Warm weather brings the mouth-watering smells of barbecue, along with the less-appealing scents of sweaty body odor.
Sweat is the body's response to excess heat, whether from the sun, exercise, fever, menopause or some combination of these. Like it or not, sweat is what keeps a human being alive on a hot day. Without sweat and the cooling it provides, we would cook ourselves to death.
How to deal with sweat depends on whether you want to combat odor, skip the wet altogether or do nothing.
Animals pant to rid their bodies of excess heat. Humans also generate excess heat just by living -- all year long no matter how hot it is outside -- and we can breathe out some of this heat with every exhalation. But mostly we cool ourselves by sweating from glands. As the glands excrete water onto our skin and it evaporates away into the air, that removes heat from our surface.
Of the more than 2 million sweat glands under most people's skin, women have more, but men have more of the type associated with strong odors. There are two types: eccrine glands and apocrine glands.
Eccrine glands are spread over the body, and they move water as well as a mixture of minerals that differs depending on the person and how acclimated he is to heat. (If your sweat stings your eyes, you are a salty sweater and possibly not well acclimated to the heat.)
But the strongest smells come from sweat produced by apocrine glands, located under the arms, around the breasts and in the groin. Some of these odors are pheromones, the "personal scent" that attracts the opposite sex, which some people find unpleasant. More universally disliked are odors from the sweat that's caused by stress, which is chemically different from the sweat evoked by heat or exercise.
Sweat from the apocrine glands contains small amounts of fatty acids, which are very tasty to the main culprit in bad odors: bacteria that live on the skin. Bacteria gobble up sweat and then you stink.
Diet also plays a role: After a night of too much pasta aglio e olio and red wine, excess morning-after sweat comes with strong eau de garlic. Red meat, curry and onions also make the odor worse.
ROLL IT ON
Many deodorants cover up bad odors with more conventionally approved scents, such as tuberoses or even bacon: "Power Bacon" comes with the label, "for those with active lifestyles -- or people who just sweat like pigs."
Most deodorants are labeled for men or for women, and although manufacturers often use exactly the same ingredients for both, unisex deodorants make up as little as 10 percent of the market.
Some deodorants also disinfect the armpit with an alcohol base that makes the skin slightly acidic and thus less attractive to bacteria. Others contain a specific ingredient, most often triclosan, that inhibits the growth of bacteria and other microbes on the skin. (Deodorant soaps often contain triclosan, but studies have found no benefits from antibacterial soaps, either for preventing infection or for reducing bacteria.)
HEAD IT OFF
Antiperspirants have a different function: to stop sweat by clogging the pores or ducts through which sweat pours. Most antiperspirants use some version of aluminum -- lately, aluminum zirconium compounds that are less likely to cause irritation than earlier forms.
Because antiperspirants alter a bodily function, unlike deodorants, they are subject to FDA regulations. To boast "all day protection" requires only that the brand reduce sweat by 20 percent; and for "extra strength," only by 30 percent. Many antiperspirants contain deodorants.
You might be one of the lucky people whose sweat doesn't smell, which you might be able to determine by simply sniffing -- if you weren't always living in your body, and thus so used to its odors your brain generally ignores them.
Or you can use the "ear wax" test: If your ear wax is white and flaky, you are missing a chemical that odor-causing bacteria feed on, according to LiveScience, leaving you odor-free. Alternately, you could suffer from hyperhidrosis, excessive sweating.
While the aluminum in antiperspirants was once suspected of contributing to increased risks for breast cancer and Alzheimer's disease, studies have failed to support both hypotheses. Research, however, has not solved the problem of why one person's antiperspirant seems to lose its effectiveness after about six months, at which point brands must be switched. Neither does anyone understand what causes the yellow staining on clothes, but manufacturers are studying the "yellowing phenomenon."
LIVE IT UP
To avoid side-effects of commercial antiperspirants, from skin irritation to yellow clothing, "natural" alternatives can be made using plant oils and extracts that have antibacterial powers, including white thyme essential oil, rosemary essential oil, lavender essential oil and castor oil.
Also low-tech, wearing natural fabrics can reduce sweating. Wicking fabrics may soak up some of the sweat, but the remaining moisture and its accompanying bacteria can smell worse. Try wearing several light natural-fabric layers instead.
In extreme cases, there are injections of Botox, which paralyzes and shrinks the sweat glands by blocking a neurotransmitter that stimulates them. Most often used for those with hyperhidrosis, Botox is also being marketed to brides, grooms and promgoers who want to avoid embarrassment as well as ruining expensive clothes. Several injections in the armpits can last up to eight months -- but that benefit is offset by the need to get several injections in your armpits.
There is another alternative: Clean yourself several times throughout the day.
It's also possible to learn to live with strong odors. But this is most feasible for hermits, shut-ins and people who stay under rocks in the woods.
ActiveStyle on 08/04/2014
Print Headline: Sweat is body’s cooling unit, odor is byproduct