The decision last month by Los Angeles County Superior Court Judge Elihu Berle found coffee purveyors such as Starbucks and 7-Eleven were in violation of a popularly approved 1986 California law that requires businesses to disclose if their products contain any of a list of more than 850 substances that are confirmed or suspected carcinogens.
At issue with coffee is a substance called acrylamide – a byproduct of the reaction between sugars and amino acids when they are heated, like roasting coffee, frying potato chips or almost anything cooked at a high temperature. Acrylamide has a carcinogenic effect when fed in massive amounts to rodents, but links between the chemical and cancer in humans remain unproven.
“Since acrylamide was first found in certain foods in 2002, dozens of studies have looked at whether people who eat more of these foods might be at higher risk for certain cancers, the American Cancer Society says on its website.”Most of the studies done so far have not found an increased risk of cancer in humans.”
The requirement of a warning for coffee despite the tenuous nature of the acrylamide findings rankled critics, some of whom say making overly inclusive lists of items that require labels threatens to make all warnings less effective.
“There’s a very widespread sense – and coffee’s a perfect example of it – that everything causes cancer, so I don’t believe any of it,” says Jeff Niederdeppe, a professor at Cornell University who studies how mass media messaging shapes health behaviour.
Research shows that it’s possible for ubiquitous labelling to backfire if it hasn’t been designed and targeted in ways that will drive home a message to an intended audience.
“Repeated exposure to a warning message without immediate consequences may diminish effectiveness. Such false alarms may or may not be associated with real danger,” David Stewart and Ingrid Martin wrote in landmark research on the subject in 1994.
“Research has demonstrated the recipients’ sensitivity to potential hazards is influenced by their awareness of expert disagreement and knowledge of serious mistakes made by experts in the past (e.g. everything causes cancer in laboratory rats, products or chemicals that were once considered safe are later found to be toxic and vice versa),” they wrote.
People can become desensitized after repeated exposures, false alarms, incorrect warnings when warnings are disproportionately extreme or don’t show immediate harm, the researchers found, citing examples such as reversed warnings on the level of unhealthy cholesterol in eggs and the danger of consuming certain preservatives or artificial sweeteners.
Bright colours, large text and prominent placement on the fronts of packages are important factors that improve the effectiveness of warning labels, research has shown.