Black Tea Benefits, Side Effects & Common Myths

black tea health benefits and side effects

Black tea is produced from  Camellia sinensis. Tea leaves contain polyphenols namely catechins. Processing of black tea includes the complete oxidation of catechins into oligomeric flavanols includes theaflavin which gives it a brisk taste. The full fermentation of tea leaves along with caffeine gives black tea its characteristic color and aroma. Almost 78% of western countries consumed black tea.

What is Theaflavin?

During the process of full fermentation, the polyphenols namely catechins get oxidized with the help of biocatalysts. Theaflavin is responsible for the specific taste of black tea.

Common myths of Black tea ?

1. Protect DNA damage and suppress cancer by stopping mutagenicity: Experiments showing strong evidence showed that black tea may suppress cancer in animals in laboratory conditions. But still, there is a lack of research related to its effect on humans.
2. Reduce bad cholesterol: The long-term effects of tea consumption on cardiovascular risk factors, such as cholesterol levels and atherosclerosis, are not fully understood.
3. Weight Loss: it reduces weight but there is still a lack of evidence on the human model that it alone helps in weight loss.
4. Reduce stress: it contains caffeine that may help in the reduction of stress but caffeine also when taken in excess amount causes anxiety.
5. Lowers blood sugar
6. Protects osteoporosis: More than 3 cups of black tea should be consumed to make it effective. But high consumption of black tea should be avoided as it might cause certain hindrance in the normal activity of the body.

What are the potential side effects of Black tea?

Caffeine content: One cup of tea contains about 50 milligrams of caffeine. Caffeine acts as a stimulant for the central nervous system. Excess caffeine causes sleeplessness. Excess intake of black tea may cause kidney diuretic. Which results in frequent urination leading to decrease in blood sodium and potassium. Although caffeine content in black tea is lesser than that of coffee but on an average maximum 2 to 3 cups will be taken.
· Caffeine may cause an adverse effect on diabetic patients
· Pregnant women’s should avoid caffeine as it crosses the placenta and caused abortion. Caffeine also interferes with the breast milk leads to sleep disorders in babies.

·Normal mean caffeine content of black tea is 21-33 mg/cup after 1 minute of steeping, 35-46 mg/cup after 3 minutes of steeping and 39-50 mg/cup after 5 minutes of steeping.

Health Benefits of the Black Tea

· Anticancer
· Prevents heart disease
· Weight loss
· Lowers blood sugar
· Protects osteoporosis
· Reduce stress
· Reduce Cholesterol

Side Effects of the Black Tea

· Arrhythmia – irregular heartbeat.
· Hypertension
· Tachycardia – rapid heart rate.
· Insomnia
· Tremor
· Iron deficiency
· Diuresis – excessive urination.
· Constipation
· Anaemia
· Abortion

Reference 1 – Journal of Pharmaceutical and Sciences and Research
Reference 2 – Rodman Media


  1. Thank you very much for sharing the benefits and side effects of black tea. I used green tea and just read above some folks saying it takes longer than black teas and others saying it takes less time.


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