What, Meat Worry?

Jim’s video on meat substitutes, published last week, arrived just in time for those of you freaked out by today’s big news about the risks of processed meats and red meats:

A reader scoffs at today’s announcement from the World Health Organization:

Humans and hominids have been consuming charred red meat and smoked red meat since they learned to use fire, so if red meats were as carcinogenic as this article implies, we would’ve died out. The evidence that obesity increases one’s risk of developing a malignant disease is much more conclusive.

Another reader corrects that one:

An 18 percent increase in the risk of colorectal cancer would not put much evolutionary pressure on us, particularly given that meat would have been a valuable source of dietary protein and fat (and cooking would have major positive effects on microbial health and digestion costs). After all, we only have about a 1.5 percent lifetime risk of colorectal cancer up to age 64, so the absolute risk imposed by red meat would be a meager 0.27 percent increase in death up to age 64.

Moreover, cancer risk disproportionately affects older adults beyond their reproductive prime. This tiny increase in absolute risk plus its delayed impact means that there would be virtually no effect on a person’s ability to successfully reproduce, i.e., no significant evolutionary pressure.

The first reader responds: “Good critique of my post—and your risk analysis, IMO, makes the point that panicking over red meat is silly.” Another seems to agree:

The chances of dying reach 100% over the years of living. So enjoy it while you can.

Another reader is more specific:

Everyone has to die of something—and I am not convinced that bacon is such a bad way to go.

Or how another puts it, “My response to the WHO”:

And in case you missed the cold water Ed threw on the WHO’s press release:

These classifications are based on strength of evidence not degree of risk. Two risk factors could be slotted in the same category if one tripled the risk of cancer and the other increased it by a small fraction. They could also be classified similarly even if one causes many more types of cancers than the other, if it affects a greater swath of the population, and if it actually causes more cancers.

So these classifications are not meant to convey how dangerous something is, just how certain we are that something is dangerous. But they’re presented with language that completely obfuscates that distinction.

Ed instead recommends “Cancer Research UK’s excellent explainer about the new ruling.”