An interesting study from a university study in Sydney, Australia, reports that what you eat influences how you smell — or rather, what you eat affects your body odor and, as a result, may affect other peoples’ response to how you smell. In addition, how you smell can also tell the story of your health, particularly in relation to the axillary (i.e., underarm) area of your body. (You may have noticed that body odor, good or bad, generally exudes from your armpits more than any other area.)

There are several reasons why people sweat. Stress, anxiety, fear, exercise, high temperatures, nervousness, anger and fever can all trigger a sweat response. Age, overall health profile and weight can, too, but even given the same factors, some people simply generate more sweat than other people on any given day. Skin spectrophotometry was used in the study1 to measure levels of carotenoids, naturally occurring antioxidant pigments, as a gauge of fruit and vegetable intake.

According to the scientists’ premise, eating lots of fruits and vegetables, which contain many potent carotenoids, will positively affect what you smell like. There are more than 700 types of natural carotenoids, the most well-known being beta-carotene. You probably have about 10 or 20 different carotenoids circulating through your bloodstream at any given time.2

The study included a food frequency questionnaire. Fast-forwarding to the conclusion, the upshot was that people — in this case, men — generally emit more pleasant-smelling sweat, described as having “more floral, fruity, sweet and medicinal qualities,” when they eat more produce as opposed to carbs. Females were given the task of evaluating the sweat samples.

On the purely physical side of the attractiveness equation, yellower, more carotenoid rich-skin was generally thought to be more appealing.3 Many think that what someone eats may affect, for good or for ill, the smell of their breath, but doesn’t modify their body odor, but the study showed that it definitely does.

In fact, some people avoid eating onions or garlic because they have that perception. But that’s not what happens, The Salt points out: “Body odor is created when the bacteria on our skin metabolize the compounds that come out of our sweat glands.”4

So Vegetable Sweat Smells Better — What Else?

Study author Ian Stephen, of Macquarie University in Sydney, Australia, noted that the smell of someone’s sweat gives off more than just odor: It also conveys a person’s health status and immune fitness, and may even influence someone’s ability to attract a mate. “We’ve known for a while that odor is an important component of attractiveness, especially for women,” Stephen said, explaining that in the study, several descriptors were given to the female sweat smellers to prompt their perceptions of what they detected.

“Women basically found that men who ate more vegetables smelled nicer.”5 Interestingly, the men who had a penchant for pasta, white potatoes and bread had the strongest-smelling and least pleasant-smelling sweat of all — including compared to a high intake of fat, meat, eggs and tofu.

Consumption of the latter group of foods (fat, meats, egg and tofu) was actually associated with more pleasant smelling sweat when self-reported dietary data was factored in. Stephens’ study wasn’t the first to test whether a person’s diet influences their body odor.

A study by researchers in the Czech Republic, published in 2006,6 reported that women prefer the smell of men on a non-meat diet compared to those who ate meat. The male study subjects were placed into two groups, one group on “meat” and the other on “non-meat” diets for two weeks, wearing pads in their armpits to collect their perspiration during the final 24 hours. The 30 females assisting them were asked to assess the sweat samples for their pleasantness, attractiveness, masculinity and intensity.

A month later, the same group of guys repeated the drill but switched their diets. The scientists concluded that red meat consumption has a negative impact on perceived body odor and, further, on hedonicity — perceived body odor stored in the memory,7 and the premise remained consistent when the men’s diets were changed. In the featured study, meanwhile, meat intake did not appear to affect how pleasant the women rated men’s sweat, although they did find it to be more “intense” among the meat-eaters.8

Never Let ‘Em See You Sweat

One study indicated that women aren’t the only ones to make judgments based on the smell of another person’s sweat. The Monell Chemical Senses Center conducted a study on how, for both sexes, the smell of someone’s body odor influences social judgments. Case in point: Research shows that body odor can be perceived by others as a “psychosocial” stress indicator, which may lead men to negatively judge a woman’s emotional state and make further psychological evaluations, such as judging her competence.

Forty-four women provided sweat samples under the following conditions: untreated exercise sweat, untreated stress sweat and treated (with a commercial antiperspirant) stress sweat. The results were quite interesting, the study reports:

“Axillary odors obtained from women experiencing psychosocial stress could negatively influence personality judgments of warmth and competence made about other women depicted in video scenarios. A separate group of male and female evaluators rated the women in the videos while smelling one of the three types of sweat samples.

Women in the video scenes were rated as being more stressed by both men and women when smelling the untreated versus treated stress sweat. For men only, the women in the videos were rated as less confident, trustworthy and competent when smelling both the untreated stress and exercise sweat in contrast to the treated stress sweat. Women’s social judgments were unaffected by sniffing the pads.”9

The researchers concluded that the study has implications in regard to influencing “multiple types of professional and personal social interactions and impression management” and led to better “understanding of the social communicative function” of what people smell like. Needless to say, the implications of how some people can judge someone else’s body odor, good or bad, are huge, especially if they trust their own interpretations.

Don’t Sweat the Small Stuff

In today’s world, bathing regularly and using deodorant and antiperspirant is commonplace. There are probably not many who intentionally go around smelling like last week’s workout T-shirt. But a hundred years ago, B.O. — the bad kind — was just a fact of life. Keeping it under control was a fruitless endeavor (pun intended). Blocking your armpit sweat glands has been the American way for several generations.

It first emerged when a high school student from Cincinnati attended an exposition in Atlantic City in the summer of 1912 to see if she could promote the liquid antiperspirant her surgeon father had created. The doctor’s invention was to alleviate sweaty hands — a bit of a problem when you’re trying to perform surgery when air conditioning, although invented 10 years prior, wasn’t considered a requirement in every hospital.

Edna Murphey had tried the product herself and found that it did the job on both wetness and odor. She named it Odorono (Odor? Oh No!). But Victorian sensibilities hadn’t yet caught up to the fact that people can smell bad for any number of reasons. Body odor also wasn’t necessarily considered something that should be repressed, or even if it could be, remained off limits in terms of discussion. Response was tepid.

Mum was a more successful roll-out, marketed as early as 1888 for its ability to kill odor-causing bacteria. But that was an era when bathing and excessive amounts of perfume were the only answers to body odor. Dress shields, a pair of thin, half-moon-shaped pads (usually cotton or even rubber) strapped to the upper arms to soak up the offending underarm moisture was the best solution anyone could think of.

That smelling bad wasn’t necessarily desirable was a novel concept. Luckily, the expo where Murphey endeavored to market her father’s product was a long one and so was that particular summer. Customers figured they may as well give it a try, so while sales were pretty stinky at first, they soon flourished. In a few months, Murphey had $30,000 to spend on much-needed publicity. Smithsonian magazine noted:

“Although the product stopped sweat for up to three days — longer-lasting than modern day antiperspirants — the Odorono’s active ingredient, aluminum chloride, had to be suspended in acid to remain effective. (This was the case for all early antiperspirants; it would take a few decades before chemists came up with a formulation that didn’t require an acid suspension.)”10

Odorono still had problems, though, a really big one being aluminum chloride being used as the main ingredient, although for different reasons than today. The wrinkle was soon ironed out by a psychological “bazinkle” — a clever marketing ploy persuading people they had an odor problem that everyone around them was too kind to tell them about. That did it. Sales skyrocketed by 112 percent in a single year.

How Diet, Deodorant, Antiperspirant, Chemicals and Fabric Can Be Related

It’s probably no surprise that a century later, the deodorant/antiperspirant industry was a booming $18 billion enterprise. Ironically, body odor became a bigger problem within a few years of deodorant hitting the scene for one simple reason: the invention of synthetic fabric.

A European study observed that polyester fabric worn by athletes had a profoundly increased tendency to absorb sweat smells. It stated: “The polyester T-shirts smelled significantly less pleasant and more intense, compared to the cotton T-shirts.”11 Worse, some fabrics scientists tested were even treated with toxic triclosan.

But there’s also the problem of the chemicals often used to make deodorant and antiperspirant. Both aluminum chloride and aluminum chlorohydrate can interfere with estrogen receptors in breast cancer cells, and estrogen plays a well-known role in breast cancer. Parabens used as a preservative have also been linked to cancer.

There’s also the fact that sweating is a natural and beneficial bodily response on many levels, and blocking it via antiperspirant is not a good idea. An all-natural deodorant can be made by mixing equal amounts of baking soda, softened coconut oil and either organic cornstarch or arrowroot powder.

If you have sensitive skin, you might try using a little less soda. Make sure the mixture stays mixed, as warm weather can cause some ingredients to “settle.” To incorporate a fragrance, a few drops of lavender essential oil (or your favorite) can also be added. Simply washing your armpits with soap and water is also an effective way to remove odors. Between making your own all-natural deodorant and eating lots of vegetables and fruit, your perspiration will take on a sweet-smelling quality, and so will your health.