Communicating to the consumer the risks associated with a product is correct, but labels are not always the best strategy to address healthy choices. A California judge has ruled that all those who sell coffee, from the giant Starbucks-recently landed in Italy with a branch in Milan-at the bar under the House, will be held, if they are located in the state of surf and Silicon Valley, to affix a label indicating that it is a potentially carcinogenic substance. News has made some noise because many people around the world make extensive use of this natural stimulant. But is coffee really carcinogenic? In this case, as for meats or alcohol, the answer must be pursued by the parties of the international Agency for Research on Cancer (AIRC). In the years ‘ 90, this institution, which orders the carcinogenicity studies of the various substances published in the scientific literature, had included coffee in category 2B, that of possible carcinogens for humans. In 2016, however, after examining over 500 new studies, he downgraded it to Category 3 (non-human carcinogen) and concluded that there is no evidence that its consumption is associated with an increased risk of developing cancer. For some types of tumours, it seems to even have a protective role. That judge, however, has not sentenced on anything. Coffee is a complex mixture of substances: some, like polyphenols, are antioxidants and have a positive effect. Others, however, may have adverse effects. The substance indicted, specifically, is acrylamide, considered a probable carcinogen for humans. Acrylamide is found in coffee because it is produced in modest quantities during the roasting of the beans, but it is also formed in the roasting of cereals and cooking at high temperatures of foods containing starch, such as potatoes, bread and biscuits. Coffee exposures have not been associated with an increased risk of tumours. As a precaution, large producers of roasted cereals (corn flakes and similar) or chips have reduced the preparation temperature in order to avoid their development. It is not clear whether this is possible even for the roasting of coffee. However, the coffee is not consumed directly, like the fries, but it is an infusion. As a result, the possible exposure levels are even lower. Another good reason not to label as “carcinogenic” coffee is precisely related to the spread of acrylamide: for consistency, the label should also be placed on many other foods, such as rusks, potatoes, bread, corn flakes… Breakfast spending would become really difficult and it is not said, as we will see, that health would benefit. Furthermore, the problem could also cover other food categories. The Red Meats worked were classified by AIRC as certainly carcinogenic to humans: the obligation to label should also affect Bresaola, Culatello and Crudo. The end result would be that, on the proliferation of labels, the alarm signal would soon pass as a formality and would not receive more attention. If the objective of these standards is to inform the consumer, it would be risky to offer distorted information, because no label, especially if so generic, can quantify the risk associated with consumption. The assessed studies of AIRC, in fact, are conducted in the laboratory on pure substance, with cells and laboratory animals, at very high concentrations and for exposure times higher than those with which generally one has to do in daily life. The label on the espresso cup does not tell us, therefore, if that single cup is dangerous for our health, if it becomes over the years or if we have to drink five or ten a day to see really increase in a measurable way our personal risk of getting sick.
All experts, analysing the data available in human and animal studies, are able to determine whether a substance is carcinogenic, but cannot quantify the risk for a specific individual. That depends on the individual predisposition. The development of a tumour is influenced by many factors such as age, genetic heritage and lifestyles. Demonizing a single product leads to unnecessary alarmism, without really educating the consumer to make positive choices for health. For example, even potato chips contain acrylamide, but eating french fries every day should not worry so much for this reason, but because a chip-based diet leads to obesity, which in turn is an important risk factor for cancers of the gastrointestinal, kidney, thyroid and gynaecological tumours, as well as cardiovascular disease and diabetes. The European Food Safety Authority (EFSA) proposed as a reference value for acrylamide a daily dose of 170 micrograms per kilogram of body weight: exceeding this dose would increase (to a slight extent) the incidence of tumours. According to a Portuguese research, an espresso contains about 30 micrograms of acrylamide. Therefore, considering only acrylamide contained in the coffee, the risk of tumours for an adult man of average build (70 kg) would increase only if he drank 400 cups of espresso per day.