TNF and metabolic syndrome: Moreover, a recent study demonstrated that the supplementation with EVOO characterized by a high OC concentration had a positive effect on patients with metabolic syndrome and hepatic steatosis, by inducing a significant decrease of pro-inflammatory cytokines such as interleukin 6 (IL6), interleukin 17A (IL17A), tumor necrosis factor α (TNFα) and interleukin 1β (IL1β) (6), thus confirming the hepato-protective action of EVOO which had been observed in two previous human studies (7, 8).