Researcher Falsely States That Energy Drinks Contain More Caffeine Than Coffee

Research by radiologists at the University of
Bonn
finds that caffeine in energy drinks has cardiovascular effects
similar to those
of caffeine in other beverages. That’s not terribly surprising, but
it is bound to be seen in a sinister light given the media-driven
scare about these products, especially because one of the
researchers incorrectly states that energy drinks contain more
caffeine than coffee does. “The amount of caffeine is up to three
times higher than in other caffeinated beverages like coffee or
cola,”
said Jonas Dorner, who together with his collaborators
presented the findings of a heart imaging study at a meeting of the
Radiological Society of North America. “There are many side effects
known to be associated with a high intake of caffeine, including
rapid heart rate, palpitations, rise in blood pressure and, in
the most severe cases, seizures or sudden death.”

The implication is pretty clear: Energy drinks pose a
potentially deadly threat because they contain so much caffeine.
Yet the drinks that Dorner and his colleagues gave their 18
subjects contained 32 milligrams of caffeine per 100 milliliters,
compared to 76 milligrams per 100 milliliters for
Starbucks coffee. So Starbucks coffee contains more than twice
as much caffeine per milliliter as energy drinks, as opposed to
one-third as much, as Dorner suggests. That’s a pretty big
mistake—and one that is likely to be repeated in future coverage of
this issue because it jibes with the attention-grabbing claim that
energy drinks are more dangerous than other caffeinated
beverages.

In any event, the effects observed by Dorner and his colleagues
are not very alarming:

Compared to the baseline images, results of cardiac MRI
performed one hour after the study participants consumed the energy
drink revealed significantly increased peak strain and peak
systolic strain rates (measurements for contractility) in the left
ventricle of the heart. The heart’s left ventricle receives
oxygenated blood from the lungs and pumps it to the aorta, which
distributes it throughout the rest of the body.

“We don’t know exactly how or if this greater contractility of
the heart impacts daily activities or athletic performance,” Dr.
Dorner said. “We need additional studies to understand this
mechanism and to determine how long the effect of the energy drink
lasts.”

The researchers found no significant differences in heart
rate, blood pressure or the amount of blood ejected from the left
ventricle of the heart between the volunteers’ baseline and second
MRI exams.

“We’ve shown that energy drink consumption has a short-term
impact on cardiac contractility,” Dr. Dorner said. “Further studies
are needed to evaluate the impact of long-term energy drink
consumption and the effect of such drinks on individuals with heart
disease.”

In other words, this study does not document any harmful or
lasting effects from consuming energy drinks. And if caffeine poses
a risk to people with heart disease, that risk presumably would be
greater in the case of coffee, which supplies a bigger dose. If the
caffeine in coffee does not scare you, there is no reason, aside
from alarmist press coverage, why the caffeine in energy drinks
should.