# Coffee and tea intake

Source: https://onco.cc/technologies/coffee-intake-cancer/  
OnCo record `coffee-intake-cancer` (Technology). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

Coffee does not cause cancer: IARC downgraded it in 2016, and cohort studies link two to three cups a day with lower rates of liver and womb cancer. Drinks of any kind served above 65 C are classed as a probable cause of oesophageal cancer, so the temperature, not the coffee, is the risk.

## Summary

IARC reclassified coffee in 2016 from 'possibly carcinogenic' (Group 2B, a 1991 verdict driven by confounding with smoking) to 'not classifiable' (Group 3), while classifying beverages drunk above 65 C as Group 2A for oesophageal squamous cell carcinoma. Umbrella reviews of prospective cohorts show coffee consumption associated with lower risk of hepatocellular carcinoma (about 30-40% lower per 2-3 cups/day, the most consistent finding, including in people with liver disease) and endometrial cancer, and with lower cancer mortality; associations with other sites are null. After diagnosis, coffee intake was associated with lower recurrence and death in the CALGB 89803 colon cancer cohort and in advanced colorectal cancer (CALGB 80405), findings that are hypothesis-generating and unconfirmed by trials. Green tea and its catechins have not delivered in randomised chemoprevention trials (prostate, breast). This is an example of an exposure that generates endless headlines but has a stable, modest evidence base: coffee is safe, probably good for the liver, and not a treatment.

## Fields

- Kind: Technology
- Status: established
- Last checked: 2026-09-08
- Principle: Coffee polyphenols, diterpenes and caffeine improve insulin sensitivity, reduce hepatic fibrosis markers and induce hepatic detoxifying enzymes; the protective association is strongest where those mechanisms are most relevant (liver, endometrium).
- Strengths: Large, consistent cohort evidence; IARC review resolved earlier confounded signal; No downside for most people
- Limitations: Observational only; Reverse causation and residual confounding possible; Overinterpreted in survivorship

## Sources

- Wikipedia: https://en.wikipedia.org/wiki/Health_effects_of_coffee
- IARC Monograph 116: coffee, mate and very hot beverages (Lancet Oncol 2016): https://doi.org/10.1016/S1470-2045(16)30239-X
- Umbrella review (BMJ 2017): https://doi.org/10.1136/bmj.j5024

## Connected records

- cancers: [Colorectal cancer](https://onco.cc/cancers/colorectal/), [Endometrial cancer](https://onco.cc/cancers/endometrial/), [Hepatocellular carcinoma](https://onco.cc/cancers/hcc/), [Oesophageal cancer](https://onco.cc/cancers/esophageal/)
- fronts: [Diet, Exercise & Lifestyle](https://onco.cc/fronts/nutrition-lifestyle/), [Prevention & Risk](https://onco.cc/fronts/prevention/)
- technologies: [Green tea and EGCG extracts](https://onco.cc/technologies/green-tea-egcg/), [HCC surveillance in cirrhosis (ultrasound + AFP)](https://onco.cc/technologies/hcc-surveillance/), [Mediterranean and plant-forward dietary patterns](https://onco.cc/technologies/mediterranean-plant-forward-diet/)
- institutions: [International Agency for Research on Cancer (IARC / WHO)](https://onco.cc/institutions/iarc/)
- terms: [Dietary pattern scores (Mediterranean, HEI, AHEI, DASH, WCRF/AICR)](https://onco.cc/terms/dietary-pattern-scores/), [Unproven diet claims (alkaline, juice, 'anti-cancer' diets)](https://onco.cc/terms/unproven-diet-claims/)
- bottlenecks: [Misinformation and unproven therapies](https://onco.cc/bottlenecks/b-misinformation/)
- key papers: [Carcinogenicity of drinking coffee, mate, and very hot beverages](https://onco.cc/key-papers/paper-loomis-lancet-oncol/), [Coffee consumption and health: umbrella review of meta-analyses of multiple health outcomes](https://onco.cc/key-papers/paper-poole-bmj/)

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