Dark chocolate inhibits platelet aggregation in healthy volunteers

Platelets. 2003 Aug;14(5):325-7. doi: 10.1080/0953710031000123681.


Cardiovascular disease is a leading cause of death in the UK. The flavonoids found in cocoa may produce a cardio-protective role for chocolate with a high cocoa content. Thirty healthy volunteers were randomised to receive 100 g of white, milk or dark chocolate, and assessments of platelet function were undertaken on venous blood samples before and after chocolate consumption. White and milk chocolate had no significant effect on platelets. However dark chocolate inhibited collagen-induced platelet aggregation in platelet rich plasma. In the future dark chocolate may have a role in prevention of cardiovascular and thromboembolic diseases.

Publication types

  • Clinical Trial
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Blood Platelets
  • Cacao*
  • Cardiotonic Agents
  • Collagen
  • Humans
  • Platelet Activation
  • Platelet Aggregation Inhibitors*
  • Platelet Function Tests


  • Cardiotonic Agents
  • Platelet Aggregation Inhibitors
  • Collagen