Flow Mediated Dilation in Response to Black Tea

Inclusion Criteria: * Males and post menopausal (\> 1 year) females, not on hormone replacement therapy * Aged \>18 and \< 65 years * Body mass index (BMI) of \>=18.0 and =\<35.0 kg/m2 * Hypertension as previously diagnosed by primary care or hospital physician. * If untreated, office BP between 140/90 mmHg and 160/100 mmHg on screening * If treated, a controlled blood pressure (\<160/100) on stable medication for at least 4 weeks Exclusion Criteria: * Tea drinkers: having typically consumed \> 1 cup of black tea per week. * Current smoker or has stopped smoking less than 6 months before start of study * Self reported alcohol intake of \>21 units/week * Established cardiovascular disease other than hypertension * Clinically significant arrhythmia * Diabetes mellitus * Chronic Kidney Disease \> stage 2 * 10-year cardiovascular risk equivalent to 20% or greater using the QRisk2 calculator * Abnormality of laboratory blood tests considered clinically significant * Any other significant intercurrent condition/disease