How much coffee is too much - and does the way your cuppa's prepared make any difference to its impact on our health?
To answer those questions, Breakfast talked to our resident GP, Dr Rosemary Leonard A recording of this will be available shortly.
The way the coffee is brewed as well as the quantity consumed can affect the caffeine level.
And the rise in the number of trendy coffee shops could be adding to an increase in caffeine intake because the coffee is traditionally drip fed through the filter whereas instant coffee contains a much lower caffeine content.
The British Coffee Association says its research shows drinking three cups of coffee a day can reduce the risk of fatal liver disease by up to 40 percent.
Per 150ml cup: A brewed coffee (drip method) contains 115mg of caffeine.
An instant coffee contains 65mg of caffeine.
A decaffeinated cup has 3mg caffeine. A 30ml espresso cup contains 40mg of caffeine.
This compares with a brewed cup of tea which contains 40mg of caffeine and an instant tea which contains just 30mg.
Scientists have discovered that coffee protects against liver cirrhosis, a life-threatening illness usually caused by drinking too much alcohol, which kills around 4,000 Britons every year.
Research also shows that drinking three cups of coffee a day can reduce the risk of developing Alzheimer's disease by as much as 60%.
The Faculty of Medicine in Lisbon, Portugal found that healthy elderly people, with no signs of the brain disease, had consumed an average of three to four cups of coffee a day since the age of 25.
Link with brain disease
However, those with the illness - which affects one in ten Britain's over the age of 85 - drank just one coffee a day.
80% of adults drink coffee within the course of a week. Coffee is not the only beverage to contain caffeine, but it does contain the most.
Caffeine acts as a stimulant to the heart and central nervous system. Caffeine is also known to increase blood pressure in the short-term, although there is no conclusive evidence that there are long-term effects on blood pressure.
The effects are most likely when excessive quantities are taken or in highly sensitive people for example, those with high blood pressure / pregnant women.
Coffee has been linked with a number of the risk factors for coronary heart disease, including increased blood pressure and high blood cholesterol levels.
However, no relationship has been found between coffee drinkers and likelihood of developing coronary heart disease.
There is no evidence that coffee does any long-term harm. However, caffeine does have a very mild diuretic effect - so it's recommended drinkers have a glass of water afterwards to counteract it.