California ordered to add cancer warning to coffee, but the science doesn’t hold up

washingtonpost.com - Storm clouds are brewing in California’s coffee cups. Companies across the state will have to add a cancer-warning label to coffee, a judge ruled this week, because the drink contains a chemical called acrylamide.

Los Angeles County Superior Court Judge Elihu M. Berle sided with a nonprofit organization in a case against Starbucks, Peets and dozens of other coffee chains, saying that businesses that sold coffee were in violation of a state regulation called Proposition 65. Prop 65 requires businesses with at least 10 employees to disclose any carcinogens and toxic chemicals in their products.

The lawsuit, filed by an organization called the Council for Education and Research on Toxics, cites the presence of acrylamide in coffee. The International Agency for Research on Cancer, a branch of the World Health Organization, describes acrylamide as a human neurotoxin and a “group 2A probable carcinogen.”

With those classifications, the chemical certainly does not sound like something people want floating in their morning pick-me-up. But experts said coffee drinkers should not change their habits on the basis of the new ruling.

“The name, ‘acrylamide,’ it makes it sound scary,” said Michelle Francl, a chemist at Bryn Mawr College in Pennsylvania. But, she pointed out, a liquid labeled “oxidane” sounds ominous, even though that’s a fancy term for water.

Rodents fed massive amounts of acrylamide do develop cancer. This is an “acceptable and appropriate” way to determine a carcinogenic effect, said J. Leonard Lichtenfeld, the American Cancer Society’s deputy chief medical officer. But anything — including water and oxygen — can be unsafe at the wrong dosage. Those lab rats and mice were dosed at rates 1,000 to 10,000 times higher than what humans consume in food, according to the American Cancer Society.

Links between cancer and acrylamide in humans are weak or need to be replicated in additional studies, said Timothy Rebbeck, a professor at the Dana-Farber Cancer Institute in Boston.

Lichtenfeld agreed. “There are no well-done human studies that answer the question definitively,” he said. What research there is indicates that the human body does not absorb the chemical at the same rate as rodents do, and we also metabolize it differently.

“From a practical standpoint would we recommend people stop drinking coffee as a result of the judge’s decision? No,” Lichtenfeld said. “That’s not what the science shows us.”