IARC cancer classification

The World Health Organization’s (WHO) International Agency for Research on Cancer (IARC) recently concluded that the popular artificial sweetener aspartame, widely used in foods and diet drinks, is “possibly carcinogenic to humans,” an alarming conclusion because aspartame is used in thousands of low-calorie products. However, another WHO organization, the Joint Expert Committee on Food Additives (JECFA), concluded that it is safe to consume aspartame. Can we make sense of the conflicting conclusions?
After many years of sensational reporting about the cancer risks from Bayer’s Roundup weedkiller, with the main ingredient of glyphosate, it appears that the tide may be finally turning in the courtroom. When presented with complex science, juries understand it and get it right.
What chemicals, specifically, pose a danger as a potential human carcinogen? To address this issue two competing approaches, which use scientific data to evaluate chemicals for this danger, are at odds. Can we tease out which of these two may be “better”?