Walkability & Metabolic Health 🚶
Hey friends, welcome to the March Madness edition of the humanOS newsletter! 🏀
But this newsletter isn't really about basketball (although now that I mention it, studies show that playing team sports has massive benefits for cardiometabolic health - I should probably feature that sometime soon). Actually, this week, I thought we would take a look at how our surroundings affect our risk of developing obesity and metabolic syndrome. We know, of course, that prevalence of obesity has gone up, both globally and in the US. According to the CDC, obesity has risen to 42.4% prevalence among adults, and diagnosed type 2 diabetes has risen to 11.3%(although this is thought to be an underestimation).
The underlying causes of the obesity epidemic are complex and can’t really be pinned on any single factor, which is why it is such a terrible challenge from a public health standpoint. But one influential variable that has been identified is the built environment, meaning the spaces where we live, work, and engage in leisure activities on a day-to-day basis. This can strongly affect levels of physical activity, especially at a population level. For example, living in a place with sidewalks, and which is in reasonably close proximity to work and other amenities, obviously makes it a whole lot easier to walk places rather than drive.
This, in turn, may help mitigate weight gain, and that can blunt some of the downstream metabolic consequences of obesity over time. For instance, we know that insulin resistance often accompanies obesity, which ultimately leads to the development of type 2 diabetes. Additionally, insulin resistance frequently coexists with high blood pressure, perhaps due to the impact of elevated insulin on sodium absorption by the kidneys.
So, how exactly does “walkability” affect this constellation of conditions that make up metabolic syndrome? To learn how the built environment affects insulin resistance, obesity, type 2 diabetes, and hypertension, scroll on down 👇🏻
This Week's Research Highlights
Researchers in Ontario examined data from 1,128,181 adults with normal blood sugar at baseline. The walkability of the neighborhood in which every individual lived was analyzed and they were divided into ten categories based on levels of walkability. After following them for an average of eight years, the researchers found that incidence of pre-diabetes was 20% higher among individuals living in the least walkable areas, compared to the most, after adjusting for age, sex, and income. Pre-diabetes is an important window for intervention, as an estimated 70% of those with prediabetes go on to develop type 2 diabetes, but lifestyle interventions (including walking) can effectively reverse that unfortunate trend.
The same research team examined data on transportation behavior, aspects of the built environment, and health outcomes in Toronto residents between 2003 and 2009. They drew upon the Canada census, a transportation survey, a national health survey and a validated administrative diabetes database, and were able to capture walkability by graphically depicting availability of walkable destinations. They found, unsurprisingly, that individuals in the most walkable areas were more than twice as likely to use public transit or active transportation, compared to those in the least walkable areas. Individuals living in the least walkable areas were 18% more likely to be overweight or obese, and 33% more likely to have type 2 diabetes, compared to counterparts in highly walkable areas.
🚶🏾 Moving from an unwalkable area to a highly walkable neighborhood is linked to lower risk of hypertension.
Researchers examined data from participants in a large Canadian health survey, and linked the survey data to a population-based healthcare database that identified hypertension diagnoses. They defined residential walkability for subjects using a walkability score that was based on walking distances to a diverse set of nearby amenities, including grocery stores, restaurants, schools, etc. From there, they compared otherwise similar individuals who had relocated from a low-walkable area to either a 1) highly walkable area or 2) another low-walkable area. They found that those who had moved from an area of low walkability to a neighborhood of high walkability had a 54% reduced risk of developing high blood pressure, compared to those who moved to a low walkability area.
Random Trivia & Weird News
Quebec native Jean Béliveau went out for a walk one day…and just didn’t stop. He kept going for eleven years, going through 54 pairs of shoes in the process. His unfathomably patient wife waited at home for him. This is purported to be the longest uninterrupted circumnavigation by foot.
Podcasts We Loved This Week
- Mark Mattson: The benefits and science of intermittent fasting. Via STEM-Talk.
- Kevin Hall & Stephan Guyenet: Carbohydrate-insulin model vs the energy balance model. Via Sigma Nutrition Radio.
Products We Are Enjoying
If you are trying to increase levels of physical activity throughout the day - especially if you are not fortunate enough to live in a highly walkable environment - some kind of movement tracker is basically a must. Can’t manage what you don’t measure, right? Pedometers have actually been around since the 1700s, but modern digital activity trackers obviously offer a lot of other benefits, such as heart rate monitoring, as well as a much cooler user interface.
Fitbit has been one of the most popular for quite a while, and it is one that we continue to rely upon here (and of course, you can easily sync your Fitbit data to your humanOS Dashboard for a more complete view of your activity patterns over the course of time).
humanOS Catalog Feature of the Week
Thanks for reading, as always. If you're looking for more health research, be sure to visit with us on Twitter on @humanOS_me.