What Is the Autoimmune Protocol Diet? Here's What a Dietitian Has to Say

The autoimmune protocol (AIP) diet is designed to lessen the severity of symptoms associated with autoimmune diseases, and it does this through elimination and then identification of inflammatory foods, additives and intolerances. The diet is restrictive, particularly in the initial phases, but many people with autoimmune conditions have used it in hopes of finding a long-term eating approach that decreases symptoms and provides relief. Here's all you need to know about the autoimmune protocol diet.

What Is the Autoimmune Protocol Diet?

The autoimmune protocol diet originated from the paleo diet, sometimes referred to as the caveman or hunter-gatherer diet. The paleo diet is centered around eating whole or very minimally processed foods, like our ancient ancestors did, and the goal of the diet is to improve and restore health by decreasing inflammation created by a modernized food supply. The AIP diet uses those same paleo principles but takes them a step farther by using an elimination protocol to identify additional foods that may cause an inflammatory immune response. The purpose of the AIP diet is to avoid those identified foods in hopes of relief from autoimmune symptoms.

Research is extremely limited and is focused on very small groups with the same disease. Some studies also lack a control group, and there are possible conflicts of interest in other research studies. Overall, more research is needed in order to establish a conclusion on the effectiveness of the AIP diet.

Results from the few studies available are mostly positive, and this is particularly promising for people who have limited treatment options, or options that aren't highly effective. Anecdotal reports suggest some level of symptom relief ranging from mild to significant, and it appears to offer some level of benefit for autoimmune conditions such as irritable bowel disease, according to studies published in 2017 and 2019 from Scripps Clinic in La Jolla, California. However, it's important to remember that, according to the Autoimmune Association, there are more than 100 autoimmune diseases, so just because AIP may show emerging promise in one disease, it won't necessarily be effective for others.

Some advocates say AIP can be a game changer for autoimmune disease management, but others find the benefits minimal for such a restricted diet. The real challenge is following the AIP diet, which is very restrictive, particularly during the elimination and reintroduction phases, and adapting to limited food choices.

How Does It Work?

If you're considering a restrictive diet like the AIP, it usually helps to understand how you may benefit by giving up many of your favorite foods, so here's a brief explanation: The immune system is designed to keep the body healthy by detecting and fighting off foreign invaders (like bacteria and other pathogens) that enter the body, and a primary way it does this is by producing antibodies to attack invaders that are a threat. This works well—unless the immune system gets confused and starts producing antibodies to attack healthy cells.

Initially, this signifies a low level of autoimmunity, but the level can gradually increase due to inflammatory immune responses that slowly lead to the onset of an autoimmune disease. Perhaps the most important thing to understand, though, is that the immune system is malfunctioning (as evidenced by autoimmunity and inflammation) and overworked, and both have also made the immune system hypersensitive. Consequently, small irritants (like foods and additives) and stressors often trigger an immune system reaction, creating additional inflammation which causes autoimmune symptoms to flare up, or increase in severity.

How to Follow the Autoimmune Protocol Diet

Getting started varies based on an individual's current diet, but many guides advise first learning about the paleo diet and putting those eating principles into practice before jumping headfirst into the AIP.

AIP Phase 1: Elimination

The goal with Phase 1 is to eliminate foods that may trigger an inflammatory immune response or harm gut health. It's recommended that this phase continues for 4 to 12 weeks. This entails cutting out:

• Grains
• Legumes
• Nuts and seeds
• Nightshades
• Dairy
• Eggs
• Refined or processed oils
• Refined sugars
• Sugar substitutes
• Coffee
• Alcohol

AIP Phase 2: Reintroduction

Foods that were eliminated in Phase 1 are slowly introduced one at a time to see if and how an immune reaction is triggered. To do this, one food is chosen and eaten several times over the course of a day, and you monitor for any subtle signs or symptoms (such as headaches, increased joint pain, bloating, etc.) of an immune response over the next 24 hours. You then avoid that food the next day and eat as you did in Phase 1 for the next 3 to 7 days before repeating the process with another food. The goal is that once reintroduction is complete, you will be able to identify your trigger foods and develop an individualized, long-term eating approach.

Foods to Eat and Foods to Avoid on the Autoimmune Protocol Diet

Exactly what foods can you eat, and what do you have to avoid? Here's the answer, starting with the foods that are excluded.

Foods to Avoid on the AIP diet

• All grains: Both gluten-containing grains like wheat, barley and rye and non-gluten grains like oats, rice, corn, quinoa and amaranth, as well as their flours
• All gluten: The gluten-containing grains and flours above, as well as products with ingredients containing gluten, such as soy sauce, salad dressings, breading, coatings, etc.
• All dairy: Milk, yogurt, butter, cream, cheese, sour cream, whey and whey protein
• Eggs: Whole eggs, whites and yolk, as well as products with egg as an ingredient
• Nightshades: Bell peppers, hot peppers, eggplant, tomatoes, potatoes and spices made from peppers (Sweet potatoes are OK.)
• Legumes: Beans, peas, lentils and vegetables with edible seeds and pods, such as snow peas and green beans
• Refined vegetable oils: Canola, corn, cottonseed, peanut, sunflower and soybean
• Chemicals and additives in processed foods: Natural and artificial colorings and flavorings, emulsifiers, added nitrates, trans fats, MSG, etc.
• Added sugars: Refined sugars and sweeteners like granulated sugar, brown sugar and corn syrup, as well as natural-sounding sugars like honey, maple syrup and coconut sugar
• Sugar substitutes: Non-nutritive sweeteners such as aspartame, saccharine, sucralose and stevia, plus sugar alcohols, such as erythritol and xylitol
• Nuts and seeds: All nuts and seeds, as well as products made from them, such as flours, oils and butters (Coconut and coconut products are OK.)
• Spices from seeds or associated with nightshades: Celery seed, nutmeg, cumin, cayenne pepper, etc.
• Alcohol
• Coffee

Foods You Can Eat on the AIP diet

• Unprocessed meat, poultry and seafood
• Green leafy and cruciferous vegetables: Spinach, lettuces, kale, mustard and turnip greens, cabbages, chard, broccoli, cauliflower, Brussels sprouts, watercress, etc.
• Nonstarchy vegetables and fruits: Asparagus, artichokes, celery, radishes, mushrooms, avocado, cucumber, pumpkin, squash, zucchini, okra, olives, onions, leeks, etc.
• Low-glycemic starchy vegetables: Beets, carrots, celeriac, parsnips, rutabagas, sweet potatoes, turnips, yams, etc.
• Fruits: All fruits, with an emphasis on lower-glycemic, higher-fiber choices like berries and citrus. Overall fruit intake should be kept moderate.
• Fats and oils: Animal-based fats such as bacon fat, lard and pan drippings; plant-based oils, such as avocado, coconut and palm
• Probiotic-rich foods: Kombucha, unpasteurized sauerkraut, unpasteurized fermented vegetables like kimchi, carrots, beets, and pickles, and dairy-free kefir or yogurt with active, live cultures
• Seasonings: Fresh herbs and spices made from leaves; garlic, ginger and horseradish; small amounts of sweeteners like honey or molasses; capers; most vinegars; salt (in moderation)

Autoimmune Protocol Diet Recipes

Meal planning and cooking on the AIP diet is challenging, particularly in the beginning, and picking up takeout is often out of the question, but there are several cookbooks now that help guide you. When it comes to finding recipes online, your best bet is to search paleo or Whole30 recipes. Not all of these will fit within AIP (watch for tomato products), but some will work or can easily be adapted by substituting another AIP-friendly oil, spice or condiment. Here are some starter AIP-friendly recipes (with necessary modifications noted):

Garlic Roasted Salmon and Brussels Sprouts (Substitute ½ cup broth for the white wine.)

Zucchini & Mushroom Sauté

Air-Fryer Scallops

Cranberry-Balsamic Chicken Thighs

Cucumber & Avocado Salad

Air-Fryer Sweet Potato Fries (Omit cayenne pepper.)

Broiled Ginger-Lime Chicken (Omit nutmeg and cayenne pepper.)

Fish with Coconut-Shallot Sauce (Use regular canned coconut milk instead of light.)

Roasted Vegan Cauliflower Soup with Parsley-Chive Swirl

Lemon-Turkey Soup

Bottom Line

The autoimmune protocol diet is one of the most restrictive diets, so making sure to get adequate amounts of allowed foods to meet energy and nutrient needs is key. Working with a dietitian before and during the diet is one of the best ways to ensure this and get needed guidance. Anyone with other underlying health conditions should check with their doctor first. Avoid the AIP diet if you're pregnant, and athletes may also find the diet isn't capable of meeting their carbohydrate needs.

It's important to realize, though, that the goal is not to follow the AIP diet as written for the rest of your life. Rather, it's to use the AIP diet to identify foods that trigger a reaction, so you can create an individualized, less restrictive, long-term eating approach.

Carolyn Williams, Ph.D., RD, is a culinary nutrition expert known for her ability to simplify food and nutrition information, and is the author of two cookbooks, Meals That Heal: 100 Everyday Anti-Inflammatory Recipes in 30 Minutes or Less and One-Pot Meals That Heal. She is also co-host of the Happy Eating podcast, which explores the influence that diet and lifestyle have on mental wellness. You can follow her on Instagram @realfoodreallife_rd or on carolynwilliamsrd.com.