Acrylamide
Acrylamide is a chemical that forms when starchy foods and coffee beans are browned at high heat. It causes cancer in animals, and Europe's food-safety authority isn't comfortable with how close typical intake comes to the animal-tumour dose — but large studies in people have not shown it causing cancer, apart from a few loose ends.
Don't avoid coffee over acrylamide. If you want to cut your intake, fried potatoes are the bigger source.
What it is and where it comes from
Acrylamide forms in the browning reaction that colours and flavours food cooked at high heat — the same Maillard reaction that roasts coffee. In Europe's food-safety authority's exposure assessment, fried potato products were generally the main source. Coffee is one of the main sources for adults, but across sixteen national surveys of adults it never made up more than a quarter of intake, though it reaches about a third in the elderly.[1]
The animal evidence, and why the regulator is uneasy
Acrylamide damages DNA and causes cancer in animals, so the European Food Safety Authority (EFSA) declined to set a safe intake level. Instead it compared typical dietary exposure with the dose that causes tumours in animals. The gaps ran from roughly 425-fold down to 89-fold (the narrowest in toddlers), against the 10,000-fold margin it considers reassuring. On its own terms that margin is not comfortable, and EFSA says so — while adding in the same sentence that "the available human studies have not demonstrated [acrylamide] to be a human carcinogen."[2]
The classifications reflect that gap. The World Health Organization's cancer agency, IARC, lists acrylamide the chemical as probably carcinogenic (Group 2A) on the animal evidence. Coffee the drink, which it reviewed in 2016, is "not classifiable" (Group 3).[3]
What studies in people show
Mostly nothing. A 2022 dose-response meta-analysis of 1.15 million people and 48,175 cancers found no link between dietary acrylamide and cancer at any site it examined, and no threshold above which risk appeared. The one exception was lung cancer in smokers.[4]
The other loose ends are in women. That analysis left out gynaecological cancers. An earlier meta-analysis that included them found small remaining endometrial and ovarian signals among never-smokers, which its authors said "cannot be excluded."[5] A later dose-response analysis of the gynaecological cancers found the same: ovarian and endometrial risk rising in never-smokers, and breast cancer mostly unrelated, except in premenopausal women, where risk rose from about 20 µg a day, roughly the average intake.[6] Coffee itself, meanwhile, goes with lower endometrial cancer risk; see Coffee.
What to do
- Keep drinking coffee if you enjoy it. Acrylamide in coffee is an animal-derived concern that human studies have not confirmed.
- Look at fried potatoes first if you want less acrylamide; they contribute more than coffee for most adults. The wider picture on cooking compounds is in Foods to avoid.
Further reading
- EFSA Panel on Contaminants in the Food Chain (CONTAM). Scientific Opinion on acrylamide in food. EFSA Journal 2015.[7]
- Filippini T et al. Dietary Acrylamide Exposure and Risk of Site-Specific Cancer: A Systematic Review and Dose-Response Meta-Analysis of Epidemiological Studies. Front Nutr 2022.[8]
- Pelucchi C et al. Dietary acrylamide and cancer risk: an updated meta-analysis. Int J Cancer 2015.[9]
- Adani G et al. Dietary Intake of Acrylamide and Risk of Breast, Endometrial, and Ovarian Cancers: A Systematic Review and Dose-Response Meta-analysis. Cancer Epidemiol Biomarkers Prev 2020.[10]
- Loomis D et al. Carcinogenicity of drinking coffee, mate, and very hot beverages. Lancet Oncol 2016.[11]