Energy Drinks May Not Beat Sleepiness
High-Sugar, Low-Caffeine Drinks Might Not Make Up for Lost Sleep
July 20, 2006 -- If you're skimping on sleep, you might not want to count on
high-sugar, low-caffeine "energy drinks" to keep you alert for
"Sugar rushes" from such drinks don't appear to be very effective at
overcoming sleepiness, write Clare Anderson, BSc, PhD, and colleagues in
Anderson is a lecturer in the human sciences department of England's
Loughborough University. Her study included 10 healthy young adults (average
age: 22 years) without sleep problems.
Participants agreed to sleep for only five hours before taking an attention
test, in which they clicked a button when a clock appeared on the computer
After their short night's sleep, participants ate their usual breakfast and
headed to the researchers' lab. They hadn't consumed alcohol or caffeine during
the previous day. They also wore activity monitors on their wrists to confirm
that they hadn't broken the five-hour sleep limit.
At the lab, the researchers fed each participant a can of minestrone soup
for lunch. They also gave them either a high-sugar, low-caffeine, lightly
carbonated energy drink or a sugar-free, caffeine-free, lightly carbonated
Both drinks tasted the same, and participants didn't know which was which.
They took the test twice, waiting a week between tests, drinking the energy
drink in one session and the ordinary drink in the other session.
After downing the drinks, participants took the attention test. Their scores
were similar with both drinks. About 70 minutes after drinking the high-sugar,
low-caffeine energy drink, their attention scores began to lag behind their
scores with the sugar-free, caffeine-free drink.
Neither drink was high in caffeine. But based on previous studies by other
researchers, Anderson and colleagues conclude that caffeine is probably more
helpful than sugar in helping sleepy people pay attention, especially when
followed by a short nap.