The best diet for ankylosing spondylitis

Ankylosing spondylitis (AS)—a form of arthritis—is an autoimmune systemic disease that causes pain and swelling in the spine. It routinely affects the sacroiliac joint, which connects the bottom of the spine to the pelvis. According to the National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS), the inflammation caused by ankylosing spondylitis leads to stiffness and mild episodes of back pain that come and go. In severe cases, back pain and stiffness are constant.  

There is no cure for ankylosing spondylitis, but several treatments such as medication and movement can reduce symptoms and help improve the overall quality of life. Another area of interest is diet. Although experts don’t recommend a specific ankylosing spondylitis diet, people living with this condition may benefit from eating a healthy, balanced diet rich in fruits, vegetables, lean proteins, whole grains, and plenty of omega-3 fatty acids. 

What is the best diet for ankylosing spondylitis? 

The research is limited on the connection between diet and ankylosing spondylitis symptoms. According to a 2018 study review, there is little evidence that diet influences the severity of ankylosing spondylitis. However, anecdotal data from this study review found that many ankylosing spondylitis patients believe that diet affects their symptoms and have adjusted their eating to try and improve symptoms.

“Typically, an anti-inflammatory diet is going to help fight inflammation and prevent other chronic diseases from occurring,” says Mary Wirtz, a clinical registered dietician. So, if an individual with any inflammatory condition including ankylosing spondylitis is interested in making dietary changes, a dietary pattern aimed at reducing inflammation is a good place to start.

More specifically, ankylosing spondylitis can be supported with a low-inflammation diet like the Mediterranean or DASH diet, which prioritizes high fiber, low-fat eating, with lots of fresh fruits and vegetables, explains Jacob Hascalovici, MD, the chief medical officer at Clearing and a clinical assistant professor at the Albert Einstein College of Medicine. If changing the diet leads to weight loss, then the spine needs to hold less weight which, in itself, can decrease pain.

People with ankylosing spondylitis may also be at a greater risk of developing inflammatory bowel disease (IBD), according to data from a 2019 study review. With that in mind, eating a diet that is IBD-friendly can help manage additional gastrointestinal symptoms. Some common diets recommended for IBD include the low FODMAP diet, a gluten-free diet, or a high fiber diet. 

There haven’t been many studies on a low-starch diet for ankylosing spondylitis, but some people have reported an improvement in symptoms. The theory is that gut bacteria called Klebsiella feed on starchy foods and multiply. The immune system produces antibodies to fight this bacteria, putting the body at risk for inflammation. The low-starch diet includes cutting starch by 40% (starchy foods include bread, pasta, grains, rice, peas, potatoes, and even bananas) for an extended period of time (at least six weeks).

There are various types of diets that can help you reduce inflammation and maintain overall health. What’s more, certain foods may either improve or worsen symptoms differently for each person.To track the impact diet has on your symptoms keep a food diary for a few weeks. Record what you eat, along with any observations about how you feel after a meal. Look for patterns and foods that provide a positive or negative response. 

7 foods to eat

When it comes to recommending specific foods for ankylosing spondylitis, one of the best ways to approach a healthier way of eating is to follow a Mediterranean style diet. This eating plan, which is touted for its anti-inflammatory benefits, is a high fiber, nutrient, and antioxidant-rich diet, also low in added sugars and saturated fats, according to Wirtz. More specifically, Wirtz says to focus on fruits, vegetables, beans and lentils, whole grains (oats, barley, quinoa, etc.), lean protein sources, including fish and skinless poultry, and omega-3 fatty acid-rich fat sources such as nuts, seeds, and plant-based oils. 

With that in mind, here are six foods, nutrients, and food groups that may benefit ankylosing spondylitis and potentially reduce disease activity. 

1. Calcium-rich food and beverages

Calcium can help keep bones strong and healthy, something that is critical for people with ankylosing spondylitis. Consuming enough dairy can decrease risk of osteoporosis. Low-fat dairy products like yogurt and cheese, tofu, dark leafy greens, broccoli, and canned salmon are a few examples of calcium-rich foods to consider. 

2. Vitamin D-rich foods and beverages 

Like calcium, vitamin D plays a significant role in keeping bones healthy and strong. A natural source of vitamin D (aka the sun!) is ideal, but not always possible. To boost your vitamin D intake, aim to include food and drinks rich in this essential, fat-soluble nutrient. Some good examples include fatty fish, vitamin D fortified milk, egg yolks, vitamin D fortified cereals (just make sure they’re low in sugar!), and low-fat, low-sugar yogurt. 

3. Omega-3 fatty acids

Foods high in omega-3 fatty acids are a critical part of an ankylosing spondylitis diet, according to the Spondylitis Association of America. Optimizing omega-3 fatty acid intake can help reduce inflammation and offset other chronic diseases such as diabetes and cardiovascular disease. Good examples of omega-3 rich foods include fatty fish like salmon, mackerel, and sardines. Plus, flax seeds, walnuts, and chia seeds. If you’re unable to get enough omega-3s from your diet, the National Institutes of Health Office of Dietary Supplements says a supplement may help prevent deficiencies. 

4. Fresh fruit

Brightly colored fruits like raspberries, strawberries, blueberries, and blackberries are a top pick for any healthy diet, especially for an ankylosing spondylitis diet. Berries are full of vitamins, minerals, fiber, and an anti-inflammatory antioxidant called anthocyanin. Other key fruits to include are cherries, which have anti-inflammatory benefits, and avocados (yes, they are a fruit!). Plus, any other fruit you enjoy snacking on or adding to a meal. 

5. Green leafy vegetables and other veggies

Vegetables, specifically, dark green leafy veggies like kale, spinach, Swiss chard, and collards, are packed with antioxidants, lutein, folate, magnesium, and other nutrients that boost overall health. Broccoli, which contains sulforaphane, an antioxidant with anti-inflammatory properties, is another vegetable to include in an ankylosing spondylitis diet. 

6. Whole grains

Eating whole grains like oat bran, lentils, brown rice, oatmeal, and quinoa boosts your fiber intake, which can help lower blood levels of C-reactive protein, and, consequently, reduce inflammation, according to the Arthritis Foundation. Whole grains can also help digestion and may decrease gastrointestinal symptoms of bloating and constipation. 

7. Lean proteins

Aim for a healthy dose of beans and legumes, which contain antioxidants, fiber, magnesium, iron, potassium, and other anti-inflammatory compounds. And, whenever possible, swap out protein sources high in saturated fat for leaner protein sources like turkey and chicken. They cause less inflammation in the body.

4 foods and drinks to avoid

The studies and research on the connection between food and ankylosing spondylitis symptoms are limited, making it difficult to recommend avoiding any specific food or drinks. That said, steering clear of foods that increase inflammation can lead to better health, and hopefully, help you feel better. Additionally, Dr. Hascalovici says people with ankylosing spondylitis would be well-served to avoid too many high-fat foods or sweets (which can lead to weight gain). Extra weight can exacerbate joint pain and raise inflammation levels. Here are four things to avoid. 

1. Added sugars

“Foods that cause inflammation and may worsen ankylosing spondylitis symptoms are high in added sugars,” Wirtz says. This includes cookies, sweets, desserts, sodas, pastries, and many packaged cereals, among others. Many of these items contain high-fructose corn syrup and other added sugars, which, according to research, can cause inflammation in the body when consumed in excessive amounts. Avoiding these foods can also help you maintain a healthy weight.

2. Saturated and trans fat

Wirtz says foods high in saturated fat like beef, pork, cheese, full-fat milk, and butter, among others, can trigger symptoms. Additionally, high-fat foods contribute to weight gain and increase inflammation. Trans fats like margarine, partially hydrogenated vegetable oils, and shortening are other items to eliminate or reduce. Data from a 2017 study found that trans-fatty acids increase your inflammatory profile. 

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3. Red meat

Red meat, is a food group you should consider eliminating or at least reducing. According to a 2021 cross-sectional study, a high intake of red meat is associated with early onset of rheumatoid arthritis. This is in addition to evidence that higher red meat consumption is also associated with an increased risk of certain cancers, cardiovascular disease, and other autoimmune diseases. 

4. Alcohol

According to the National Institute of Arthritis and Musculoskeletal and Skin Diseases, regularly consuming alcohol can interfere with the balance of calcium and the production of vitamin D, both crucial nutrients for bone health and people with ankylosing spondylitis. 

Is fasting good for ankylosing spondylitis?

Fasting is a way of eating that involves abstaining from food for hours or days. In general, you will eat during a specified time based on the plan you’re following. For example, alternate-day fasting recommends rotating days of eating with days of fasting. Time-restricted or intermittent fasting limits your calories to an eight to 12-hour window. Currently, no guidelines exist to recommend fasting for ankylosing spondylitis. However, some research supports fasting for other inflammatory conditions such as psoriatic arthritis. 

Moreover, a 2019 study found that fasting reduces inflammation and improves chronic inflammatory diseases. Fasting is a drastic diet change. If you’re considering this way of eating, talk to your healthcare provider before giving it a go. 

Other ways to treat ankylosing spondylitis 

In general, Dr. Hascalovici says people with ankylosing spondylitis should keep their overall stress levels low, exercise regularly, and try to maintain a healthy weight.

Standard treatment options for ankylosing spondylitis typically include physical therapy, medication, and exercise, according to the Mayo Clinic. Overall, the goal of any treatment plan for ankylosing spondylitis is to reduce pain and stiffness and improve quality of life. Also, many treatment plans emphasize preventing or delaying spinal deformity and other complications. 

Medications

Over-the-counter (OTC) and prescription medications are common treatment options for ankylosing spondylitis. Nonsteroidal anti-inflammatory drugs (NSAIDs) like naproxen and ibuprofen are the first line of defense to help relieve pain and stiffness and reduce inflammation. However, NSAIDs can result in gastrointestinal side effects like constipation. Fortunately, fiber is a good food for ankylosing spondylitis and it can also prevent constipation. 

If OTC meds are not enough, your physician may recommend prescription medications. According to the Mayo Clinic, some of the more common treatments for ankylosing spondylitis include biologics like Humira (adalimumab), Cimzia (certolizumab pegol), Enbrel (etanercept), Simponi (golimumab), Remicade (infliximab), Cosentyx (secukinumab), and Taltz (ixekizumab). 

Physical and occupational therapy

Your provider may recommend working with a physical or occupational therapist to improve joint function and learn new ways to protect joints, minimize pain, and conserve energy while performing daily tasks, according to the NIAMS. 

Stay active

Exercise is one of the top ways to manage ankylosing spondylitis symptoms. It helps with joint motion and function—along with managing weight. Consider adding posture training to an overall fitness routine. The Physical Activity Guidelines for Americans recommend that adults get a minimum of 150 minutes of moderate-intensity cardiovascular exercise each week. The guidelines also suggest two days of resistance training. People with ankylosing spondylitis should focus on low-impact activities like swimming, walking, yoga, and stretching. 

Join a support group

Finding strength by leaning on others is another way to manage the ups and downs of living with ankylosing spondylitis.

Supplements

If you’re not getting enough omega-3s, vitamin D, or calcium in your diet, you may want to consider adding a supplement. Fish oil supplements contain omega-3 fatty acids, which have anti-inflammatory effects, according to the American Heart Association. Vitamin D is another supplement that can be beneficial for ankylosing spondylitis. Research from a 2015 study found that supplementing with vitamin D consistently displays anti-inflammatory effects in human cell lines.

When to see your doctor

Ankylosing spondylitis is a medical condition that is best managed by a treatment team consisting of physicians, physical therapists, registered dietitians, and other healthcare experts. If you notice worsening symptoms or find that the pain and stiffness are interfering more with your daily life and preventing you from doing the things you used to enjoy, make an appointment with your doctor. If you are under the care of a specialist, like a rheumatologist or gastroenterologist, bring your concerns to them so they can provide professional medical advice specific to your condition and symptoms.