The Role of Foods in Autoimmunity: Exploring the Autoimmune Protocol (AIP) Diet

Author: Rohan Smith | Functional Medicine Practitioner | Adelaide, SA

Quick Answer

The Autoimmune Protocol (AIP) diet is a structured elimination and reintroduction approach designed to help identify foods that may aggravate inflammation or immune activity in people with autoimmune conditions. It focuses on removing common dietary triggers, prioritising nutrient-dense foods, and systematically reintroducing foods to assess individual tolerance. Research suggests this approach may help some individuals manage autoimmune-related symptoms, although responses vary and clinical supervision is recommended (1–3).

Understanding Autoimmune Disease

Autoimmune diseases occur when the immune system mistakenly targets the body’s own tissues, leading to chronic inflammation and tissue damage. Conditions such as rheumatoid arthritis, systemic lupus erythematosus, multiple sclerosis, and autoimmune thyroid disorders are commonly associated with symptoms including joint pain, digestive disturbances, and fatigue commonly seen in autoimmune conditions (4–6).

Core Concept: Why Food Matters in Autoimmunity

Food does more than provide energy. Dietary patterns can influence inflammatory signalling, gut barrier integrity, and immune tolerance. Certain foods may increase intestinal permeability or immune activation in susceptible individuals, while others support micronutrient status, antioxidant defences, and immune regulation (7–9). This relationship underpins the rationale for dietary interventions such as the AIP diet.

What Is the Autoimmune Protocol (AIP) Diet?

The AIP diet is a therapeutic variation of the Paleo diet developed specifically for people with autoimmune conditions. It emphasises:

• Temporary elimination of foods commonly associated with immune activation or inflammation
• High intake of nutrient-dense, whole foods
• A structured reintroduction phase to identify personal food triggers

The goal is not permanent restriction, but improved symptom awareness and dietary personalisation (2,3).

Foods Typically Eliminated During AIP

During the elimination phase, foods commonly removed include:

• Grains: wheat, rice, oats, corn
• Dairy: milk, cheese, yoghurt, butter
• Legumes: beans, lentils, soy, peanuts
• Nightshades: tomatoes, potatoes, eggplants, capsicum
• Nuts and seeds: including seed oils
• Eggs
• Processed foods: refined sugars, additives, preservatives

These foods are removed because they may influence gut permeability, immune reactivity, or inflammatory pathways in some individuals (8–11).

Foods Emphasised on the AIP Diet

Despite its restrictions, the AIP diet encourages a wide range of nutrient-dense foods:

• Vegetables: leafy greens, cruciferous and root vegetables (excluding nightshades)
• Fruit: consumed in moderation, particularly berries
• Animal proteins: grass-fed meats, poultry, and wild-caught fish
• Healthy fats: olive oil, avocado oil, coconut oil
• Herbs: fresh culinary herbs for flavour and phytonutrients
• Fermented foods: such as sauerkraut and kimchi, where tolerated

This pattern supports micronutrient intake, antioxidant exposure, and gut microbiome diversity, which are relevant to immune regulation (7,9,12).

The Reintroduction Phase: A Critical Step

After several weeks on the elimination phase, foods are reintroduced one at a time in a structured manner. This process helps identify foods that may trigger symptoms such as joint pain, digestive discomfort, fatigue, or skin reactions. Reintroduction is essential to avoid unnecessary long-term restriction and to establish a sustainable, individualised diet (2,3).

When the AIP Diet May Be Considered

The AIP diet may be considered for individuals with autoimmune conditions who continue to experience symptoms despite standard care, particularly when digestive symptoms, food sensitivities, or unexplained inflammation are present. It is commonly explored in conditions such as autoimmune thyroid conditions such as Hashimoto’s (4–6).

Limitations and Considerations

The AIP diet is not appropriate for everyone. Potential limitations include nutritional inadequacy if poorly implemented, social and psychological burden, and the risk of overly restrictive eating patterns. Evidence supporting AIP is still emerging, with most studies being small or observational. Clinical supervision is recommended, particularly for individuals with complex medical histories or nutritional vulnerabilities (2,13,14).

Next Steps: A Functional Medicine Perspective

Dietary strategies are often most effective when combined with a broader assessment of gut health, nutrient status, stress physiology, and immune regulation. Exploring the role of the gut microbiome and immune regulation may provide additional insight into symptom drivers and guide a more targeted, personalised plan.

Key Insights

• The AIP diet is a structured elimination and reintroduction approach, not a lifelong restriction
• Food choices may influence immune activity and inflammatory pathways in susceptible individuals
• Responses to AIP vary, highlighting the need for personalisation
• Professional guidance helps minimise risk and optimise outcomes

Find Out What’s Driving Your Autoimmunity

If you are looking for functional medicine–led nutritional support to explore dietary strategies for autoimmune-related symptoms, Elemental Health and Nutrition offers a personalised, evidence-informed approach focused on safety, clarity, and long-term sustainability.

References

1. Aranow C. Pathogenesis of autoimmune disease. J Clin Invest. 2011.
2. Ballantyne S, et al. Clinical outcomes of the Autoimmune Protocol diet in inflammatory bowel disease. Inflamm Bowel Dis. 2019.
3. Konijeti GG, et al. Efficacy of the Autoimmune Protocol diet for inflammatory bowel disease. Crohns Colitis 360. 2017.
4. Weetman AP. Autoimmune thyroid disease. Autoimmunity. 2004.
5. Smolen JS, et al. Rheumatoid arthritis. Lancet. 2016.
6. Dinas PC, et al. Fatigue in autoimmune disease. Autoimmun Rev. 2019.
7. Calder PC. Nutrition, immunity and inflammation. Proc Nutr Soc. 2013.
8. Fasano A. Leaky gut and autoimmune disease. Clin Rev Allergy Immunol. 2012.
9. Belkaid Y, Hand TW. Role of the microbiota in immunity. Cell. 2014.
10. Vojdani A. Lectins, agglutinins, and autoimmune reactivity. Altern Ther Health Med. 2015.
11. Manzel A, et al. Role of Western diet in autoimmune diseases. Autoimmun Rev. 2014.
12. DeFilippis F, et al. Diet and gut microbiota interaction. Nat Rev Gastroenterol Hepatol. 2020.
13. Mayer EA, et al. Gut–brain–immune interactions. Gastroenterology. 2015.
14. Krebs NF, et al. Risk of restrictive diets. Pediatrics. 2019.
15. Gibson PR, et al. Food intolerance and immune activation. Gut. 2015.