Sweating the Smell Stuff

SMELL LIKE AN EGYPTIAN

Humans have been hiding their stinkiness by dousing themselves with fragrances for ages. The ancient Egyptians came up with a number of fresh and fruity scents. Some floral scents lasted as long as 20 years, and incense was also heavily used. (It had the benefit of masking not just the smell of a single user, but everybody in the room.) And in ancient Asia, people discovered that applying finely ground salt to the underarms worked wonders. When reapplied regularly during the day, the salt killed bacteria.
That’s the thing— sweat by itself is odorless. Bacteria on the skin are what release smells when they start to break down sweat’s trace amounts of fats. Diet, gender, age, hygiene levels, and genetics all give everybody a slightly different smell. Meat-eaters, for example, release more fats and proteins in their sweat, so they tend to smell stronger than vegans. Women’s sweat tends to contain more sulfur, creating an oniony smell when bacteria go at it. Men, on the other hand, release more fatty acids that end up smelling cheesy. And shaved armpits are more likely to be smelly than hairy ones because the hair often wicks out enough moisture to help keep bacteria in check.
DRY UP 
By the turn of the 20th century, deodorant manufacturing was in full swing. For example…
• The first modern antiperspirant was called Everdry, introduced in 1903. It had some problems, though. With an active ingredient of aluminum chloride, Everdry was acidic enough to irritate the skin and shorten the life of shirts by slowly eating holes under the arms. (That’s still a problem: Even today, those embarrassing yellow armpit stains come from the ingredients of antiperspirants, not the sweat itself.)
• Mum, however, was the first commercial deodorant ever, introduced in Philadelphia in 1888. Bristol-Meyers bought the brand in 1932, and in the 1950s, playing off of the gimmick of the newly invented ballpoint pen, marketers created Ban Roll-On using the same rolling-ball design.
• A chemist in Chicago named Jules Montenier reduced some of the damage in 1941 by adding a chemical called nitrile, which neutralized the acidity of aluminum chloride. He created Stopette, the best-selling deodorant of the 1950s. When Montenier’s patent ran out in the late 1950s, Stopette was eclipsed by several new brands, including Gillette’s Right Guard, the first spray deodorant.
• Today, aluminum choloride remains the active ingredient of choice in many antiperspirants. How does it work? Its tiny particles get wedged into the sweat glands, creating a plug that keeps sweat from coming out. And because, technically, it alters your natural body functions, the FDA classifies antiperspirants as “drugs.”
BENEFITS OF BO
Most people in the United States today use deodorants to mask their smell, but there are actually some positives to BO.
• Humans’ unusually stinky BO gives them a disadvantage in hunting, of course, requiring a downwind approach to prey. But it may have also helped early humans to survive by making them unappetizing to predators.
• Researchers at the University of California, Berkeley, found that a compound in male underarm sweat activates brain areas that improve women’s mood and sexual receptiveness.
• The smell of your sweat may be an early health warning. If your sweat smells a little like bleach, it can be a sign of liver or kidney disease; if it smells fruity, a sign of diabetes.