Green Tea: More Than Just a Warm Drink
If you've visited the clinic during winter, you may have noticed one of us sipping on a cup of green tea during your consultation. It is a winter staple around here, especially when coughs, colds and flu are making the rounds. But green tea is much more than a comforting drink.
For centuries, it has been enjoyed as both a beverage and a traditional herbal medicine. Today, it is one of the most extensively researched herbal drinks in the world. Green tea comes from the Camellia sinensis plant and is naturally rich in compounds called catechins. The best studied of these is epigallocatechin gallate (EGCG), which has been extensively researched for its antioxidant, anti-inflammatory and antiviral properties. While no single food or drink can prevent illness, green tea is a simple habit that may help support your health when combined with the lifestyle foundations we talk about regularly in the clinic.
In one study involving more than 2,000 Japanese schoolchildren, those who regularly drank green tea were significantly less likely to develop influenza than children who drank very little. Another study involving healthcare workers found that participants taking a supplement containing green tea catechins and theanine (another constituent of green tea) were significantly less likely to develop influenza during the winter months than those taking a placebo. These studies don't mean green tea will stop you catching every cold or flu, but they do suggest it may play a supportive role as part of an overall healthy lifestyle.
Although we often think of green tea during winter, there are so many other health benefits to consider. Research suggests it may play a role in supporting cardiovascular health, lowering blood pressure and reducing LDL cholesterol.In terms of metabolic health, a meta-analysis of 17 randomly controlled trials found green tea catechins improved blood sugar control, including fasting glucose, alongside modest reductions in body weight and waist circumference in overweight adults.
In our dispensary at PHF, we often compound formulas for vaginal issues and urinary issues. Emerging research suggests green tea has applications in supporting both vaginal and urinary health. It's one of the reasons we sometimes include it as part of a personalised treatment plan for women experiencing recurrent urinary tract infections or vaginal microbiome imbalances.
EGCG has also been researched in brain health and aging, and green tea shows benefits in this area for improving cognition.
One of the things I love most about herbal medicine is that a single plant can have many different therapeutic applications, and green tea is a wonderful example.
If you're going to drink green tea, it's worth making it properly. Boiling water can make green tea taste bitter and may affect some of its more delicate compounds. Instead, allow the kettle to cool for two or three minutes after boiling (to around 80–85°C), then steep the tea for three to four minutes before drinking.
One final tip: if you're iron-deficient or have low iron stores, try to enjoy your green tea between meals rather than with food. Tea can reduce the absorption of non-haem iron from plant foods, so spacing it away from meals may help maximise iron absorption.
Green tea certainly isn't a cure-all, and it's not a substitute for the foundations of good health. But it's inexpensive, widely available and supported by a growing body of research. Whether you're looking for a warming drink this winter or simply another way to support your health, it's a simple habit that may offer benefits well beyond keeping you warm.
Bobbie X
References
1. Umeda M, et al. Preventive effects of tea and tea catechins against influenza and acute upper respiratory tract infections: A systematic review and meta-analysis. European Journal of Nutrition. 2021;60:4189-4202.
(Highest level of evidence supporting the immune health section.) 2. Park SK, Park JH, Kwon YC, et al. Association between green tea consumption and influenza among Japanese schoolchildren. Public Health Nutrition. 2011;14(10):1791-1796.
(Large observational study of >2,000 schoolchildren.)
3. Matsumoto K, Yamada H, Takuma N, et al. Effects of green tea catechins and theanine on preventing influenza infection among healthcare workers: A randomised controlled trial. BMC Complementary and Alternative Medicine. 2011;11:15.
(Human RCT supporting influenza prevention.)
4. Musiał C, Kuban-Jankowska A, Górska-Ponikowska M. Beneficial properties of green tea catechins. International Journal of Molecular Sciences. 2020;21(5):1744.
(Excellent review covering antioxidant, anti-inflammatory and antiviral mechanisms.)
5. Yang CS, Wang H. Tea and tea polyphenols for prevention of chronic diseases. Molecules. 2016;21(12):1679.
(Comprehensive review of cardiometabolic, anti-inflammatory and healthy ageing research.)
Please note: This article is intended for educational purposes and should not replace personalised medical advice. If you have an underlying medical condition, are pregnant or breastfeeding, or take prescription medications, speak with your healthcare practitioner before making significant changes to your diet or supplement routine.