New research from the University of South Australia has answered that question, determining the level at which caffeine consumption can lead to high blood pressure, which is one of several unsafe conditions experts link to heart disease.
She further added that according to the study of the above data, to maintain a healthy heart and high blood pressure, people must start using the limit of coffees to less than a six cups a day.
Coffee consumption was also associated with reducing the risk of both developing and dying from cancer, cardiovascular disease, diabetes and respiratory disease, as well as increasing life expectancy.
So no, there's no reason to completely cut out coffee, but it is smart to pay attention to how much you're really drinking.
Their results showed that "Coffee drinking was inversely associated with mortality, including among those drinking 8 or more cups per day and those with genetic polymorphisms".
Is there a point when coffee becomes more harmful than helpful?
The team used data from the UK Biobank including 347,077 participants aged 37-73 years.
Hyppönen said, "An estimated three billion cups of coffee are enjoyed every day around the world". "Knowing the limits of what's good for you and what's not is imperative", Hyppönen said in the press release.
The examination of the health benefits of coffee is one that has been widely assessed, with a similar study by Imperial College London and the International Agency for Research on Cancer finding that participants with the highest consumption of coffee had a lower risk of all-causes of death.
The team state that their research confirms the point at which excess caffeine can lead to high blood pressure and marks the first time an upper limit has been placed on safe coffee consumption and cardiovascular health.
The findings, likely, won't have much of an impact on most of us in the USA - the average American drinks 1.6 cups a day (compared to eight in Finland, the coffee capital of the world, according to the International Coffee Organization).
The researchers focused on the caffeine-metabolizing gene CYP1A2, which is believed to help better process caffeine. They wrote that "coffee drinking can be a part of a healthy diet". They looked at effects of coffee and tea drinking among Iranian populations on heart disease and kidney disease.