The acute cardiovascular effects of an L-Theanine and L-Glycine beverage in postmenopausal women at rest

Project Description

Pilot Randomised Control Trial to test the acute effects of a beverage containing L-Theanine and L-Glycine (THE-Gly) on resting cardiovascular physiological responses in postmenopausal women.

This study has received University of Canberra Human Research Ethics Approval (UCHREC - 89428) and it is registered with the Australia New Zealand Clinical Trial Registry (ACTRN12625001335482).

The aim of this study is to investigate the effects of a single dose of two amino acids L-Theanine and L-Glycine (The-Gly) on resting cardiovascular responses in postmenopausal women.

Participation

If you are a female aged 45 years of age or older, have reached menopause naturally, are not on hormone replacement therapy, and currently reside in the Greater ACT region (including Queanbeyan), Australia, you are invited to participate in this research project.

Participants will not be eligible if they are under 45 years of age, have experienced menopause due to hysterectomy (surgical), medical conditions, or treatments, or are currently on hormonal replacement therapy.

Participants who agree to participate in the research will be asked to:

  • Consume a functional beverage containing L-Glycine and L-theanine or a placebo.

  • Answer questions about their diet, stress, physical activity, sleep, and smoking habits.

  • Attend two in-person clinic visits at the University of Canberra to measure anthropometric data, heart rate variability, blood pressure, physical function, and cardiometabolic biomarkers (via a finger prick blood test).

  • Complete a treadmill exercise test, which may require exercising at a high or maximal level of effort (until you feel you cannot continue). This test will be supervised by qualified staff, and your safety will be closely monitored throughout.

Participation in the research is completely voluntary and participants may, without any penalty, decline to take part or withdraw at any time without providing an explanation

Contact us for more information

Meet the Team

  • Ms Harshini Meegaswatte

    PhD Student

    (Food Science & Nutrition)

    University of Canberra

    Researcher Profile

  • Prof Stuart Semple

    Professor in Exercise Physiology & Rehabilitation

    (University of Canberra)

    Researcher Profile

  • Dr Ekavi Georgousopoulou

    Assistant Professor in Nutrition & Dietetics

    (University of Canberra)

    Researcher Profile

  • Dr Katie Speer

    Post-Doctoral Clinical Trial Coordinator

    (University of Canberra)

    Researcher Profile

  • Dr Siraphat Taesuwan

    Assistant Professor Nutrition & Dietetics

    Chiang Mai University (Thailand)

    Researcher Profile

  • A/Prof Jane Kellett

    Associate Professor in Nutrition and Dietetics

    (University of Canberra)

    Researcher Profile

  • Prof Andrew McKune

    Professor in Sport & Exercise Science (University of Canberra)

    Researcher Profile

  • Prof Nenad Naumovski

    Professor in Food Science & Human Nutrition

    (Singapore Institute of Technology)

    Researcher Profile

Recent Publication on this and similar topics from our team

  1. Meegaswatte H, Taesuwan S, McKune AJ, Panagiotakos DB, Veysey M, Naumovski N (2026) The Association Between the American Heart Association Life’s Essential 8 and Metabolic Syndrome Among Postmenopausal Women: Findings from National Health and Nutrition Examination Survey 2011–2020. Evidence to impact: Science with purpose, National Nutrition & Dietetics Research Summit, Melbourne, Australia

  2. Meegaswatte H, Taesuwan S, McKune AJ, Panagiotakos DB, Veysey M, Naumovski N (2026) The Association Between the American Heart Association Life’s Essential 8 and Depression Trajectories Among Postmenopausal Women: Findings from National Health and Nutrition Examination Survey 2011–2020. Evidence to impact: Science with purpose, National Nutrition & Dietetics Research Summit, Melbourne, Australia

  3. Meegaswatte H, Taesuwan S, McKune AJ, Panagiotakos DB, Veysey M, Naumovski N (2026) Association Between Life’s Essential 8 and Depression Trajectories in Postmenopausal Women: Evidence from NHANES 2011–2020. One Health, One Nutrition: Ensuring Optimal Nutrition for People and the Planet, Nutrition Society of Sri Lanka Annual Session Colombo, Sri Lanka.

  4. Meegaswatte H, Speer K, McKune A, Naumovski N (2026) Functional Foods and Nutraceutical Approaches for the Management of Cardiovascular Health in Postmenopausal Women. The Nutrition Society of Sri Lanka Annual Session Colombo, Sri Lanka.

  5. Meegaswattee H, Taesuwan S, McKune AJ, Panagiotakos DB, Veysey M, Naumovski N (2025). The Association Between the American Heart Association Life’s Essential 8 and Depression Trajectories Among Postmenopausal Women: Findings from National Health and Nutrition Examination Survey 2011–2020. Nutrition Society of Australia Annual Scientific Meeting, Gold Coast, Australia.

  6. Meegaswatte H, McKune AJ, Panagiotakos DB, Osiriphun S, Leksawasdi N, Rachtanapun P, Veysey M, Naumovski N, Taesuwan S. (2025) The Association Between the American Heart Association Life’s Essential 8 and Metabolic Syndrome Among Postmenopausal Women: Findings from NHANES 2011–2020. Nutrients. 17(10):1688 https://doi.org/10.3390/nu17101688

  7. Meegaswatte H, Speer K, McKune AJ & Naumovski N. (2024). Functional Foods and Nutraceuticals for the Management of Cardiovascular Disease Risk in Postmenopausal Women. Rev Cardiovascular Med 25(12), 460. https://doi.org/10.31083/j.rcm2512460

  8. Bulman A, D’Cunha NM, Marx W, Turner M, McKune A, Naumovski N (2025) The effects of L-theanine consumption on sleep outcomes: A systematic review and meta-analysis, Sleep Medicine Reviews, 81, 102076, https://doi.org/10.1016/j.smrv.2025.102076

  9. Bulman A, D’Cunha NM, Marx W, Turner M, McKune AJ, Naumovski N. (2023). The Effects of L-Theanine Supplementation on Quality of Sleep: A systematic Review. Federation of European Nutrition Societies (FENS). Belgrade, Serbia. Proceedings 91, 32. https://doi.org/10.3390/proceedings2023091032

  10. Williams J, D’Cunha NM, Kellett J, Georgousopoulou EN, McKune AJ, Mellor DD, Naumovski N (2022). Physicochemical, antioxidant and sensory properties of Mango Sorbet containing L-theanine as a potential functional food product. Journal of Food Science and Technology. 59 https://doi.org/10.1007/s13197-022-05570-6

  11. Naumovski N, Sergi D (2022). [Ed.] Food Bioactives: Impact on Brain and Cardiometabolic Health – Findings from In Vitro to Human Studies. Foods. https://doi.org/10.3390/books978-3-0365-4042-9

  12. Bulman A, D’Cunha NM, Naumovski N (2022) Tea and sleep: a focus on active ingredients. Food Australia. Bulman A, D’Cunha NM, Marx W, McKune AJ, Jani R, Naumovski N (2021) Nutraceuticals as Potential Targets for the Development of a Functional Beverage for Improving Sleep Quality. Beverages. 7(2). https://doi.org/10.3390/beverages7020033Williams J,

  13. D’Cunha NM, Anstice N, McKune AJ, Naumovski N. (2020) The effect of green tea amino acid L-theanine on physiological responses: a protocol for clinical trial. Exploratory Research and Hypothesis in Medicine. 10.14218/ERHM.2020.00048

  14. Williams J, McKune AJ, Georgousopoulou EN, Kellett J, D’Cunha NM, Sergi D, Mellor DD, Naumovski N. (2020) The effect of L-theanine incorporated in a functional food product (mango sorbet) on physiological responses in healthy males: a pilot randomised controlled trial. Foods. 9(3), 371 https://doi.org/10.3390/foods9030371

  15. Williams J, Everett JM, D’Cunha NM, Sergi D, Georgousopoulou EN, Keegan RJ, McKune AJ, Mellor DD, Anstice N, Naumovski N. (2019). The effects of green tea amino acid L-theanine consumption on the ability to manage stress and anxiety levels: a systematic review. Plant Foods for Human Nutrition, 75 (12-23) https://doi.org/10.1007/s11130-019-00771-5Naumovski N,

  16. Foscolou A, D’Cunha NM, Tyrovolas S, Chrysohoou C, Sidossis LS, Rallidis L, Matalas AL, Polychronopoulos E, Pitsavos C, Panagiotakos D. (2019). The Association between Green and Black Tea Consumption on Successful Aging: A combined Analysis of the ATTICA and MEDiterranean Islands (MEDIS) Epidemiological Studies. Molecules, 24(10) 1862; DOI: https://doi.org/10.3390/molecules24101862

  17. Williams J, D’Cunha NM, Sergi D, Kellett J, Mellor E, Georgousopoulou E, McKune AJ, Naumovski N. (2019) The physiological effects of L-Theanine incorporated in a functional food product (mango sorbet) consumption in males: a pilot randomised controlled trial. Nutrition Society Australia 43rd Annual Scientific Meeting, Newcastle, NSW, Australia.

  18. Williams J, Sergi D, McKune AJ, Georgousopoulou EN, Mellor DD, Naumovski N. (2019). The beneficial health effects of green tea amino acid L-Theanine in animal models; promises and prospects for human trials.  Phytotherapy Research, 33(3): 571. https://doi.org/10.1002/ptr.6277

  19. Williams J, Gouws C, D’Cunha NM, Kellett J, Georgousopoulou EN, Mellor C, Naumovski N. (2018). The antioxidant and rheological properties of the potential functional food product (mango sorbet) containing green tea amino acid L-theanine. Asia Pacific Conference on Clinical Nutrition, Adelaide, Australia, MDPI Proceedings 2(573); doi:10.3390/proceedings21210573.

  20. Sergi D, Williams LM, Thomas J, Mellor DD, Naumovski N. (2017) The effects of L-theanine and EGCG on Palmitic acid induced inflammation in mouse hypothalamic neuronal cell lines (mHypoE-N42). Nutrition Society Australia Annual Scientific Meeting, Melbourne, VIC, Australia. Journal of Nutrition & Intermediary metabolism, 8. https://doi.org/10.1016/j.jnim.2017.04.140

  21. Lau SO, Georgousopoulou EN, Kellett J, Thomas J, McKune A, Mellor D, Roach PD, Naumovski N. (2016). The effect of green tea catechins supplementation on markers of cardiovascular disease risk in human clinical trials: a systematic review. Beverages, 2(2): 16. https://doi.org/10.3390/beverages2020016

  22. Williams J, Kellett J, Roach PD, McKune A, Mellor D, Thomas J, Naumovski N. (2016). L-theanine as a functional food additive: Its role in disease prevention and health promotion. Beverages, 2(2):13. https://doi.org/10.3390/beverages2020013

  23. Lau S, Naumovski N. (2016). The effect of green tea catechin supplementation on cardiovascular disease risk markers in human clinical trials – a systematic review. Dietitians Association of Australia 33rd National Conference, Melbourne, VIC, Australia. Nutrition and Dietetics, 73, S1 https://doi.org/10.1111/1747-0080.12775

  24. Everett J, Gunathilake DRLA, Dufficy L, Roach PD, Thomas J, Upton D, Naumovski N. (2015). Theanine consumption, stress and anxiety in human clinical trials: a systematic review. Joint Annual Scientific Meeting of the Nutrition Society of New Zealand and the Nutrition Society of Australia, Wellington, New Zealand. Journal of Nutrition and Intermediary Metabolism, 4(6)

  25. Naumovski N, Blades, BL, Roach PD. (2015). Food Inhibits the oral bioavailability of the major green tea antioxidant epigallocatechin gallate in humans. Antioxidants, 4(2):373. 10.3390/antiox4020373

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