Cancer Experts Give Coffee Positive Rating

If it seems like good news for coffee lovers keeps appearing in the headlines, you’re right! And the latest comes from the International Agency for Research on Cancer (IARC), the cancer agency of the World Health Organization. They just finished evaluating the carcinogenicity of drinking coffee and a few other beverages; here’s what they said …

The Good News!
Based on an extensive review of more than 1,000 human and animal studies, there is no conclusive evidence that drinking coffee causes cancer according to the IARC. Coffee was given a “3” on a 1 to 4 scale of classifications, where “1” indicates substances that are carcinogenic to humans and “3” states that substances are not classifiable as carcinogenic. This is an improved score from when it was evaluated in 1991 as possibly carcinogenic, and it’s a rare occurrence when IACR positively reclassifies the food, chemicals and occupational exposures it evaluates. Tea and caffeine also have a “3” classification. And it’s interesting that only one substance (of the 900 studied) in nylon called caprolactam has received a “4” – probably not carcinogenic to humans – rating.

There’s More …
Additionally, IARC stated that their research review found coffee drinkers had reduced risk of liver and uterine lining cancers, along with no increased risk of pancreas, female breast and prostate cancers. And although IACR does not look at the benefits of the substances it studies, this evaluation adds to the abundance of already-existing research producing positive health messages associated with moderate coffee consumption, including:

  • Lower risk of death from all causes (cardiovascular disease, diabetes, neurologic diseases, suicide)
  • Decreased risk of developing type 2 diabetes, liver and other cancers, neurologic diseases and cardiovascular disease
  • Improved memory, alertness and concentration

Read more here for the Dietary Guidelines Advisory Committee’s positive coffee and health news.

Mate and Very Hot Beverage Warning
In the same report, scientists called out a warning about beverages served at very hot temperatures (>149F), classifying them as probably carcinogenic (2A rating). Mate, an infusion made from dried leaves of the ilex paraguariensis tree, is traditionally served in South America and in other parts of the world at a very hot temperature, often with a metal straw. It is associated with increased risk of esophageal cancer in studies. According to the National Coffee Association, coffee in America typically is safely served at a temperature averaging about 140F. Some flavor experts recommend serving coffee between 120F and 140F for optimal taste.

The Bottom Line
There has been criticism of IARC’s classification system of studied substances because it does not address the likelihood of actually developing cancer (cancer risk) from the substances in each category. At any rate, the IACR gave a positive nod to coffee and health by calling out its association to reduced risk of several cancers and by upgrading its classification based on findings from an extensive body of research. All of this supports drinking moderate amounts of coffee as part of a healthy lifestyle. Cheers to that next cuppa joe!

www.thelancet.com/oncology  Published online June15, 2016  http://dx.doi.org/10.1016/S1470-2045(16)30239-X

International Agency for Research on Cancer. Volume 116: coffee, mate and very hot beverages. IARC Working Group. Lyon, France; 24-31 May, 2016. IARC Monogr Eval Carcinog Risks Hum (in press).


Beth Witherspoon, MPH, RDN, has a passion for communicating culinary and nutrition information. She is a registered dietitian/nutritionist who consults with Community Coffee Company to help communicate the flavor and health benefits of coffee.