Living near major roads linked to risk of dementia, Parkinson's, Alzheimer's and MS

January 23, 2020

Science Daily/University of British Columbia

Living near major roads or highways is linked to higher incidence of dementia, Parkinson's disease, Alzheimer's disease and multiple sclerosis (MS), suggests new research published this week in the journal Environmental Health.

Researchers from the University of British Columbia analyzed data for 678,000 adults in Metro Vancouver. They found that living less than 50 metres from a major road or less than 150 metres from a highway is associated with a higher risk of developing dementia, Parkinson's, Alzheimer's and MS -- likely due to increased exposure to air pollution.

The researchers also found that living near green spaces, like parks, has protective effects against developing these neurological disorders.

"For the first time, we have confirmed a link between air pollution and traffic proximity with a higher risk of dementia, Parkinson's, Alzheimer's and MS at the population level," says Weiran Yuchi, the study's lead author and a PhD candidate in the UBC school of population and public health. "The good news is that green spaces appear to have some protective effects in reducing the risk of developing one or more of these disorders. More research is needed, but our findings do suggest that urban planning efforts to increase accessibility to green spaces and to reduce motor vehicle traffic would be beneficial for neurological health."

Neurological disorders -- a term that describes a range of disorders, including Alzheimer's disease and other dementias, Parkinson's disease, multiple sclerosis and motor neuron diseases -- are increasingly recognized as one of the leading causes of death and disability worldwide. Little is known about the risk factors associated with neurological disorders, the majority of which are incurable and typically worsen over time.

For the study, researchers analyzed data for 678,000 adults between the ages of 45 and 84 who lived in Metro Vancouver from 1994 to 1998 and during a follow-up period from 1999 to 2003. They estimated individual exposures to road proximity, air pollution, noise and greenness at each person's residence using postal code data. During the follow-up period, the researchers identified 13,170 cases of non-Alzheimer's dementia, 4,201 cases of Parkinson's disease, 1,277 cases of Alzheimer's disease and 658 cases of MS.

For non-Alzheimer's dementia and Parkinson's disease specifically, living near major roads or a highway was associated with 14 per cent and seven per cent increased risk of both conditions, respectively. Due to relatively low numbers of Alzheimer's and MS cases in Metro Vancouver compared to non-Alzheimer's dementia and Parkinson's disease, the researchers did not identify associations between air pollution and increased risk of these two disorders. However, they are now analyzing Canada-wide data and are hopeful the larger dataset will provide more information on the effects of air pollution on Alzheimer's disease and MS.

When the researchers accounted for green space, they found the effect of air pollution on the neurological disorders was mitigated. The researchers suggest that this protective effect could be due to several factors.

"For people who are exposed to a higher level of green space, they are more likely to be physically active and may also have more social interactions," said Michael Brauer, the study's senior author and professor in the UBC school of population and public health. "There may even be benefits from just the visual aspects of vegetation."

Brauer added that the findings underscore the importance for city planners to ensure they incorporate greenery and parks when planning and developing residential neighbourhoods.

https://www.sciencedaily.com/releases/2020/01/200123152616.htm

City parks lift mood as much as Christmas

The greener the greenspace, the happier and less self-absorbed people are

August 20, 2019

Science Daily/University of Vermont

New research shows that visitors to urban parks use happier words and express less negativity on Twitter than before their visit -- and that their elevated mood lasts for up to four hours. The effect is so strong that it's equivalent to the mood spike on Christmas, the happiest day each year on Twitter. With increasing urbanization and mood disorders, this research may have powerful implications for public health and urban planning.

Feeling unhappy and cranky? The treatment: take a walk under some trees in the park.

That may not be the exact prescription of your doctor, but a first-of-its-kind study shows that visitors to urban parks use happier words and express less negativity on Twitter than they did before their visit -- and that their elevated mood lasts, like a glow, for up to four hours afterwards.

The effect is so strong -- a team of scientists from the University of Vermont discovered -- that the increase in happiness from a visit to an outpost of urban nature is equivalent to the mood spike on Christmas, by far the happiest day each year on Twitter.

With more people living in cities, and growing rates of mood disorders, this research may have powerful implications for public health and urban planning.

The new study was published August 20 in People and Nature, an open-access journal of the British Ecological Society.

GREEN MATTERS

For three months, a team of scientists from the University of Vermont studied hundreds of tweets per day that people posted from 160 parks in San Francisco. "We found that, yes, across all the tweets, people are happier in parks," says Aaron Schwartz, a UVM graduate student who led the new research, "but the effect was stronger in large regional parks with extensive tree cover and vegetation." Smaller neighborhood parks showed a smaller spike in positive mood and mostly-paved civic plazas and squares showed the least mood elevation.

In other words, it's not just getting out of work or being outside that brings a positive boost: the study shows that greener areas with more vegetation have the biggest impact. It's notable that one of the words that shows the biggest uptick in use in tweets from parks is "flowers."

"In cities, big green spaces are very important for people's sense of well-being," says Schwartz; meaning that efforts to protect and expand urban natural areas extend far beyond luxury and second-tier concerns -- "we're seeing more and more evidence that it's central to promoting mental health," says Taylor Ricketts, a co-author on the new study and director of the Gund Institute for Environment at UVM.

In recent years, "a big focus in conservation has been on monetary benefits -- like: how many dollars of flood damage did we avoid by restoring a wetland?" Ricketts says. "But this study is part of a new wave of research that expands beyond monetary benefits to quantify the direct health benefits of nature. What's even more innovative here is our focus on mental health benefits -- which have been really underappreciated and understudied."

MEASURING HAPPINESS

The new study relied on the hedonometer. This online instrument -- invented by a team of scientists at UVM and The MITRE Corporation, including Chris Danforth and Peter Dodds, professors at UVM's Complex Systems Center and co-authors on the new study -- has been gathering and analyzing billions of tweets for more than a decade, resulting in numerous scientific papers and extensive global media coverage. The instrument uses a body of about 10,000 common words that have been scored by a large pool of volunteers for what the scientists call their "psychological valence," a kind of measure of each word's emotional temperature.

The volunteers ranked words they perceived as the happiest near the top of a 1-9 scale; sad words near the bottom. Averaging the volunteers' responses, each word received a score: "happy" itself ranked 8.30, "hahaha" 7.94, and "parks" 7.14. Truly neutral words, "and" and "the" scored 5.22 and 4.98. At the bottom, "trapped" 3.08, "crash" 2.60, and "jail" 1.76. "Flowers" scored a pleasant 7.56.

Using these scores, the team collects some fifty million tweets from around the world each day -- "then we basically toss all the words into a huge bucket," says Dodds -- and calculate the bucket's average happiness score.

PARK POSITION

To make the new study, the UVM team fished tweets out of this huge stream -- from 4,688 users who publically identify their location -- that were geotagged with latitude and longitude in the city of San Francisco. This allowed the team to know which tweets were coming from which parks. "Then, working with the U.S. Forest Service, we developed some new techniques for mapping vegetation of urban areas -- at a very detailed resolution, about a thousand times more detailed than existing methods," says Jarlath O'Neil-Dunne, director of UVM's Spatial Analysis Laboratory in the UVM Rubenstein School of Environment and Natural Resources and a co-author on the new study. "That's what really enabled us to get an accurate understanding of how the greenness and vegetation of these urban areas relates to people's sentiment there."

"This is the first study that uses Twitter to examine how user sentiment changes before, during, and after visits to different types of parks," says Schwartz, a doctoral student in the Rubenstein School and Gund Institute graduate fellow. "The greener parks show a bigger boost."

Overall, the tweets posted from these urban parks in San Francisco were happier by a dramatic 0.23 points on the hedonometer scale over the baseline. "This increase in sentiment is equivalent to that of Christmas Day for Twitter as a whole in the same year," the scientists write.

THE CAUSE OF AFFECT

"Being in nature offers restorative benefits on dimensions not available for purchase in a store, or downloadable on a screen," says UVM's Chris Danforth, a professor of mathematics and fellow in the Gund Institute. He notes that a growing body of research shows an association between time in nature and improved mood, "but the specific causal links are hard to nail down."

The team of UVM scientists consider several possible mechanisms through which urban nature may improve mental health, including Green Mind Theory that suggests that the negativity bias of the brain, "which may have been evolutionarily advantageous -- is constantly activated by the stressors of modern life," the team writes.

"While we don't address causality in our study, we do find that negative language -- like 'not,' 'no,' 'don't,' 'can't,' -- decreased in the period immediately after visits to urban parks," says Danforth, "offering specific linguistic markers of the mood boost available outside." Conversely, the study shows that the use of first-person pronouns -- "I" and "me" -- drops off dramatically in parks, perhaps indicating "a shift from individual to collective mental frame," the scientists write.

Of course, Twitter users are not a representative sample of all people -- just who are the "twitter-afflicted" (as Adam Gopnik wrote in a recent issue of the New Yorker) who pick up their phone to tweet from a park? Still, Twitter users are a broad demographic, earlier research shows, and this approach to near-real-time remote sensing via Twitter posts -- not based on self-reporting -- gives a new window for scientists onto the shifting moods of very large groups.

The nature of happiness has been pondered by philosophers for centuries and studied by psychologists for decades, but this new study suggests it might be as clear as that: in nature, people tend to be more happy -- and that's a finding "that may help public health officials and governments make plans and investments," says UVM's Aaron Schwartz.

https://www.sciencedaily.com/releases/2019/08/190820081859.htm

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