New Study: Eating More of This Protein Could Slow Autoimmune Symptoms

Of what we know about autoimmune illness, one of the most pervasive understandings is that in many cases, autoimmune symptoms are often strongly tied to inflammation. One major contributor to inflammation tends to be dietary pattern. And even though so much insight on autoimmune conditions is relatively new, multiple sclerosis is one of the longer-known diagnoses connected to the body’s immune system in this way.

A team of researchers in Sweden and China noted that previous science, such as a 2022 study in Italy, found that “a Mediterranean diet, including regular fish consumption, correlated with lower disability status in MS patients.” With that in mind, the team—specializing in a combination of neuroscience and nutrition—set out to narrow in on fish consumption and its effects on this condition.

First, the study defines multiple sclerosis (MS) as “a complex inflammatory and neurodegenerative disorder of the central nervous system,” noting there are also genetic and environmental factors involved. The included study participants had Expanded Disability Status Scale (EDSS) scores, a common ranking scale used to determine the severity of disability in MS patients.

A January 2025 study published in the peer-reviewed Journal of Neurology, Neurosurgery and Psychiatry, researchers followed patients from a Swedish population-based case-control study. At the outset, 2,880 newly diagnosed MS patients were onboarded to the study between 2005 and 2015, then they completed a digital follow-up questionnaire in 2021 to track changes in their lifestyle over that time.

A total of 1,719 participants completed both a digital questionnaire asking about their lifestyle habits and “were followed up with EDSS” in the Swedish MS registry. While participants were also asked about a variety of lifestyle factors, including smoking, sun exposure, body mass index (BMI), and alcohol consumption, the research team stated these factors “did not substantially alter the primary association” of MS progression and fish consumption in the team’s final analysis.

But one aspect of diet was very telling. Part of the questionnaire asked about an average consumption—ranging from “never/seldom” to “daily”—of both oily and lean fish. Few participants answered “daily,” so the “daily” and “weekly” responses were combined.

“Likely due to the anti-inflammatory and neuroprotective properties of nutrients found in fish,” the study concluded that MS patients who ate more fish also experienced a reduced risk of disability progression. Both oily and lean fish consumption resulted in positive health outcomes.

Researchers discovered a favorable outcome was “more pronounced” when they limited their analysis to the participants who reported consistent fish consumption. For those who increased their fish consumption after an MS diagnosis, the study reports they experienced a “reduced risk” in confirmed disability worsening.

Oily fish, categorized as having more than 3% fat content, included species such as salmon, tuna, and more. Lean fish, meanwhile, had a fat content of less than 3% and included haddock, cod, pollock, and pike perch, among others.

Omega-3 fatty acids and taurine, common nutrients found in fish, were both cited as likely providing health benefits to MS patients. The study remarks, “While omega-3 fatty acids, predominantly found in oily fish, may contribute to reduced disability progression, the beneficial effects observed from lean fish consumption suggest that other factors may also play a significant role.”

Researchers also noted because diet “profoundly influences gut microbiota,” there’s even more reason to believe that the positive connection between better MS progression outcomes and fish consumption “might also be mediated through favorable modifications of gut microbiota composition and function.”

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