Putting too much zip in your life can be deadly

"I (HEART) CAFFEINE" (Credit: Shutterstock/iStockphoto/C&EN)

Caffeine Jitters

Sales boost in energy drinks and deaths linked to the products make scientists and regulators worry about safe levels of the stimulant

By Lauren K. Wolf

Caffeine fiends the world over frequently show their love for the stimulant and the buzz it induces.

When Matthew Penbross woke on a morning in August 2007—a day in which he’d be competing in motocross races near Port Macquarie, Australia—he wanted to be prepared. To improve his reaction speed on the start line, the 28-year-old began drinking Red Bull Energy Drinks soon after he rolled out of bed. All told, he would drink seven or eight of the caffeinated beverages within a seven-hour period.

After his second race that day, Penbross wasn’t feeling well. But despite some short-lived chest pains, he kept riding and went on to win a race in the afternoon. Twenty minutes after he crossed the last finish line of the day, though, his heart stopped.

Penbross had no family history of heart disease, and he regularly drank a few Red Bulls per day, news reports later stated. The hospital doctors who treated his collapse and helped him recover went on to suggest that the excessive amount of caffeinated energy drinks he consumed was the likely culprit (Med. J. Aust.2009,190, 41).

Stories like Penbross’ have surfaced with increasing frequency in recent years. According to a report released last month by the U.S. Substance Abuse & Mental Health Services Administration, the annual number of emergency room visits associated with energy drinks increased to 20,000 in 2011, a 36% boost from the previous year. Late last year, the New York Times reported that the U.S. Food & Drug Administration is investigating reports of five deaths linked to Monster Energy drinks and 13 deaths linked to 5-Hour Energy shots.

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