In a meta-analysis of 13 cohort studies which included 1,353 patients with multiple sclerosis (MS), omega-3 supplementation was linked to significant reductions in inflammatory gene expression and Expanded Disability Status Scale (EDSS), the latter of which is a standard tool for assessing the impairment and degree of the condition.
 
MS is an autoimmune illness which is a leading cause of disability due to degeneration of the central nervous system, and presently has no cure. According to the National MS Society, one million people in the U.S. over the age of 18 currently live with the disease.  
 
“The health benefits of omega-3 fatty acid supplementation on inflammatory gene expression (IGE) and multiple sclerosis (MS) are becoming more evident,” the authors wrote. “However, an overview of the results from randomized controlled trials is lacking.”
 
In the meta-analysis, the researchers conducted a search of all clinical trials which investigated the effects of omega-3 fatty acid intake on EDSS and IGE in MS patients which had data for EPA, DHA, and ALA omega-3 fatty acids. The study periods ranged from 3 to 144 weeks.
 
According to the authors, a significant inverse relationship was found between DHA and EDSS scores, while EPA and total omega-3 fatty acid concentrations did not have a significant effect.
 
 However, all omega-3 fatty acid concentrations were linked to a significant upregulation of the gene expression of PPAR-y, as well as a downregulation of the expression of the inflammatory cytokines TNF-a and IL-1.
 
“Furthermore, in autoimmune diseases, omega-3 fatty acids have been shown to have antioxidant, anti-inflammatory, and neuroprotective effects,” the authors wrote. The activation of PPAR-y has been linked in previous studies to improved lipid metabolism, adipocyte differentiation, and vascular protection. Meanwhile, higher oxidative stress and cytokines  are linked to disease progression in MS patients.
 
“Long-term, more extensive, and well-designed randomized, controlled trials are still required to understand these impacts fully,” the authors concluded.