The autoimmune protocol (AIP) diet aims to reduce inflammation and relieve other symptoms of autoimmune disorders. What can a person eat on this diet, and is there evidence of any benefits?
An autoimmune disease causes the immune system to attack and damage healthy tissues or organs by mistake.
The AIP diet may help reduce inflammation and other symptoms of autoimmune conditions. Learn more about the diet and its potential effects below.
The AIP is an elimination diet, so it involves not eating certain types of food for several weeks at a time and carefully noting any effects on health.
Researchers have described the AIP diet as an extension of the paleo diet. A person usually eats lean proteins, vegetables, fruits, nuts, and seeds.
The AIP diet focuses on foods rich in vitamins and other nutrients. A person following it will not eat anything with added sugar or other additives that can trigger an autoimmune response.
A person should adhere to the diet strictly for a few weeks, then slowly reintroduce the eliminated foods and take careful note of any reaction. A reaction, such as a surge in symptoms, can indicate that they should exclude that food in the long term.
Limited research indicates which specific foods the AIP diet includes. A person following the diet may be able to eat:
- any vegetables, except those from the nightshade family
- high-quality seafood that are rich in omega-3 fatty acids
- fermented foods
- lean meats and liver
- small amounts of fruit
- oils, such as olive, coconut, and avocado oils
In general, the diet focuses on whole foods and those that do not contain additives such as sugar.
There are several food groups to avoid when following an AIP diet.
Little guidance is tailored to people with any specific autoimmune condition, but a study in people with IBS recommends avoiding:
- nightshades, such as tomatoes, potatoes, peppers, and eggplants
- some vegetable oils
- nuts and seeds
- food additives, such as refined or added sugars
Learn more about the different types of autoimmune disease here.
The theory behind the AIP diet is that avoiding gut-irritating foods and eating nutrient-rich ones will reduce inflammation.
One hypothesis about how autoimmune conditions begin is called the leaky gut theory. It states that if there is a problem with the bacterial composition of a person’s gut, environmental triggers of inflammation — such as toxins and viruses — can breach the gut wall and access other parts of the body.
Supporters of this theory say that eating the right foods may help prevent symptoms of inflammation, although many experts are skeptical.
Many proponents of the leaky gut theory believe that the AIP diet can help prevent the immune system from attacking tissues and reduce the symptoms of autoimmune diseases.
Few clinical studies have looked into the effectiveness of the AIP diet — in general or as a means of managing any specific autoimmune disease.
In 2017, some researchers found that eliminating certain foods as part of the AIP diet improved symptoms of inflammatory bowel disease.
In a 2019 study, 17 female participants aged 20–45 with Hashimoto’s thyroiditis, another autoimmune disease, followed the AIP diet as part of a 10-week health coaching program.
Tests showed no changes, but the participants reported a reduction in symptoms and an improvement in their quality of life. The authors suggested that the AIP diet, as part of a wider treatment program, could help people with the condition.
Some scientific evidence suggests a link between gut health and inflammatory disease. A growing body of research, for example, indicates that there may be a link between bacterial growth in the gut and inflammatory and autoimmune diseases, such as Crohn’s disease.
Other studies suggest that the composition of gut bacteria may trigger immune and inflammatory reactions in other parts of the body.
In addition, researchers have noted that inflammation affects how well the gut wall functions and that food allergies can make it more porous. This could indicate a link between problems with the gut wall and autoimmune diseases, and confirming it will require further studies.
Supporting claims that the AIP diet can reduce symptoms of other autoimmune diseases will require more research.
There is not enough evidence to confirm that the AIP diet can reduce inflammation or benefit people with any autoimmune disease.
However, some research indicates that certain foods could make symptoms worse. These include highly processed foods and foods that contain unhealthful fats, added sugar, or added salt. Eating fewer of these types of food is likely to be healthful.
Anyone starting a strict elimination diet should take care, as cutting out legumes, grains, and dairy, for example, can lead to nutritional deficiencies.
Discuss any big dietary change with a doctor, who may be able to recommend additional resources and help determine whether the diet is suitable.
Can supplements help with inflammation? Find out here.
What is the difference between the anti-inflammatory diet and the AIP diet?