Contact with nature during childhood could lead to better mental health in adulthood
May 21, 2019
Science Daily/Barcelona Institute for Global Health (ISGlobal)
Almost 3,600 people participated in a European study on the impact of green and blue spaces on mental health and vitality.
Adults who had close contact with natural spaces during their childhood could have a better mental health than those who had less contact, according to a new study by the Barcelona Institute for Global Health (ISGlobal), an institution supported by "la Caixa," involving four European cities.
Exposure to natural outdoor environments has been associated with several health benefits, including a better cognitive development and better mental and physical health. However, few studies have explored the impact of childhood exposure to natural environments on mental health and vitality in adulthood. Furthermore, studies have more frequently considered green spaces (gardens, forests, urban parks) than blue spaces (canals, ponds, creeks, rivers, lakes, beaches, etc.).
This study, published in the International Journal of Environment Research and Public Health, was performed within the framework of the PHENOTYPE project with data from almost 3,600 adults from Barcelona (Spain), Doetinchem (Netherlands), Kaunas (Lithuania) and Stoke-on-Trent (United Kingdom).
The adult participants answered a questionnaire on frequency of use of natural spaces during childhood, including purposeful ¬-e.g. hiking in natural parks- and non-purposeful -e.g. playing in the backyard- visits. They were also asked about their current amount, use and satisfaction with residential natural spaces, as well as the importance they give to such spaces. The mental health of the participants in terms of nervousness and feelings of depression in the past four weeks, as well as their vitality -energy and fatigue levels- were assessed through a psychological test. The residential surrounding greenness during adulthood was determined through satellite images.
The results show that adults who were less exposed to natural spaces during their childhood had lower scores in mental health tests, compared to those with higher exposure. Myriam Preuss, first author of the study, explains that "in general, participants with lower childhood exposure to nature gave a lower importance to natural environments." No association was found between childhood exposure and vitality, or the use of or satisfaction with these spaces in adulthood.
Wilma Zijlema, ISGlobal researcher and study coordinator, underlines that the conclusions "show the importance of childhood exposure to natural spaces for the development of a nature-appreciating attitude and a healthy psychological state in adulthood." Currently, 73% of Europe's population lives in urban areas with often limited access to green space and this number is expected to increase to over 80% by 2050. "Therefore, it is important to recognize the implications of growing in up in environments with limited opportunities for exposure to nature," she adds.
"Many children in Europe lead an indoors lifestyle, so it would be desirable to make natural outdoor environments available, attractive and safe for them to play in," explains Mark Nieuwenhuijsen, director of ISGlobal's Urban Planning, Environment and Health Initiative. In most countries, activities in nature are not a regular part of the school's curriculum. "We make a call on policymakers to improve availability of natural spaces for children and green school yards," he adds.
https://www.sciencedaily.com/releases/2019/05/190521193735.htm
Just 20 minutes of contact with nature will lower stress hormone levels
April 4, 2019
Science Daily/Frontiers
Taking at least twenty minutes out of your day to stroll or sit in a place that makes you feel in contact with nature will significantly lower your stress hormone levels. That's the finding of a study that has established for the first time the most effective dose of an urban nature experience. Healthcare practitioners can use this discovery, published in Frontiers in Psychology, to prescribe 'nature-pills' in the knowledge that they have a real measurable effect.
"We know that spending time in nature reduces stress, but until now it was unclear how much is enough, how often to do it, or even what kind of nature experience will benefit us," says Dr. MaryCarol Hunter, an Associate Professor at the University of Michigan and lead author of this research. "Our study shows that for the greatest payoff, in terms of efficiently lowering levels of the stress hormone cortisol, you should spend 20 to 30 minutes sitting or walking in a place that provides you with a sense of nature."
A free and natural stress-relieving remedy
Nature pills could be a low-cost solution to reduce the negative health impacts stemming from growing urbanization and indoor lifestyles dominated by screen viewing. To assist healthcare practitioners looking for evidence-based guidelines on what exactly to dispense, Hunter and her colleagues designed an experiment that would give a realistic estimate of an effective dose.
Over an 8-week period, participants were asked to take a nature pill with a duration of 10 minutes or more, at least 3 times a week. Levels of cortisol, a stress hormone, were measured from saliva samples taken before and after a nature pill, once every two weeks.
"Participants were free to choose the time of day, duration, and the place of their nature experience, which was defined as anywhere outside that in the opinion of the participant, made them feel like they've interacted with nature. There were a few constraints to minimize factors known to influence stress: take the nature pill in daylight, no aerobic exercise, and avoid the use of social media, internet, phone calls, conversations and reading," Hunter explains.
She continues, "Building personal flexibility into the experiment, allowed us to identify the optimal duration of a nature pill, no matter when or where it is taken, and under the normal circumstances of modern life, with its unpredictability and hectic scheduling."
To make allowances for busy lifestyles, while also providing meaningful results, the experimental design was novel in other aspects too.
"We accommodated day to day differences in a participant's stress status by collecting four snapshots of cortisol change due to a nature pill," says Hunter. "It also allowed us to identify and account for the impact of the ongoing, natural drop in cortisol level as the day goes on, making the estimate of effective duration more reliable."
Nature will nurture
The data revealed that just a twenty-minute nature experience was enough to significantly reduce cortisol levels. But if you spent a little more time immersed in a nature experience, 20 to 30 minutes sitting or walking, cortisol levels dropped at their greatest rate. After that, additional de-stressing benefits continue to add up but at a slower rate.
"Healthcare practitioners can use our results as an evidence-based rule of thumb on what to put in a nature-pill prescription," says Hunter. "It provides the first estimates of how nature experiences impact stress levels in the context of normal daily life. It breaks new ground by addressing some of the complexities of measuring an effective nature dose."
Hunter hopes this study will form the basis of further research in this area.
"Our experimental approach can be used as a tool to assess how age, gender, seasonality, physical ability and culture influences the effectiveness of nature experiences on well-being. This will allow customized nature pill prescriptions, as well as a deeper insight on how to design cities and wellbeing programs for the public."
https://www.sciencedaily.com/releases/2019/04/190404074915.htm
Being surrounded by green space in childhood may improve mental health of adults
February 26, 2019
Science Daily/Aarhus University
Children who grow up with greener surroundings have up to 55 percent less risk of developing various mental disorders later in life. This is shown by a new study emphasizing the need for designing green and healthy cities for the future.
A larger and larger share of the world's population now lives in cities and WHO estimates that more than 450 millions of the global human population suffer from a mental disorder. A number that is expected to increase.
Now, based on satellite data from 1985 to 2013, researchers from Aarhus University have mapped the presence of green space around the childhood homes of almost one million Danes and compared this data with the risk of developing one of 16 different mental disorders later in life.
The study, which is published today in the Journal PNAS, shows that children surrounded by the high amounts of green space in childhood have up to a 55% lower risk of developing a mental disorder -- even after adjusting for other known risk factors such as socio-economic status, urbanization, and the family history of mental disorders.
The entire childhood must be green
Postdoc Kristine Engemann from Department of Bioscience and the National Centre for Register-based Research at Aarhus University, who spearheaded the study, says: "Our data is unique. We have had the opportunity to use a massive amount of data from Danish registers of, among other things, residential location and disease diagnoses and compare it with satellite images revealing the extent of green space surrounding each individual when growing up."
Researchers know that, for example, noise, air pollution, infections and poor socio-economic conditions increase the risk of developing a mental disorder. Conversely, other studies have shown that more green space in the local area creates greater social cohesion and increases people's physical activity level and that it can improve children's cognitive development. These are all factors that may have an impact on people's mental health.
"With our dataset, we show that the risk of developing a mental disorder decreases incrementally the longer you have been surrounded by green space from birth and up to the age of 10. Green space throughout childhood is therefore extremely important," Kristine Engemann explains.
Green and healthy cities
As the researchers adjusted for other known risk factors of developing a mental disorder, they see their findings as a robust indication of a close relationship between green space, urban life, and mental disorders.
Kristine Engemann says: "There is increasing evidence that the natural environment plays a larger role for mental health than previously thought. Our study is important in giving us a better understanding of its importance across the broader population."
This knowledge has important implications for sustainable urban planning. Not least because a larger and larger proportion of the world's population lives in cities.
"The coupling between mental health and access to green space in your local area is something that should be considered even more in urban planning to ensure greener and healthier cities and improve mental health of urban residents in the future," adds co-author Professor Jens-Christian Svenning from the Department of Bioscience, Aarhus University.
https://www.sciencedaily.com/releases/2019/02/190226112426.htm
Being raised in greener neighborhoods may have beneficial effects on brain development
February 23, 2018
Science Daily/University of California - Los Angeles
A new study shows for the first time that exposure to green space during childhood is associated with beneficial structural changes in the developing brain.
Primary schoolchildren who have been raised in homes surrounded by more greenspace tend to present with larger volumes of white and grey matter in certain areas of the brain. Those anatomic differences are in turn associated with beneficial effects on cognitive function. This is the main conclusion of a study published in Environmental Health Perspectives and led by the Barcelona Institute for Global Health (ISGlobal), a center supported by the "la Caixa" Foundation, in collaboration with the Hospital del Mar (Spain) and the UCLA Fielding School of Public Health (UCLA FSPH).
The study was performed in a subcohort of 253 schoolchildren from the BREATHE project in Barcelona (Spain). Lifelong exposure to residential greenspace was estimated using satellite-based information on the children's addresses from birth up through to the time of the study. Brain anatomy was studied using high-resolution 3D magnetic resonance images (MRI). Working memory and inattentiveness were evaluated with computerized tests.
"This is the first study that evaluates the association between long-term exposure to greenspace and brain structure," says Dr. Payam Dadvand, ISGlobal researcher and leading author of the study. "Our findings suggest that exposure to greenspace early in life could result in beneficial structural changes in the brain."
The data analysis showed that long-term exposure to greenness was positively associated with white and grey matter volume in some parts of the brain that partly overlapped with those associated with higher scores on cognitive tests. Moreover, peak volumes of white and grey matter in the regions associated with greenspace exposure predicted better working memory and reduced inattentiveness.
Contact to nature has been thought to be essential for brain development in children. A previous study of 2,593 children ages 7 to 10 from the BREATHE project showed that, during the 12-month course of the study, children who attended schools with higher outdoor greenspace had a greater increase in working memory and a greater reduction in inattentiveness than children who attended schools with less surrounding greenness.
The Biophilia hypothesis suggests an evolutionary bond of humans to nature. Accordingly, green spaces are suggested to provide children with opportunities for psychological restoration and prompt important exercises in discovery, creativity and risk taking, which, in turn, are suggested to positively influence different aspects of brain development. Furthermore, greener areas often have lower levels of air pollution and noise and may enrich microbial inputs from the environment, all of which could translate into indirect benefits for brain development.
"The study adds to growing evidence suggesting that early life exposure to green space and other environmental factors can exert measurable and lasting effects on our health through the life course," says co-author Michael Jerrett, department chair and professor of Environmental Health Sciences at the UCLA Fielding School of Public Health.
"These results also might provide clues on how such structural changes could underlie the observed beneficial effects of greenspace exposure on cognitive and behavioral development," explains Dr. Jesus Pujol, from the Radiology unit at Hospital del Mar and co-author of the study.
"This study adds to the existing evidence about the benefits of transforming our cities by increasing access to the natural environment," says Prof. Jordi Sunyer, an ISGlobal researcher and last author of the study.
Further studies are needed to confirm the results in other populations, settings and climates, evaluate other cognitive and neurological outcomes and examine differences according to the nature and quality of greenspace and children's access to and use of them.
https://www.sciencedaily.com/releases/2018/02/180223100626.htm
Living close to green spaces is associated with better attention in children
An ISGlobal study analyses for the first time lifelong residential exposure to greenness in children
October 25, 2017
Barcelona Institute for Global Health (ISGlobal)
How do green spaces affect cognitive development in children? A new study concludes that children with more greenness around their homes may develop better attention capacities.
Natural surroundings, including green spaces, may be beneficial for brain development in children, but evidence is still limited. A previous ISGlobal study already indicated that green spaces within and surrounding schools could enhance cognitive development in children between 7 and 10 years of age. In the current study, the authors expanded on this finding by evaluating the impact of greenness surrounding all the residential addresses of children since birth and characterizing cognitive development at earlier stages in life.
The analysis, published in Environment Health Perspectives, was based on data from 1,500 children of the INMA -- Environment and Childhood Project cohort in Sabadell and Valencia, collected during 2003-2013. The ISGlobal team analysed residential surrounding greenness -- at 100, 300 and 500 metres distance- at birth, 4-5 years and 7 years of age. Two types of attention tests were performed at 4-5 and 7 years of age. The research shows that children with higher greenness around their homes had better scores in the attention tests.
Payam Dadvand, ISGlobal researcher and first author of the study, emphasizes "this is the first time that the impact of lifelong residential exposure to green spaces on attention capacity in children has been studied." These results "underline the importance of green areas in cities for children's health and brain development," says Dadvand.
Jordi Sunyer, study coordinator and head of the Child Health Programme at ISGlobal, points out that "the possibility that exposure to different types of vegetation might have different impacts on neurodevelopment remains an open question." Therefore, Sunyer considers further studies should be done in other settings with different climates and vegetation.
"Green spaces in cities promote social connections and physical activity and reduce exposure to air pollution and noise, and are therefore essential for the development of the future generations' brains" adds the study coordinator.
https://www.sciencedaily.com/releases/2017/10/171025103123.htm