Tag Archives: odor

Your reaction to smells could say a lot about your political preference, a new study suggests

A surprising study has found that people who are easily disgusted by strong odors like sweat or urine tend to prefer more authoritarian leaders, and it might all have a lot to do with diseases.

Image credits: Hanna Esser.

Disgust is a basic emotion, and it was a very important tool for survival over countless generations. Disgust is basically a way of saying “I’ll have none of that,” and it’s most commonly related to nasty smells or foods.

Just think about someone being disgusted — it has a lot to do with a person’s senses. The nose is wrinkled or turned away, the eyes partially or entirely closed. The whole body is shutting down its sensorial information, and for a good reason: many things that are disgusting are rotten, dirty, or infectious — you don’t want to be near them, and you certainly don’t want to smell or eat them. Disgust is useful largely because it helps you avoid potential diseases, but different people have different tolerance levels.

Researchers had an idea that there would be a connection between how people are disgusted by smell and how they want their country to be led. The idea is that people who have a strong urge to avoid unpleasant smells would also avoid mingling with other groups of people such as immigrants. They would be against multiculturalism and would fall towards the authoritarian side of the political spectrum, researchers suspected. They were right.

‘There was a solid connection between how strongly someone was disgusted by smells and their desire to have a dictator-like leader who can supress radical protest movements and ensure that different groups “stay in their places”. That type of society reduces contact among different groups and, at least in theory, decreases the chance of becoming ill’, says Jonas Olofsson, who researches scent and psychology at Stockholm University and is one of the authors of the study.

Among other questions, researchers asked international participants to rate their levels of disgust for body odors, both their own and others and then gauged their political preferences, looking for correlations.

While seeming completely unrelated, the connection between smell and politic inclinations does make a lot of sense. After all, if disgust is a means of isolating yourself from unwanted, potentially dangerous, then people who are more easily disgusted might also want to be more isolated from other people which they consider as potentially dangerous. Isolationism and a negative attitude towards immigrants and different groups of people is a trademark of authoritarian governments. Still, it’s remarkable that such a clear correlation can be established between odors and ideology.

’Understanding the shared variance between basic emotional reactivity to potential pathogen cues such as body odours and ideological attitudes that can lead to aggression towards groups perceived as deviant can prompt future investigations on what are the emotional determinants of outgroup derogation. In the next future, this knowledge might inform policies to prevent ethnocentrism’ says Marco Tullio Liuzza from Magna Graecia University of Catanzaro, Italy, also one of the authors.

US participants who were easily disgusted by smells were more likely to vote for Trump — which perfectly fits the theory. Image credits: Gage Skidmore.

Notably, researchers also added an extra question for US participants: how they will vote in the 2016 presidential election. Since Donald Trump ticks the boxes for authoritarianism, he was an excellent example to test the theory. Lo and behold, people who dislike bodily odors the most were more likely to vote for Trump.

This is interesting because Trump himself has often said that other people disgust him physically, and is reportedly obsessed with hygiene.

‘It showed that people who were more disgusted by smells were also more likely to vote for Donald Trump than those who were less sensitive. We thought that was interesting because Donald Trump talks frequently about how different people disgust him. He thinks that women are disgusting and that immigrants spread disease and it comes up often in his rhetoric. It fits with our hypothesis that his supporters would be more easily disgusted themselves’, says Jonas Olofsson.

This seems to suggest that authoritarian beliefs are heavily ingrained in some people’s brains, similarly to smell preferences.

‘The research has shown that the beliefs can change. If contact is created between groups, authoritarians can change. It’s not carved in stone. Quite the opposite, beliefs can be updated when we learn new things.’

However, Jonas Olofsson is optimistic. The most important thing is to keep a communication channel between opposing groups, and change can happen, he says.

‘The research has shown that the beliefs can change. If contact is created between groups, authoritarians can change. It’s not carved in stone. Quite the opposite, beliefs can be updated when we learn new things.’

Journal Reference: Liuzza et al. Body odour disgust sensitivity predicts authoritarian attitudes.

Cancer sniffing dog

Dogs will sniff out stomach cancer in new Japanese trial

Cancer sniffing dog

Credit: Central Bark.

It’s remarkable — almost unbelievable — but one of the most accurate cancer diagnosing tool is man’s best friend. Studies have time and time again shown this to be true. One 2011 study found dogs can identify breast and lung cancer with a 95% accuracy compared to a biopsy. UK doctors working at the Milton Keynes hospital found canines are 93% effective at sniffing prostate cancer. Now, a new clinical trial will begin shortly in Japan to gauge how accurate dogs can sniff stomach cancer.

The cutest bio-detector

Some 6,000 Japanese individuals living in the Yamagata Prefecture will have their urine analyzed at a lab belonging to the Nippon Medical School, just outside of Tokyo. Trained dogs will then be tasked with identifying the cancerous samples.

It’s thought dogs achieve this feat by being able to discern odors released by cancerous cells which are oblivious to us humans. They are able to pick up a scent in a dilution of one to a thousand parts.

Given that so many studies have proven dogs’ propensity for sniffing cancer, why don’t we actually see them everywhere in a hospital, especially in those wards where cancer is diagnosed? Dogs have a sensitive smell but so do humans and like us, dogs need training too. Training a dog to accurately identify cancer odors can take years and somewhere around $45,000 per canine, according to Cynthia Otto, Director of the Penn Vet Working Dog Center at the University of Pennsylvania’s School of Veterinary Medicine. Otto says she’s often contacted by people from third world countries who’ve read various papers about cancer-sniffing dogs and got excited, not realizing how intense and expensive the training can be.

Another important caveat is that, again like humans, a dog’s sensitivity is susceptible to mood, diet, and even the owner’s behavior. A professional dog sniffer will also likely suffer if it doesn’t get to sniff cancer all day long.

“These dogs need the reward of finding people or they can get depressed. During the 9/11 search and rescue effort, emergency responders had to stage fake body finds so that the dogs could be rewarded. Cancer screening dogs need the same thing to avoid stress,” Sara Chodosh explained for Popular Science. 

Nevertheless, given their staggering accuracy, there is value in training dogs to identify various forms of cancer even though they will never be used on a wide scale. Ultimately, everyone hopes that all of these clinical trials such as the upcoming one in Japan will single out the compounds the dogs are able to detect. Then, it’s only a matter of developing a device, perhaps fitted with a miniature spectrometer, that can mimic the canine’s cancer-sniffing ability.

“One of the largest misunderstandings we face is that people think we are trying to say that dogs are better than machines – we’re not,” said Claire Guest, a specialist in human and animal behaviour and the doctor responsible for the British research into cancer sniffer-dogs.

“There are already machines which act as ‘electronic noses’ that are designed to identify chemicals such as cocaine, and this is what we are trying to do with cancer.

“Of course, no dog is going to be 100 percent – but at the moment there is no machine out there that can do what the dogs are doing. Cancer detection is extr

Since 2013, a team from the University of Liverpool and the University of the West of England (UWE) in Bristol have developed a device “Odoreader” that can accurately detect bladder cancer by detecting specific volatile molecules found in the odor of urine, akin to an artificial dog’s nose. As more data is gathered, these devices will become more and more accurate. The dogs can then take a much-deserved break.

Odor receptors discovered in lungs

Researchers at Washington University in St. Louis and the University of Iowa have found out that we don’t just smell with our noses, we also smell with our lungs… sort of. But while your nose might tell you that something is or isn’t good for you, your lungs might make you cough it out.

Smelling with your lungs

“They’re beautiful cells,” said Ben-Shahar, of the pulmonary neuroendocrine cells he has been studying in lung tissues. The flask-like cells that are full of serotonin (stained green here) and other chemicals extend processes up through the epithelial cells (purple) lining the airways to monitor the chemical makeup of each breath. The top part of the image is a plan view of the airway lining and the bottom part is a section through the lining.

“They’re beautiful cells,” said Ben-Shahar, of the pulmonary neuroendocrine cells he has been studying in lung tissues. The flask-like cells that are full of serotonin (stained green here) and other chemicals extend processes up through the epithelial cells (purple) lining the airways to monitor the chemical makeup of each breath.

The odor receptors in your lungs are very different from those in your nose. Instead of being located in the membranes of nerve cells, they are located in neuroendocrine cells – cells that receive neuronal input and send out hormones to the blood. So basically, instead of sending out a nerve signal that allows your brain to ‘read’ the smell, they dump hormones that make your airways constrict.

It comes as quite a surprise that an entire class of odor receptors went undetected for so long.

“We forget,” said Yehuda Ben-Shahar, PhD, assistant professor of biology, in Arts & Sciences, and of medicine at Washington University in St. Louis, “that our body plan is a tube within a tube, so our lungs and our gut are open to the external environment. Although they’re inside us, they’re actually part of our external layer. So they constantly suffer environmental insults,” he said, “and it makes sense that we evolved mechanisms to protect ourselves.”

To put it simply, pulmonary neuroendocrine cells, or PNECs are guards, whose job is to make sure nothing harmful enters your lungs. If for any reason, they defect, this could lead to a broad range of afflictions, such as chronic obstructive pulmonary disease (COPD) and asthma. Patients with these diseases are told to avoid traffic fumes, pungent odors, perfumes and similar irritants, which can trigger airway constriction and breathing difficulties.

Every breath you take

A diagram of the airway lining suggests how the pulmonary neuroendocrine cells (red) trigger a response to inhaled chemicals. When a chemical (orange triangle) docks on a receptor (black) they dump secretory chemicals (thin orange arrows), which have an immediate but localized effect on muscles (blue) and nerves (pink), possibly triggering responses such as a cough. Copyright: Ben Sahar.

A diagram of the airway lining suggests how the pulmonary neuroendocrine cells (red) trigger a response to inhaled chemicals. When a chemical (orange triangle) docks on a receptor (black) they dump secretory chemicals (thin orange arrows), which have an immediate but localized effect on muscles (blue) and nerves (pink), possibly triggering responses such as a cough. Copyright: Ben Sahar.

Earlier, a team at the University of Iowa, where Ben-Shahar was a postdoctoral research associate, studied genes expressed by patches of tissue from lung transplant donors. They found a ciliated group of cells that could perceive bitter smells and kick it out, if found dangerous. But people are vulnerable to more than just bitter smells, so Ben-Shahar decided to look again. This time he found that these tissues also express odor receptors, not on ciliated cells but instead on neuroendocrine cells – and this made a lot of sense.

“When people with airway disease have pathological responses to odors, they’re usually pretty fast and violent,” said Ben-Shahar. “Patients suddenly shut down and can’t breathe, and these cells may explain why.”