Should You Morning Cup Of Coffee Come With A Cancer Warning? California Thinks So

News broke late Thursday afternoon, March 29, 2018, that a California judge ruled that coffee companies—corporate and indie roasters, retailers, shops, and distributors alike—must bear a label that warns of cancer.

The culprit is acrylamide, a coffee roasting by-product that's been shown to cause genetic mutations and cancer in research on rodents, but hasn't to the same degree in humans. The science points to a difference in the way humans and rodents absorb and metabolize acrylamide, but findings are inconsistent at best—according to the National Cancer Institute, dietary acrylamide has not been shown to cause cancer in humans, but coal workers who use acrylamide and breathe it in have been shown to have neurological damage. There are quite a few variables that have affected this research including quantifying just how much acrylamide a person has been exposed to based on their diet.

The lawsuit arose when The Council for Education and Research on Toxics, a non-profit group, sued a group of coffee roasters, distributors, and retailers including Starbucks for allegedly skirting a California law that demands they either issue a warning on foods that contain certain levels of acrylamide or reduce levels of acrylamide in the product. The coffee companies have argued that the levels of acrylamide in coffee are too insignificant to cause cancer but Superior Court Judge Elihu Berle decided on Thursday that Starbucks and other coffee roasters did not sufficiently show that the cancer threat of acrylamide and other chemical compounds released during the coffee roasting process was insignificant enough to skirt the labeling law.

Given the inconsistent research, it's not surprising that some major players disagree with the ruling. The American Institute for Cancer Research (AICR) issued a press release Friday morning debunking the decision, saying that coffee, even with acrylamide, is cancer protective. The press release quotes three doctors in favor of coffee, one in-house at AICR and the other two from Harvard T. H. Chan School of Public Health citing its cancer-protective qualities.

According to the press release, Dr. Walter Willett, professor of Epidemiology and Nutrition at Harvard T. H. Chan School of Public Health, said “It is really unfortunate because most of the human studies published so far have failed to find links between acrylamide and different types of cancer. We have looked at coffee, acrylamide intake, and acrylamide blood levels, and there is no hint of increased cancer risk, and in fact, we have only found health benefits of coffee per se.”