The purpose of this study is to compare the effects on blood pressure of a daily intake of a flavonoid-rich cocoa drink with that of the same drink from which the flavonoids have been largely extracted.

Flavonoids are natural substances found in fruits and vegetables, tea and red wine. The investigators know that people who eat a diet rich in these foods are less likely to have heart disease. This, in part, may be due to the blood pressure lowering effect of flavonoids. Cocoa beans are a rich natural source of flavonoids. Unfortunately when cocoa is made into chocolate most of the flavonoids are destroyed. The aim of this study is to find out the effect of cocoa flavonoids on blood pressure after 12 weeks of daily consumption of a specially prepared chocolate drink that is rich in flavonoids.

Inclusion Criteria:

• Males or females of any age.
• Diagnosis of hypertension and on antihypertensive treatment.
• Stable blood pressure that has reached the British Hypertension Society (BHS) audit standard (<150/90mmHg).

Exclusion Criteria:

• Participation in another clinical trial.
• Any reason to suspect that the patient will not comply with drinking a chocolate beverage every day for the trial duration.