Scientists want to know how nature’s scents benefit our health

Spending time in nature is good for us. Studies have shown that contact with nature can improve our well-being by influencing emotions, influencing thoughts, reducing stress and improving physical health. Even a brief exposure to nature can help. A well-known study found that hospital patients recovered faster if their room had a window overlooking a natural environment.

Knowing more about the effects of nature on our bodies could not only benefit 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 on how seeing nature affects us. There has been less attention to what the nose knows. That is 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 consequent consequences for our emotions and behavior,” says Gregory Bratman, assistant professor of environmental and forest sciences at the University of Washington.

“But compared to research on the benefits of seeing nature, we don’t know nearly as much about how the impact of nature’s scents and olfactory cues affect us.”

In a paper published May 15th arrival Scientific progressBratman and colleagues from around the world outline ways to expand research on how scents and scents from natural environments affect our health and well-being.

The interdisciplinary group of experts in olfaction, psychology, ecology, public health, atmospheric science and other fields is based at institutions in the US, Britain, Taiwan, Germany, Poland and Cyprus.

At its core, the human sense of smell, or olfaction, is a complex chemical detection system in constant operation. The nose is packed with hundreds of olfactory receptors, which are advanced chemical sensors. Together they can detect more than 1 trillion odors, and that information is relayed directly to the nervous system for our minds to interpret – consciously or otherwise.

The natural world releases a steady stream of chemical compounds to keep our olfactory system busy. Plants in particular excrete volatile organic compounds VOCs, which can remain in the air for hours or days. VOCs perform many functions for plants, such as repelling herbivores or attracting pollinators. Some researchers have studied the impact of plant VOC exposure on humans.

“We know bits and pieces of the big picture,” Bratman said. “But there is still so much more to learn. We propose a framework, based on important research from many others, on how to explore the intimate links between olfaction, nature and human well-being.”

Nature’s odor-mediated effects likely come through different routes, according to the authors. Some chemical compounds, including a subset of compounds from the invisible realm of plant VOCs, may be acting on us without us knowing it.

In these cases, olfactory receptors in the nose could initiate a ‘subthreshold’ response to molecules of which people are largely unaware. Bratman and his co-authors call for vastly expanded research into when, where and how these undetected biochemical processes associated with natural VOCs can affect us.

Other olfactory cues are consciously picked up, but scientists still don’t fully understand their full impact on our health and well-being. For example, some scents may have “universal” interpretations for people – something that almost always smells pleasant, like a sweet-smelling flower.

Other scents are closely linked to specific memories, or have associations and interpretations that vary by culture and personal experience, as research by co-author Asifa Majid of the University of Oxford shows.

“Understanding how olfaction mediates our relationships with the natural world and the benefits we receive from it are multidisciplinary endeavors,” says Bratman. “It includes insights from research on olfactory function, indigenous knowledge, Western psychology, anthropology, atmospheric chemistry, forest ecology, Shinrin-yoku (or ‘forest bathing’) neuroscience and more.”

Research into the possible links between our sense of smell and positive experiences with nature includes research by co-author Cecilia Bembibre at University College London, which shows that the cultural significance of smells, including those from nature, can be shared across communities in communities are passed on. New Generation. Co-author Jieling Xiao from Birmingham City University has delved into the associations people have with scents in the built environment and city gardens.

Other co-authors have shown that nature leaves its signature in the air we breathe. For example, forests emit a complex chemical environment into the air. Research by co-author Jonathan Williams of the Max Planck Institute of Chemistry and the Cyprus Institute shows how natural VOCs can react and mix in the atmosphere, impacting the olfactory environment.

The authors also call for more research to investigate how human activity is changing nature’s olfactory footprint – both through pollution, which can alter or destroy odorants in the air, and by reducing habitats that emit beneficial scents.

“Human activity is changing the environment so quickly in some cases that we are learning about these benefits while at the same time making them harder for people to access,” says Bratman.

“As research illuminates more of these connections, we hope we can make more informed decisions about our impact on the natural world and the volatile organic compounds it produces. As we say in the article, we live within chemical contexts that understanding this better could contribute to human well-being and advance efforts to protect the natural world.”