Short-term effects of Tulsi herbal tea on mood, stress, cognition and cardiovascular function

INTERVENTION: This is a preliminary randomized placebo‐controlled cross‐over study comparing the time course of changes in mood,, stress, cognitive health and cardiovascular function after a single dose of 300ml tulsi tea (hot to warm) and 300ml filtered water (hot to warm). The interventions will be either Tulsi herbal tea 4g standardized commercial grade tea bag steeped in 300ml filtered warm‐hot water or Placebo decaff black tea 300ml. Participants will receive the two interventions as a beverage on two separate occasions in a randomized crossover sequence with a minimum of 48 hours washout. Doses will be administered by healthcare professionals at the study site. CONDITION: Stress cardiovascular function cognitive health mood PRIMARY OUTCOME: Cognitive Function assessed using CogState computerized battery SECONDARY OUTCOME: Cardiovascular function assessment (pulse rate, brachial blood pressure, central blood pressure and arterial stiffness) will be performed using the SphygmoCor technology which is a validated measure of central aortic pressure pulse wave parameters. The blood pressure will be measured twice following 5 minutes seated rest using SphygmoCor (AtCor Medical, Sydney, Australia). ; this is a composite outcome Measurement of the Mood states using a Profile of Mood States (POMS) questionnaire consisting of 65‐adjectives that participants will rate the level (1‐5 scale) at which they have been feeling before the drink, and 40 minutes after the consumption of the drink. stress, is assessed by salivary cortisol using ELISA assay INCLUSION CRITERIA: ‐aged between 18 and 60 years, English speaking and able to give written informed consent ‐non‐smokers ‐ willing to avoid caffeine‐containing drinks, alcohol and prescription medications for 24 hours prior to the testing sessions