Drinking a blend of tea for breakfast has been a longstanding British and Irish custom for over 200 years and the term breakfast tea has been applied by manufacturers since the early 18th century. English breakfast tea is a black tea blend, most commonly described as rich and robust and taken with milk and sugar. 

Many would say that drinking tea is an intrinsic part of British culture and even argue the health benefits of drinking multiple cups per day! Tea contains three forms of natural antioxidants called polyphenols, which are proven to have positive effects on the body. For instance, drinking more than three cups a day has been found to reduce the risk of a heart attack.

However, the total caffeine content of tea falls between 20–60 mg per cup. Therefore, it's best not to drink more than about 4 cups per day. After consuming about six mugs in a day, you may experience some anxiety or a slightly increased heart rate. Drinking between 8 and 10 daily mugs means you are at greater risk of caffeine intoxication which can include restlessness, nervousness, digestive distress and an increased heart rate.

Despite this, to dangerously overdose on caffeine by drinking tea would require incredible stamina and drinking effort – around 250 mugs of tea in just one day. Thus, as is the case with most drinks, consumption in moderation poses little threat. As ever, balance is required, and most likely some teeth polishing.