Why should we become more engaged in civil society? For health, that's why!

I am an intense believer in the social determinants of health and looking at health problems through a social-ecological lens (i.e. determinants of health exist at multiple social levels of influence and are not just attributable to the individual or to the healthcare system). I think this is why I’ve also gotten incredibly interested in politics – from this perspective, government policies can influence population and environmental health.  An interesting social determinant of health, social capital, has made me realize how we as individuals can collectively make a difference in shaping the quality of our shared spaces, and potentially overall community health – through influencing policies and working with government.

Social capital, a concept originating from the work of Robert Putnam, among others, embodies the norms of reciprocity (gift giving with the expectation of receiving), social and civic participation and trust in society. Another, complimentary view is that social capital refers to the network of social relationships that provide access to resources. Regardless of the definition, when you have more of these things you have more social capital (sometimes called cohesion). Although both definitions are relevant, I am speaking more to the former definition in the discussion that follows.

Richard Wilkinson was the first to introduce social capital to studies on health. He found that societies that are more socially cohesive, with smaller income gaps (more egalitarian) have higher life expectancies and lower infant mortality rates. Other authors have found that societies with higher levels of income inequality and lower social cohesion have higher levels of crime and violence and higher mortality rates. At a more local level, it has been found that residents who are more involved in the community tend to be happier where they live, regardless of the physical quality of their homes.  Some studies have even found that as the level of social cohesion in an area increases, the prevalence of obesity decreases. 

Social capital is complex – these studies show how it may influence health. An obvious explanation is that it improves the quality of our immediate social and physical environments, as well as society at large. One caveat is that social capital itself can be shaped by many different factors operating at many different levels of social organization (e.g. at the neighbourhood/community, region, province, and country level), which thus impacts the quality of our spaces. Social capital therefore, is not a one-way street, rather an intricate web of interaction.

Open space in question, complete with dog

    

My plan is to add to social capital and hopefully improve the quality of my neighbourhood, by becoming more civically engaged. I’ve read a lot lately about how greenspace can potentially be beneficial for mental and physical health, and how it is also good for the environment (I have blogged a bit about this too). I enjoy being outdoors in natural areas – it makes me happy – and I also have a dog, with no back-yard.  Unfortunately there are no dog parks or interesting greenspaces within walking distance of my home.  I often take my dog to an open space close by. It’s a piece of land that separates two suburban neighbourhoods, with trees and a man-made marsh that was constructed to deal with street water runoff. Other neighbourhood residents also bring their dogs, kids toboggan down the banks of the marsh in the winter, and residents of houses bordering the space often use it as their personal dumping ground (a pet-peeve of mine discussed in a previous post). There is no landscaping and the space is never maintained.

Neighbours like to use it as their own personal dump

I would really like to have this space converted into a dog-friendly park (that is maintained), with perhaps a community composter (since everyone dumps their s**t anyway), and even a community vegetable garden. Although, my partner brought to my attention that probably dog parks and food don’t mix – I’ll have to think the vegetable garden through a little bit more…

I really had no idea how to go about making this happen until I read an interesting post on the City of Gatineau’s website:  

“Ville de Gatineau is revising its land use and development plan. Would you care to share your thoughts about how your neighbourhood or the city should develop? This is the time! This revision will extend over three years, with meetings scheduled to start this spring!”

This first meeting for my area is this June the 6^th. I plan to go to see how I can voice my ideas and connect with others who may share my view and/or be able to help me. This will be the first time (other than voting in various elections) that I am involved in the running of my community. I’ll keep you updated as to how this pans out. And I urge everyone else to do the same. Finally, I will not be a hypocrite, especially with respect to my own research!  

      

Leal C, & Chaix B (2011). The influence of geographic life environments on cardiometabolic risk factors: a systematic review, a methodological assessment and a research agenda. Obesity reviews : an official journal of the International Association for the Study of Obesity, 12 (3), 217-30 PMID: 20202135

Home cookin', leftovers, and your health

CC image: Kathleen Franklin

Home cooking is where it’s at. In my view, getting people to cook at home with wholesome foods is one way to combat the obesity epidemic.  And of course, home cooked meals *can* taste great; that’s chef-dependent of course. Foods prepared outside of the home are higher in calories, fat, and sodium, and a recent meta-analysis found that children and adolescents who eat shared family meals at least 3 times per week are less likely to be overweight or eat unhealthy foods than children who eat fewer shared meals. There are two main problems with home cooking, aside from the multitude of barriers to actually being able to cook (e.g. time/work schedule, knowledge and skills). Rather, these are outcomes of cooking that I will discuss based on a recent experience.

First, we waste a whole lot o’ food. Research in the UK has shown that 2.2 million tonnes of food is thrown away due to cooking, preparing, or serving too much. That’s just food that we’ve managed to work with – it doesn’t include fresh produce, meats/fish, dairy, etc. In the US, 30% of all food is thrown away each year.

All of this waste is obviously costly, as we’re paying for food that we don’t eat. In the case of the US, this amounts to US$48.3 billion! But food waste is also harmful to the environment. Rotting food releases methane, one of the most potent greenhouse gases. A UK research group estimates that if food were not left to rot in landfills, this would be the greenhouse gas equivalent of removing 1 in 5 cars from the road.  And we can’t forget all of the fertilizers, pesticides, and energy going into growing/raising food that we just toss into the trash.

Okay, home cooking is great but waste is bad. What do we do? Eating your leftovers is one way to get the best of both worlds. Hang on though, leftovers need to be handled and stored properly in order to avoid illness. I have a dietetics bachelor’s degree but am the worst for food safety (probably because more often than not I don’t get sick). I’m the one that leaves the ham sandwich in the car in 30 degree weather (that’s Celsius) all day and then eats it unperturbed on the way home from work.  Or leaves a defrosting tenderloin on the top shelf in the fridge or even out on the counter for the entire day (both no-no’s).

 But the other day, I did get sick – not badly mind but enough to make me realize that food safety does matter if I want to avoid having to take a day off of work. My significant other thought he was doing a service (which he was) by bringing home leftovers from a conference at work. It was some sort of pasta with a béchamel sauce and chicken.  We reheated it in the microwave at home and ate about half of what was brought home. The next day, we both could not stray too far from the toilet…This was no coincidence – same symptoms and the pasta was the only thing we had in common for the previous 24 hours. We threw the rest of it out.

So what went wrong? I can’t say for sure because there are so many things that could have happened, but I’ll touch on a few here. It’s hard for bacteria to grow in foods that are held at temperatures less than 4°C (40°F) or more than 60°C (140°F) – in between is called the ‘danger zone’. When serving prepared hot foods, like this pasta dish, it is imperative that the food be above 60°C. Additionally, time is a factor. Food left out for more than 2 hours is more prone to bacterial contamination. Perhaps the pasta was held in this danger zone – something that caterers should know to avoid, or not thrown out after 2 hours.  My partner may have also taken the pasta and unknowingly left it out for too long. Reheating the pasta at home didn’t seem to do anything. The Canadian Food Inspection Agency (CFIA)  recommends reheating leftovers to 75°C – maybe we didn’t hit that mark.   

  

When other people make your food there is always the possibility that they didn’t adequately wash their hands, or use clean serving utensils or pots/containers. That’s something out of your control but you can ensure that you do these things when you make your own food.  

Other ways to deal with leftovers to prevent illness: 

• Put hot leftovers in shallow containers and place immediately in the fridge. Really hot items can be left out for a bit then put in the fridge after the steam stops. Leave lids off or wrap loosely until food becomes fridge temperature (to avoid explosions)
• A great way to keep leftovers is to freeze them
• Eat leftovers left in the fridge (as opposed to the freezer) within 2 to 3 days
• Throw out uneaten leftovers - i.e. once reheated, don’t keep the left over leftovers
• Thaw frozen leftovers in the fridge or microwave. This is something I need to think about doing – I always thaw my soup at room temperature
• Never refreeze thawed leftovers – they should be eaten or thrown out  
• When reheating leftovers, stop the microwave half-way through and stir the dish in order to ensure even heat distribution (we didn’t do this with the pasta dish)
• The CFIA recommends using a digital thermometer to check food temperatures but I don’t really see this as something that I would do let alone the general public. Maybe… if I get sick again….
• And finally, when in doubt, throw it out!

The more we cook at home, the better for our health. But sometimes we cook too much. Instead of throwing out food, which is bad for the environment and our pocketbooks, think ‘leftovers for lunch’ and perhaps even for a second dinner. But be mindful of how you handle, store, defrost, thaw, and reheat leftovers. 

Other great resources include:

The Food Safety Network http://www.foodsafetynetwork.ca/aspx/public/default.aspx

United States Department of Agriculture: Food Safety and Inspection Service http://www.fsis.usda.gov/factsheets/safe_food_handling_fact_sheets/index.asp

Love Food Hate Waste: tips for reducing household food waste http://www.lovefoodhatewaste.com/

Hammons AJ, & Fiese BH (2011). Is Frequency of Shared Family Meals Related to the Nutritional Health of Children and Adolescents? Pediatrics PMID: 21536618

Quested T, & Johnson H (2009). Household Food and Drink Waste in the UK WRAP

Part 2 Building Design: Fooling people into taking the stairs

I just got back from a conference in Montreal – one on obesity at that. The hotel, the location for the conference, held sessions on floors 1-4 and on sub floors below the lobby – ample opportunity to use the stairs.  There were two main problems: 1) the stairs were confusing – you’d get up to one floor but then couldn’t find the next set of stairs to the next floor and have to walk quite a distance to get to them; and 2) there were escalators in between these floors in plain sight from the main floor lobby, somewhat easy to navigate, and were a brilliant, flashy gold colour. I, more often than not, took the flashy-fancy escalators. 

In my last post, I reflected on how easy it is to be physically inactive nowadays and went on to discuss point-of-decision prompts as a way to get people to use the stairs instead of escalators or elevators. These prompts appear promising, but what if buildings are not designed to make taking the stairs easier or enjoyable, such as was the case at the obesity conference? To answer this, in today’s post I will discuss the recommendations provided by New York City’s Active Design Guidelines to make buildings enjoyable places to walk – and some instances make walking the more convenient form of transportation. The guidelines were developed based on the best available evidence in the literature, as well as on current best practices in architecture and design. So keep in mind that even though these are recommendations there is no guarantee that they’ll work to increase physical activity.  At the same time however, they have direct synergies with sustainability, such as decreasing electricity and building material use (so, in my opinion, are at least worth considering).

There are three main categories of building design recommendations that I’ll touch on in my discussion below: 1) Elevators and escalators; 2) stairs; and 3) supportive design elements. I think that the more recommendations implemented, the more likely that building design will be successful at increasing the physical activity levels of its users.    

Design of elevators and escalators

Mechanized options for travel between floors should be designed to be hard to find, or at least less prominent (not the case for the escalators at my conference). Decreasing their speed can make them less efficient than walking, and save on electricity. Installing the minimum number of elevators required by building codes could also decrease efficiency by increasing volume of users. Other ways to make elevators less efficient than walking include programming them to:

• Be skip-stop (they don’t stop on every floor so you have to get out and walk up a floor);
• Open at each floor (this may not make sense in buildings with 30+ floors);
• Open and close very slowly (which is beneficial for persons with disabilities) 

Design of stairs

Stairs should be the main attraction. They should be visible from the lobby and elevators, and always located close to building occupants (i.e. office areas). One way to draw attention to them is to put the lobby of the building on the second floor, accessible from the ground floor via a grand staircase, with elevators accessible only at the lobby (meaning people have to use the stairs to access the elevators). Point-of-decision prompts can also help (as I discussed in Part I).  A great example of making stairs interesting -maybe a bit extreme and perhaps not sustainable, but cool nonetheless- is the piano stairs:  

Additionally, stairs should:

• Open to and be accessible at each floor (no locked doors);
• Be seen – if stairwells are a must they should be transparent;
• Receive large amounts of natural light;
• Be well ventilated

Canadian Museum of Nature, Ottawa (ON): CC images Michelle Hotchin

In order to improve the overall experience, stairs themselves should be designed for comfort, aesthetics, safety, and ease of maintenance. Art and articulated and unique stair composition can increase interest. Balustrades, handrails and landings can provide architectural points of interest, especially for grand staircases. Floor finishes should be slip resistant and colour or textural contrasts can be used to increase safety. Step height should be comfortable for small children (i.e. not too high), and staircases should be wide enough for groups traveling in opposite directions to safely pass. Finally, stairs should be easy to maintain. Long lasting materials should be chosen that are easy to clean and discourage vandalism or graffiti.   


   

Cooper Union New Academic Building, New York, NY: CC images

Supportive design elements

There are some things that can be included in building design that make being physically active easier and more enjoyable. Change rooms and showering facilities are big ones for me. My work building currently does not have one. I figured it would be quite easy to add a shower – one for men and one for women and no need for change rooms as our washrooms are so large. No dice though, my request was immediately shut down by my organization – citing no money. Always the excuse. I plan to press the issue. Bike parking and storage are also important. In NYC, several laws have been enacted that mandate certain buildings and facilities provide bicycle parking or other accommodation for cyclists. Storage can also prevent damage to building interiors when bikes are brought inside, and also prevent nasty notes from being sent to you when you forget your bike lock. 

Design of building exteriors should also have the pedestrian/cyclist in mind and interestingly can influence building users and non-users alike. Here are a few examples that can enliven, and improve the comfort/convenience and safety of the streetscape:

• Reducing set-backs (space between the road and building) and providing multiple entry points 
• Adding awnings or canopies (to provide shelter from the weather)  
• Porches, stoops, and terraces can add to the social environment and provide ‘eyes on the street’ 
• Paying attention to nearby parks, open spaces and public gathering areas so that the building does not adversely affect them (e.g. minimizing the cast of building’s shadow, and the potential for creating unpleasant wind conditions)

Building in New Orleans (LA): CC image

The design of public buildings (including point-of-choice prompts) has the potential to not only increase physical activity, but also to vastly improve the quality of our shared spaces. Perhaps residential spaces could also be designed to promote physical activity and reduce sedentary behaviour. The hard part is that people generally choose what they live in and where they live.  It is my hope that more and more researchers examine how design of our spaces (from houses to cities) may influence not only obesity but overall health, with high quality epidemiological methods - something that is currently lacking.              

Bloomberg MR, Burney D, Farley T, Sadik-Khan J, & Burden A (2010). Active Design Guidelines: Promoting Physical Activity and Health in Design City of New York

Part 1: Building design to increase physical activity

We all know that we are not getting enough physical activity these days. In fact, 52% of Canadian adults 20 years of age or older are considered inactive, and 88% of children aged 5-19 years don’t meet Canada’s physical activity guidelines. It’s one out of many reasons why the prevalence of overweight and obesity is so high. But physical activity has other health benefits, in addition to staving off obesity and cardiovascular disease, such as reducing stress and improving concentration, promoting correct physical growth in children, and maintaining mobility and independence in the elderly. 

The problem is that it’s just too easy to be physically inactive.  Our society has, for all intents and purposes, engineered physical activity out of the built environment – important, especially when you consider that schools and many jobs require us to be sitting for most of the day to begin with.  Take for instance stair climbing; it is a great means of increasing cardiovascular output, but the need for it has all been eliminated by the design of modern buildings.  Escalators and elevators are easy to access and do the work for us, but are energy guzzlers - elevators account for 3-10% of a building's energy uses. Stairs, our healthy and environmentally friendly benefactor, are difficult to find, often ugly and dark, and sometimes invite anti-social activity. It’s no wonder people don’t use them.

Can we design public buildings then to increase physical activity? This is a burgeoning area of research with evaluation studies still lacking. In the next post, I’ll discuss some recommendations made by the City of New York in their Active Design Guidelines, based on the best available evidence and best practices.  However, I’d like to discuss here point-of-decision prompts as a way to get people to use the stairs instead of escalators and/or elevators – a bit different than design per se but related and still very relevant and interesting.  I was actually pleasantly surprised to see that there was a large enough body of research to warrant a systematic review on the subject.

Motivational sign from Kino Québec (not sure why the guy is blue).  More info is available at: http://www.kino-quebec.qc.ca/marche/promotions.asp 

This very recent systematic review was published in the Scandinavian Journal of Public Health in 2010 and included 25 studies that examined the role of posters (n = 16), stair-rise banners (n = 5), both (n =4), or posters and floor graphics (n = 1) in helping people decide to take the stairs versus elevators (n = 8) or escalators( n = 18).  The majority of studies were conducted in public transit stations (e.g. train, bus, airport), shopping malls, or office buildings.  All used the interrupted time-series design (before-after where the ‘before’ sample does not necessarily contain the same individuals as the ‘after’ sample).               

Of the 42 comparisons (more than one comparison often conducted in a study), 31 reported modest but significant increases in stair climbing, 10 reported no association, and 1 reported an inverse association. The non-significant results were more likely to be reported by studies examining stairs versus elevators. There were no consistent differences between men and women. Of the significant studies that calculated odds ratios, those in favour of the intervention ranged from 1.05 – 2.93. Results appear promising with perhaps more work to be done to get people to use stairs instead of elevators versus escalators.  

Motivational sign from NYC Active Design Guidelines

There are some important things to keep in mind about this review and the included studies:

• Follow-up times were fairly short (at most 6 months). Some studies found that stair climbing decreased back to baseline over time (I guess as the novelty wore off)  
• I’m not certain as to how denominators were calculated at the ‘point-of-decision’. This was not discussed in the review but likely easy to find out by accessing individual articles  
• Only studies that looked at stair ascent were included. I think descent is equally important  
• It’s not readily apparent which messages and/or mediums work best 
• The same authors conducting different studies make up a large proportion of the included studies. This appears to happen in 4 instances and amounts to 16/25 studies.  This increases the likelihood of a bias occurring in one study being replicated in another, and both (or in some cases 6) being included in the review 
• Finally, as I alluded to earlier, the study designs are methodologically weak. The authors of the review recommend a control-site but comment on the difficulties of making this happen in practice.  In my opinion, stronger designs are more difficult in public transit buildings and malls – but feasible in office buildings (e.g. randomizing buildings and following the same people within each building). 

Point-of-decision prompts look like promising ways to get people to take the stairs (another review came to similar conclusions) but I think that more high quality research is warranted.  Additionally, what if point-of-decision prompts were accompanied by changes in actual building design? You’ll have to read my next post to find out. Stay tuned.

Nocon M, Muller-Riemenschneider F, Nitzschke K, & Willich SN (2010). Increasing physical activity with point-of-choice prompts -- a systematic review Scandinavian Journal of Public Health, 38, 633-38

Battle of the bike lanes - in NYC and now Ottawa-Gatineau?

Hat tip to Atif who brought this story to my attention this past November.  Over the last three years the Bloomberg administration has created over 200 miles of bike lanes and passed several bicycle friendly laws. This has been to the detriment of infrastructure supporting car use. To me, this is great news but to others that have a special attachment to their cars, or fear delivery trucks won’t be able to make their morning deliveries, this is terrible news. A similar story is starting to unfold in Ottawa; a ‘not-in-my-backyard’ mentality.

There is a war raging now in New York City – over bike lanes

In NYC, vocal opposition by drivers and elected officials has led to the removal of newly established bike lanes in Brooklyn and on Staten Island – lanes that communities originally wanted after extensive public consultation.  It seems that in the US, if you don’t agree with the government and don’t get your way, then you sue (if you have the means that is). That’s precisely what’s happening in New York City. A bike lane along Prospect Park West, a road forming the boundary between the Prospect Park and the well-to-do neighbourhood of Park Slope, is at the centre of a lawsuit brought on by wealthy, well-connected Brooklyn residents. According to the Times, almost three quarters of Park Slope residents are in favour of the bike lane; however this drops to 50% of residents who live along Prospect Park West, prime real-estate that overlooks the park.

A nice butt shot of me on one of NYC's off-road bike lanes

Opponents have cited many faults by the DOT - erroneous, misleading statistics, lack of transparency and public consultation, sub-par design, reduced room for cars, reduced safety, to name a few.  As reported by the Times, room for the legal complaint to be made stems from a state statute that allows challenges to government actions considered to be arbitrary or unfair. Nowhere do I see these two requirements being met by bike lane opponents. It just seems like a complaint against changing the status quo and making life slightly less convenient.

From an overall perspective, DOT statistics show that bicyclist fatalities and crashes in NYC have decreased almost 19% from 2006 to 2010, with the number of cyclists doubling from 2006-2010, and increasing 13% from 2009-2010. However, I did not come across stats on percentage of mode share (although this is likely premature as I discuss below). For Prospect Park specifically, DOT reports that crashes involving injuries are down 63%, speeding by cars is down from 75% to 20%, and cycling on the sidewalk is down 80%. Area residents and users of the lane also report feeling safer. Opponents, however, feel that the numbers have been deliberately 'fudged'. As reported by TransportationNation, the lawyer of the group filing the lawsuit stated:

“Everyone should be concerned about DOT’s misuse of the data. Everyone. This case is about a government agency wrongfully putting its thumb on the scale by fudging the data and colluding with lobbyists. That is not what ‘public integrity’ means. Some people on both sides of the issue are affluent and have political connections. So, the continuous, one-sided name-calling is hardly appropriate. But, more importantly, it keeps people from focusing on the real issue in the case, which I suspect is the true aim.”

Clearly an independent third party needs to evaluate use and safety of biking infrastructure if these statistics are to be believed. At the same time, new biking infrastructure will take some getting used to (by users and non-users alike) and time to increase awareness in the general NYC community (to increase the number of users), so an in-depth evaluation right away, in my mind, is premature. Additionally, it’s pretty hard to argue with people who think that a bike lane is a terrorist plot. I am truly amazed and saddened by this on-going saga. I mean they are bike lanes after all – meant to reduce congestion and greenhouse gas emissions, and increase safety for all…  

Some debris left in a NYC bike lane; Creative Commons Image  

Foreshadowing for Ottawa-Gatineau?

Certainly, the biking infrastructure in the Ottawa-Gatineau area is not quite as extensive and the proposed plan to create a segregated bike lane on Laurier Street has not generated nearly the level of disaccord; however, it’s there. Interestingly more lanes are planned; the National Capital Commission has quietly announced plans to implement a segregated bike lane on Wellington Street.

The idea of implementing biking infrastructure is to make cycling more enjoyable, safe, and convenient, and driving less convenient – ultimately, to change the commuting mode share.  

Complaints in NYC and in Ottawa have some commonalities

Why do all this for only a select few people? Only the hardiest of hardy cycle all the time and that’s not a lot, especially given our winters. Cycling will never catch on:

Well the point is to encourage MORE people to take their bikes instead of their cars. This will take time for people to switch and for infrastructure to keep up with demand. Biking in winter (as well as in the other three seasons) is possible if it becomes the norm – with dedicated bike lanes that are well-connected and maintained throughout all seasons (a colleague of mine has discussed Finland’s meticulously ploughed bike lanes in winter). 

Bike lanes take away parking spots for paying customers:

This is debatable. Cyclists take up much less space than cars and have easier access to stores and shops (along with public transit users). Thus, bike lanes with bike parking have the capacity to bring in more paying customers; previous estimates in Germany and the UK show that pedestrianised areas can increase the number of shoppers by 20-40%.  And an Australian study determined that each square metre of space allocated to cars contributed just $6/h in shopping expenditures, while each square metre of space allocated to bicycles brought in five times as much ($31/h).

A recent Globe & Mail article also highlighted the problem of traffic congestion and excessive commute times potentially affecting the economic performance of urban centres in Canada. The Toronto Board of Trade’s international city rankings on Prosperity, which measures cities on a number of economic, social and structural indicators, put only two Canadian cities in the top 10 overall (Calgary and Toronto); none cracked the top 12 for transportation. Clearly driving, which has the highest mode share in Canada, is not all that efficient.     

If you want more economic convincing, a writer at the Economist makes a good case for bike lanes (in NYC) ‘from an economic perspective;’ which is definitely worth a read.

Some final thoughts

I think that many people are aware that the design of our residential spaces (at least in North America) is not sustainable. By comparison, we are much more slowly piecing together how our commuting/convenience lifestyle may be at least partially to blame for our growing waistlines and associated chronic diseases. Many people say they would like to do something to change but when it comes down to it, they can’t sacrifice the convenience.  I think we all must be willing to try new things and accept some level of inconvenience if we are to put a halt to both environmental degradation and obesity.  At the same time, we need to measure the impacts of these changes to determine how we can do better, and that public money is spent wisely.  Cyclists need to do their part as well: respect pedestrians, the rules of the road, and not assume that pedestrians or motorists will behave in the right/legal/expected way. Finally, bike lanes are not a be all and end all of sustainable transit – the trick will be balancing the needs of all types of active (e.g. biking, walking, & rollerblading) and public (e.g. rail, tram, bus, etc.) transit modes while making driving less desirable.      

WHITEHEAD, T., SIMMONDS, D., & PRESTON, J. (2006). The effect of urban quality improvements on economic activity Journal of Environmental Management, 80 (1), 1-12 DOI: 10.1016/j.jenvman.2005.01.029

Lee, A., & March, A. (2010). Recognising the economic role of bikes: sharing parking in Lygon Street, Carlton Australian Planner, 47 (2), 85-93 DOI: 10.1080/07293681003767785

Is green good for our health?

Is being in a ‘green’ environment good for our health and well-being? Are we starved of this connection with nature? Richard Louv thinks so, author and chairman of the Children and Nature Network.  He has coined the term ‘nature-deficit disorder’ to reflect the psychological, physical and cognitive repercussions of our lack of contact with nature, especially among children in their vulnerable developing years.  Although Mr Louv specifies that this is not a formal diagnosis, I am not in love with the term because I find that it does bring forth this meaning to me. I admit that I haven’t yet read “Last Child in the Woods” (am planning to once the single copy on loan at UO has been brought back finally), but I wanted to investigate the scientific evidence for this idea a little further.  And then discuss, in the grand scheme of things, whether the evidence really matters anyway.

The Child and Nature Network has been busily compiling together the evidence base for nature and health.  While it is important for an advocacy group to do this, I find it somewhat biased from my perspective as an epidemiologist – where are the studies that examined these types of relationships but didn’t find anything? So like any good epidemiologist would do, I set out to look for some systematic reviews and meta-analyses.    

 

Without much looking I came across a recent systematic review that sought to examine studies that compared health outcomes in natural and synthetic environments, usually over a short duration. Twenty-five studies were included, with most being cross-over or controlled trials; although seven were randomized controlled trials. The most common outcomes were scores on various self-reported emotions. This is somewhat problematic in that respondents often can guess what is being studied (especially if it’s a non-randomized cross-over study) and will sometimes adjust their responses. More robust study designs (such as RCTs or at least randomizing order of exposure to each of the environments) can help to mitigate this bias. Other common outcomes included physiological measures such as cardiovascular functioning (blood pressure or pulse), and hormone levels (salivary or urinary cortisol, amylase, and adrenaline). Less common outcomes included immune function, physical activity, motor performance, cerebral brain activity, engagement, memory recall, and sleeping hours. There were too few of these to conduct a meta-analysis so I won’t discuss them further – you can get more info here.

The meta-analysis revealed (see Table 1 above) a possible benefit of natural versus synthetic environments for energy, anxiety, anger, fatigue and sadness. No benefit was seen for more objective measures like blood pressure and cortisol levels. There was a benefit reported for attention before effect sizes were adjusted for baseline levels. Because only 3 out of the 5 attention studies had baseline measures, this may have reduced statistical power, as the effect size decreased only slightly but the confidence interval increased.

Important points to keep in mind:  

·         Most of the included studies were experimental in design and included college students, adult males, or physically active adults – so the overall finding of the meta-analysis is not generalizable to the overall population, or to children 

·         Outcomes were examined over a very short duration. Some beneficial effects may take longer to manifest and/or require repeated or prolonged exposure to the natural environment

·         We’re not sure what exactly in the natural environment is responsible for these beneficial effects. Does this matter?

·         I am a little concerned with regard to the small number of studies, as well as study quality (this was not formally assessed). We may find a different association with a larger number of high quality studies

What does this all mean then? Over the short-term natural environments may reduce negative emotions and improve energy levels but they don’t appear to improve some cardiovascular and endocrine measures of health. Of course, I have to add the requisite last line: ‘more studies of high quality are needed,’ to make any definitive conclusions.         

Now from my own expertise and knowledge, I know that there have been more and more studies conducted to determine how the residential environment influences physical activity and/or obesity. This is a difficult area of research – perhaps why results have been mixed and effect sizes often small in comparison to the effects of individual and family characteristics. As I discussed in a previous post, some of these studies have found a positive association between the availability/amount of green space and the physical activity and obesity levels of area residents (in both adults and children). For the most part however, these have been cross-sectional associations, and overall, findings are not consistent from study to study. Putting this aside, we’re not even sure if it’s the greenery itself or simply the open space that invites people to be more physically active. Certainly greenery adds to the aesthetics and quality of the built environment, and aesthetics, as a general theme, has been previously associated with physical activity and obesity (see my previous post). Who knows though, we’d have to ask people why.       

In summary, the evidence of nature and health isn’t hugely convincing but not dismissive either – it’s there in some form. What we don’t know is whether it’s simply being active and away from our gadgets that helps the most – perhaps it’s not necessarily the ‘nature’ itself. Whether it’s the chicken or the egg doesn’t really matter to me and probably will never be totally discernible. As a society we are much more sedentary then in days gone by, and so it follows, less connected to nature. Green spaces can recycle the harmful outputs of urban living and add to the quality of our living spaces. To me, these two concepts go hand in hand. Paraphrasing a remark made by the artist Robert Bateman that was reiterated by Mr. Louv: if we don’t know about nature, we will be less likely to care for it and do something to preserve it. This is especially important among our children who will be the ones left to take care of the planet. Getting outside gets us physically active and connected to nature. So even though the evidence may not be sound, there is no harm in advancing this issue – it can only improve the quality of our spaces and help to sustain the world for future generations. Perhaps what is needed now are well conducted intervention studies to determine how green spaces can best be designed to maximize health, well-being, and sustainability benefits.  

Bowler DE, Buyung-Ali LM, Knight TM, & Pullin AS (2010). A systematic review of evidence for the added benefits to health of exposure to natural environments. BMC public health, 10 PMID: 20684754