you won't stick to it.

There isn't one diet to manage all psoriatic arthritis pain and stiffness. But eating a wide range of healthy foods can go a long way toward improving your health and your joint symptoms.