Coffee and Pancreatic Cancer Risk Among Never-Smokers

September 30, 2019

Researchers believe that previous findings about coffee consumption’s possible link to an increased risk of pancreatic cancer come from confounding factors that were not accounted for, such as smoking.

There was no link found between coffee consumption and pancreatic cancer in women, according to UK researchers who recently reported their findings in the International Journal of Cancer.

The authors theorized that previous findings about coffee consumption’s possible link to an increased risk of pancreatic cancer might come from confounding factors that were not accounted for, such as smoking. They also suspected that biased recall about coffee consumption might have skewed results. Believing that a study specifically analyzing never smokers would offer clarification, they embarked on just such a study.

The UK study looked at 309,797 never-smoking women who self-reported their daily coffee consumption at a mean age of 59.5 years (SD 5.0 years) for a median of 13.7 years (IQR: 12.2–14.9), using record linkage to national health cancer and death registries. Within that time frame, there were 962 cases of incident pancreatic cancers registered. Researchers used Cox regression to calculate adjusted relative risks [RRs] of incident pancreatic cancer with 95% confidence intervals [CIs] relative to baseline coffee consumption. After they adjusted for known and unknown confounding factors, such as body mass index and alcohol intake, RRs of pancreatic cancer in never-smokers who reported usually consuming 1–2, 3–4, or ≥ 5 cups of coffee daily, compared to non coffee drinkers, were 1.02 (CI 0.83–1.26), 0.96 (0.76–1.22), and 0.87 (0.64–1.18), respectively (trend p = 0.2).

It is well known that smoking is a significant risk factor for pancreatic cancer. Furthermore, studies have shown a strong correlation between coffee consumption and smoking. In this cohort, 26% self-reported as current smokers who drink 5 or more cups of coffee per day. At the same time, only 11% of smokers did not drink coffee at all. The analysis also took into consideration other major potentially confounding factors, such as BMI, socio-economic status, and meat consumption.

Through a meta-analysis of these results three additional research studies, investigators failed to find an association between coffee consumption and pancreatic cancer risk in those who had never smoked (summary RR = 1.00, CI 0.86–1.17 for ≥2 vs. zero cups of coffee per day).