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Can Tighter Packaging Lower Sperm Counts?

A new study isn't enough to resolve decades of debate, even if many media outlets reported it that way.

News in Briefs

Boxers versus briefs—it's a perennial debate. But now, according to the New York Times, USA Today, and The New Yorker, science has an answer: For those hoping for a higher sperm count, boxers are the clear winner. Journalists point to a new study that finds a connection between lower sperm counts and tighter underwear; they suggest this answers the question once and for all. The study seems to confirm a popular belief that goes back at least two decades: A 1994 episode of Seinfeld features Elaine telling a horrified Kramer that his briefs are killing his sperm.

Turning Up the Heat

While Elaine seemed sure that tight underwear hurts sperm, the actual research has, for decades, been inconclusive: Some studies say briefs lower fertility, while others find they have no effect. What is known is that the testicles, like a fine wine, prefer milder temperatures. But it's unclear to what extent wearing briefs affects fertility.

In Hot Water

This new study isn't enough to resolve decades of debate. Though it was the largest study of its kind, it still only surveyed 656 people: men in couples seeking infertility treatments. As Lidia Mínguez-Alarcón, one of the study's authors, says, "It may not be possible to generalize our findings." There are also other problems: For instance, while the researchers tried to control for confounding variables (such as hot-tub use), so many things affect sperm count that it's hard to blame everything on undies. But Mínguez-Alarcón says that the study's findings could still be useful to those seeking infertility treatment—and, in any case, wearing looser underwear probably won't hurt.

A version of this story originally appeared in the December/January 2019 issue of Pacific Standard.