Hold the Sriracha: We Don't Really Know Anything About Capsaicin and Cancer

Maybe you’ve heard about capsaicin, the molecule in hot peppers that kills cancer, and that you should eat with a glob of fat for maximum anti-cancer destruction? The internet sure does. Writes Elite Daily: “Scientists theorize capsaicin to be a trigger of apoptosis, which encourages cells, including mutated ones, to be turned into new cells.” That’s sort of right (though we’d argue apoptosis is less “encouragement” and more “cellular suicide,” the remnants of which end up eaten by phagocytes), but don’t start dunking everything in a frothy mix of butter and Frank’s Red Hot. Chill before you chili. What’s important here is that, yes, capsaicin does show apoptotic properties, but the science referenced here is in vitro and far from settled.

The story seems to have been spawned by Time Magazine, which references a study by Massey University researcher David Popovich. Capsaicin applied directly to a cancer cell culture triggers apoptosis, Popovich found. In vitro research is certainly necessary, but a replacement for a phase 3 trial in humans or actionable day-to-day advice this is not. For instance, camel piss kills cancer cells in petri dishes, and no one is lining up to mainline that yet.

That spicy foods influence cancer is an intriguing idea, and one that’s been around for decades. The best reporting on capsaicin and cancer comes with a big squirt of caveat. Take it away, Memorial Sloan Kettering Cancer Center: “Whether capsaicin can protect against or cause cancer is uncertain. More studies are needed to determine how capsaicin actually interacts with cancer cells or aids in their prevention.”

Taking the nuanced approach toward the hot pepper, two University of Minnesota cancer experts evaluated the “conflicting role of capsaicin” in animal and epidemiologic studies in 2011. Preclinical evidence looks good, but studies of human groups culturally inclined to eat spicier foods were inconclusive.

This isn’t to say you should steer clear from your favorite hot sauce — if you’re the guy from The Oatmeal with a throbbing hard-on for little snacky Tesla effigies made out of bacon and Sriracha, go for it. Or not. Whatever — hot peppers aren’t pure capsaicin, anyway.

But don’t guzzle it because you think science says you should, ‘cause cancer research hasn’t really figured this one out yet.