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Autoimmune Protocol (AIP) Diet

The Autoimmune Protocol (AIP) diet — an extension of the Paleolithic diet — is a multiphase elimination diet used to reduce symptoms of autoimmune diseases. It’s based on the theory that certain foods trigger inflammation or cause an imbalanced gut microbiome. A few open-label, uncontrolled studies suggest improvements in quality of life, IBD disease activity, and inflammatory markers, but more research is needed.

Our evidence-based analysis on autoimmune protocol (aip) diet features 8 unique references to scientific papers.

Research analysis led by and reviewed by the Examine team.
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Summary of Autoimmune Protocol (AIP) Diet

Primary information, health benefits, side effects, usage, and other important details

What is the AIP diet?

The AIP diet is an extension of the Paleolithic diet and was developed by Sarah Ballantyne, PhD, who earned her doctorate in medical biophysics. [1] She authored her AIP diet book in 2014 after experimenting with a Paleolithic diet to improve her own health.

The diet is based on the theory that certain foods could trigger inflammation or cause dysbiosis (an unbalanced gut microbiome), worsening autoimmune disease activity. It is a multiphase elimination diet that encourages the inclusion of bone broth and fermented foods, as well as lifestyle habits such as sleep hygiene, physical activity, and stress management.

How is the AIP diet implemented?

The AIP is an elimination diet that initially restricts:

  • Grains

  • Legumes

  • Nightshade vegetables

  • Dairy

  • Eggs

  • Nuts

  • Seeds

  • Ultra-processed oils

  • Coffee

  • Refined or artificial sweeteners

  • Alcohol

  • Food additives

  • Non-steroidal anti-inflammatory drugs (NSAIDS)

These are replaced with:

  • Approved vegetables

  • Fruits

  • Certain varieties of yam and potato

  • Minimally processed meat

  • Minimally processed vegetable oils

  • Maple syrup

  • Honey

  • Vinegar

  • Bone broth

  • Nondairy fermented foods

Protocols vary, and some recommend limiting saturated fats, omega-6 fats, natural sugars, and fruits. The length of the elimination phase depends on how quickly a person notices improvements. During the reintroduction phase, foods are introduced individually, about one week apart. The AIP also encourages health-supporting lifestyle habits such as sleep hygiene, physical activity, and stress management.

What are the benefits of the AIP diet?

Current research on the AIP is limited to open-label (where participants are aware of their treatment), uncontrolled exploratory studies that have examined the effects of the diet on inflammatory bowel disease (IBD) and Hashimoto’s thyroiditis. Improvements in quality of life, IBD disease activity, and markers of inflammation were reported, but randomized controlled trials (RCTs) are needed to confirm these early findings. [2] 

The AIP diet could improve health by encouraging people to increase their physical activity and improve their sleep and stress management habits. It could also increase fruit, vegetable, and fiber intake while reducing the consumption of highly processed foods. Diets high in fiber and polyphenols (beneficial compounds in plants) have been shown to reduce markers of intestinal permeability (or “leaky gut”) and increase quality of life in people with IBD. [3] 

What are the drawbacks of the AIP diet?

The AIP is a restrictive diet that may be difficult to adhere to and could place people at risk of nutrient deficiencies if they follow the elimination phase for too long.

Research on the AIP is extremely limited, and the current studies don’t provide strong evidence that the diet itself is improving disease activity. The studies experienced high dropout rates; a few of the participants with IBD experienced worsening disease activity; and no markers of thyroid function or thyroid antibodies changed after 10 weeks on the AIP diet in women with Hashimoto’s thyroiditis. Without control groups, it’s impossible to determine whether the observed improvements happened as a result of time, the placebo effect, or other factors. Notably, all three studies on the AIP for IBD relief came from a single experiment done by one research group on the same participants.

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Human Effect Matrix

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The Human Effect Matrix summarizes human studies to tell you what effects Autoimmune Protocol (AIP) Diet has on your body, how much evidence there is, and how strong these effects are.

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Grade Level of Evidence
Robust research conducted with repeated double-blind clinical trials
Multiple studies where at least two are double-blind and placebo controlled
Single double-blind study or multiple cohort studies
Uncontrolled or observational studies only
Level of Evidence
? The amount of high quality evidence. The more evidence, the more we can trust the results.
Outcome Magnitude of effect
? The direction and size of the supplement's impact on each outcome. Some supplements can have an increasing effect, others have a decreasing effect, and others have no effect.
Consistency of research results
? Scientific research does not always agree. HIGH or VERY HIGH means that most of the scientific research agrees.
Notes
grade-d
Minor
- See study
Limited evidence indicates that BMI is either unaffected or reduced after the AIP, but dietary intake data has not been quantified. The restrictive aspects of the diet likely explain the weight loss.
grade-d Minor - See study
Though hs-CRP levels were lower after the AIP in one study, they remained within normal levels for the duration of the study. Our confidence in these results is very low due to the lack of control groups, small sample sizes, lack of blinding, and high risk of bias in these studies.
grade-d
Minor
Very High See 2 studies
In small, open-label, uncontrolled studies, most participants with IBD experienced reductions in disease activity, but it did worsen in some cases. A single sub-study of gene expression identified some changes that could indicate elevations in regulatory T-cell activity. Our confidence in these results is very low due to the lack of control groups, small sample sizes, lack of blinding, and high risk of bias in these studies.
grade-d Minor Very High See 2 studies
In small, open-label, uncontrolled studies, most participants reported improvements in health-related or disease-specific quality of life. Our confidence in these results is very low due to the lack of control groups, small sample sizes, lack of blinding, and high risk of bias in these studies.
grade-d
Minor
- See study
Limited evidence indicates that weight is either unaffected or reduced after the AIP, but dietary intake data has not been quantified. The restrictive aspects of the diet likely explain the weight loss.
grade-d Minor - See study
Though WBC count was lower after the AIP in one study, levels remained within normal levels for the duration of the study. Our confidence in these results is very low due to the lack of control groups, small sample sizes, lack of blinding, and high risk of bias in these studies.
grade-d - See study
CRP is not significantly affected by the AIP. Our confidence in this result is very low due to the lack of control groups, small sample sizes, lack of blinding, and high risk of bias in these studies.
grade-d - - See study
Fecal calprotectin is not significantly affected by the AIP. Our confidence in this result is very low due to the lack of control groups, small sample sizes, lack of blinding, and high risk of bias in these studies.
grade-d - - See study
Markers of thyroid function and levels of thyroid antibodies were unaffected by the AIP. Our confidence in these results is very low due to the lack of control groups, small sample sizes, lack of blinding, and high risk of bias in this study.
grade-d - - See study
No markers of thyroid function were affected by the AIP. Our confidence in this result is very low due to the lack of control groups, small sample sizes, lack of blinding, and high risk of bias in these studies.
grade-d - - See study
No markers of thyroid function were affected by the AIP. Our confidence in this result is very low due to the lack of control groups, small sample sizes, lack of blinding, and high risk of bias in these studies.

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Things to Note

Primary Function:

Also Known As

AIP

Caution Notice

Restrictive diets, such as the AIP, could exacerbate the risk of nutrient deficiencies in individuals with IBD.

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Click here to see all 8 references.