No, your coffee isn’t going to prevent cancer
A recent study by a team of Chinese researchers suggests that an increase in coffee consumption may be associated with a reduced risk of prostate cancer.
Sounds like great news for caffeine lovers! At least, that’s how it was presented in the news release that followed publication of the study:
Drinking several cups of coffee every day may be linked to a lower risk of developing prostate cancer, suggests a pooled data analysis of the available evidence, published in the online journal BMJ Open.
Each additional daily cup of the brew was associated with a reduction in relative risk of nearly 1%, the findings indicate.
The researchers acknowledge that because of the observational design of the included cohort studies, unmeasured or uncontrolled factors in the original studies may have skewed the pooled risk estimate.
The amount of coffee drunk may also have been misclassified as it depended on recall. And the type of coffee and brewing methods varied among the studies. The design and methods of the included studies also varied, so caution in interpreting the findings is warranted, they say.
And they conclude: “This study suggests that increased coffee consumption may be associated with a reduced risk of prostate cancer. Further research is still warranted to explore the underlying mechanisms and active compounds in coffee.
Despite the hype, and before you race out the door for that double espresso, you may want to take a closer look at the scientific evidence on which these potential health benefits are based.
To reduce your risk of prostate cancer by 7.5%, you would need to drink 10 cups of coffee per day. That’s a lot of java, especially since the findings suggest a mere association between coffee intake and prostate cancer reduction for the general population—a far cry from a definitive causal link that would apply to each individual.
And while the findings of the study may make excellent fodder for water cooler conversations and Zoom calls, results from observational studies that draw associations between particular substances and health outcomes—positive or negative—should not be the basis for regulatory or judicial decisions.
Instead, these studies should only be used to design and conduct further research that determines what definitive causal links do or do not exist between exposure, dosage, and health hazards or benefits.
It is only when we move beyond the speculative nature of observational and association studies that we can make accurate assessments of risk and, more importantly, well informed decisions about how to manage them.
In the meantime, we hope you’ll take the coffee study—and others like it—with a grain of salt. Although that may cause hardening of your arteries.