The REAL Study

Project Description

The Effects of Green Rooibos Tea Extract on Anxiety Levels (REAL) Study

This study has received University of Canberra Human Research Ethics Approval (UCHREC -13602)

This project is registered with the Australia New Zealand Clinical Trial Registry (ACTRN12624000373572)

 

Anxiety disorders are one of the world’s leading health burdens and can affect individuals of all ages, gender, and socioeconomic statuses. Chronic anxiety can also significantly reduce overall health and wellbeing. Pharmacological interventions are often sought by individuals experiencing anxiety due to their convenience and quick action. However, anti-anxiety medications typically have serious side effects, such as nausea/dizziness, headaches, weight gain, fatigue/drowsiness sexual problems, gastrointestinal upset, etc.

Recently, there has been an increasing need for research into plant-derived bioactive compounds for treatment and management of anxiety as consumers are demanding more natural products. Aspalathin, a naturally occurring plant substance with diverse health promoting properties, is one of the main constituents of green rooibos tea. Consuming teas and their extracts with greater aspalathin concentrations have been shown to exert several physiological and psychological benefits that may improve cardiometabolic outcomes and alleviate stress/anxiety.

The use of functional food supplements is becoming increasingly popular. They offer several advantages over pharmacological medications including lesser or no adverse side effects and greater convenience/ affordability.

The aim of this study is to explore the potential effects of green rooibos tea extract on anxiety levels in individuals with mild to moderate anxiety. We will also investigate the potential effects of green rooibos tea extract on the perception and biomarkers of stress as well as lifestyle and gut microbiome.

We would like to hear from you if you:

  1. Are interested in consuming a functional green Rooibos tea extract

  2. Live with mild-moderate anxiety (but otherwise healthy)

  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. Daily supplementation of green Rooibos tea extract or a placebo (tablet) for eight weeks

  2. Wear a watch-like actigraphy device for one week prior and one week after the intervention

  3. Perform cardiorespiratory fitness testing

  4. Provide non-invasive biological samples (saliva and stool) and complete lifestyle and stress questionnaires

What is in it for me:

  1. A better understanding of the effects of Rooibos extract on anxiety levels.

  2. A summary of report of overall health, stress and fitness (valued at AU$ 1500) 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

  • Dr Katie Speer

    Post-Doctoral Clinical Trial Coordinator

    (University of Canberra)

    Click Here
  • Prof Andrew McKune

    Prof Andrew McKune

    Professor in Sport & Exercise Science

    (University of Canberra)

    Researcher Profile

  • Prof Nenad Naumovski

    Professor in Food Science & Human Nutrition

    (University of Canberra)

    Researcher Profile

Recent Publication on this and similar topics from our team

  1. ADM partners with the University of Canberra to dive deeper into the benefits of green rooibos on mental wellbeing

  2. 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

  3. 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

  4. 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

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

  6. 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

  7. 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

  8. 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

  9. 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

  10. 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

  11. 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.

  12. 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

  13. 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.

  14. 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

  15. 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

  16. 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

  17. 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

  18. 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)

  19. 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

Previous

THESleep Project
Next

Health and Mood in Young People