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Nanofoods are On the Rise, But Their Impact on Human Health Is Still Uncertain
CHICAGO--"Nanofoods" now on the market promise everything from
mouth-watering bursts of flavor to fresher produce, but speakers at the
2009 AAAS Annual Meeting said very little is known about how tiny
particles added to foods and food packaging might affect human health.
There
are nearly 800 commercial products that contain
nanomaterials--particles so small that 80,000 of them could line up
comfortably across the width of a human hair.
So far,
nanofoods and food packaging with nanoparticles make up only 10%
of this total, but worldwide sales of nanofoods "are expected to reach
U.S. $6 billion by 2012," said Qasim Chaudry, a food safety
scientist at the Central Science Laboratory in the United Kingdom.
Nanofood
manufacturers want to include the particles as flavor boosters,
replacements for fats and sugars, delivery systems for vitamins, and in
the case of packaging, coverings that keep foods fresher for longer and
may someday act as sensors that tell a consumer when their food is
starting to spoil.
It's unlikely that nanoparticles would ever
be used for "unlimited synthesis of foods assembled from atoms and
molecules," Chaudry said, noting that they would take too much energy
to manufacture.
But what happens to a nanoparticle once it is eaten? Researchers know that nanomaterials have
unique properties as a result of their tiny size, including vastly enhanced
surface area and different kinds of chemical reactivity than their bulk
counterparts.
Expanded
surface area can help a cocoa-dusted nanoparticle taste like a rich
mouthful, but it's still unclear what happens
to a nanofood after it is swallowed, said Hermann Stamm, a risk
assessment researcher at the European Commission's Joint Research
Center.
Stamm
cautioned that there are "extremely limited studies" on how
nanoparticles are absorbed by the body's tissues, and "only a narrow
range of effects have been studied" for a few types of particles such
as nanosilver.
Without studies showing how these products might
affect human health, it can be difficult to devise safety regulations
for nanofoods, said Thane Scott Thurmond, a food safety researcher at
the U.S. Food and Drug Administration.
Other questions "do exist
regarding the regulatory status of these products," Thurmond suggested.
For instance, if a substance has already been deemed "generally
recognized as safe" by the FDA, would that seal of approval
automatically be conferred to nanosized versions of the product?
It's
a question that the FDA is reviewing, said Thurmond, who said the
agency is expected to issue guidance on the topic by the end of the
year.

