Summary: A new study inspires researchers to explore the impact of nature’s scents on human health and well-being. If the visual aspects of nature have been widely studied, the olfactory dimension remains under-explored.
Scientists provide a framework for studying how natural scents, perceived consciously and unconsciously, can affect our emotions, thoughts and physical health.
Highlights:
- The human olfactory system can detect over a trillion odors.
- Plants release volatile organic compounds (VOCs) that are potentially beneficial to health.
- Further research is needed to understand the full impact of natural fragrances on human well-being.
Source: University of Washington
Spending time in nature is good for us. Studies have shown that contact with nature can improve our well-being by affecting emotions, influencing thoughts, reducing stress and improving physical health.
Even brief exposure to nature can help. A well-known study found that hospitalized patients recovered more quickly if their room had a window overlooking a natural setting.
Learning more about the effects of nature on our bodies could not only contribute to our well-being, but could also improve the way we care for land, preserve ecosystems and design cities, homes and parks. Yet studies on the benefits of contact with nature have typically focused primarily on how seeing nature affects us.
There has been less focus on what the nose knows. That’s something a group of researchers wants to change.
“We are immersed in a world of odorants and we have a sophisticated olfactory system that processes them, with impacts on our emotions and behavior,” said Gregory Bratman, assistant professor of environmental and forestry sciences at the University of Washington.
“But compared to research on the benefits of observing nature, we know much less about how the impacts of scents and olfactory cues from nature affect us.”
In an article published on May 15 in Scientists progressBratman and colleagues around the world describe ways to expand research into the impact of odors and scents from natural environments on our health and well-being.
The interdisciplinary group of experts in olfaction, psychology, ecology, public health, atmospheric sciences and other fields is based at institutions in the United States, United Kingdom, Taiwan, Germany, Poland and Cyprus.
At its core, the human sense of smell, or olfaction, is a complex chemical sensing system in constant operation. The nose is full of hundreds of olfactory receptors, which are sophisticated chemical sensors.
Together, they can detect over a trillion odors, and this information is transmitted directly to the nervous system for our minds to interpret – consciously or not.
The natural world releases a constant stream of chemical compounds to occupy our olfactory system. Plants in particular give off volatile organic compounds, or VOCs, that can linger in the air for hours or even days.
VOCs serve many functions for plants, such as repelling herbivores or attracting pollinators. Some researchers have studied the impact of exposures to plant VOCs on humans.
“We know pieces of the big picture,” Bratman said. “But there is so much more to learn. We provide a framework, informed by important research by many other researchers, for how to study the intimate connections between olfaction, nature, and human well-being.
According to the authors, the olfactory impacts of nature probably take different routes. Certain chemical compounds, including a subset of those in the invisible realm of plant VOCs, can act on us without our knowledge.
In these cases, olfactory receptors in the nose could initiate a “subthreshold” response to molecules that people are largely unaware of.
Bratman and his co-authors are calling for significantly more research into when, where, and how these undetected biochemical processes linked to natural VOCs can affect us.
Other olfactory signals are sensed consciously, but scientists do not yet fully understand their full impacts on our health and well-being. Some scents, for example, may have “universal” interpretations for humans – something that almost always smells pleasant, like a fragrant flower.
Other scents are closely linked to specific memories, or have associations and interpretations that vary depending on culture and personal experience, as research by co-author Asifa Majid of the University of Oxford has shown .
“Understanding how olfaction plays a mediating role in our relationships with the natural world and the benefits we derive from it is a multidisciplinary endeavor,” Bratman said.
“It involves knowledge from research on olfactory function, indigenous knowledge, Western psychology, anthropology, atmospheric chemistry, forest ecology, Shinrin-yoku – or “forest bathing” – neuroscience, and much more.”
The investigation into potential links between our sense of smell and positive experiences with nature includes research led by co-author Cecilia Bembibre of University College London, which shows that the cultural significance of smells, including those of nature , can be transmitted in communities to everyone. new generation.
Co-author Jieling Xiao from Birmingham City University looked at the associations people have with scents in built environments and urban gardens.
Other co-authors showed that nature leaves its signature in the very air we breathe. Forests, for example, release a complex chemical environment into the air. Research by co-author Jonathan Williams of the Max Planck Institute for Chemistry and the Cyprus Institute shows how natural VOCs can react and mix in the atmosphere, with implications for olfactory environments.
The authors also call for more studies to investigate how human activity changes nature’s olfactory footprint, both through pollution, which can change or destroy odors in the air, and through reduction habitats that release beneficial odors.
“Human activity is changing the environment so quickly in some cases that we are discovering the benefits while making them harder for people to access,” Bratman said.
“As research sheds more light on these connections, we hope to be able to make more informed decisions about our impacts on the natural world and the volatile organic compounds that result from them.” As we say in the article, we live in the chemical contexts created by nature.
“Better understanding this can contribute to human well-being and advance efforts to protect the natural world.” »
Other UW co-authors on the paper are Peter Kahn, professor of psychology; Connor Lashus, graduate student in the School of Environmental and Forest Sciences; and Anne Riederer, clinical associate professor of environmental and occupational health sciences. Other co-authors are Gretchen Daily of Stanford University; Richard Doty of the University of Pennsylvania; Thomas Hummel of the Technical University of Dresden; Lucia Jacobs of the University of California, Berkeley; John Miller of Wildwood|Mahonia; Anna Oleszkiewicz from the University of Wrocław; Hector Olvera-Alvarez of Oregon Health and Science University; Valentina Parma of the Monell Chemical Senses Center; Nancy Long Sieber and John Spengler of Harvard University; and Chia-Pin Yu of National Taiwan University.
About this olfaction and well-being research news
Author: James Urton
Source: University of Washington
Contact: James Urton – University of Washington
Picture: Image is credited to Neuroscience News
Original research: Free access.
“Nature and human well-being: The olfactory pathway” by Gregory Bratman et al. Scientists progress
Abstract
Nature and human well-being: The olfactory pathway
The world is undergoing massive atmospheric and ecological changes, resulting in unprecedented challenges to human well-being. Olfaction is a key sensory system through which these impacts occur.
The sense of smell influences life quality and satisfaction, emotions, emotion regulation, cognitive function, social interactions, food choices, stress, and depressive symptoms. Exposures via the olfactory pathway can also lead to (anti-)inflammatory outcomes.
There is a need to better understand how odors generated by nature (i.e., natural olfactory environments) affect human well-being.
With perspectives from a range of health, social, and natural sciences, we provide an overview of this unique sensory system, four consensus statements regarding olfaction and the environment, and a conceptual framework that integrates the olfactory pathway in an understanding of the effects of natural effects. environments on human well-being.
We then discuss how this framework can contribute to better consideration of the impacts of policy and land use decisions on natural olfactory environments and, therefore, on planetary health.