After water, tea is the most popular drink in the world.
While the green variety of tea dominates in the Far East, black tea accounts for the vast majority of sales in the Western world.
Although coffee lovers may disagree, a cup of black tea is the perfect drink to wake up to in the morning.
There are good reasons for this too; as well as tasting great, black tea has a range of science-backed health benefits.
This article will take a look at the drink in more detail as well as examine the interesting ways it can improve our health.
What Is Black Tea?
Tea is available in four different varieties; black, green, oolong, and white.
Interestingly, all four varieties of tea come from the same leaves of the same plant; the Camellia sinensis.
The difference between black and green tea solely depends on the processing of the tea leaves.
The drink has long been valued for its health properties in China and India, where it has been a traditional part of society for many centuries.
In the Western world, tea first came to Europe in the 17th century; arriving in the Netherlands in 1610 and appearing in England in 1658 (1).
A four-step production process is necessary to make black tea;
Key Point: Black and green tea leaves come from the same plant, but black tea gains its unique characteristics from a four-stage production process which includes fermentation.
Health Benefits of Black Tea
Over the years, numerous research has been undertaken on the health properties of black tea.
Fortunately, there are a lot of positive points to consider.
Here are eleven purported health benefits of drinking black tea.
1. Rich In Polyphenols
Black tea is a rich source of various polyphenols including flavanols, flavonols, and phenolic acids.
Among these polyphenol groups, black tea is a particularly high source of catechins, theaflavins, kaempferol, quercetin and gallic acid (3).
Directly responsible for the bitter and astringent flavors in tea, these polyphenols are believed to play a part in boosting internal antioxidant systems.
Additionally, they are involved in regulating several biological processes, including inflammatory response.
Some polyphenols demonstrate benefits in vitro (test tube) but not in vivo (inside a living organism). However, studies show the benefits of black tea polyphenols both in vitro and in vivo.
For instance, research shows that tea polyphenols help prevent increases in oxidized DNA from carcinogen exposure. Additionally, these polyphenols appear to increase blood-antioxidant levels and lower the risk of chronic disease (4, 5).
Key Point: Black tea contains numerous health-protective polyphenols.
2. May Help Regulate Blood-Glucose Levels
High blood sugar levels are harmful whether someone has diabetes or not.
For example, chronically high blood glucose levels are associated with numerous chronic diseases. Various studies link high blood sugar with type 2 diabetes, cancer, vascular disease, and dementia, among others (6, 7).
As a result, keeping blood-glucose levels within a healthy range is something that everyone should strive for. On this note, black tea may play a helping hand.
Firstly, a recent randomized, controlled trial demonstrated that black tea consumption can significantly decrease blood glucose levels following sugar intake (8).
Furthermore, there is a linear inverse association between high black tea consumption and diabetes (9).
Also, several polyphenols found in black tea demonstrate the ability to inhibit carbohydrate hydrolyzing enzymes.
This slowing of carbohydrate digestion would improve blood-glucose regulation, and possibly reduce diabetes risk (10).
Key Point: High-dose black tea consumption can help regulate blood-sugar levels and reduce risk factors for diabetes.
3. May Lower the Risk of Cancer
Several systematic reviews and meta-analyses suggest that black tea consumption may reduce the incidence of oral cancer and bladder cancer.
Using 87 datasets, researchers found that the risk of both these cancers consistently fell with a one cup-increase in black tea per day (11).
Despite this, we have to remember that correlation doesn't equal causation, and there were also no statistically significant effects on other common forms of cancer.
However, further studies show that black tea polyphenols may play an anti-cancer role in the body.
Specifically, black tea polyphenols activate Nrf2 transcription factor, key proteins which upregulate internal antioxidant enzymes (12).
Key Point: Higher consumption of black tea may lower the risk for cancer.
4. Improves Physical Performance
Although most people immediately think of coffee as a caffeine-enriched performance booster, black tea has a similar (but slightly milder) effect.
Mainly as a result of its caffeine content, black tea has various performance-enhancing benefits. First, as systematic reviews show, caffeine intake can improve strength and muscular endurance (15).
There are also studies showing that doses as low as 100 mg of caffeine have beneficial effects by increasing the 'time to exhaustion' during exercise (16).
Coffee is the better choice for performance and exercise, but a cup (or two) of black tea may provide some benefits.
Key Point: Black tea contains caffeine and helps to improve strength and endurance during exercise.
5. Anti-Bacterial Properties
Another benefit of black tea is that it has anti-bacterial properties.
These properties mean that, in some instances, black tea may kill or slow the growth of certain types of bacteria.
Bacteria can cause a range of illnesses, from minor problems such as pimples and skin rashes to potentially life-threatening conditions like meningitis (17).
Specifically, black tea exhibits a protective effect and inhibits the growth of M. luteus and B. Cereus, which are common bacterial infections in humans (18).
Despite this, extracts of black tea have minimal protective effect against other bacteria such as salmonella, E. coli and Staphylococcus aureus.
Key Point: Black tea has antimicrobial activities, and it can inhibit the growth of certain bacteria.
6. May Improve Dental Health
Firstly, black tea can have a negative yellowing effect on teeth if we don't brush properly.
However, other than that, it appears to be very healthy for our oral health.
Here is a summary of current research findings;
Key Point: Black tea consumption appears to have a beneficial impact on dental health.
7. Improves Focus and Concentration
Once again, owing to the presence of caffeine, black tea can help to improve focus and concentration.
The evidence is clear that caffeine intake can have various cognitive benefits.
As a source of caffeine, black tea will provide these same benefits in a dose-dependent manner.
One recent study, specifically on black tea, also shows that the drink improves attention, awareness, and daily cognitive function (26).
Key Point: Black tea exerts a beneficial impact on mental alertness and cognitive processes.
8. May Decrease Risk of Stroke
Interestingly, recent studies find a link between reduced stroke incidence and black tea consumption.
One study monitored a total of 75,961 Swedish adults.
Over a follow-up period of 10.2 years, participants drinking more than four cups of black tea per day had "significantly lower risk" of stroke than those who didn't drink black tea (27).
An additional meta-analysis of nine studies involving 194,965 individuals had similar findings.
In this particular study, people drinking more than three cups per day had a 21% lower stroke risk than people who drank one cup or less (28).
The link between lower stroke risk and higher black tea consumption may be related to blood pressure. Markedly, a systematic review of randomized, controlled trials shows that regular consumption reduces blood pressure (29).
Key Point: In observational population studies, higher black tea intake reduces the risk of stroke.
9. Enhances Skin's UV Resistance
In animal studies, mice fed black tea had significantly fewer UV-induced tumors control subjects (30).
Clearly, what happens to a mouse does not mean the same thing occurs within a human. However, this kind of study is not possible in humans due to the obvious ethical implications.
However, further research is necessary to confirm this.
Key Point: Polyphenols can strengthen the skin's resistance against UV damage.
10. May Help Protect Cardiovascular Health
Cardiovascular disease (CVD) is, unfortunately, a prevalent chronic disease in the world today.
To illustrate this, CVD accounts for a substantial 31% of all deaths, and 17.7 million people die each year from the condition (33).
Although CVD is multi-factorial in causation, there are specific factors which can increase risk.
Despite this, it is worth remembering that any such effect would only have a slight effect. Chronic diseases are influenced by overall lifestyle choices such as alcohol consumption, diet, exercise, sleep and smoking.
While individual foods and drinks may have a beneficial effect, the overall lifestyle is the most critical consideration.
Key Point: Black tea intake may help improve certain risk factors for cardiovascular disease.
11. Cheap and Convenient
Black tea is a reasonably cheap drink that offers several health benefits.
Furthermore, teabags are very convenient; we can take them to the workplace with ease, and a cup of tea only takes a few minutes to make.
As a result, it is easy for people to enjoy tea no matter where they are.
One last consideration is that tea can be even more beneficial if it is replacing an unhealthier drink choice.
For people who might find plain water unappetizing, tea (and coffee) provide a much healthier alternative to soda and fruit juice.
Key Point: Black tea is healthy, convenient and great value for money.
Disadvantages of Black Tea
Despite black tea being an overall healthy choice, there are a few potential side effects to be aware of.
While the benefits outweigh the drawbacks, the following considerations can be potential issues;
1) May Impact Iron Absorption
Drinking black tea may inhibit the absorption of iron, and this inhibition is especially likely with (plant-based) non-heme iron.
This effect appears to be due to the presence of tannins in black tea (42).
2) Caffeine Sensitivity
Some people have either sensitivity or intolerance to caffeine.
In rare cases, caffeine allergies can even present themselves, which can lead to skin rashes, hives, and in severe cases, anaphylaxis (44).
Since black tea contains a moderate amount of caffeine, it can cause issues for anyone who suffers from caffeine-related problems.
3) Hypokalemia (Low Blood Potassium)
Low blood potassium (hypokalemia) is a severe and potentially life-threatening serious condition (45).
It is worth re-emphasizing that this is a very rare condition, and it only usually presents from consuming several grams of caffeine per day.
Key Point: In rare situations, black tea can have some potential drawbacks. However, these are relatively rare, and the advantages outweigh the disadvantages.
The Different Types of Black Tea
Tea plants now grow in many countries around the world, and there are numerous different types of black tea.
These teas are often named based on their region; they can also be either single origin or a blend of different black tea leaves.
Although the flavor of each variety is somewhat similar, there are slight differences in the flavor characteristics.
Some of the most famous black teas are listed below alongside their country of origin;
Ceylon (Sri Lanka)
English Afternoon Tea
English Breakfast Tea
Golden Monkey (China)
Irish Breakfast Tea
Lapsang Souchong (China)
Regarding the tea blends, the 'breakfast tea' varieties tend to be the strongest.
Earl Grey and Lady Grey are popular mild-tasting blends.
Personally, I'd recommend a breakfast tea for early in the morning, and an Earl Grey blend for later in the day.
Black Tea Is Good For You
All in all, black tea is a popular and delicious drink that offers a variety of health benefits.
Alongside coffee, it is one of the very best early-morning drinks.
That said, given its affordability and convenience, black tea is an excellent option for any time of day.