We've all been there: It's a sweltering hot day; you've walked several blocks to work, feel like you're sweating from every pore, and just hope beyond hope your coworkers won't be smelling your BO all day. Other than those particularly stinky days, odor is just something that happens after a workout or if you've been a little lax on hygiene for a few days. Right?
Not quite. Even when no one thinks you smell, you smell. And scientists who study volatile organic compounds (VOCs) have long known that every person has a distinct odor, just like they have distinct fingerprints. Some scientists call it your "odorprint." It's why dogs can track fugitives on the run and why perfume smells slightly different on you than it does on anyone else.
But your odorprint can also influence your health and relationships, even though our noses aren't sensitive enough to consciously pick out one person from another.
Here, 5 things your specific scent says about you:
1. It could make you a mosquito magnet.
If stepping outside in the summer makes you feel like an all-you-can-eat buffet for mosquitoes, your odorprint might be to blame. Based on a recent study of fraternal and identical twins, scientists believe the genes that make up a person's specific body odor could have a hand in attracting mosquitos. The scientists asked 74 brave volunteers to stick a hand into a Y-shaped tube, while their fraternal or identical twin stuck their hand in another hole. The researchers then released mosquitoes at the end of the tube and recorded which twin the bugs preferred to bite. Identical twins were bitten equally, but in fraternal twins—who share far fewer genes than identical twins—mosquitoes clearly preferred to bite one twin over the other. While mosquitoes won't hesitate to sink their teeth into anyone, an estimated 20% of people are especially attractive to the pesky little bugs. The scientists hope that understanding which genes make mosquito-attracting scents will help them develop more effective bug repellents. In the meantime, try planting these 8 mosquito-repelling plants and using these 6 effective methods to keep the bugs from biting.
2. It could find you a love connection.
Add this to the increasing body of evidence that opposites really do attract: Researchers believe, based on studies in both animals and humans, that you're more attracted to romantic partners with body odor different from your own. In one study, scientists asked women to rate the smell of T-shirts their male peers had worn for 2 consecutive days according to which smells they found more attractive. They found the women rated T-shirts higher if the man who wore it had a body odor chemically different from their own.
But don't start requesting dates to wear 2-day-old shirts. "The idea that smell plays a role in finding a mate is probably true for most animals, and may be one of many characteristics that contribute to human mate selection," says Gary Beauchamp, a biopsychologist and former director of the Monell Chemical Senses Center. Though it may contribute, smell obviously isn't the be-all-end-all of finding a perfect match, according to Beauchamp, and given that we have one of the least-sensitive noses of all animals, humans can't consciously choose based on smell anyway.
3. It tattles when you're stressed.
We're not talking about the epic sweat stains a stressful day can leave on your clothes—although scientists have found that stress does make you sweat. We're talking about a more subtle change in body odor. When you're stressed all the time, your body odor changes in ways your friends might not be able to detect, but a dog definitely can. As in, animals can actually smell fear. Beauchamp says that statement is true, and that animals with sensitive noses—like dogs—can smell stress caused by fear, that big project you're facing at work, or problems with friends and family. But stress doesn't change your intrinsic body odor. Instead, it adds to your personal scent, and Beauchamp says animals that can smell your stress are also smelling your regular odor—like if you recognized a friend's face, but also noticed they got new glasses.
4. It makes you friends (or loses 'em).
If you make it a habit to walk into work smelling like you haven't showered in a week, chances are you'll lose a few friends. But even if you always smell like sunshine, your body odor could ward off new friends—or attract them to you. When researchers in Poland conducted another T-shirt experiment to test their theory that smell indicates personality, they found that people could pick out certain personality traits based only on smell. After asking 30 men and 30 women to wear the same white cotton T-shirts for 3 consecutive nights, the scientists had 100 men and 100 women smell a shirt and then describe the personality of the person who wore it. Volunteers accurately guessed when the T-shirt belonged to someone extroverted, dominant, or neurotic. They found no correlation between scent and agreeableness, openness to experience, and conscientiousness. So, if you consider yourself a dominant person, potential friends and lovers might smell it before you even start talking.
5. It speaks volumes about your health.
Disease, like stress, isn't always a part of your odorprint, but adds to it once you become ill. "There's no doubt that animals, including humans, produce odors indicative of disease," says Beauchamp. But he and other scientists are still unsure exactly how disease affects scent. To help them understand, scientists once again turned to dogs. In a study published in European Urology, a dog trained to recognize the smell of prostate cancer correctly identified 30 of 33 prostate cancer patients from the smell of their urine. And even humans can sometimes recognize when a person is sick based on their noses. When scientists injected study participants with a compound that would ramp up their immune system—similar to if they were sick—volunteers who smelled the T-shirts the "sick" participants wore were able to identify that they were more likely sick than participants injected with a placebo. (Learn how you can ramp up your immune system to prevent colds and flu naturally with the plan in Ultimate Immunity.)
But knowing that diseases like cancer and diabetes change a person's smell doesn't help doctors diagnose disease yet. A goal for scientists like Beauchamp is to someday use odorprint to diagnose illness in a way that's faster and more accurate than current diagnosis technologies.