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Time for tea: mood, blood pressure and cognitive performance effects of caffeine and theanine administered alone and together.
Psychopharmacology (Berl) 2008; 195(4):569-77P

Abstract

RATIONALE

Although both contain behaviourally significant concentrations of caffeine, tea is commonly perceived to be a less stimulating drink than coffee. At least part of the explanation for this may be that theanine, which is present in tea but not coffee, has relaxing effects. There is also some evidence that theanine affects cognitive performance, and it has been found to reduce blood pressure in hypertensive rats.

OBJECTIVES

To study the subjective, behavioural and blood pressure effects of theanine and caffeine administered alone and together, in doses relevant to the daily tea consumption of regular tea drinkers.

MATERIALS AND METHODS

In a randomised, double-blind, placebo-controlled study, healthy adult participants (n = 48) received either 250-mg caffeine, 200-mg theanine, both or neither of these. They completed ratings of mood, including anxiety, and alertness, and had their blood pressure measured before and starting 40 min after drug administration. Anxiety was also assessed using a visual probe task.

RESULTS

Caffeine increased self-rated alertness and jitteriness and blood pressure. Theanine antagonised the effect of caffeine on blood pressure but did not significantly affect jitteriness, alertness or other aspects of mood. Theanine also slowed overall reaction time on the visual probe task.

CONCLUSIONS

Theanine is a physiologically and behaviourally active compound and, while it is unclear how its effects might explain perceived differences between tea and coffee, evidence suggests that it may be useful for reducing raised blood pressure.

Authors+Show Affiliations

Department of Experimental Psychology, University of Bristol, 12a Woodland Road, Bristol, BS8 1TU, UK. Peter.Rogers@bristol.ac.ukNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Comparative Study
Journal Article
Randomized Controlled Trial
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

17891480

Citation

Rogers, Peter J., et al. "Time for Tea: Mood, Blood Pressure and Cognitive Performance Effects of Caffeine and Theanine Administered Alone and Together." Psychopharmacology, vol. 195, no. 4, 2008, pp. 569-77.
Rogers PJ, Smith JE, Heatherley SV, et al. Time for tea: mood, blood pressure and cognitive performance effects of caffeine and theanine administered alone and together. Psychopharmacology (Berl). 2008;195(4):569-77.
Rogers, P. J., Smith, J. E., Heatherley, S. V., & Pleydell-Pearce, C. W. (2008). Time for tea: mood, blood pressure and cognitive performance effects of caffeine and theanine administered alone and together. Psychopharmacology, 195(4), pp. 569-77.
Rogers PJ, et al. Time for Tea: Mood, Blood Pressure and Cognitive Performance Effects of Caffeine and Theanine Administered Alone and Together. Psychopharmacology (Berl). 2008;195(4):569-77. PubMed PMID: 17891480.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Time for tea: mood, blood pressure and cognitive performance effects of caffeine and theanine administered alone and together. AU - Rogers,Peter J, AU - Smith,Jessica E, AU - Heatherley,Susan V, AU - Pleydell-Pearce,C W, Y1 - 2007/09/23/ PY - 2007/07/19/received PY - 2007/09/03/accepted PY - 2007/9/25/pubmed PY - 2008/4/1/medline PY - 2007/9/25/entrez SP - 569 EP - 77 JF - Psychopharmacology JO - Psychopharmacology (Berl.) VL - 195 IS - 4 N2 - RATIONALE: Although both contain behaviourally significant concentrations of caffeine, tea is commonly perceived to be a less stimulating drink than coffee. At least part of the explanation for this may be that theanine, which is present in tea but not coffee, has relaxing effects. There is also some evidence that theanine affects cognitive performance, and it has been found to reduce blood pressure in hypertensive rats. OBJECTIVES: To study the subjective, behavioural and blood pressure effects of theanine and caffeine administered alone and together, in doses relevant to the daily tea consumption of regular tea drinkers. MATERIALS AND METHODS: In a randomised, double-blind, placebo-controlled study, healthy adult participants (n = 48) received either 250-mg caffeine, 200-mg theanine, both or neither of these. They completed ratings of mood, including anxiety, and alertness, and had their blood pressure measured before and starting 40 min after drug administration. Anxiety was also assessed using a visual probe task. RESULTS: Caffeine increased self-rated alertness and jitteriness and blood pressure. Theanine antagonised the effect of caffeine on blood pressure but did not significantly affect jitteriness, alertness or other aspects of mood. Theanine also slowed overall reaction time on the visual probe task. CONCLUSIONS: Theanine is a physiologically and behaviourally active compound and, while it is unclear how its effects might explain perceived differences between tea and coffee, evidence suggests that it may be useful for reducing raised blood pressure. SN - 0033-3158 UR - https://www.unboundmedicine.com/medline/citation/17891480/Time_for_tea:_mood_blood_pressure_and_cognitive_performance_effects_of_caffeine_and_theanine_administered_alone_and_together_ L2 - https://dx.doi.org/10.1007/s00213-007-0938-1 DB - PRIME DP - Unbound Medicine ER -