Cancer Protective Properties of Cocoa: A Review of the Epidemiologic Evidence

Abstract

Due to their high concentration of catechins and procyanidins, bioactive compounds with distinct properties, cocoa and chocolate products may have beneficial health effects against oxidative stress and chronic inflammation, risk factors for cancer and other chronic diseases. This review focuses on the epidemiologic evidence for protective effects against cancer and overall mortality. The very small number of observational epidemiologic studies offers weak support for a reduction in mortality and little data related to cancer, whereas several intervention studies, despite their short duration, have reported some favorable changes in biomarkers assessing antioxidant status but very few findings related to inflammatory markers. In moderation, cocoa products may offer strong antioxidant effects in combination with a pleasurable eating experience. The benign profile of its fatty acids in combination with the low content of sugar of dark chocolate should lessen concerns about the adverse effects of cocoa products. Future nutritional trials need to assess a larger number of biomarkers that may be relevant for cancer risk, whereas epidemiologic studies require valid dietary assessment methods to examine the association of cocoa products with cancer risk in larger populations and to distinguish possible cancer protective effects of cocoa products from those due to other polyphenolic compounds.

Notes

^a Abbreviations are as follows: TEAC, trolox equivalent antioxidant capacity; TBARS, thiobarbituric acid reactive substances; LDL, low density lipoprotein; NA, not assessed; ORAC, oxygen radical absorbance capacity; CRP, C-reactive protein; TNFα, tumor necrosis factor α; IL6, interleukin 6; IL1β, interleukin 1β; TRAP, total radical trapping parameter; FRAP, ferric reducing ability; MDA, malondialdehyde; ↑ or ↓, significant increase or decrease; (↑ or ↓), nonsignificant increase or decrease; ⊘, no change.