Is it acceptable to smell food?

The right scent: does mint make you productive?

In working environments, design, light, acoustics and temperature control are constantly being optimized. But what about the scent? An interview with the renowned odor researcher Prof. Johannes Frasnelli from the University of Quebec.

by Hannes Hilbrecht

inperspective: Professor Frasnelli, you were born in Switzerland, grew up in South Tyrol and have been living and working in Canada for many years. Can you smell people overseas better?

Prof. Johannes Frasnelli:I would like to answer the question the other way around: North Americans cannot smell too good for us Europeans. A body odor that we hardly notice in Europe, that is still acceptable to us, is already noticeable as unpleasant in the USA or Canada.

inperspective: Why?

Prof. Frasnelli: It's not a genetic difference, it's a cultural one. There are different hygiene standards in North America. People shower more often, some several times a day. The noses of the locals react much more intensely to the unfamiliar smell of sweat.

inperspective: Why do people sometimes smell strong, and what influences our body odor?

Prof. Frasnelli: We mainly sweat out water and salt, i.e. salt water, through our skin. That is largely odorless. In the armpit and genital area we give off other odors. These are very individual. Every person - with the exception of identical twins - has their own unique body odor. We can model this smell, with care products or through our diet. If we eat garlic or curry, we don't just smell it in our mouths.

inperspetive: Do we always smell consciously, or does our brain also subconsciously perceive information from the air?

Prof. Frasnelli:We smell all the time. With every breath we smuggle odor molecules into our nose. The information is immediately passed on to the brain. In fact, in the vast majority of cases we are not even aware that we are smelling something. We only perceive the smell consciously if it changes suddenly or is particularly intense. We know this from poorly ventilated halls or offices in which 20 people sit. If someone is new to it, that person will smell a strong smell. The people who are already in the room do not even notice it.

Subscribe to inperspective for free now

inperspective: What effect can subconscious odor perception achieve?

Prof. Frasnelli: Good examples are your own apartment or bed linen. We are no longer aware of the smell of our home. In our brain, familiar scents can still trigger a feeling of security. They subconsciously influence our psyche. It has been proven that the scent of the parents, especially the mother, has a calming effect on children. Odors that we are barely or not at all aware of can arouse or de-excite us sexually. In women, body odor determines the attractiveness of the counterpart even more than in men.

inperspective: What happens in our brain when we smell?

Prof. Frasnelli: When we breathe through our nose, we humidify and filter the air we suck in. The olfactory molecules attach to the olfactory cells, which are located in the so-called olfactory mucous membrane. There individual substances fit like keys on the receptors. We experience a nerve impulse. This is passed on to the limbic system. This is a special area in our brain that controls more than our reactions to olfactory stimuli. We remember and learn with the help of our limbic system, we develop emotions. It is a highly functional area that the fragrances stimulate.

inperspective: How do our memories influence our liking or disapproval for a smell?

Prof. Frasnelli: Very strong. When I was a child, a fire devil set a car near my parents' apartment in the middle of the night. Exciting for a nine year old. When I smell burnt rubber today, I think back. The smell makes me excited. The emotions that we associate with a scent shape our sense of smell in the long term. Someone who survives a serious car accident is likely to experience fear, consciously or subconsciously, rather than excitement from plumes of burned rubber.

inperspective: Let's talk about smells and the office. It has been known for years that noise can make us sick because it stresses us out. Can smells trigger or promote disease?

Prof. Frasnelli: I am convinced that in 20 years we will talk about odor nuisance just as we do now about noise nuisance. Two decades ago, health damage from noise was not an issue, just as many people today do not consider smells to be harmful. They also cause stress. And we don't know how odor pollution can still affect our organism.

inperspective: Are there any starting points for anticipating the medical consequences of strong smells - for example on office workers?

Prof. Frasnelli: There are people who have acute health problems with odor due to hypersensitivity. They react extremely to any kind of scent, can only use unscented soaps and not apply eau de toilette. The body feels the consequences immediately, because those affected feel very uncomfortable.

inperspective: What are the difficulties when companies or architects want to preventively exclude dangers from odors?

Prof. Frasnelli: The individuality in perceiving smells. One example is a pig fattening facility near a village. The smell is intense. Someone who works for the fattening farm and has lived in the village for many years will not be stressed by it, even if the concentration of the molecules increases. If someone moves into the village and the pig fattening system increases the operation, it stinks more and people who are not used to it can suffer a lot from it. One does not notice it, the other's quality of life declines.

inperspective: Have these corresponding effects on our brain been verifiably researched?

Prof. Frasnelli: We have been able to demonstrate experimentally how much our memories and expectations influence the perception of scents. For example, we presented test subjects with a scent sample with parmesan. Most of them liked this very strong smell. They were reminded of the previous vacation in Italy, of pasta, pizza, salad. Then we labeled the same smell sample as vomit. And those who had just perceived the same scent as appetizing suddenly felt disgust.

Inperspective: To put it another way, I am thinking of tiger ointment, cold baths in winter, essential oils: Can smells support healing processes or prevent stress illnesses in office workers?

Prof. Frasnelli:Interesting that you bring that up. Cold baths or similar preparations containing eucalyptus, camphor (known as tiger balm) or menthol not only irritate our olfactory nerves, but also the trigeminal nerve, the fifth cranial nerve. The smells mentioned cause arousal at the receptors of the trigeminal nerve. We believe we are breathing cold air. This suggests to us that the blocked nostril must be freer. But that's not true at all. Cold baths do not relieve swelling in the nose. It just seems freer to us. We outsmart our senses, manipulate our perception. However, these remedies do not have a pharmacological influence on our common cold.

inperspective: Can smells - if used properly - still have a positive effect on our health?

Prof. Frasnelli: What is exciting is that the same cells that perform an olfactory function in the nose have been found in other organs such as the liver or kidneys. What they have to do there inside us and whether odors from the air can even reach these olfactory sensors has not yet been adequately researched.