STOCKHOLM (Reuters) - Potato crisps, french fries, biscuits and bread, eaten
daily by millions of people round the world, contain alarmingly high amounts of
a substance believed to cause cancer, Swedish scientists said on Wednesday.
Research carried out at Stockholm
University in cooperation with the government food safety agency showed that
acrylamide, well known as a probable cancer-causing agent, is formed in very
high concentrations when carbohydrate-rich foods such as rice, potatoes and
cereals are fried or baked -- but is not present when they are boiled.
The results of the research were deemed so important, and so surprising, that
the scientists took the rare step of going public with their findings before
publishing them in an academic journal and having them reviewed by other
scientists.
"I have been in this field for 30 years and I have never seen anything like
this before," said Leif Busk, head of the National Food Administration's
research department, of the results of the study.
Food Administration officials told a news conference they had found that an
ordinary bag of potato crisps may contain up to 500 times more acrylamide than
the maximum concentration the World Health Organization (WHO) allows in drinking water.
French fries sold at Swedish franchises of the U.S. fast-food chains Burger
King Corp, a unit of Britain's Diageo plc, and McDonald's contained about 100
times the equivalent of the WHO limit for water, they said.
The U.S. Environmental Protection Agency classifies acrylamide, a colorless, crystalline solid, as a "medium
hazard probable human carcinogen."
The WHO has ruled that one liter of drinking water should contain no more
than one microgram of acrylamide.
A tougher European Union drinking water directive due to take effect at the end of 2003 sets
the maximum permitted concentration at 0.1 microgram per liter, Stockholm
University said in a statement -- one-tenth of the WHO limit.
A microgram is one-millionth of a gram.
NEW KNOWLEDGE
Acrylamide is known to cause damage to the human nervous system, and the
International Agency for Research on Cancer says it has been found to induce
gene mutations and cause stomach tumors in animals.
"The discovery that acrylamide is formed during the preparation of food, and at high
levels, is new knowledge. It may now be possible to explain some of the cases of
cancer caused by food," Busk said.
"Fried, oven-baked and deep-fried potato and cereal products may contain high
levels of acrylamide," the Administration said.
Boiling the same products did not form acrylamide, said Margareta Tornqvist,
an associate professor at Stockholm University's environmental chemistry
department.
Her study first looked at the buildup of acrylamide in a hemoglobin reactive
in the blood of rodents fed with heated rat food, compared with rodents eating
the same rat food unheated.
Acrylamide levels proved to be about 10 times higher in rats eating the
heated food.
Tornqvist and her team then tested protein-rich hamburger steaks and again
detected an acrylamide buildup related to the heating process, though smaller
than for rat food.
Assuming that the heated rat food's acrylamide buildup must originate in a
source other than proteins, the scientists tested carbohydrates and found that
heating potatoes formed a concentration of acrylamide in them between 12 and 40
times greater than in the heated hamburgers, Tornqvist said.
"This was surprisingly high and implies a remarkably high cancer risk
stemming from a single compound," she said.
Busk said the Food Administration's follow-up analysis based on more than 100
random samples was not extensive enough for the agency to recommend the
withdrawal of any products from shops or to advise people to change their eating
habits. The raw materials used in the analyzes had shown no trace of acrylamide.
Among the products analyzed in the study were potato crisps made by Finnish
company CHIPS ABP, whose shares fell 15 percent to six-month lows, breakfast
cereals made by U.S. Kellogg, Quaker Oats Co, part of PepsiCo Inc, and Swiss
Nestle, and Old El Paso brand tortilla chips.
"Burger King is interested in studying the information closely and will
launch its own investigation into the subject," Burger King said in a statement.
NEWS TO FOOD INDUSTRY
CHIPS ABP, in a statement to the Helsinki stock exchange, said: "For us,
these are completely new findings which have never before been known to the
world's foodstuffs industry."
Nestle spokesman Marcel Rubin said the group did not at present think the
findings were very grave. "If it had been serious, the Swedish authorities would
not have said that no change is required in eating habits."
McDonald's Sweden media relations manager Birgitta Mossberg told Reuters the
company was taking the research seriously. "But it is important not to draw
hasty conclusions," she said.
Spokesmen for the other companies were not immediately available for comment.
"We will evaluate this study and look at it but it is important to say that
Sweden has not withdrawn any products from the market," said European Commission
spokeswoman Beate Gminder.
Liliane Abramsson-Zetterberg, a toxicologist at the Swedish Food
Administration, said that while the cancer risk from acrylamide was much higher
than levels accepted for other known carcinogens, smoking remained a bigger
risk.
