Impact of Cocoa Consumption on Inflammation Processes—A Critical Review of Randomized Controlled Trials

Background: Cocoa flavanols have strong anti-inflammatory properties in vitro. If these also occur in vivo, cocoa consumption may contribute to the prevention or treatment of diseases mediated by chronic inflammation. This critical review judged the evidence for such effects occurring after cocoa consumption. Methods: A literature search in Medline was performed for randomized controlled trials (RCTs) that investigated the effects of cocoa consumption on inflammatory biomarkers. Results: Thirty-three RCTs were included, along with 9 bolus and 24 regular consumption studies. Acute cocoa consumption decreased adhesion molecules and 4-series leukotrienes in serum, nuclear factor κB activation in leukocytes, and the expression of CD62P and CD11b on monocytes and neutrophils. In healthy subjects and in patients with cardiovascular diseases, most regular consumption trials did not find any changes except for a decreased number of endothelial microparticles, but several cellular and humoral inflammation markers decreased in patients suffering from type 2 diabetes and impaired fasting glucose. Conclusions: Little evidence exists that consumption of cocoa-rich food may reduce inflammation, probably by lowering the activation of monocytes and neutrophils. The efficacy seems to depend on the extent of the basal inflammatory burden. Further well-designed RCTs with inflammation as the primary outcome are needed, focusing on specific markers of leukocyte activation and considering endothelial microparticles as marker of vascular inflammation.