Understanding What Foods Flare Up Ankylosing Spondylitis

October 11, 2025 •

4 min read

While there is no single diet that can cure or definitively prevent ankylosing spondylitis (AS) flare-ups, a staggering number of individuals report that specific dietary triggers worsen their symptoms. Understanding what foods flare up ankylosing spondylitis is a key part of managing the chronic inflammation associated with this condition.

Quick Summary

Chronic inflammation in ankylosing spondylitis may be triggered or worsened by certain dietary components. Limiting high-sugar and high-fat processed foods, red meat, alcohol, and potentially gluten-containing grains can help manage symptoms by reducing systemic inflammation. An anti-inflammatory diet focusing on whole foods, healthy fats, and fiber is often recommended.

Key Points

Processed sugars and refined grains are inflammatory: Excessive intake of added sugars and refined carbohydrates, found in many processed foods and beverages, can significantly increase systemic inflammation.
Avoid unhealthy saturated and trans fats: Saturated fats from red meat and dairy, and trans fats from processed foods, are known to promote inflammation and should be limited.
Reduce red and processed meat intake: Compounds in red meat and the high sodium content of processed meats can aggravate inflammation in individuals with AS.
Watch for individual triggers like gluten and starch: For some, gluten-containing grains or starchy foods may worsen symptoms due to the gut-immune connection common in AS.
Limit alcohol and other stimulants: Excessive alcohol can interfere with medication, damage the gut, and weaken bones, while caffeine may also act as a trigger for some individuals.
Consider an anti-inflammatory diet: Adopting an overall healthy eating pattern, such as the Mediterranean diet, can help reduce inflammation and manage weight, which is beneficial for AS management.

The Connection Between Diet and Inflammation

Ankylosing spondylitis (AS) is a chronic, inflammatory autoimmune disease that primarily affects the spine and sacroiliac joints. The hallmark of AS is inflammation, and diet is a significant factor known to influence inflammation levels throughout the body. While a specific, universal AS diet does not exist, many patients find relief by adopting an anti-inflammatory eating pattern and avoiding particular foods they identify as triggers. These food triggers can exacerbate the autoimmune response and contribute to painful flare-ups.

Sugary and Processed Foods

Excessive intake of added sugars and refined carbohydrates is consistently linked to increased inflammation. These foods can cause a spike in blood sugar, which triggers the release of inflammatory messengers. This category includes more than just candy and desserts; it also encompasses many processed foods and sugary beverages.

Foods to limit or avoid:
- Sodas, juices with added sugar, and energy drinks.
- Baked goods, pastries, and candy.
- Refined grains, such as white bread, white rice, and crackers.
- Packaged snacks and pre-made sauces that contain added sugars.

Unhealthy Fats

Not all fats are created equal. While healthy fats like omega-3 fatty acids are anti-inflammatory, saturated fats and trans fats promote inflammation.

Saturated Fats: Found in high concentrations in red meat and full-fat dairy products, these fats can aggravate inflammation.
Trans Fats: Often listed as "partially hydrogenated oils" on food labels, trans fats should be avoided altogether due to their strong link to inflammation and heart disease. They are commonly found in fried foods, fast food, and certain baked goods.
Omega-6 Fatty Acids: While essential in moderation, many Western diets contain an excess of omega-6 fatty acids compared to omega-3s, which can lead to a pro-inflammatory state. Common sources include corn, soy, and sunflower oils, as well as mayonnaise and salad dressings.

Red and Processed Meats

Red meat, including beef, lamb, and pork, contains compounds like saturated fat and an inflammatory marker called Neu5Gc that can worsen inflammation. Processed meats, such as bacon, sausage, and deli meats, are often high in sodium and preservatives, further contributing to inflammation. Reducing or eliminating these from the diet may lead to symptom improvement for some individuals.

Gluten and Starch

For some people with AS, particularly those with gut issues, grains containing gluten (wheat, barley, rye) may trigger inflammation. Given the known link between AS and inflammatory bowel diseases like Crohn's disease, it is theorized that a gluten-free or low-starch diet could be beneficial for a subgroup of patients. A low-starch diet limits starches that may feed certain gut bacteria (like Klebsiella) which have been hypothesized to contribute to AS inflammation.

Alcohol and Caffeine

Excessive alcohol consumption has several detrimental effects on individuals with AS. It can:

Aggravate inflammation.
Decrease nutrient absorption.
Interact negatively with AS medications, especially NSAIDs.
Weaken bones and increase the risk of osteoporosis, a common complication of AS.

Some people also find that caffeine can be a trigger, particularly in caffeinated beverages like coffee and soda.

Nightshade Vegetables and Dairy

Certain foods are individual triggers. Nightshade vegetables (tomatoes, potatoes, peppers, eggplant) are a common source of anecdotal reports, though scientific evidence for a link with AS flares is lacking. Similarly, some people with AS report that dairy products worsen their inflammation, though there is no consensus on this. The best way to identify these personal triggers is to eliminate them temporarily and observe any changes in symptoms.

Comparison of Pro-Inflammatory vs. Anti-Inflammatory Foods


Category	Pro-Inflammatory (Foods to Limit)	Anti-Inflammatory (Foods to Favor)
Carbohydrates	Refined grains (white bread, pasta), added sugars, processed snacks, high-starch foods (potatoes)	Whole grains (quinoa, brown rice, oats), fruits, non-starchy vegetables, legumes
Fats	Saturated fats (red meat, full-fat dairy), trans fats (fried foods, margarine), excess omega-6 oils	Omega-3 rich foods (fatty fish like salmon, flaxseed, walnuts), olive oil, avocados
Protein	Red meat (beef, pork), processed meats (bacon, sausage)	Fatty fish, lean poultry, legumes, nuts, seeds
Drinks	Sugary drinks, excessive alcohol, caffeine	Water, herbal teas
Other	Highly processed foods, artificial sweeteners, high-sodium foods	Fresh herbs and spices (turmeric, ginger, garlic), colorful fruits and vegetables

How to Identify Your Personal Triggers

Since dietary triggers can vary between individuals, keeping a food and symptom diary is highly recommended. This practice involves documenting your meals and any subsequent symptoms (e.g., pain, stiffness, fatigue). An elimination diet, conducted under the supervision of a healthcare provider or registered dietitian, can also help pinpoint specific food sensitivities. Remember that any dietary change should support, not replace, standard medical treatment for AS.

Conclusion

While diet alone is not a cure for ankylosing spondylitis, what you eat can significantly impact your inflammation levels and overall well-being. By understanding what foods flare up ankylosing spondylitis, such as processed sugars, unhealthy fats, and red meat, and opting for a diet rich in anti-inflammatory whole foods, individuals can better manage their symptoms. Working closely with a healthcare professional is crucial to develop a personalized nutrition plan that complements medical treatment and improves quality of life. The Spondylitis Association of America offers valuable resources on managing AS with diet.

Frequently Asked Questions

There is no single best diet for AS, but an anti-inflammatory approach, such as the Mediterranean diet, is often recommended. This diet emphasizes whole foods, healthy fats, fruits, vegetables, and lean protein, while limiting processed foods, sugar, and unhealthy fats.

While not a trigger for everyone, some individuals with AS, particularly those with gut sensitivity, may experience flares from gluten. Since AS is linked to gut inflammation, eliminating gluten on an individual basis and monitoring symptoms may be helpful.

Not necessarily. Some people with AS find that dairy products exacerbate their inflammation, but this is a personal sensitivity. It is best to track your symptoms after consuming dairy. If you find it to be a trigger, consider alternative calcium sources like almonds, fortified plant milks, and dark leafy greens.

Red and processed meats contain saturated fats and other compounds that can promote inflammation. Many AS patients report symptom improvement by limiting or avoiding red meat, making lean proteins like fish or poultry better choices.

The low-starch diet is based on the theory that certain gut bacteria, fed by starch, may trigger inflammation in AS. While some patients report benefits, scientific evidence is limited. The diet involves reducing starchy foods like bread, pasta, and potatoes, and increasing protein and non-starchy vegetables.

Foods rich in omega-3 fatty acids (fatty fish, flaxseed), antioxidants (colorful fruits and vegetables), and fiber (whole grains, legumes) can help reduce inflammation. Anti-inflammatory herbs like turmeric and ginger can also be beneficial.

Excessive alcohol can worsen inflammation, interact with medications, and contribute to osteoporosis, all of which can increase the risk of an AS flare. It is best to limit or avoid alcohol, especially if you are taking medication.