black&white #07: Green tea: truth, myth and legend

4 min steep

When we set up Canton back in 2007, we didn’t think much about the health benefits of tea, even though many were coming to light. If anything, we felt those early associations, particularly between green tea and health, were hampering the potential for good quality, loose leaf tea to become truly mainstream in the UK. So we pushed any health benefits to one side and put taste and provenance front and centre. And to some degree, that’s still the approach we take 14 years on. We tend to find that if a company flags health first when selling tea, they care less about the quality.

But, the public mood is changing. Faced with the pressures of the 21st century – technology, sedentary lifestyles, ultra-processed food – people in the UK are beginning to recognise the importance of body, mind and soul. Almost every week, a new study is published on the health benefits of tea – with those focused on green tea making up a large proportion of these. Why? Because green tea tends to have high levels of polyphenols (antioxidant-packed micronutrients), catechins (antioxidant-packed flavonoids) and L-theanine (an amino acid which reduces anxiety and stress).  

But what does that actually mean? Green tea has been endowed with health-giving powers said to help you live longer for centuries. Recent popular claims include assisting weight loss and warding off coronavirus. Some have scientific merit and some don’t.

1. Green tea can help you live longer

That’s some claim but 15 years ago when we first started Canton we came across a tea website that said ‘This tea can help prevent death!’. Laws on misleading advertising have tightened up a bit since.  A recent study of Chinese tea drinkers found that on average, green tea drinkers lived 15 months longer than non-tea drinkers. But, as Dr Jenna Macchiochi, Lecturer in Immunology at University of Sussex, points out, there’s no causal link – so ‘tea drinkers live longer’ does not necessarily mean ‘drinking tea leads to living longer’. Damn.

2. Green tea reduces the risk of heart disease

The results certainly look promising. A few months back, we mentioned a new study from the University of California, Irvine, which showed that compounds in both green and black tea relax blood vessels by activating ion channel proteins in the blood vessel wall. The discovery helps explain the antihypertensive properties of tea and could lead to the design of new blood pressure-lowering medicines.

A 2013 review of 11 studies also found that green (and black) tea could help lower cholesterol and blood-pressure. But the authors cautioned that most of the clinical trials reviewed were short-term and longer-term trials were needed. Green tea also contains high levels of a catechin called EGCG, and researchers in 2018 found that this compound could help break up dangerous plaque in blood vessels. Our bodies are pretty good at breaking this compound down, but researchers noted that by engineering the molecule slightly, we might be able to make new medicines to treat heart attack and stroke.

3. Green tea and diabetes management and prevention

There’s nothing conclusive so far. A recent study in Japan appeared to show that green tea consumption was associated with lower mortality in type 2 diabetes patients – but again, nothing causal has been established. A meta-analysis back in 2015 also found that tea could help maintain stable insulin levels and reduce waist circumference, but that other effects were not significant.

4. Green tea can help you lose weight

This claim actually has some clout. Two dutch reviews compared catechin-plus-caffeine mixtures (i.e. green and black tea) to caffeine-only mixtures and found that compared to placebo and caffeine-only, catechin-plus-caffeine was more likely to break down fat. They also found that those consuming catechins like EGCG from green tea had a 1.3 kg greater weight loss, and were more likely to maintain this loss. 

So, with the proliferation of so-called ‘skinny teas’ (urgh), it’s best to just explore green teas and find the ones you love and – you know what’s coming - a healthy diet and lots of exercise.

5. Green tea and anti-viral properties

Green tea is full of EGCG, a natural antioxidant that has been proven to contain various antimicrobial and antiviral properties. Though researchers are not yet sure whether you can benefit from EGCG’s antiviral properties by ingesting green tea, many are optimistic about the potential of EGCG to treat viral infections – incredibly from HIV to coronavirus. One study even suggests that green tea could hold the key to reducing antibiotic resistance. That would be cool.

So, although it’s clear that more research is needed across the board, green tea does have some evidence-based health-giving qualities. And what’s more, the naturally occurring polyphenols and catechins found in green tea could help researchers engineer new, more effective medicines.

Explore our own small but fabulous range of green teas here.

- Jennifer Wood, Founder