Lack of a specific fatty acid in fat tissue can trigger the abnormal immune system response that causes multiple sclerosis (MS) by attacking and damaging the central nervous system, according to a new study1.

Fat tissue in patients diagnosed with MS were found to have abnormal levels of oleic acid, a monounsaturated fatty acid found at high levels in cooking oils, meats (beef, chicken, and pork), cheese, nuts, sunflower seeds, eggs, pasta, milk, olives, and avocados.

This lack of oleic acids leads to a loss of the metabolic sensors that activate T cells, that mediate the immune system’s response to infectious disease, researchers said. Without the suppressing effects of these regulatory T cells, the immune system can attack healthy central nervous system cells and cause the vision loss, pain, lack of coordination, and other debilitating symptoms of MS.

Regulatory T Cell Levels

When researchers introduced oleic acids into the fatty tissue of MS patients in laboratory experiments, levels of regulatory T cells increased.

We’ve known for a while that both genetics and the environment play a role in the development of MS. “This paper suggests that one of environmental factors involved is diet,

said senior author Dr. David Hafler, chair of the neurology department at Yale University.

Obesity triggers unhealthy levels of inflammation and is a known risk factor for MS, an observation that led him to study the role of diet in MS, Hafler noted. He stressed, however, that more study is necessary to determine whether eating a diet high in oleic acid can help some MS patients.

The work was supported by grants from the; the National Multiple Sclerosis Society (NMSS; the Nancy Taylor Foundation for Chronic Diseases; and Race to Erase MS.


  1. Saige L. Pompura, et al. Oleic acid restores suppressive defects in tissue-resident FOXP3 Tregs from patients with multiple sclerosis. J Clin Invest. 2021;131(2):e138519 ↩︎


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