Reuters April 24, 2002 02:53 PM ET
UPDATE 3-Crisps, french fries, bread may cause cancer-study
Reuters April 24, 2002 02:53 PM ET
(Adds research detail paragraphs 14-18, company comment 22-25)
By Peter Starck
STOCKHOLM, April 24 (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 Organisation (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 DGE.L , and McDonald's MCD.N contained about 100 times the equivalent of the WHO limit for water, they said.
The U.S. Environmental Protection Agency classifies acrylamide, a colourless, crystalline solid, as a "medium hazard probable human carcinogen".
The WHO has ruled that one litre 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 litre, Stockholm University said in a statement -- one-tenth of the WHO limit.
A microgram is one-millionth of a gram.
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 tumours 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 haemoglobin 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 analyses had shown no trace of acrylamide.
Among the products analysed 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 K.N , Quaker Oats Co, part of PepsiCo Inc PEP.N , and Swiss Nestle NESZn.VX , 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.