Effects of increasing ratios of dietary omega-6/omega-3 fatty acids on human monocyte immunomodulation linked with atherosclerosis

The aim of this study was to identify a reliable ratio of omega-6/omega-3 fatty acids for regulating monocyte immunomodulation linked with atherosclerosis. We evaluated monocyte behavior on treatment with various dietary fatty oils with increasing fatty acid ratios (ω6:ω3): canola oil (ω6,5.6:ω3,1), olive oil (ω6,13.4:ω3,1), corn oil (ω6,52:ω3,1), coconut oil (saturated), and fish oil (ω6,1:ω3,2). Oxidized LDL-treated monocytes were treated with 0.5% and 2% oil emulsions (v/v) for 0, 2, 4, and 8 h. Oil red 'O' and Nile red staining demonstrated 70% and 30% lipid accumulation only in coconut and corn oil. The levels of IL-1β, IL-12β, IL-6, macrophage colony stimulation factors (IFNγ, IKBKγ1, IKK), and atherosclerosis-related immunomodulatory genes (TLR-4, TGFBR2, and IL33) were significantly increased after 8 h only in corn and coconut oil. Canola (5.6:1) and fish (2:1) oils are beneficial for immunoregulation and suppress macrophage-induced foam cell formation and atherosclerosis development.