What Is the Autoimmune Protocol (AIP) Diet: Does It Work?

Perhaps you have heard of this new diet that recently hit the scene? The Autoimmune Protocol diet, AIP for short, is a relatively new way of eating that claims to reduce inflammation, improve immune function, and help manage the symptoms of autoimmune diseases. 

What exactly is the AIP diet, and what should you know before you get started? 

What is the Autoimmune Protocol Diet? 

API diet

The Autoimmune Protocol (AIP) diet is an elimination-focused diet that may help individuals struggling with autoimmune diseases. 

As an elimination diet, it involves avoiding certain foods for several weeks while carefully monitoring for changes in health.

AIP is rooted in the Paleo diet, although it is considered to be even more restrictive. It includes mostly vegetables (with some exceptions) and animal proteins from meats while eliminating grains, legumes, nightshade vegetables, eggs, dairy, nuts and seeds, coffee, alcohol, refined sugars, and processed foods. 

Who Can Benefit From the AIP Diet?

AIP is an autoimmune diet designed to reduce inflammation and help control symptoms of autoimmune conditions. 

An autoimmune disease is a condition that develops when your immune system mistakenly attacks the healthy tissues of your own body. There are over 80 identified autoimmune diseases, including psoriasis, multiple sclerosis, fibromyalgia, rheumatoid arthritis, lupus, Hashimoto’s thyroiditis, and inflammatory bowel disease (IBD) (1).

Common symptoms of autoimmune conditions include fatigue, headache, digestion or gut issues, pain, swelling, hair loss, low-grade fever, skin rashes, and stiff or painful joints.

According to the National Institute of Health (NIH), more than 24 million people are affected by autoimmune disorders in the United States (1). 

How Does This Diet Work?

While the root cause of autoimmune conditions is not entirely understood, one hypothesis poses that imbalances in the gut microbiome or healthy gut bacteria and low-grade inflammation can result in damage to the gut wall. 

This theory suggests that autoimmune diseases are triggered as the result of tiny holes or “leaks” in the gut wall, also known as a leaky gut syndrome.

It is thought that these holes may allow bacteria, food particles, and digestive enzymes to escape through the walls of the gut lining in the digestive system.

The leaked bacteria and food particles may then prompt an immune system response, resulting in widespread inflammation and further damage to healthy body tissues.

Additionally, complex interactions between genetics, the environment, chronic stress, and the immune system may contribute to the formation of autoimmune diseases (1-3). 

The principle behind AIP is that avoiding gut-irritating foods will reduce inflammation and allow the leaky gut time to heal. 

Proponents of the AIP diet claim that this diet improves the walls of the gut and resets the immune system by identifying and eliminating foods that trigger inflammation in the body.

Few studies have investigated leaky gut syndrome; however, researchers do agree that certain diseases are associated with greater intestinal wall permeability (4). 

It is important to note that AIP is not a cure for autoimmune diseases. However, it may help you manage the problem symptoms of your autoimmune disease and improve gut health and functioning. 

Foods to Avoid

The AIP diet is an elimination diet, meaning that certain foods are removed from the menu for 30 days or longer while the gut heals. 

Foods eliminated as part of the AIP diet include:

  • Grains and gluten, including wheat and rice
  • Legumes, such as peanuts, chickpeas, beans, and lentils
  • Refined and added sugars, such as those found in cookies and cakes
  • Nuts and seeds, including items derived from this food group such as coffee, chocolate, cumin, coriander, and certain vegetable seed oils.
  • Vegetables in the nightshade family; include tomatoes, potatoes, peppers, and eggplants.    
  • Eggs 
  • Dairy, including milk, cheese, butter, and ghee
  • Alcohol
  • Processed foods
  • Food additives
  • Artificial sweeteners
  • Blue-green algae products, including chlorella and spirulina

Fruits remain a controversial component in the AIP diet. Some approaches recommended eliminating sugar, including fructose- a natural sugar found in fruits. The Paleo Way recommends limiting fructose intake to no more than 20 grams per day (5). This equates to about two servings of fruit, depending on the type. Fruits that are higher in fructose include kiwis, raisins, watermelon, bananas, grapes, and apples. Certain berries, such as raspberries and strawberries, are lower in fructose.

The AIP diet also avoids nonsteroidal anti-inflammatory drugs (NSAIDs), including ibuprofen and aspirin. Be sure to speak with your doctor before stopping an aspirin regimen. 

Foods to Eat

The list of foods that you cannot eat on the AIP diet may sound overwhelming at first, but here comes the fun part of the diet… the foods that you can eat! The AIP diet includes a variety of foods that are rich in vitamins, nutrients, minerals, and amino acids.

Be sure to stock your fridge and pantry with the following:

  • Vegetables, except for nightshades
  • Lean meat
  • Organ meats
  • Olive oil
  • Fermented foods that don’t contain dairy. Examples include kombucha, pickled vegetables, sauerkraut, kimchi, and non-dairy kefir. 
  • Sweet potatoes
  • Cassava and cassava flour
  • Arrowroot starch
  • Coconut, coconut oil, and coconut milk
  • Maple syrup and honey, in small amounts
  • Avocado and avocado oil
  • Bone broth
  • Gelatin from grass-fed beef
  • Animal fats, such as lard
  • Vinegars, including red wine, balsamic, and apple cider vinegar
  • Green teas, black teas, and herbal teas not derived from seeds
  • Fruits, in moderation

Individuals following the AIP diet are encouraged to consume a wide variety of vegetables, with an emphasis on cruciferous vegetables. Examples include broccoli, cauliflower, and cabbage. Additional veggies that you can load your plate with include green beans, mushrooms, beets, and carrots, to name a few. While technically considered a legume, green beans are generally accepted as part of the AIP diet. 

Good quality seafood and shellfish, especially fatty fish, are emphasized in this diet due to their omega-3 content. Omega-3 fatty acids are involved in regulating the body’s inflammatory response and work to reduce inflammation. Research has consistently found a connection between higher omega-3 fatty acid intake and reduced inflammation in the body (6, 7). Additionally, seafood and shellfish are excellent protein sources. Foods like salmon, tuna, halibut, and sardines are good sources of omega-3s. You should aim to consume high-quality seafood at least three times per week, although more is better.

Honey and maple syrup are controversial components of the AIP diet, with some proponents recommending natural sugars in small amounts, while others recommend removing added sugars entirely. Currently, the paleo autoimmune protocol recommends eliminating all natural and artificial sweeteners from the diet, including honey and maple syrup (5). 

How Long Should You Follow the AIP Diet

The AIP diet is a type of elimination diet, meaning that you follow a strict eating plan for a set number of weeks before gradually adding foods back into the diet while monitoring for symptoms. Elimination-type diets are useful for identifying food sensitivities, intolerances, and allergies. 

There are two phases: the elimination phase and the reintroduction phase. In general, the typical amount of time spent in the elimination phase is about 4 to 6 weeks. This allows time for the healing process. 

The final step is the reintroduction phase. In this phase, eliminated foods or food groups are slowly reintroduced into the diet one at a time over 2 to 3 days. During this time, you can carefully monitor for symptoms of inflammation. Some people may find it useful to keep a food journal or symptom diary during this phase to monitor for change.

Examples of symptoms include skin changes or rash, joint pain, headaches, fatigue, bloating, stomach pain, and digestive problems. A return in symptoms could indicate a food intolerance, and you may consider eliminating that food from your diet. 

Some individuals may decide to adopt the AIP diet as part of long-term lifestyle changes due to its nutrient content or because of the overall reduction in autoimmune disease symptoms.

However, you may want to consult a registered dietitian or healthcare professional if you plan to eliminate many foods from your diet, as this could result in nutritional deficiencies. 

What Does the Research Say?

AIP is a relatively new dietary pattern and much of the science surrounding its benefits remains mostly theoretical. There is currently a lack of clinical trials evaluating the efficacy of AIP, which makes it difficult to provide concrete recommendations about this diet. 

However, preliminary studies do suggest that AIP may be beneficial for individuals with an autoimmune disease. 

One study from 2019 looking at the impact of AIP on 15 adults with IBD found that participants experienced an improvement in disease symptoms and quality of life as early as three weeks after dietary modifications (8). 

Similarly, a 2017 study that examined the effect of AIP on adults with active IBD found that participants had significant improvements in symptoms following the 6-week elimination and 5-week maintenance phase (9). 

Additionally, research has noted that autoimmune diseases, including food allergies, celiac disease, and IBD, are associated with greater gut permeability or porousness (4, 10, 11). However, further research is needed to explore the relationship between leaky gut syndrome and autoimmune diseases. 

The Final Word

Living with an autoimmune condition presents a number of health challenges and side effects. The AIP diet may help reduce inflammation and improve the quality of life for the many people struggling with autoimmune diseases. Theoretically, AIP may also help heal a leaky gut. However, clinical trials are needed to support this hypothesis. 

Additionally, this diet may encourage individuals to eat healthier, as it restricts processed foods, refined carbohydrates, calories, and added sugars while emphasizing lean meats, plants, and veggies. This diet may also help with weight control and obesity as it requires careful meal plans and can be used as the building blocks for a weight loss program.

It is important to note that there is limited research exploring the efficacy of the AIP diet, and some people may find this elimination-focused diet has too many restrictions. Individuals with a history of eating disorders may want to avoid the AIP diet due to the restrictive nature. Furthermore, people with multiple food aversions or food allergies may find that this diet does not offer enough variety to meet nutritional needs.  

Keep in mind that eating habits and food choices are only one piece of the puzzle when it comes to managing an autoimmune disease. Getting enough sleep and exercise, stress management, and quitting smoking are also important lifestyle factors that may help reduce inflammation in the body. Consider talking to a health professional to determine if the AIP diet is right for you.


  1. “Autoimmune Diseases.” National Institute of Environmental Health Sciences, U.S. Department of Health and Human Services, www.niehs.nih.gov/health/topics/conditions/autoimmune/index.cfm.
  2. Minihane, Anne M et al. “Low-grade inflammation, diet composition and health: current research evidence and its translation.” The British journal of nutrition vol. 114,7 (2015): 999-1012. doi:10.1017/S0007114515002093
  3. Belkaid, Yasmine, and Timothy W Hand. “Role of the microbiota in immunity and inflammation.” Cell vol. 157,1 (2014): 121-41. doi:10.1016/j.cell.2014.03.011
  4. Arrieta, M C et al. “Alterations in intestinal permeability.” Gut vol. 55,10 (2006): 1512-20. doi:10.1136/gut.2005.085373
  5. “Autoimmune Protocol.” The Paleo Way, thepaleoway.com/autoimmune-protocol.
  6. Simopoulos, Artemis P. “Omega-3 fatty acids in inflammation and autoimmune diseases.” Journal of the American College of Nutrition vol. 21,6 (2002): 495-505. doi:10.1080/07315724.2002.10719248
  7. Li, Kelei et al. “Effect of marine-derived n-3 polyunsaturated fatty acids on C-reactive protein, interleukin 6 and tumor necrosis factor α: a meta-analysis.” PloS one vol. 9,2 e88103. 5 Feb. 2014, doi:10.1371/journal.pone.0088103 
  8. Chandrasekaran, Anita et al. “An Autoimmune Protocol Diet Improves Patient-Reported Quality of Life in Inflammatory Bowel Disease.” Crohn’s & colitis 360 vol. 1,3 (2019): otz019. doi:10.1093/crocol/otz019
  9. Konijeti, Gauree G et al. “Efficacy of the Autoimmune Protocol Diet for Inflammatory Bowel Disease.” Inflammatory bowel diseases vol. 23,11 (2017): 2054-2060. doi:10.1097/MIB.0000000000001221
  10. Visser, Jeroen et al. “Tight junctions, intestinal permeability, and autoimmunity: celiac disease and type 1 diabetes paradigms.” Annals of the New York Academy of Sciences vol. 1165 (2009): 195-205. doi:10.1111/j.1749-6632.2009.04037.x
  11. Groschwitz, Katherine R, and Simon P Hogan. “Intestinal barrier function: molecular regulation and disease pathogenesis.” The Journal of allergy and clinical immunology vol. 124,1 (2009): 3-20; quiz 21-2. doi:10.1016/j.jaci.2009.05.038
Allison Herries

Allison Herries, MS, RDN, CDN - Contributor

Allison Herries, MS, RDN, CDN, is a registered dietitian and freelance nutrition writer with more than five years of experience in the nutrition and dietetics field. Her specialties include diet and aging, nutrition for older adults, intuitive eating, nondiet approaches to health, and nutrition research. Allison loves food and nutrition and she loves sharing her nutrition knowledge with the world.

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