THE Sleep Project

Project Description

The effect of green tea amino acid L-Theanine formulation on markers of stress and quality of sleep (THESleep Project)

This project has received University of Canberra Human Research Ethics Approval (HREC 2023-13247).

This project is registered with the Australia New Zealand Clinical Trial Registry (ACTRN12623000776606)

Several factors including anxiety, depression, and stress are associated with the quality of sleep and the cyclic effects of insomnia. Sleep disturbances, in turn, can increase and exacerbate stress as a result of negative sleep experiences. Furthermore, inadequate sleep and disturbed sleeping patterns are associated with seven of the top fifteen leading causes of death, such as accidents, cardiovascular disease (CVD), type 2 diabetes mellitus (T2DM) and hypertension. Despite these negative health outcomes, the implementation of strategies to reduce stress and improve sleep quality can contribute to improving health and wellbeing.

In recent years, there has been an increasing need for research into plant-derived bioactive compounds for the treatment and management of sleep disturbances as consumers are demanding more natural products. L-Theanine (L-THE) is a non-essential amino acid making up nearly 50% of the amino acids present in green tea, and accounts for approximately 1-2% of the tea’s dried weight. L-THE has been shown to exert several physiological and psychological benefits that may alleviate stress and anxiety and improve sleep quality. Findings from our team over the past several years have identified that L-THE can be considered as a supplement for the management of stress and anxiety and for improving sleep quality, however, there is limited evidence on the dose response effects of this compound.

This research project will provide a potential formulation/product that could be a natural alternative to pharmaceutical sleep aids in the management of sleep disturbances.

The aim of this research project is to explore the potential effects of different concentrations of L-THE on the quality of sleep in individuals with mild to moderate sleep disturbances. Furthermore, we will also investigate the effectiveness of L-THE formulation on the perception and biomarkers of stress (HRV, DASS-21, salivary cortisol and alpha amylase).

We would like to hear from you if you:

  1. Have Difficulty sleeping

  2. Are interested in consuming a functional beverage containing green tea amino acid L-Theanine

  3. Have no known digestive issues

  4. Are between 18 and 65 years of age

  5. Are currently residing in the Greater Australian Capital Territory Region (Including Queanbeyan)

What is involved:

  1. The study will be conducted over 3 weeks.

  2. Consume a functional beverage product containing L-theanine or a placebo nightly for two weeks following a one-week baseline.

  3. Wear a watch-like actigraphy device that will measure sleep and physical activity.

  4. Answer questions about sleep, stress, and diet.

  5. Attend 3 x 1 hour in-person clinics at the University of Canberra to measure heart rate, heart rate variability, and blood pressure.

What is in it for me:

  1. A better understanding of the effects of stress on sleep quality.

  2. A summary of sleep quality results at the end of the study.

  3. After successful completion of the study individuals will be provided with a $50 gift voucher.

Contact us for more information

Meet the Team

  • Mrs Amanda Bulman

    PhD Candidate

    (Food Science & Human Nutrition)

    Researcher Profile
  • Prof Andrew McKune

    Prof Andrew McKune

    Professor in Sport & Exercise Science

    (University of Canberra)

    Researcher Profile

  • Ms Grace Thomas

    Research Assistant

    (University of Canberra)

    Researcher Profile

  • Dr Ekavi Georgousopoulou

    Assistant Professor in Nutrition & Dietetics
    (University of Canberra)

    Researcher Profile

  • A/Prof Dale Rae

    Associate Professor

    (University of Cape Town, RSA)

    Researcher Profile

  • Prof Nenad Naumovski

    Professor in Food Science & Human Nutrition

    (University of Canberra)

    Researcher Profile

Recent Publication on this topic from our team

  1. 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

  2. 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

  3. 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

  4. Bulman A, D’Cunha NM, Naumovski N (2022) Tea and sleep: a focus on active ingredients. Food Australia.

  5. 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/beverages7020033

  6. Williams J, 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

  7. 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

  8. 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/s11130-019-00771-5

  9. Naumovski N, 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

  10. 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.

  11. 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

  12. 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.

  13. 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

  14. 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

  15. 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

  16. 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

  17. 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)

  18. 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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