As a bunch of people who bloody love bloody good tea, we believe in the notion that tea is indeed good for you. It’s a no-brainer really. It tastes amazing, keeps you alert without big peaks and troughs and contains zero calories if you drink it without milk and sugar.
Not really, obviously there is quite a bit more to it than that.
There is a massive body of research into the observable positive health impacts tea can have for those who drink it regularly, including some compelling evidence that it can literally help you not die. That’s what we’re interested in here today.
In this blog, we’ll be going through some of the major talking points around tea and health, looking at some studies in these areas and offering our opinion on them.
Our focus will be on ‘true tea’ - from the camellia sinensis plant. Common types include black tea, green tea, white tea, oolong tea and pu-erh tea. If you’re looking for more specific information on other types of tea, our posts on earl grey and rooibos are a good starting point.
We'll end each section with a healthy pinch of salt.
We’re not medical professionals but a bunch of scientifically minded people with an interest in tea. Consult someone better qualified than Chanui to give you health advice if you’re making major lifestyle changes.
So put down that giant, colourful can of energy drink, grab a cuppa and let’s get healthy.
Tea contains antioxidants
Aaah antioxidants, the marketer’s dream. Often used interchangeably with ‘good for you’, everyone has heard of this word but many don’t really know what it means or why they are supposed to be good for you.
So what are antioxidants? Watch the following video for an excellent breakdown on the subject.
In very basic terms oxidation = chemical reaction that can break down organic substances. Including living tissues.
Antioxidants are compounds that help to prevent or slow damage to cells caused by free radicals. Tea contains various forms of antioxidants including epigallocatechin gallate, catechins, theaflavins, and thearubigins.
So the hypothesis follows that by supplementing our diet with more antioxidant rich foods, we might be able to help prevent the problems associated with the free radicals that are generated in oxidation.
However, as detailed in the above video, it’s not as simple as more = better health. There are much more complicated relationships at play.
There is evidence to suggest that having a varied diet featuring lots of antioxidant rich foods will help you live longer and tea is one of them. We’ve deliberately put this at the top of the blog since they likely play a role in any causal relationships between tea and health.
The Chanui grain of salt:
Drink a cup or two of green tea in-between your beans, olive oil and chard-based meals. It might help you live longer.
This is one of the more widely believed and publicised things that drinking tea regularly can help with but, as ever, it’s more complicated than saying more tea = better heart.
This meta analysis looked at a load of previous studies to see if drinking tea has any effect on heart health and overall mortality. They found 22 studies that included over 850,000 people and looked at outcomes like heart disease, stroke, heart-related deaths, and overall deaths.
The results showed an association between increasing tea consumption by three cups per day and all of the above.
In other words, people who drank more tea had a reduced risk of all these health problems compared to those who drank less tea or no tea at all.
However, this study was based on observational research, meaning it shows an association but not a cause-and-effect relationship.
Think of it this way, there are so many other factors involved in the lives of the people included in all these studies so it’s impossible to say with certainty that it was the tea that caused better health. It could be that these people were eating healthy food and exercising more but also just happened to like the taste of tea.
The Chanui pinch of salt:
Drinking three cups of tea per day almost certainly isn’t doing most people’s hearts any harm and there is plenty of evidence to suggest it might be good for your heart. This study is one such example.
So why not drink three cups a day? It might just save your life.
This is kind of covered off in the antioxidants section as the hypothesis is similar:
Tea (camellia sinensis), that contains polyphenols which have a powerful antioxidant activity that can prevent the formation of free radicals that may cause damage and cell death. Therefore it has been suggested that green tea might reduce cancer risk, a theory that has been tested through a number of studies on human populations, which examined the link between green tea consumption and cancer. Source
This study from 2009 involved 142 studies and over 1.1 million participants.
It found that some studies suggested a potential benefit of drinking green tea in reducing cancer risk, while others found no effect or even a slight increase in risk!
The review concluded that the evidence for a clear cancer-preventive effect of green tea consumption simply isn’t strong enough.
For a more specific look, in this 2011 meta analysis, the researchers gathered and analysed data from 13 studies that looked at tea consumption and prostate cancer risk.
For green tea, they found that in Asian populations, there was a possible link between higher green tea consumption and a lower risk of prostate cancer.
However, this link was only borderline significant, meaning it was not strong enough to be conclusive. When they looked specifically at studies that compare people with and without the disease, there was a statistically significant association showing that higher green tea consumption was associated with a lower risk of prostate cancer.
But when they looked at studies which follow people over time, they didn't find a significant link.
When it came to black tea, they didn't find any significant association between black tea consumption and prostate cancer risk. Sorry english breakfast fans.
Chanui’s fist of salt:
Most of the studies analysed took place in Asia, making it even more difficult to draw any solid causation between drinking more tea and cancer prevention across wider geographic regions.
So while there are loads of other reasons to drink tea, preventing cancer probably isn’t one of them.
We’ve been championing tea’s potential for contributing to positive mental health for a long time. Admittedly on a more anecdotal basis but you can’t deny that unwinding with a lovely cup of tea or the positive feeling of chatting with your best friend over a couple of cups isn’t good for your mental health!
However, there is actually some very compelling data to suggest that drinking tea can have a measurable effect on your likeliness of being diagnosed with depression.
This meta-analysis set out to understand the relationship between tea consumption and the risk of depression. The researchers analysed data from 11 observational studies involving a total of 22,817 participants, including 4,743 cases of depression.
The researchers found that people who drank higher volumes of tea were 31% less likely to develop depression than those who consumed less tea.
To go even further, they looked to see if there was a dosage based linear relationship and found that yes indeed there is! For every three cups of tea drank per day, the risk of depression decreased by 37%.
A few Chanui fistfuls more (of salt)
This one seems pretty solid. More tea = less depressed. Makes sense.
Green tea specifically is widely believed to help with weight management due to the fact it is roughly made up of 35% polyphenols, specifically catechins.
In researching this article, we found this video essay which is well worth a watch if you have nine minutes to spare.
The short version is that green tea has a small but favourable benefit for weight loss.
Green tea seems to help in the following ways:
By increasing our metabolic rate
The grossly over-simplified version is that the catechins in green tea help to increase the presence of a chemical called norepinephrine which in turn slightly increases the number of calories our body uses.
It also contains caffeine which also raises the metabolic rate.
Together, these might raise energy expenditure by 4% according to this study.
By increasing fat oxidation
Chemicals in green tea send a message to the nervous system telling it to mobilise more fat as an energy source, usually activated in our fight or flight response. Specifically in the abdominal area.
By limiting nutrient absorption
Green tea catechins inhibit one of the key digestive enzymes which help break down carbohydrates.
This study found that drinking tea when eating a load of rice, reduced glucose absorption by 25%!
Basically, if the carbs aren’t absorbed into your blood as glucose, you’ll just pass it and avoid the dreaded glucose spikes that you often hear are bad for people struggling with their weight.
By suppressing appetite
This is the one you might be more aware of since ‘green tea’ is often written within a few words of ‘intermittent fasting’.
In layman’s terms, gherlin is the hunger hormone so the more gherlin you have in your system, the hungrier you’ll feel. The catechins in green tea are known to reduce gherlin.
This study showed that 12 weeks of treatment with high-dose green tea extract resulted in significant weight loss, reduced waist circumference, and improved lipid profiles without any side effects or adverse events in women with central obesity.
The Chanui salt flats:
If you’re looking for a tail-wind in your journey towards losing a few kilos of fat, particularly from the more health problematic belly area, why not try drinking a few cups of green tea per day? The benefits seem to stack high against any risks.
Hopefully your kidneys are still functioning after all the salt we’ve administered throughout this post.
This is clearly a very complicated topic as it’s very difficult to measure only one variable when it comes to matters of diet and lifestyle.
It’s tempting to draw a causal link between a fit and healthy person and the litres of tea they drink per day but the truth is there are too many other factors to say anything definitively.
Having said that, on balance there does seem to be more than enough evidence to suggest that regularly drinking tea is indeed a healthy choice. Particularly when you consider that it might be taking the place of the several 400+ calorie cups of caramel lattes someone is putting away each day.
It goes without saying but just in case: if you have any serious medical conditions then please seek medical advice from trained medical professionals!