Halting Inflammatory and Autoimmune Disease Through Small Eating Tweaks

Could cutting back on certain foods high in the amino acid methionine halt the development and progression of inflammation and autoimmune diseases such as multiple sclerosis in those at high risk? New research published in Cell Metabolism says yes.Methionine is an essential amino acid needed for T cell production. Meat, eggs, and other animal foods contain high levels of methionine.Russell Jones, PhD and program leader of Van Andel Institute Metabolic and Nutritional Programming group notes that the amino acid methionine is vital to the health of the immune system. His study finds that for individuals predisposed to inflammatory and autoimmune diseases, cutting down on methionine intake can reduce activity of immune cells that lead to disease and provide healthier outcomes. His research suggests dietary interventions for these disorders is much needed.When healthy tissue in the immune system is mistakenly attacked and destroyed, autoimmune disorders develop. Multiple sclerosis is the most common central nervous system disease. The immune system targets the myelin sheet that protects nerve cells in the brain and spinal cord. This damage impairs messages meant to travel to and from the brain, which leads to progressively worsening symptoms including numbness, muscle weakness, balance and coordination problems and decline in cognitive function. Currently, there are not treatments that slow or stop multiple sclerosis without adding risk of infection or cancer.Dr. Catherine Larochelle, study co-author and clinician-scientist in neuroimmunology and neurologist at the Multiple Sclerosis Clinic at the Centre of Hospitalier de Universidad in Montreal notes that the cause of multiple sclerosis is poorly understood. Scientists recognize that genes related to the immune system are suspect and the environment also plays a role. Metabolic factors such as obesity also raise the risk of multiple sclerosis, which makes the thought of dietary intervention to reduce the work on the immune system attractive.Jone, Larochelle and their colleagues discovered that dietary methionine feeds the process of T cells responding to an immune response to fight off pathogens by quickly reproducing and differentiating into certain subtypes. A portion of the reprogrammed T cells cause inflammation. While this is a normal function of the immune response, if it lingers, damage can occur such as the nerve damage that happens with multiple sclerosis.In mouse models with multiple sclerosis where methionine was greatly reduced, T cells were altered and their chance of causing inflammation in the brain and spinal cord was greatly reduced. This caused a delay in the onset of the disease and slowed its advancement.According to Jones, limiting methionine in the diet is like cutting off the fuel supply for the over-active inflammatory response without impacting the rest of the immune system. He notes that research must be trialed in humans prior to dietary guidelines being drafted. His team also has plans to study whether novel medications can be developed that impact metabolism of methionine.A previous study in 2019 from Locasale Lab at Duke University found that limiting methionine could improve the chemotherapy and radiation effects during cancer treatment. In addition, other research finds that restricting methionine can possibly reverse fatty liver disease and may have implications for brain health and longevity.For clinicians working with individuals with autoimmune disease or those at risk for autoimmune conditions (family history), a diet restricted in methionine may be too early to suggest, but reducing sources of methionine from animal sources such as eggs, fish, nuts/seeds, meat and whole grains certainly cannot hurt. Foods that are low in methionine include:

• Beans, legumes
• Fruit
• Vegetables
• Low-fat dairy products
• Pea protein

By Lisa Andrews, MEd, RD, LDReferences:

1. Dominic G. Roy, Jocelyn Chen, Victoria Mamane, Eric H. Ma, Brejnev M. Muhire, Ryan D. Sheldon, Tatiana Shorstova, Rutger Koning, Radia M. Johnson, Ekaterina Esaulova, Kelsey S. Williams, Sebastian Hayes, Mya Steadman, Bozena Samborska, Amanda Swain, Audrey Daigneault, Victor Chubukov, Thomas P. Roddy, William Foulkes, J. Andrew Pospisilik, Marie-Claude Bourgeois-Daigneault, Maxim N. Artyomov, Michael Witcher, Connie M. Krawczyk, Catherine Larochelle, Russell G. Jones. Methionine Metabolism Shapes T Helper Cell Responses through Regulation of Epigenetic Reprogramming. Cell Metabolism, 2020; 31 (2): 250 DOI: 10.1016/j.cmet.2020.01.0062
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