A Kyushu man in his 20s died last year from caffeine intoxication after drinking large quantities of caffeinated beverages daily over a long period to fight fatigue, researchers at Fukuoka University said.

Although something, possibly part of a caffeine pill, was extracted from his stomach, his death was most likely caused by consuming too many caffeinated drinks, according to the university's forensic medicine faculty.

Because there was no sign of a deliberate overdose, the man's death was considered accidental.