The Autoimmune Protocol (AIP) Diet for Acne Inversa: What the Evidence Actually Shows

Written by Dr. rer. nat. Dennis Alexander Kwiatkowski

The Autoimmune Protocol (AIP) diet — a strict elimination diet derived from paleo principles and marketed for autoimmune and inflammatory conditions — appears regularly in hidradenitis suppurativa (HS) patient communities, often presented as a transformative intervention with strong personal endorsements. The actual evidence base specific to HS is limited, the protocol itself is demanding, and the trade-offs between potential benefit and the costs of long-term restrictive eating deserve more honest examination than they typically receive online.

This article explains what AIP is, what specific evidence exists for it in HS, what is plausible mechanistically and what is not, and how to think about whether trying it is reasonable for an individual patient. It is not a how-to guide for the diet itself — that is appropriately the territory of a registered dietitian working with you individually.

Educational content only. Significant dietary changes, particularly elimination diets, should be undertaken with professional guidance from a registered dietitian, ideally one experienced in chronic inflammatory disease. This is especially important for patients with any history of disordered eating, who should not pursue elimination diets without specific clinical oversight.

Key takeaways

• AIP is a strict elimination diet that removes grains, legumes, dairy, eggs, nightshade vegetables, nuts, seeds, processed foods, alcohol, and several other categories during an elimination phase, followed by structured reintroduction.
• The evidence base specifically in HS is very limited — small case series and patient-reported observations rather than controlled trials. The broader autoimmune disease evidence base is also weaker than enthusiastic claims suggest.
• Mechanistically plausible mechanisms exist (anti-inflammatory effects, microbiome shifts) but plausible mechanism is not the same as demonstrated clinical benefit in HS.
• The costs are real: time, expense, social and family impact, potential nutritional gaps, and the risk of developing disordered eating patterns in vulnerable individuals.
• The honest position is that AIP is an experiment with weak evidence, not a treatment. Patients who try it should do so with professional guidance and a clear endpoint for evaluation.

What AIP actually is

The Autoimmune Protocol is a more restrictive variant of the paleolithic (“paleo”) diet, specifically designed by Sarah Ballantyne and others as a candidate intervention for autoimmune and chronic inflammatory conditions. The protocol has two phases.

Elimination phase. Typically 30 to 90 days. Eliminates grains (including pseudograins like quinoa), legumes (including peanuts and soy), dairy products, eggs, nightshade vegetables (tomatoes, potatoes, peppers, eggplant), nuts and seeds (including coffee, which is botanically a seed), refined sugars, processed foods, alcohol, and food additives. Permits meat, fish, most vegetables (excluding nightshades), fruits in moderation, healthy fats (coconut oil, olive oil, avocado), and bone broth.

Reintroduction phase. Foods are systematically reintroduced one at a time over weeks, monitoring for symptom recurrence. The goal is to identify a personalized long-term eating pattern that excludes specific foods to which the individual reacts while restoring as much variety as possible.

The protocol is restrictive enough that following it correctly requires substantial planning, meal preparation, and shopping discipline. Eating out, social meals, work catering, and travel become significantly more complicated. The expense — high-quality meat, fresh produce, specialty cooking fats, and replacement products — is meaningfully higher than ordinary dietary patterns.

What the actual evidence shows in HS

The empirical evidence for AIP specifically in HS is limited to small case reports, case series, and patient-reported observations. There are no randomized controlled trials, no large observational cohorts, and no systematic review-level evidence specific to AIP and HS.

The broader dietary evidence in HS — covered in more detail in companion articles on dairy, brewer’s yeast, and weight management — consists of several small observational studies and case series suggesting that:

• Brewer’s yeast exclusion produced reported improvement in approximately 70% of patients in observational cohorts
• Dairy exclusion produced reported improvement in approximately 83% of patients in one published case series
• Mediterranean dietary patterns are associated with lower HS activity in observational data
• Patients with HS have lower adherence to Mediterranean dietary patterns than population averages

What the AIP-specific evidence does not show:

• A controlled comparison of AIP versus other dietary patterns versus no dietary change
• A clear answer to which specific eliminations within AIP are doing the work, if any
• Long-term outcomes beyond several months
• Reproducible effect sizes across different patient populations

The honest reading: it is plausible that some patients with HS experience improvement on AIP, given the inclusion of both dairy and yeast-containing foods (sources with some weaker observational support) and the general anti-inflammatory composition of the protocol. It is not established that the full AIP elimination is more effective than less restrictive interventions, that benefit is sustained long-term, or that the effect size justifies the costs for most patients.

The Vural et al. 2024 review of dietary considerations in HS, published in the International Journal of Dermatology, examined the available literature systematically and concluded that the evidence supporting a substantial role of diet in HS remains weak, that dietary alterations alone should not be considered independent solutions, and that patients’ willingness to experiment with new diets makes them vulnerable to misleading interventions.

What is mechanistically plausible

The hypotheses behind AIP in inflammatory disease generally include:

Anti-inflammatory effects of food restriction. Elimination of common dietary triggers of inflammation (processed foods, refined sugars, certain inflammatory fatty acids) plausibly reduces systemic inflammatory burden. The Mediterranean diet, which shares some features with AIP without the strictest eliminations, has well-documented anti-inflammatory effects.

Microbiome modulation. The gut microbiome influences systemic inflammation and immune function, and dietary patterns substantially shape microbiome composition. Plausible mechanism; less clear that AIP specifically optimizes this versus other dietary patterns.

Reduction of food-specific inflammatory triggers. For individual patients with specific food sensitivities or intolerances (lactose, fructose, gluten in celiac disease), elimination produces real benefit. The question is whether AIP-level breadth of elimination is necessary versus targeted elimination of specific triggers identified through structured testing.

mTOR pathway modulation. Some dietary components (particularly leucine-rich animal proteins and milk proteins) activate the mTOR pathway, which has roles in inflammation and follicular biology relevant to HS. Western-pattern diets high in mTOR-activating foods have been hypothesized to aggravate HS. AIP reduces some but not all mTOR-activating components.

These mechanisms are plausible. They do not amount to a proven case that AIP specifically — versus less restrictive alternatives — is the right intervention for HS.

The costs that often go unmentioned

Discussion of dietary interventions in patient communities often focuses on potential benefits and downplays costs. An honest assessment of AIP requires acknowledging the real costs of long-term restrictive eating.

Nutritional gaps. A strictly executed AIP can produce inadequate intake of calcium (without dairy), vitamin D, B vitamins, iron (without legumes for vegetarians), fibre, and certain essential fatty acids if not deliberately planned. Long-term AIP without professional dietary guidance carries real nutritional risk.

Social and family impact. Restrictive diets affect family meal planning, social gatherings, work meals, travel, and dining out. The cumulative social cost over months to years is substantial and often underestimated at the start.

Financial cost. Quality meat, fresh produce, specialty fats, and replacement products are more expensive than conventional dietary staples. For households without disposable income, sustained AIP is financially burdensome.

Time and effort. Meal planning, shopping, and preparation for AIP requires substantial time investment. For working parents, shift workers, or anyone with limited time and energy, the practical burden is real.

Risk of disordered eating. Restrictive diets can be a path into disordered eating, particularly in patients with predisposition. The development of orthorexia — preoccupation with “pure” or “clean” eating that becomes psychologically harmful — is a documented risk of long-term restrictive eating patterns. Patients with any history of eating disorder, body image disturbance, or anxiety around food should be particularly cautious and ideally should not pursue elimination diets without clinical oversight.

Opportunity cost. Time, energy, and attention spent on strict dietary management is time not spent on other interventions with stronger evidence — medical management, lifestyle factors with better data (smoking cessation, weight management, friction reduction), or psychological wellbeing.

Disappointment. Patients who undertake significant restrictive eating with high hopes for transformation and experience little improvement often report substantial disappointment that affects their overall coping with the disease.

A reasonable approach

If a patient is considering AIP, several principles tend to produce better outcomes than enthusiastic ad hoc adoption.

Have realistic expectations. AIP is an experiment, not a treatment. It might help; it might not. Pre-commit to a defined trial period (typically 60 to 90 days) and a defined evaluation point after which you assess whether benefit is sufficient to justify continuation.

Work with a registered dietitian. This is not optional for safe elimination diets. A dietitian experienced in chronic inflammatory disease can identify nutritional gaps, structure reintroduction, and monitor for problems. In Germany, dietitian (Diätassistent or Ökotrophologe) consultation may be partially covered under GKV when prescribed for medical indications.

Do not stop medical therapy. AIP is at most an adjunct to evidence-based medical management. Patients who discontinue dermatology care or biologic therapy to pursue dietary management alone make a decision unsupported by current evidence.

Document carefully. Track symptoms, photographs, flare frequency, and pain levels through the elimination period. Without systematic tracking, attribution of any change to the diet is unreliable — too many other factors vary simultaneously.

Consider a less restrictive starting point. A Mediterranean-pattern diet, or targeted elimination of specific food categories with stronger HS-specific evidence (brewer’s yeast, dairy in some patients) carries far less burden than full AIP and may capture much of the potential benefit. Starting less restrictive is often more sustainable and more informative.

Reintroduce systematically if you eliminate. The reintroduction phase is where the actual personalized information emerges. Patients who stay on the strict elimination indefinitely without reintroduction usually accumulate restriction without benefit.

Stop if it is not working or is causing harm. A fair trial period followed by continuation only with clear benefit, rather than indefinite continuation regardless of effect, is the appropriate framework. Restrictive eating without benefit is pure cost.

When AIP is not appropriate

Specific situations where AIP should not be undertaken, or should not be undertaken without specific clinical oversight:

• Any history of an eating disorder. Including current or past anorexia, bulimia, binge eating disorder, orthorexia, or other disordered eating patterns.
• Pregnancy or breastfeeding. The increased nutritional demands of pregnancy and lactation make restrictive eating particularly risky.
• Active growth periods (children, adolescents). Restrictive eating during growth is risky and rarely appropriate.
• Underweight or rapid weight loss. Further restriction in patients with already-low body weight is harmful.
• Pre-existing nutritional deficiencies. Should be corrected first; further restriction may worsen them.
• Significant mental health conditions. Restrictive eating can interact with depression, anxiety, OCD, and other conditions in ways that worsen mental health.
• Inability to access or afford the diet sustainably. Half-attempted elimination produces costs without informational benefit.

If any of these apply, alternative approaches — Mediterranean dietary pattern, targeted symptomatic elimination, focus on other modifiable factors — are more appropriate than full AIP.

Other dietary approaches worth knowing about

For patients interested in dietary intervention but unwilling or unable to commit to full AIP, several alternatives have either better evidence or lower cost:

Mediterranean dietary pattern. Well-evidenced anti-inflammatory pattern across many chronic conditions. Permits more variety than AIP, is socially manageable, and has the strongest broader evidence base. Available evidence in HS specifically is observational but consistent in showing lower disease activity with higher Mediterranean diet adherence.

Targeted elimination based on observed triggers. Some patients identify specific foods that consistently precede flares for them. A targeted elimination of those specific items — without committing to full AIP — captures the personal benefit without unnecessary restriction.

Brewer’s yeast elimination. Has the strongest specific evidence within HS-relevant elimination diets and is less burdensome than full AIP. The dedicated article on brewer’s yeast and HS covers this in detail.

Dairy reduction. Reasonable evidence base in HS specifically; relatively manageable as a single category to eliminate. The companion article on dairy and HS covers the evidence.

Mediterranean plus specific eliminations. A reasonable compromise position — adopt a Mediterranean dietary base, eliminate categories with HS-specific evidence (brewer’s yeast, dairy, ultra-processed foods, refined sugars), without the full AIP exclusions.