Omega-3 fatty acid intake reduces circulating concentrations of IL-6, TNF-alpha, and CRP in humans with metabolic or cardiovascular disease and following exercise-induced stress.

Study: Effect of a Diet Supplemented with Marine Omega-3 Fatty Acids on Inflammatory Markers in Subjects with Obesity: A Randomized Active Placebo-Controlled Trial

People with obesity who took fish oil supplements for 8 weeks had less of a harmful inflammation marker called IL-6 in their blood, compared to those who took a fake pill. This suggests omega-3s help calm inflammation in people with metabolic issues.

Study: The efficacy of omega-3 fatty acids (O3FAs) as a complementary in colorectal cancer patients: A systematic review and meta-analysis.

This study found that taking omega-3 supplements lowered three key inflammation markers in cancer patients after surgery. Since the same markers are targeted in the claim about heart or metabolic disease after exercise, it supports the idea that omega-3s reduce these inflammation signals in stressed bodies.

Study: Supplementation of omega-3 fatty acids can reduce tumor necrosis alpha ( TNF-α) levels and pain intensity in osteoarthritis patients

This study found that taking omega-3 supplements lowered a harmful inflammation marker called TNF-alpha in people with knee arthritis. Since the claim says omega-3s reduce similar inflammation markers in people with heart or metabolic diseases, this supports that idea—even though it didn’t test those exact groups.