James DiNicolantonio and James O’Keefe summarize evidence that omega-6 fatty acids promote inflammation, while omega-3s are anti-inflammatory. Seed oils high in linoleic acid contribute to atherosclerotic risk via impacts on inflammation, oxidative stress, and other downstream effects; conversely, omega-3s suppress some of these same pro-inflammatory mechanisms. Marine omega-3 dosing was also shown to reduce oxidized LDL levels in patients with high triglycerides, and reviews of dietary omega-3s have shown an association with improvements in inflammatory biomarkers including CRP and IL-6.
“Using long-chain omega-3s to suppress low-grade inflammation may benefit numerous chronic diseases such as rheumatoid arthritis, atherosclerosis, dyslipidaemia, diabetes, obesity, and heart failure. The consumption of omega-6 seed oils may have the opposite effect.”