Thank you! Your submission has been received!
Oops! Something went wrong while submitting the form


"By denying scientific principles, one may maintain any paradox." – Galileo Galilei

Weight of the Evidence

The International Agency for Research Against Cancer (IARC) claims its Monograph working groups evaluate the “weight of the evidence” when making their classifications on carcinogenicity. “Weight of the evidence” is defined as “the measure of credible proof on one side of a dispute as compared with the credible proof on the other.” When scientists take a “weight of the evidence” approach they give the greatest weight to studies of the highest quality and credibility.

IARC claims to use the “weight of evidence,” but it does not.

  • IARC has developed a reputation for cherry picking studies when evaluating a potential cancer hazard. According to IARC Senior Toxicologist Kathryn Z. Guyton, “As few as two are needed to establish carcinogenicity.”
  • Moreover, IARC openly refuses to consider many of the studies relied upon by leading regulatory bodies because they are considered business confidential and thus are not publicly available.
  • Finally, IARC frequently ignores the professional conclusions of well-regarded scientists, reinterpreting some studies and coming to their own, sometimes contradictory conclusions.

Simply stated, relying on a handful of isolated findings is not how scientists consider the “weight of the evidence.”

IARC: Weight of the Evidence