Skip to content

This study found that men who eat a lot of garlic (4 cloves in raw or capsule form) had a "more attractive" body odor to women. This is body odor, which is different than breath odor. Since this study was done in Prague (capital of the Czech Republic), one wonders about cultural biases - is this a group that normally enjoys garlicky foods? What would women who never ate foods containing garlic think about the body odor? The researchers gave an evolutionary explanation, but...first this study needs to be replicated in a group that doesn't normally eat garlic. At any rate, the study results should give reassurance to those men who enjoy eating garlic - it's attractive to women! From Medical Xpress:

Research finds men who eat garlic smell more attractive

The beneficial health properties of garlic are well known, but researchers at the University of Stirling and Charles University in Prague have uncovered another less well known and surprising property – that the body odour of men who eat garlic is attractive to women. In a study of 42 men – who each were asked to eat raw garlic, garlic capsules, or no garlic – their body odour was perceived to be 'significantly more attractive' when they had eaten garlic in bulb and capsule form than when they hadn't eaten it.

For the study, 82 women were asked to sniff the odour samples and judge them on their pleasantness, attractiveness, masculinity and intensity. Researchers found the unexpected positive effect was only achieved once the men were eating a substantial amount of garlic. When the men ate 6g of garlic, equivalent to two cloves, with bread and cheese, there was no difference in the ratings between then and when they simply ate the bread and cheese on its own. 

But when the dosage was doubled to 12g, or four cloves, the men were reported to smell more attractive than when they hadn't eaten it. In the final experiment, when the men consumed the same amount of garlic, but in capsule form, their body odour was also perceived as more attractive.

Craig Roberts, Professor of Psychology at the University of Stirling, said: "Our results indicate that garlic consumption may have positive effects on the pleasure derived from perceived body odour perhaps due to its health effects....Previous research indicates that many animal species use diet-associated cues to select mates in good physical condition. "As the health benefits of garlic consumption include antioxidant, immunostimulant, cardiovascular, bactericidal and anti-cancer effects, it is plausible that human odour preferences have been shaped by sexual selection.

The study concludes that body odour, in contrast to breath odour, is positively affected by garlic and that these two sources of odour should be strictly differentiated. As breath odour plays an important factor in intimate relationships further studies may be carried out.

An interesting small study of the human armpit bacterial community. From Real Clear Science:

Antiperspirants Alter Your Armpit Bacteria and Could Actually Make You Smell Worse

In modern society, antiperspirants are widely hailed as a godsend, dispelling the inconvenient odors wafting from armpits everywhere. But a new study casts doubts on their vaunted position. As it turns out, antiperspirants may actually make you smell worse in the long run.

For 90% of all Americans, slathering on deodorants and antiperspirants is a daily occurrence, a precautionary measure against foul odors and unsightly sweat stains. The odors arise when bacteria living in our armpits break down lipids and amino acids excreted in sweat into more smelly substances. Deodorants employ antimicrobial agents that kill off bacteria, as well as chemicals that replace noxious odors with pleasant aromas. Deodorants that double as antiperspirants, like Degree, Old Spice, and Dove, take the process one step further by physically plugging sweat glands with aluminum-based compounds.

While most of us might only concern ourselves with the dry, aromatic benefits of antiperspirants and deodorants, researchers at the Laboratory of Microbial Ecology and Technology at the University of Ghent in Belgium are more interested in the effects on bacteria. Billions of bacteria dwell in the "rain forests" under our arms, and the substances we don are mucking with their habitats!

To uncover how deodorants and antiperspirants affect armpit bacteria, Chris Callewaert, a Ph.D student specializing in microbial ecology, and a team of researchers recruited eight subjects for a task a great many people (and especially their friends) might deem unbearable: Six males and two females pledged not to use deodorant or antiperspirant for an entire month. Specifically, four subjects stopped using their deodorants and another four stopped using their antiperspirant deodorant. (Most antiperspirants are also deodorants. See image below for an example.) Another control subject who did not regularly use either was asked to use deodorant for a month. The duration was chosen because it takes approximately 28 days for a new layer of skin cells to form.

The researchers analyzed the diversity and abundance of subjects' armpit bacteria at various timepoints before they stopped using antiperspirant, during the period of abstaining from antiperspirant, and for a few weeks after resuming the use of antiperspirant. Switching hygiene habits plainly altered the armpit bacterial communities of every subject. Since no two armpits and their resident bacteria are identical, it was difficult to pinpoint precise changes brought about by deodorants or antiperspirants, but one clear trend did materialize: antiperspirants resulted in a clear increase of Actinobacteria.

You might not recognize the name of Actinobacteria, but chances are, you've smelled them. Dominated by Corynebacterium, they are the major instigators of noxious armpit odor. Other microbes that inhabit the armpit, like Firmicutes and Staphylococcus, don't produce odors as quickly, nor are those odors nearly as pungent.

Callewaert believes the aluminum compounds in antiperspirants may be to blame, killing off "good," less smelly bacteria and allowing "bad" bacteria to dominate. His study found that deodorants which lack these sweat-blocking antiperspirant compounds are actually linked to a slight decrease of stinky Actinobacteria.

Though antiperspirants and deodorants are widely used, they are only a temporary fix."The measures we utilize today do not take away the initial source: the odor causing bacteria," Callewaert told RealClearScience. "Deodorants only mask unpleasant odors. We can do better than that. The follow up of this research is finding better solutions."

And Callewaert is already working on one: "armpit bacterial transplantation"."We take away the bad bacteria from the armpit of somebody with a body odor, and replace it with the good bacteria of a relative who doesn't have a body odor," he explained."So far we have helped over 15 people. For most subjects it brings immediate improvements. Most of them on a permanent time scale, although there are also people who suffer again from a body odor after some months."