Drinking large amounts of coffee was found to raise the chances of men and women up to the age of 55 dying from any cause.
Consuming more than 28 cups a week increased their death rates by more than half, while having no effect on older people.
Younger people should avoid heavy coffee drinking, US researchers said.
The research was based on data from a large scale American lifestyle study.
Over an average period of 16 years, around 2500 deaths were recorded, just under one-third of which were due to heart and artery disease.
Participants who consumed higher amounts of coffee were also more likely to smoke, and had less healthy hearts and lungs.
The risk of death from all causes rose by more than 50% for men and women younger than 55 years of age who drank in excess of 28 cups of coffee a week.
Coffee contains a mixture of thousands of chemicals and is a double-edged sword that can have both good and bad effects on health.
Co-author Dr Carl Lavie, from Ochsner Medical Center in New Orleans, said: "There continues to be considerable debate about the health effects of caffeine, and coffee specifically, with some reports suggesting toxicity and some even suggesting beneficial effects."
Although the results showed a link with all-cause mortality, coffee-drinking had no significant effect on death rates from heart and artery disease alone.
The researchers said while younger people should avoid too much coffee, more work was needed to explore its long-term effects.