By Andy
Coghlan
French fries and chicken
nuggets from two major global fast-food
chains contain very high
levels of artery-clogging "trans" fats,
researchers warn. And the
level of trans-fats served by the chains
varies dramatically from
country to country.
Researchers who analysed
the fast food say that daily consumption of
5 grams or more of trans
fats raises the risk of heart attack by 25%.
Half of the 43
"large"-sized fast food meals, 24 from
McDonald's and
19 from KFC, examined in
the study - purchased in outlets around the
world - exceeded the 5
gram level.
Trans fats are thought to
pose a hazard by raising the proportion of
"bad" cholesterol in the
blood, leading to the accumulation of fat in
arteries. Trans fats also
increase the risk of arterial inflammation
and the development of an
irregular heartbeat.
"That's why it's called
'killer fat'," says Steen Stender of the
Gentofte University
Hospital in Copenhagen, Denmark, and lead author
of the analysis in The New
England Journal of Medicine.
Some combinations of
"large" fries and "large" chicken nuggets from
McDonald's and Kentucky
Fried Chicken outlets contained between
double and five times the
5-gram danger level.
Industrial-grade
oil
Stender says that
consuming such food regularly could drastically
increase someone's risk of
a heart attack, but the fast food
companies could solve the
problem by changing the industrial-grade
oil they use to prepare
the food.
"The good thing about
trans fatty acids is that it's easy to remove
them," notes Stender.
"When you enter a McDonald's or a KFC, you
should be entering a
trans-fatty-acid-free zone," he adds.
In a review of trans fats
in the same journal, Walter Willett at the
Harvard School of Public
Health in Boston, US, and colleagues,
conclude that in the US
alone, complete removal of the
industrially-produced
trans fats from food preparation could prevent
up to 228,000 heart
attacks per year in the US.
Peak levels
The fats are convenient
for the fast food industry because they can
be used repeatedly to fry
foods at high temperatures without breaking
down chemically. But
manufacture of the industrial-grade cooking oils
vastly increases the
proportion of trans fats in the oil, from zero
to as much as
60%.
In Stender's analysis, the
fries and nuggets containing the most
trans fat had invariably
been cooked in oil that was itself high in
fat.
The highest levels of all
were found in a meal from a KFC in Hungary
which contained 25 g of
trans fats, and had been cooked in oil
containing 35% trans fats.
Levels were also high in KFC meals bought
from Poland (20 g), Peru
(16 g) and the Czech Republic (15 g).
The highest-scoring
McDonald's meal was from New York, US (10
grams),
cooked in oil containing
23% trans fats.
Corporate public
relations
Both companies say they
are committed to phasing out the trans fats
from their cooking oils.
"We're at the early stages of reviewing
alternative oils options,
which includes looking at local taste
preferences, supply
availability, storage, as well as other factors
such as functionality,"
Christophe Lecureuil of KFC International
told New Scientist.
"McDonald's takes the
matter of trans fatty acids seriously," says
Catherine Adams, vice
president of worldwide quality systems, food
safety and nutrition at
McDonald's. "Our reduction in the US is
taking longer than
anticipated, as we have previously announced.
But
we continue to progress in
our testing and we are determined to get
it right for our
customers."
Stender found that levels
of trans fats were much lower in
merchandise from most West
European countries, and were virtually
undetectable in fries and
nuggets from Denmark, where it has been
illegal since 1 January
2004 to sell food with levels of trans fats
exceeding 2% of the total
fat in a food product. "It took less than
three months for the
industry to remove it," Stender points
out.
Journal reference: The New
England Journal of Medicine (vol 345, p
1650)
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Weblinks
* Harvard School of Public
Health
*
http://www.hsph.harvard.edu/
* KFC
*
http://www.kfc.com/
* McDonalds
*
http://www.mcdonalds.com/
* New England Journal of
Medicine
*
http://content.nejm.org/