5 Foods You Shouldn't Eat If You Have Psoriatic Arthritis

If you have psoriatic arthritis, there are a lot of reasons to eat healthy. The autoimmune disease, which strikes up to 30% of people who have psoriasis, can cause pain, swelling, and stiffness in the joints. And because extra pounds put added pressure on joints—potentially worsening psoriatic arthritis symptoms and leading to deterioration of the joints over time—patients should make it a goal to maintain a healthy weight, says Marie Jhin, MD, a board-certified dermatologist in the Bay Area who cares for patients with disease.

When psoriatic arthritis patients are thinking about their diets, they should also consider that psoriasis might slightly increase a person’s likelihood of developing other health problems, such as high blood pressure, high cholesterol, obesity, and diabetes, according to the American College of Rheumatology. This makes it especially important for psoriatic arthritis patients who also have psoriasis (which is 85%, according to the National Psoriasis Foundation) to eat foods that protect their heart and help them maintain healthy cholesterol levels. At the same time, they should avoid foods that promote inflammation, contain empty calories that can lead to weight gain, and are high in cholesterol. Read on to learn which foods psoriatic arthritis patients should avoid, plus healthier choices to add to your plate.

Sugary treats have little (if any) nutritional benefits, and the sweet stuff has been linked to weight gain, high cholesterol, and blood pressure, as well as greater risk of diabetes, cancer, and heart disease. What's more, consuming refined starches and sugar may boost the production of proinflammatory molecules known as cytokines. In other words, limiting your sugar intake is a smart strategy for everyone, but it’s especially important for those with psoriatic arthritis.

The good news: You can still satisfy your sweet tooth with fresh fruit, such as frozen grapes or bananas sprinkled with cocoa powder. “Natural fruits are fine, but the artificial stuff I would avoid,” says Dr. Jhin.

Like candy, soda delivers tons of calories and is packed with sugar (nearly three tablespoons in a 12-ounce can). And diet soda isn’t much better: diet versions, which contain artificial sweeteners like aspartame and sucralose, have been linked to increased risk of type 2 diabetes, heart disease, depression, and tooth erosion. Plus, diet sodas have no nutritional value and can still lead to weight gain—even if they’re marketed as containing zero calories.

“I wouldn’t drink a lot of soda [if you have psoriatic arthritis,” says Dr. Jhin. To wean yourself off, start watering down your soft drinks, which will cut down on the sugar and calories. If you find yourself still craving caffeine, try making the switch to unsweetened iced tea.

Canned frosting, store-bought baked treats, flavored coffee creamers, and other manufactured products are often chock-full of sugar, salt, and preservatives. In fact, one recent study published in BMJ Open found that a whopping 60% of calories in the average American’s diet can be traced back to “ultra-processed” foods that contain additives like hydrogenated oils and emulsifiers. (A few of the worst offenders? Chips, packaged snack cakes, and frozen pizza.)

All of this won’t won’t do your skin, joints, or heart any favors, says Marcy O’Koon Moss, senior director of consumer health at the Arthritis Foundation. “If you minimize processed foods, that covers a lot of bases,” she says. Instead, make it a goal to stick with fresh, whole foods. If you must grab something processed, check the ingredient list before you buy—if the list includes ingredients you recognize and if you could replicate the recipe in your own kitchen, it’s probably okay.

While it can be hard to keep track of the latest word on good and bad fats, fatty meats, especially in the form of processed meats like bacon, remain on the naughty list. Of course, they contain saturated fat, which can increase levels of “bad” LDL cholesterol and raise your risk of heart disease. Then there’s also the link between bacon and cancer; in 2015, WHO announced that processed meats like bacon are definitely a carcinogen, since cancer-causing substances can develop when meat is cooked at high temperatures, such as frying. Plus, depending on how fatty meats are prepared, they can also contain advanced glycation end products (AGEs), which have been linked to inflammation.

Moss suggests people with psoriatic arthritis, or any type of joint disease, limit their intake of fatty meat in order to maintain a healthy weight and keep inflammation under control. But she does note that “limit” doesn’t necessarily have to mean “eliminate”: “I like to say ‘minimize’ so that people aren’t too strict on themselves,” she says. In other words, rather than swearing off bacon forever, it might be more realistic to tell yourself you can indulge occasionally as a treat.

Some people with psoriatic arthritis may experience worsened symptoms after consuming dairy products, says Dr. Jhin.  "There’s always been talk about milk being a source of inflammation,” she explains. "I would tell people with any type of inflammatory disease to limit dairy. With any inflammation, dairy can be a source of aggravated inflammation."

But Dr. Jhin notes that dairy is good for you in other ways (for example, nonfat milk contains important nutrients and yogurt is packed with good-for-you probiotics), so it's fine to keep eating dairy if you can tolerate it without experiencing worsened symptoms. And in a 2015 review of 52 clinical trials, dairy products actually seemed to have mild anti-inflammatory effects in most people, although they did promote inflammation in those with allergies to cow’s milk.

If you have psoriatic arthritis, fatty fish like salmon, mackerel, trout, and eel should definitely be on the menu. They're packed with protein and vitamin D, are beneficial for your brain, and may help lower eye risks associated with diabetes. Plus, the good-for-you omega-3 fatty acids may even have anti-inflammatory effects.

And perhaps most importantly for psoriatic arthritis patients, omega-3 fatty acids are famously heart-healthy and may reduce your risk of developing heart disease. For optimal cardiovascular health, the American Heart Association recommends having two servings of fish a week.

No question about it—nuts are great for your heart. Although all varieties contain heart-healthy monounsaturated fats, walnuts are particularly beneficial; they’re a good source of alpha-linoleic acid (ALA), a type of omega-3 fatty acid that may help heart arrhythmias and reduce inflammation in the arteries after a heavy, fatty meal.

Nuts may also help prevent other diseases. In one recent study published in BMC Medicine, researchers found that people who regularly ate a handful of nuts (such as hazelnuts, walnuts, pecans, almonds, and peanuts) had a nearly 30% lower risk of heart disease, as well as 15% lower risk of cancer, 40% lower risk of diabetes, and 22% lower risk of dying prematurely of any cause. Regularly eating nuts may also help reduce harmful inflammation throughout the body, according to another recent study published in the American Journal of Clinical Nutrition.

Fresh fruits and vegetables should be part of everyone’s diet. But colorful berries—strawberries, blueberries, raspberries, acai berries, cranberries, and others—have achieved superfood status, in part because they’re a great source of antioxidants and polyphenols, which may help fight heart disease and reduce your risk of heart attack.

“You want more foods that have been shown to be high in antioxidants [if you have psoriatic arthritis],” says Dr. Jhin.

Even more reasons to love them: Berries are packed with filling fiber and good-for-you vitamins. Fresh and local is best, but frozen berries are a fine (and less expensive) choice when berries are out of season.