The Great Potato Chip Scare

Swedish scientists reported this week that eating potato chips may expose you to dangerously high amounts of the supposedly cancer-causing substance acrylamide.

Not to worry, though. You'd choke on the chips before you croaked from the chemical.

Stockholm University researchers claim to have shown that baking or frying carbohydrate-rich foods, such as potatoes and cereals, formed acrylamide, a substance classified by the U.S. Environmental Protection Agency as a "probable human carcinogen."

"I have been in this field for 30 years and I have never seen anything like this before," said Leif Busk, head of research for Sweden's National Food Administration. "The discovery ... is new knowledge. It may now be possible to explain some of the cases of cancer caused by food ... Frying at high temperatures or for a long time should be avoided," Busk added.

Should you chuck your chips and get a haz-mat team to decontaminate your pantry? Should personal injury lawyers fire up the class action lawsuit machine against potato chip makers for addicting us to an allegedly cancer-causing product? ("Lays Potato Chips, betcha can't eat just one!")


First, there isn't even a study available for review. The dire news was rushed to market via press conference. The researchers deemed their findings so important that they couldn't wait to have them officially published in an academic journal.

But science-by-press-conference is not part of the tried-and-true scientific method and almost invariably indicates junk science.

What's the rush in making these claims anyway? Humans have only been consuming baked and fried foods for thousands of years. If these foods were killing us, we likely would have noticed by now.

Yes, the EPA classifies acrylamide as a probable human carcinogen. But this is not based on any studies involving humans. The classification is based only on laboratory animal experiments that are of questionable relevance to humans.

Mice obviously aren't little people. Lab animals are bred to be prone to cancer and are so cancer prone that they get cancer simply from overeating, which they typically are allowed to do. Then, the lab animals are fed massive doses of the tested substances.

Using such experiments to predict human cancer risk isn't science — it's voodoo.

Putting aside that reality check, the claims don't pass the next one.

The researchers claim that a single potato chip may contain as much as one-millionth of a gram (a microgram) of acrylamide.

Assuming for the sake of argument that the lab animal tests are relevant to humans, the lowest dose in lab animals at which a slight increase in cancer incidence was reported is 500 micrograms per kilogram of rodent bodyweight per day, according to the EPA.

For the average 70 kilogram adult (about 154 lbs.), that would be an equivalent dose of acrylamide of 35,000 micrograms. To get an equivalent daily dose of acrylamide as the lab animals, someone of average bodyweight would have to eat 35,000 potato chips (about 62.5 pounds) per day for life.

No, I can't eat only one potato chip, but 35,000? Let's get real.

The idea that you can get cancer from acrylamide-laden potato chips is as dopey as the 1989 scare concerning the agricultural chemical Alar, formerly used on apples. Assuming the lab animal tests for Alar are relevant to humans, one would have to consume about 19,000 quarts of apple juice per day for life to get the same dose as the lab animals.

Moreover, as pointed out in the American Council on Science and Health's annual Holiday Dinner Menu, many foods naturally contain multiple supposed carcinogens, including coffee, tea, alcohol, lettuce, tomatoes, cooked meats, apples, pears, grapes, and others.

Food scares based on substances that cause cancer in lab animals can be very silly. If you want to play it safe and avoid substances in food that cause cancer in lab animals, try not to eat or drink.

Steven Milloy is the publisher of , an adjunct scholar at the Cato Institute and the author of Junk Science Judo: Self-defense Against Health Scares and Scams (Cato Institute, 2001).

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