A 40-year-old supermarket worker who suffered a fatal heart attack drank as many as four cans of Red Bull energy drink each night, the Daily Mail has reported.

Pathologist Dr. Ian Roberts said this week Alfredo Duran, 40, of Wheatley in Oxford, England, had an enlarged heart and the excessive caffeine he consumed each day may have contributed to his death.

"My feeling is — given the evidence available — it was a cardiac arrest possibly contributed to by subtoxic caffeine ingestion," Roberts told the Daily Mail.

Each can of Red Bull is said to contain 80mg of caffeine — about the same amount as a cup of coffee.

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Duran collapsed at the end of his nightly shift at Asda supermarket in September 2006 and could not be revived by workers.

A spokeswoman for Red Bull told the Daily Mail, "No one anywhere has ever shown any link between Red Bull energy drink and harmful effects."

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