Plant-based diets may successfully treat autoimmune diseases such as lichen planus, rheumatoid arthritis, Crohn’s disease (see also here and here), multiple sclerosis and some forms of cancer, which may have an autoimmune component.
Systemic inflammation may contribute to the development of autoimmune diseases. Each time meat is consumed, the body experiences a low-grade inflammation thought due to the introduction of bacterial endotoxins into the bloodstream. Arachidonic acid found in meat may directly activate the immune system, further promoting inflammation. Ingested animal hormones, found most highly concentrated in low-fat dairy, may also retain some physiological function, potentially encouraging pathological immune activation. Animal proteins, such as Neu5Gc and Alpha Gal, may be recognized as foreign after they have entered the body and trigger an immune response, exacerbating the problem even further. Processing meat can introduce compounds which may promote autoimmune diseases, such as meat glue. Finally, meat can contain live bacterial or viral contaminants, which, naturally, trigger an immune response once they have been internalized, whether via ingestion, inhalation or simple contact; this is thought to be the reason for increased incidence of specific autoimmune diseases among slaughterhouse, meat processing, and farm workers.
Some of these live contaminating bacteria are known to directly cause autoimmune diseases. This has been established for Campylobacter and Guillaine Barre Syndrome (a life-threatening, autoimmune attack on the nervous system) and Yersinia and Grave’s disease. A similar mechanism links meat consumption to antibody production against Proteus mirabilis bacteria, which ultimately cross-react with proteins in our joint tissue, potentially causing rheumatoid arthritis. Why don’t plant proteins generate similar phenomena? They are simply too different from our own. One exception is gluten, a protein produced by wheat, which triggers autoimmune mediated celiac disease in 0.7% of the population and sensitivity in a small percentage more.
Anti-inflammatory and antioxidant compounds in foods such as rosemary, cloves, ginger and turmeric have been shown to decrease inflammatory markers in vitro. Açai berries, strawberries, mushrooms and turmeric (see also here), have all been shown to decrease inflammation in vivo, sometimes with dramatic improvement in autoimmune symptoms. In the study in which it was addressed, decreases in inflammation did not appear to be accompanied by impaired immune responses to pathogens; on the contrary, the researchers observed an increase in “primary defence” IgA antibodies. Plants are also rich in potassium, which can stimulate the production of natural steroids that work to suppress inflammatory processes.
Topic summary contributed by Miranda.