Mars Smells Like Cheese, Venus Smells Like Onion?

“Men smell of cheese, and women of grapefruit or onion,” says Christian Starkenmann of Firmenich, a company in Geneva that researches flavours and perfumes for food and cosmetics companies.

This extraordinary (and, yeah, kind of funny) conclusion hales from a new study conducted by Firmenich which analyzed armpit-sweat samples from 24 men and 25 women following a 15-minute session in a sauna or on an exercise bike. Sweat from the women was found to contain high levels of an odorless sulphur-containing compound which, when mixed with bacteria usually found under the arm, transformed into a chemical called thiol–notorious for its onion-like smell. The men-sweat, meanwhile, contained large amounts of an odorless fatty acid which, when mixed with the same type of bacteria, released a distinctly cheesy smell.

The aim of the study was to isolate the differing natural scents of the sexes in hopes of developing deodorants geared specifically toward men or women, but some scientists warn that these results may or may not hold for people living outside Switzerland with different diets and different genes than the Swiss test subjects. “Other factors include what you eat, what you wash with, what you wear and what genes you inherit,” says Professor Tim Jacob of Cardiff University.