Worried about sugary drinks rotting your
teeth?
A new study suggests the acid in popular refreshments
can cause dental damage, too.
Just one day's worth of soaking in Gatorade, Red Bull
or Coke ate into the hard enamel surface of teeth, according
to a study by University of Iowa researchers.
"This isn't so much about sugar as it is about acid,"
said Dr. John Luther, associate executive director of
the division of dental practice at the American Dental
Association. "I don't think the public has thought
about acidity; they tend to think in terms of sugar."
But another expert said the study's design was "too
simplistic" and not reflective of daily exposure
to liquids by teeth.
Dr. Paul Casamassimo, a professor and chairman of the
department of pediatric dentistry at Ohio State University,
said that "when most drinks -- sports drinks, orange
juice, carbonated beverages -- are used the way they are
supposed to be, it's not a problem."
Most experts agree that the acid in many popular beverages
can etch into the thin layer of enamel that covers and
protects the exposed areas of teeth. It can also damage
the cementum -- the hard layer of calcified tissue that
covers the unexposed root area of the tooth.
"If it erodes far enough it could lead to real tooth
sensitivity," Luther said. "If the enamel is
gone, then the dentin, which is underneath, becomes more
sensitive. Acid eliminates that hard outer covering."
In its study, the University of Iowa researchers tested
the acid erosion potential of five popular drinks -- apple
juice, Coke, Diet Coke, Gatorade and Red Bull. To do so,
they immersed four extracted teeth in each of these drinks
for 25 hours, replenishing the liquids with a fresh supply
of the beverage once every five hours.
They then examined the rate of acidic enamel and cementum
erosion under a microscope.
The sports drinkg Gatorade was the worst offender, etching
into enamel to an average depth of 131 micrometers, the
researchers found. Next up was the energy drink Red Bull
(100 micrometers), followed by Coke (92 micrometers),
Diet Coke (61 micrometers) and apple juice (57 micrometers).
Results were similar when the researchers compared acid-linked
damage to cementum.
The findings were to be presented Thursday at the American
Association for Dental Research annual meeting, in Orlando,
Fla.
Luther said he was "happy with the range of acidity"
covered by the study, and said the findings "really
point to the fact that more study is needed." He
said he was also intrigued by the fact that high-acidity
sugary drinks tended to result in more acidic damage than
similar, non-sugared beverages (i.e., regular Coke vs.
Diet Coke). The reasons for that remain unclear, he said.
For his part, Casamassimo (who has conducted research
sponsored by the company that makes Gatorade) said the
long-term exposures employed in the Iowa study don't reflect
the way teeth interact with beverages in the real world.
According to Casamassimo, the Iowa study "is basically
that elementary-school science project where you put a
tooth in Coca-Cola for a period of time and it dissolves,"
he said. If that scenario did mirror real-life conditions,
"most people would have no teeth left by the time
they reached adulthood. That's not the case, of course."
In a statement, the American Beverage Association, which
represents the industry, agreed with Casamassimo. The
Iowa study, "does not reflect real-world situations,
and fails to incorporate many factors," the group
said. "A more credible study would examine live subjects
and more realistic, everyday behaviors."
Casamassimo said his own epidemiological study of 300
Ohio State athletes found no connection between particular
drinks or foods and dental erosion.
Luther acknowledged that acidic drinks can damage teeth,
but he stressed that "it's the duration of exposure
that's important."
"The problem is not only that these drinks are
acidic and contain sugar, the problem is that children
reach for these drinks and sip on them all day long,"
Luther said. "Their teeth are being bathed in it."
Casamassimo agreed. "I'm a pediatric dentist and
when we see someone who's on a sippy cup all day, that's
an eating disorder just like bulimia -- it's in the same
category in terms of its effects on teeth," he said.
"Or the older kid who sips Mountain Dew with a screw-top
cap all day at school."
Luther recommends that if a child does have a soft drink
with a meal, "that drink should be confined to the
meal, and the child should brush and floss [afterwards]."
Of course, that's not always easy, especially when it
comes to largely unsupervised older children.
"Parents really need to try and be aware of what
their kids are doing, and too often they aren't,"
said Luther, who advises that parents make sure their
kids get regular dental care. "In my own practice,
I've seen severe damage to multiple teeth by children
who have habits such as consuming up to 10 soft drinks
per day. They do it out of sight."
The dental news came on the heels of a new report released
Wednesday that showed sales of Pepsi, Coke and other brands
of "pop" are slipping for the first time in
20 years.
However, as reported by The New York Times, the
data from Beverage Digest also showed that consumers
were abandoning the fizzy drinks for bottled water, sports
drinks like Gatorade and Powerade, and energy drinks like
Red Bull and Full Throttle.
