The Autoimmune Protocol (AIP) diet is an elimination diet designed to help reduce inflammation, manage symptoms and improve quality of life for people with autoimmune diseases.
Autoimmune diseases occur when the immune system mistakenly attacks the body's healthy tissues, leading to chronic inflammation and a range of other symptoms. Conditions like rheumatoid arthritis, Crohn's disease, lupus, Hashimoto's thyroiditis, and psoriasis are just a few examples of autoimmune conditions.
The AIP diet is rooted in the principles of the paleo diet, which focuses on nutrient-dense, whole foods while eliminating ultraprocessed foods and some additional foods, such as whole grains, that supposedly interfere with nutrient absorption or promote inflammation.
The AIP diet is also based on the premise that autoimmune disorders arise from a leaky gut. The theory behind leaky gut syndrome is that the lining of your intestines may be compromised, allowing toxins and bacteria to enter your bloodstream, according to Cleveland Clinic.
Therefore, unlike the paleo diet, the AIP diet removes potential triggers that may contribute to immune system dysregulation. The goal is to reduce inflammation, support gut health and identify which foods may be causing flare-ups of autoimmune symptoms.
As a registered dietitian and someone who has tried the AIP diet protocol, I would not recommend it. Here's everything you need to know to decide whether it's right for you.
The AIP diet involves two phases: an elimination phase and a reintroduction phase. This approach is intended to help identify food triggers while giving your body time to heal. It's also meant to lower inflammation and promote a healthy gut lining.
The elimination phase involves removing all foods considered inflammatory, or that may trigger an immune system response. These foods include grains (whether whole or refined), legumes, dairy, eggs, nuts, seeds, nightshade vegetables (like tomatoes and peppers), alcohol, and all processed and refined foods.
During this phase, you'll consume approved foods that are said to reduce inflammation and support gut healing. The elimination phase typically lasts 30 to 90 days, depending on the severity of your symptoms and how they progress. The idea is that your immune system will reset, you'll lower inflammation, and your gut and body will begin to heal during this phase.
Once symptoms stabilize and you notice improvements, you'll begin the reintroduction phase. At this point, you'll gradually add foods back into the diet one at a time to determine which foods trigger symptoms.
After reintroducing a single food, you'll monitor for symptoms such as fatigue, joint pain, headaches, digestive issues, or skin reactions. If no symptoms occur within five to seven days, you can keep eating that food. If symptoms return, the food is considered a trigger and should be eliminated again.
Once you get through all the reintroductions, you'll be in maintenance mode. At this point, you'll continue to avoid your identified trigger foods, though you may decide to eat them in small amounts at times (say, a social event). This is a personal choice. You can factor in the benefits of following the AIP diet compared to the drawbacks.
Plenty of people say that the AIP diet worked for them. While this is very compelling, we're still learning about its benefits. Some small studies have shown that it can offer meaningful improvements for those with autoimmune conditions.
For example, a study among 15 people with Crohn's disease or colitis found that the AIP diet resulted in less frequent bowel movements and improved stress. However, there was no control group in this study.
Another small study, this one among 16 women with Hashimoto's thyroiditis, found significant improvements in quality of life measures, such as increased vitality. However, there were no statistically significant changes in any measure of thyroid function. Again, this was a single-arm study, which is lower quality evidence than one in which one diet is measured against another.
Additionally, a clinical study involving nine people with rheumatoid arthritis found that following the AIP diet improved pain, sleep and fatigue. However, the diet was tested while these folks were still on their medications, and again, the study size is very small.
These quality-of-life improvements can be significant for people, and I don't want to discount anyone's personal experience with the AIP diet. However, there are also many drawbacks.
While the AIP diet may help manage some autoimmune symptoms, it's a big undertaking. Here are some potential drawbacks to consider:
The elimination phase of the AIP diet is very restrictive. It removes a wide range of foods, including many nutritious foods, such as certain vegetables, nuts and legumes. These foods are included on the Mediterranean diet, widely considered the healthiest diet plan. Severe food restrictions can make the diet feel overwhelming, especially at the start, and may limit meal variety.
Breakfast was especially difficult for me. I went from eating plain Greek yogurt with blueberries and walnuts to sweet potato toast. I struggled to get enough protein at breakfast and missed my typical breakfast, which is considered healthy by almost every standard.
Eliminating entire food groups can increase the risk of nutrient deficiencies. Whole grains and legumes contribute to your fiber intake, and while you can meet fiber needs without these foods, you need to ensure you're eating enough vegetables and fruits to cover your bases.
Careful planning and working with a registered dietitian are important to ensure you get the necessary nutrients.
Following the AIP diet can make dining out, social gatherings and traveling difficult. Just think: You're out to eat with friends, and everyone is sharing appetizers, but you can't participate.
Preparing most, if not all, of your meals may be necessary. This is time-consuming and may be stressful for some people.
While there is emerging evidence that the AIP diet can help with autoimmune symptoms, the studies are small, short-term and often lack a comparison group. More research is needed to understand the benefits compared to a less-restrictive, whole-foods diet.
The strict rules of the elimination phase may lead to feelings of frustration, anxiety or even disordered eating in some people. Sometimes, disordered eating can arise in people modifying their diet to reduce symptoms, such as those with GI diseases. Many people think there's no harm in trying a strict elimination diet, such as the AIP, but studies suggest this isn't the case.
The AIP diet focuses on nutrient-dense whole foods that are minimally processed. Here's what you can eat during the elimination phase.
All vegetables are encouraged except nightshades (tomatoes, potatoes, eggplant, peppers).
Moderate amounts are allowed, with an emphasis on low-sugar options, like berries and apples.
Grass-fed beef, pasture-raised poultry, wild-caught fish and organ meats (such as liver) are allowed.
Avocado oil, coconut oil, olive oil and animal fats, like tallow or lard, are emphasized.
Bone broth is encouraged because it has amino acids that support gut healing.
Sauerkraut, kimchi (without nightshades), and coconut yogurt are encouraged to promote gut health.
Include any non-seed-based healthy spices that you like, such as garlic, turmeric and ginger.
The AIP diet eliminates all foods that could potentially trigger inflammation, irritate the gut, or provoke an immune system response. Here's what to avoid during the elimination phase.
All grains, including wheat, rice, oats, corn, quinoa and barley, are excluded.
You'll avoid beans, lentils, peas, peanuts and soy.
Milk, cheese, yogurt and butter are prohibited in the elimination phase.
Avoid both yolks and whites.
These are avoided in all forms, including nut and seed butters and seed-based spices, like cumin and mustard.
Tomatoes, peppers, eggplant and potatoes are restricted.
All sweeteners are excluded. That means avoiding honey, maple syrup, table sugar and zero-calorie substitutes (even those deemed natural).
Anything with additives, preservatives or artificial ingredients is avoided.
These substances aren't allowed during the elimination phase as they can contribute to inflammation and irritate the gut.
Both the AIP diet and anti-inflammatory diet aim to reduce inflammation and improve overall health, but they approach this in different ways, so they differ in their level of restriction and focus.
While both diets are intended to reduce inflammation, the AIP diet is more restrictive and targeted for those managing autoimmune conditions.
This is a strict elimination diet specifically designed for autoimmune conditions. It removes many foods, including nutritious whole foods like nuts, certain vegetables and legumes. After you follow the strict elimination phase, you'll follow a structured reintroduction phase to identify potential triggers.
This diet reduces inflammation by prioritizing whole, nutrient-dense foods while eliminating ultraprocessed foods, refined sugars, and unhealthy fats. It is much less restrictive than the AIP diet, allowing for a broader range of foods, such as whole grains, legumes and certain dairy products. Those on the anti-inflammatory diet will also likely get a wider range of nutrients and find it's easier to follow than those on the AIP diet.
Should you try the AIP diet?
While the AIP diet may be a helpful tool for some people with autoimmune conditions, I wouldn't suggest it as the first step. The diet is very restrictive and challenging to follow. I'm a dietitian who eats predominantly whole foods, and I still found it tough.
My personal experience is that while I may have felt some slight improvement in symptoms, it wasn't enough to warrant staying on this diet, nor was it enough to go off of or reduce medications. When I was following the AIP diet, I didn't look forward to meals the way I usually do, and I found social situations, like sharing meals with people I care about, more difficult.
That said, if you're dealing with an autoimmune condition and haven't found relief through other methods, the AIP diet may be worth trying. If you decide to attempt the AIP diet, I suggest working with a registered dietitian. Also, take note of your physical and emotional health. If the diet is interfering with either, that's a sign that it's doing more harm than good.