-By Ibrahim Suleiman PhD
Black tea is produced from the leaves of Camellia sinensis plant, often blended with few other flavoured plants. It is rich in caffeine, as well as other stimulants and antioxidants. Aside from water, black tea is the second most consumed beverage in the world. It may be consumed either as a hot or cold drink.
Many people drink black tea just because they like it. But others take it for its health benefits, such as improving mental alertness, cardiovascular health and enhancing digestion. The health benefits of black tea have been attributed to the presence of antioxidants and few other compounds that can help reduce inflammation in the body, protect the heart and blood vessels. Black tea contains 2 per cent to 4 per cent caffeine, which affects thinking and alertness, increases urine output, and may reduce the symptoms of Parkinson disease.
This article will highlight on scientifically-proven benefits of drinking black tea, as well as the nutrients it provides, and the possible risks of consuming high amounts of black tea.
1. Source of antioxidants
Antioxidants are known to provide a variety of health benefits. Consuming them can help remove free radicals, and decrease cell damage in the body. These free radicals can contribute to the development of many diseases and conditions, such as atherosclerosis and some cancers. Thus, antioxidants may ultimately help decrease the risk of chronic diseases.
Black tea is an important source of antioxidants. It was earlier reported that up to 30 per cent of the dry weight of black tea is made up of antioxidants. They have the potential to reduce cholesterol and blood sugar levels, thereby reducing the risk of diabetes, obesity and hypercholesterolemia (elevated blood cholesterol level).
The best way to consume antioxidants is through food and beverages, taking pure raw antioxidants (e.g. in the form of supplements) may be harmful to one’s health. Thus taking black tea beverages is one very important way of antioxidant consumption.
2. Protects against atherosclerosis
Atherosclerosis refers to a build-up of plaque in the walls of arteries, thereby thickening and stiffening the blood vessels. Atherosclerosis can lead to coronary heart disease, stroke, and chronic kidney disease. Consumption of black tea was reported to prevent the development of atherosclerosis. Drinking, at least, three cups of tea per day might help protect against coronary heart disease, and reduce the risk of stroke.
However, it is important to note that black tea contains caffeine, and drinking more than three cups per day would contribute a significant amount of caffeine to one’s daily intake.
3. Improves blood pressure, body’s lipid profile
High blood pressure affects approximately one billion people worldwide. It can increase one’s risk of heart and kidney failure, stroke, vision loss and heart attacks. Fortunately, changes in one’s diet and lifestyle can lower one’s blood pressure.
Part of the function of antioxidants includes lowering the risk of hypertension. Despite its caffeine content, black tea has the potential of reducing diastolic and systolic blood pressure. This is attributable to the presence of another group of antioxidants called flavonoids which are beneficial to heart health.
Flavonoids help reduce numerous risk factors for heart disease, including high blood pressure, high cholesterol, elevated triglyceride levels and obesity.
Cholesterol is commonly transported in the form of low-density lipoprotein (LDL), or high-density lipoprotein (HDL). The LDL is considered the ‘bad’ lipoprotein, while HDL is considered the ‘good’ lipoprotein. This is because it transports cholesterol away from one’s cells, and to the liver to be excreted.
When there is too much LDL in the body, it can build up in the arteries, and results in waxy deposits called plaques. This can lead to problems like heart failure or stroke. Consumption of black tea for 12 weeks resulted in lowering of bad cholesterol (LDL), improved the amount of good cholesterol (HDL), and reduced the risk of heart disease. Drinking black tea every day, as well as incorporating other lifestyle modifications like stress management strategies, may benefit those with high blood pressure.
4. Gastrointestinal health
The gut contains trillions of bacteria, which play important roles in one’s health. While some of the bacteria in your gut are beneficial for one’s health, some are not. The polyphenols found in black tea may help maintain a healthy gut by promoting the growth of good gut bacteria, and inhibiting the growth of bad gut bacteria, such as Salmonella.
In addition, black tea contains antimicrobial properties that kill off harmful substances, and improve gut bacteria and immunity by helping repair the lining of the digestive tract.
5. Lower the risk of stroke and diabetes
A stroke can occur when a blood vessel in the brain is either blocked or ruptures. It is the second leading cause of death worldwide.
Fortunately, 80 per cent of strokes are preventable. For example, managing one’s diet, physical activity, blood pressure and quitting smoking can help reduce the risk of stroke. Interestingly, studies have found that drinking black tea may also help reduce the risk of stroke.
One study followed 74,961 people for over 10 years. It found that those who drank four or more cups of black tea per day had a 32 per cent lower risk of stroke than those who did not drink tea.
Consuming large amounts of sugar, particularly from sweetened beverages, has been shown to increase blood sugar values and the risk of Type 2 Diabetes. When one consumes sugar, the pancreas secretes a hormone called insulin to carry the sugar to the cells in one’s body to be used for energy production.
Black tea is a great non-sweetened beverage that has been found to help enhance the use of insulin in the body. Black tea increases insulin activity by about 15-fold, thereby reducing excess blood sugar and fat deposits.
Risks associated with black tea consumption
Although taking black tea in moderate amounts is generally safe, and has numerous evidence-based benefits, its unguided consumption may pose some risks to one’s health.
There is no known right amount to drink. Ingredients and quality may vary from one tea to another. This makes it hard to set a standard dose. Drinking large amounts of black tea (more than four or five cups a day) may cause health problems.
All brewed tea contains minerals that when taken in excess can be poisonous. Minerals such as lead, manganese and aluminium are present in tea. In large doses, these metals can be toxic to one’s health. The longer the tea brews, the higher the concentration of these toxic elements in it. Brewing tea for a maximum of three minutes can reduce the risks of mineral toxicity.
Similarly, people who are sensitive to caffeine contained in the tea could experience insomnia, anxiety, irritability, or an upset stomach when consuming tea in large quantities. Consuming too much caffeine normally results in abnormal heart rhythm, diarrhoea and pressure build-up in the eye.
Black tea contains tannins, a molecule that has the potential of reducing the body’s ability to absorb iron (an element that is very essential for blood production). This has linked black tea consumption to anaemia (low blood level) in people with a history of iron deficiency. Such people should avoid consuming tea when taking iron supplements or eating an iron-rich meal. They should also leave an hour between eating and drinking black tea.
If one drinks tea regularly and experiences any of the above risks, one should consider reducing one’s tea consumption. If symptoms persist, one should see a doctor. One may also wish to ask one’s doctor, if intake of black tea is likely to interfere with any medications one is taking.
In summary, black tea is a great option, if one is looking for a low-calorie, non-sweetened beverage, with less caffeine than coffee or energy drinks.
It has a strong, unique flavour, and contains plenty of antioxidants, which can provide several health benefits. These include: improved cholesterol, better gut health, and decreased blood pressure.
Best of all, it is simple to make, and can easily be found at many stores or online.
