Well, the sexiness of underarm sweat is only supposition, of course. In fact, it's not only uptight 20th-century man who has tried to rid himself of the dread scourge Body Odor. The practice of dousing oneself with perfume and various sweet-smelling bath oils can be traced back to 4th-century B.C. Egypt. During the 17th century, the French raised to an art—and, in the process, created an industry—the use of perfumed oils and colognes to mask the smells of humanity. Yet it isn't certain that our ancestors knew that sweat caused B.O. The FDA said: "The relationship between body odor and perspiration was undoubtedly little understood during ancient times, and the practices used either washed away or masked unpleasant body odor."
The connection with perspiration was made in the 19th century, and in 1888 the first deodorant came on the market. It was called Mum and was followed in 1902 by Everdry and in 1908 by Hush, both antiperspirants. In 1914 Odo-Ro-No became the first to advertise in magazines. Its message was that it could remedy excessive perspiration and keep women's dresses "clean and dainty." There was no mention of the social offense given by the odor of sweat until 1919, when the antiperspirant Odo-Ro-No introduced the bad-smell-equals-social-outcast approach.
The early antiperspirants were far from perfect. During the 1930s, the American Medical Association would only deign to discuss them in the Quacks and Nostrums section of its journal. In fact, many of the early products were so harsh they caused severe rashes in the armpits, and made clothing rot. During the 1940s antiperspirants and deodorants were considered pretty much for women only, but since then men have regularly annointed their armpits in increasing numbers. No less than 91% of American women use deodorants and antiperspirants on an average of 7.6 times a week, while 84% of men apply them 7.5 times a week. For the record, deodorants, which contain antiseptics for suppressing bacterial growth, are classified as cosmetics by the FDA because they do not affect a bodily function, while antiperspirants, which literally plug the pores to prevent sweat from emerging, are considered drugs. Both are usually perfumed and many products have ingredients with both deodorant and antiperspirant properties. By the way, any athlete who avoids antiperspirants for fear they'll clog up his cooling system should rest assured that these products suppress only 20 to 40% of underarm sweat and that that kind of sweat isn't important in cooling anyway. States the FDA: "The axillary sweat glands do not appear to be essential to the proper functioning of this thermo-regulatory system." So roll, swab or spray with impunity before that next marathon.
We will now touch, though briefly and a bit skittishly, on the unpleasant subject of precisely how apocrine fluid becomes so offensive. The FDA report described apocrine sweat as being "milky, viscid and pale gray," as well as "odorless when it reaches the surface of the skin." It becomes "odoriferous only upon bacterial decomposition," and when dried it's like "glistening gluelike granules."
Thus, it's not the sweat itself that causes offense, but what's done to it by the teeming crowds of bacteria found on the skin of every human being. According to Galligan, "There are hundreds of types of bacteria on everyone's skin," he says. "The mixture differs with every person—in fact differs every day on the same person. The possible variations are infinite. The bacteria on our bodies do not thrive in a dry environment. They like a wet place where they can settle down to live and eat. They are nourished on apocrine sweat and on skin oils—such as sebum. When they eat these oils, they liberate fatty acids which have a low molecular weight and tend to evaporate into the air, which is where you can smell them. If it isn't treated or cleaned up, the smell created by the bacterial process of breaking down the oil gets worse each day for about a week. But then it reaches a steady state. There is no more room for more bacteria to reproduce. Things have reached a point of good living for the bacteria. Everyone is well and getting enough to eat, so the odor is no worse after months than after that first week."
These happy colonies of bacteria are known as microbial flora, and exist only in warm, wet conditions. Apocrine sweat, like eccrine sweat, remains odorless for days, even weeks, if it is kept in cool, clean conditions. So even it is initially as clean as honest sweat.
And now we return to our original theme: the decline of the quality of sweat in America. What's to be done about it? It's already being done. The fitness boom is probably nature's way of telling us to be ourselves. Human beings have always been strong and active creatures—hunters, warriors, farmers, laborers, food gatherers, child rearers—and however sedentary our work may become or however thoroughly we may suffocate our "pheromones" in a surfeit of perfume, we still must sweat. And if we do it by jogging along a street instead of running for our lives from a saber-toothed tiger, so be it. To sweat honestly is also to sweat joyfully.