In a joint statement released today, the World Health Organization (WHO) and the United Nations Food and Agriculture Organization said that the pesticide glyphosate (originally patented by Monsanto) “is unlikely to pose a carcinogenic risk to humans from exposure through the diet.”
This contrasts with the WHO’s International Agency for Research on Cancer’s (IARC) finding that glyphosate is “probably” carcinogenic. The joint UN/WHO statement today is consistent with every other regulatory agency in the world. No regulatory agency considers glyphosate to be carcinogenic.
The IARC finding obviously had been touted by anti-GMO groups as “proof” that glyphosate is carcinogenic, that Monsanto is part of a multi-national conspiracy to cover it up, and that despite all the handwritten notes from her, my eighth grade girlfriend actually never truly loved me.
The difference in the findings is largely due to what IARC looked for.
The IARC has 5 classifications for substances based on how likely they believe they are to cause cancer. Group 1 contains known carcinogens (including smoking, alcohol, and radiation), Group 2A contains substances that are “probably” carcinogens (glyphosate, steroids, red meat), Group 2B substances that are “possibly” carcinogens, and Groups 3 and 4 are substances that either are not believed to be carcinogenic or do not have sufficient evidence. Only one substance has ever been put into Group 4 (probably not carcinogenic) – Caprolactam. Despite being identified as a hazardous air pollutant in the US Clean Air Act of 1990, I guess the IARC believes that nearly everything causes cancer, except Caprolactam.
IARC reviews the existing literature for a substance when making a determination of its likelihood to be a carcinogen. This leaves them open to selection bias and cherry picking. It simply is not an effective method of determining a substance’s capability of causing cancer in humans. There is a significant difference between “probably” causes cancer and “does” cause cancer. This video does an excellent job explaining why:
A hazard is a theoretical potential for harm, but not necessarily an inherent risk of harm. The new statement from the UN/WHO actually investigated the risk of cancer from glyphosate, rather than hazard. The WHO themselves, while denying the findings being contradictory, acknowledged the differences between the two assessments:
IARC reviews published studies to identify potential cancer hazards… It does not estimate the level of risk to the population associated with exposure to the hazard.
What’s particularly interesting, and a delightful coincidence, is that March Against Monsanto (MAM) has their annual march scheduled “all over” on this coming Saturday, May 21st. Many local marches will be joined by March Against Myths About Modification, or MAMyths, who seek to engage MAM in a friendly discussion about modification and what precisely their concerns are. I think that nearly all pro-GMO advocates will say that they are not defending Monsanto. After all, Monsanto is a private company. Saying science communicators like myself are defending Monsanto is like saying the Pope defends rape victims. It’s just not something that happens.
It’s also worth nothing that Monsanto’s patent for glyphosate expired in 2000.
Instead, what we do is defend the science behind GM technology and combat the fear mongering put forward by groups like MAM. It’s important to remember that not all GM crops are treated with glyphosate, however announcements like these can hopefully continue to dispel myths surrounding genetic modification.