Research news and views on preventing and surviving cancer
Author: Edward L. Giovannucci, MD, ScD
Dr. Edward Giovannucci, is a professor in the departments of nutrition and epidemiology at the Harvard School of Public Health and an associate professor in the department of medicine at the Harvard Medical School. Dr. Giovannucci is a current AICR grantee working on diet strategies that can prevent prostate cancer from progressing.
A Los Angeles County Superior Judge has ruled that all coffee shops and sellers in the state of California must label their product and warn their consumers about potential cancer risk from drinking coffee. This judgement follows from a lawsuit first filed in 2010, and refers to protections under California’s Safe Drinking Water and Toxic Enforcement Act of 1986. The judge ruled that the coffee companies failed to meet the burden of proof that coffee caused no harm.
The justification is that acrylamide, which is found in roasted coffee beans, has been linked to cancer in rats. Relatively small amounts of acrylamide is common in many food items besides coffee. The levels that cause cancer in rats are much higher than those consumed through coffee and diet in general.
On a “cancer worry” scale from 0 to 10, coffee should be solidly at 0 and smoking at 10; they should not have similar warning labels.
To understand this change, it is important to examine the nature of the evidence used to reach the new conclusion. Most of the evidence is based on studies that record what men are eating, or measure blood lycopene levels, and then follow the men for any diagnosis of prostate cancer.
Then dietary or blood factors are linked to risk of cancer diagnosis. Statistical methods are used to account for other factors. Because these studies are examining associations, which may not necessarily be causal, other considerations such as biologic plausibility are taken into account in formulating the conclusions.