The IARC included a large number of new studies in an updated review of the scientific research related to coffee and cancer. As a result of this review, IARC downgraded the classification of coffee from Group 2B to Group 3, for agents 'not classifiable as to carcinogenicity to humans'1.
Specifically, IARC concluded that there is inadequate evidence to suggest any link between coffee consumption and cancer of the bladder, oral cavity, pharynx, lung, larynx, ovary, stomach, oesophagus, kidney or colorectal; or with childhood leukaemia1. Furthermore, data suggests that there is no association between coffee consumption and increased risk of pancreatic, breast or prostate cancers1. Research results also suggest that coffee drinking is associated with a reduced occurrence of cancers of the liver and uterine endometrium1.
Comprehensive reviews of the data concerning coffee drinking and risk of cancer at various sites have also been undertaken5-12.
- One 2011 meta-analysis of 40 prospective cohort studies, including over 2 million participants across Europe, North America and Asia, which assessed the association between coffee intake and cancer risk in humans quantitatively, found that coffee consumption was not associated with an increased risk of cancer5
- A 2017 meta-analysis also concluded that coffee consumption was not associated with overall cancer risk10, and these conclusions were echoed in the data published in 2019 from the UK Biobank (>300,000 participants)12
For some types of cancer, coffee intake was inversely associated with disease risk.
- A meta-analysis of observational studies published in 2016 concluded that coffee consumption was inversely associated with risk of oral, pharyngeal, colon, liver, prostate, and endometrial cancer risk as well as risk of melanoma, but associated with an increased risk of lung cancer11
- A large Japanese cohort study also found no association between coffee consumption and increased risk of total cancer mortality13
- A further 2020 umbrella review of 28 meta-analyses supported the suggestion that there is evidence for an inverse association between coffee intake and the risk of liver and endometrial cancer14
In its Scientific Opinion on the Safety of Caffeine, published in 2015, The European Food Safety Authority (EFSA) concluded that:
“Caffeine intakes from all sources up to 400mg per day (about 5.7mg/kg bw per day for a 70kg adult) consumed throughout the day do not give rise to safety concerns for healthy adults in the general population. No health concerns in relation to acute toxicity, bone status, cardiovascular health, cancer risk or male fertility have been raised by other bodies in previous assessments for this level of habitual caffeine consumption and no new data has become available on these or other clinical outcomes which could justify modifying these conclusions"2.
The body of scientific research suggests that, overall, moderate coffee drinking is not associated with an increased risk of developing cancer and in the case of certain cancers, may be associated with reduced risk. Moderate coffee consumption is typically defined as 3-5 cups per day, based on the European Food Safety Authority’s (EFSA) review of caffeine safety2.
The content in this topic overview was last edited in September 2021. Papers in the research section and further resources are added regularly.