Ever get caught sniffing your armpits in public? Yeah, you’re not alone. No matter how wonderfully-scented our deodorant, lotion, perfume, or cologne may be, we’ve all worried about B.O. at some point or another.
We have millions of sweat glands all over our bodies, but nose-crinkling body odor comes specifically from mischievous sweat glands called apocrine glands. These glands are concentrated in the hair follicles around our underarms and below the belt, and release a thick fluid (some experts believe it contains the chemical pheromones animals secrete when they want to mate), which mixes with the bacteria on our skin and hair, and creates an unpleasant stink, explains Kachiu Lee, M.D., assistant professor of dermatology at Brown University.
While we can’t change our sweat glands, there are a number of factors that can take us from feeling fresh to reapplying antiperspirant every 10 minutes.
1. Your Genes Aren’t Working In Your Favor
Go ahead and blame it on Mom and Dad—our individual ‘odor profiles’ depend in part on our genes, says George Preti, Ph.D., organic chemist at the Monell Chemical Senses Center, a non-profit institute for research on the science of taste and smell. In fact, according to Monell’s research, people of African and Caucasian descent have higher levels of a gene called ABCC11, which is associated with underarm odor, than people of Chinese, Japanese or Korean descent.
About 10 percent of people are particularly prone to B.O. because of a genetic defect that leaves them unable to produce an enzyme called FMO3, which breaks down a foul-smelling compound called TMA found in foods like eggs, conventional milk, beans, seafood, and cruciferous veggies. People with this condition—known as ‘trimethylaminuria’—are often followed by a fishy odor.
Health conditions like hyperthyroidism, diabetes, and hyperhidrosis (in which overactive nerves constantly trigger sweating) can also contribute to body odor when not managed, so talk to your doctor if you’re concerned about how much you sweat (and smell).
2. You Hang Out In Sweaty Gym Clothes
The skin bacteria that makes apocrine sweat so smelly thrives in moist environments, and when you exercise, your workout gear—especially anything tight—traps your sweat in your skin and allows B.O. to flourish. If you sweat a lot during a workout, don’t spend a second longer in your gym clothes (socks included!) than you have to, says Lee.
And when you hit the showers, make sure you really scrub off your deodorant or antiperspirant. While they form a barrier that blocks sweat and stank in the short term, these products can clog your pores and react with the bacteria on your skin, possibly making stank worse if left on for a few days, Lee says.
3. You’re Stressed
As if pre-presentation jitters aren’t bad enough, stress can also make you smell. Anxiety often causes your apocrine glands to kick into high gear and produce more sweat, leaving you victim to body odor, explains Preti. Scientists aren’t entirely sure what causes this ‘stress sweat’ phenomenon, but the only way to nip it in the bud is to squash the stress itself. Preti recommends meditating or using breathing exercises to keep your mind, nervous system, and sweat glands as calm as possible when stress strikes.
4. You Ate A Stink-Inducing Food
Sad but true: Some of the foods that leave you with dragon breath can also stink up your entire bod. The perpetrator? Hydrogen sulfide, a chemical produced when you eat foods that contain sulfur-like compounds, like garlic and broccoli. Hydrogen sulfide smells like rotten eggs and can leave you with nasty breath and smellier-than-usual body odor when you eat a lot of these foods, says Preti.
Research also suggests your overall diet can impact your natural scent and even influence your ‘attractiveness.’ One study published in Chemical Senses, for example, found that women rated the scent of men who didn’t eat red meat as more attractive than that of those who did—so apparently you really are what you eat!