black&white #22: Tea, good for the mind, body and soul

4 min steep

We’ve always been fairly reticent about the health benefits of tea. We find the tea companies that flag health first tend to care less about the quality. For us, flavour and provenance always come first. However, the body of evidence on the benefits of tea has been growing and the public mood is changing; we now know that looking after ourselves, both physically and mentally, will help us lead happier, more fulfilled lives. As ever, big business was quick to jump on the bandwagon and our desire to be healthy and feel good about ourselves has been commodified, from mindfulness apps and sleep-enhancing technologies to diet fads like “clean eating” and juice detoxes. 

What we choose to put in our bodies has become a kind of collective obsession, and ironically not always a healthy one. In the supermarkets, ultra-processed products claim to have healthy properties, whether they’re “high in fibre”, “low in fat” or “probiotic”. In reality, these highly processed foods are full of industrial ingredients – and contain flavours, emulsifiers and additives to make them addictive and super palatable. They couldn’t be further from the whole unprocessed or minimally-processed foods that constitute a healthy diet. It’s another reason why we’re stayed away from making too much of the health benefits of tea – in so many cases, players in the food industry use baseless health claims to mislead consumers and boost sales. 

Happily for us, drinking tea is actually good for you – and there’s a ton of evidence to back it up. Almost every week, another study is published on the health benefits of tea and herbal infusions. We've captured the highlights for you here.

To outline the science, tea contains a range of bioactive (i.e. having a biological effect) substances. These include flavonoids (or catechins) such as flavan-3-ols, Epigallocatechin Gallate (EGCG) and epicatechin-3-gallate which are particularly high in green and less oxidised teas. In black tea, theaflavins and thearubigins are generated from these catechins during aeration – they are polyphenols and powerful antioxidants. But what does this actually mean for our health?

1. Tea’s good for your heart

A 2019 review of the evidence found that drinking tea is associated with a reduced risk of heart disease. This is because the various antioxidants in tea reduce cardiovascular risk factors, including anti-oxidative stress, anti-inflammatory, anti-thrombotic, anti-hyperlipidemic, and anti-hypertensive effects. As ever, more research is needed to establish the “cause-and-effect” relationship, but so far, the evidence looks promising. 

Tea could also hold the key for life-saving cardiovascular medicines through molecular engineering. Last year, we mentioned a new study from the University of California 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. Similarly, researchers at Lancaster University found that the EGCG compound (the highest levels of this are found in green tea) could help break up dangerous plaque in blood vessels. Our bodies are pretty good at breaking this compound down, but by engineering the molecule slightly, we might be able to make new medicines to treat heart attack and stroke. 

2. Tea’s good for your mood, mental health and brain function

For centuries, people have associated drinking tea with feeling good. To this, I can relate. Imagine where the British would be without their morning cup of tea? It doesn’t bear thinking about. What’s fascinating though is that this “feel good” factor can be backed up by science. Research has shown that consuming L-theanine, an amino acid found in both black and green tea (and particularly in Matcha), can significantly reduce stress without affecting brain function. 

Researchers identified that the combination of L-theanine and caffeine had beneficial effects on sustained attention, memory, and suppression of distraction – as well as relaxation, by tempering the arousal effects of the caffeine. Another study found that drinking green tea reduced anxiety and benefitted memory, attention and brain function.

Drinking tea regularly has also been linked to lower levels of dementia and reduced risk of depression, particularly in older age groups. Again more research is needed, but it does appear that drinking tea throughout your life really is good for your mind, body and soul.

There is some initial evidence that the bioactive compounds in tea, such as catechins and l-theanine, could benefit your immune health by reducing viral replication. Studies indicated that the theaflavin derivatives in black tea and catechin derivatives in green tea could inhibit HIV entry into cells (though this wouldn’t necessarily happen just by drinking it). Others show that the catechins (particularly EGCG) in green tea could help prevent influenza or coronavirus infection. And one study even suggests that green tea could hold the key to reducing antibiotic resistance. Very cool.

In 2008, a study found that participants who drank green tea lost 3.3kg more weight than those who didn’t over a 12-week period. A few years later, 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.

More recently, research on the mediterranean diet found that drinking 3-4 cups of green tea daily improved fat loss.

5. Tea is good for bone and gut health

The consumption of tea has also been linked to good bone and gut health. One study found associations between tea consumption and high bone mineral density, while another showed that drinking 1-4 cups of tea daily could reduce the risk of hip fracture. Coffee, on the other hand, showed no clear association. As a rich source of polyphenols, tea can also be considered probiotic as polyphenol-rich diets boost healthy bacteria levels.

Although more research is always needed, it’s clear that drinking tea is associated with a wide range of important health benefits, both physical and mental – and we haven’t even started on the herbals!