If you want to know your risk of developing Type 2 diabetes, you're better off walking through your neighbourhood than looking inside your fridge.
A study published yesterday in the Archives of Internal Medicine found that people who live in neighbourhoods that support physical activity and healthy diets were 38 per cent less likely to get the disease than their counterparts who reside in unsupportive environments.
Diabetes, a condition in which your blood glucose (sugar) is higher than it should be, occurs when the body's pancreas doesn't secrete enough insulin - the hormone that clears sugar from the blood - or cells don't use insulin properly.
More than two million Canadians have diabetes, a number that's expected to rise to three million by the end of this decade. (The vast majority of people with diabetes have Type 2.) Despite the epidemic of Type 2 diabetes, the disease is largely preventable though physical activity, healthy eating and controlling weight.
Observational studies have linked the increase in diabetes to changes in our environment. We rely on cars to take us - and our kids - everywhere. Many of us live in suburbs so spread out that biking or walking to work, school, or the grocery store isn't an option.
What's more, highly processed and fast foods are more accessible than fresh produce and whole grains.
In the current study, researchers classified 2,285 adults, aged 45 to 84 years, by the degree to which their neighbourhood supported physical activity and healthful foods. Residents were asked if it was "pleasant" and "easy" to walk in their neighbourhood and if there were nearby exercise facilities.
They were asked if a large, high-quality selection of fruits, vegetables and low-fat foods was available in their neighbourhood. (Neighbourhood was defined as "the area within a 20-minute walk, or about a mile, from your home.")
After five years of follow up, 233 participants were diagnosed with Type 2 diabetes. Those who lived in a neighbourhood with the highest score for physical activity and healthy foods were 38 per cent less likely to develop Type 2 diabetes than those who lived in an area that scored poorly - even after accounting for socioeconomic factors as well as diet and exercise habits, family history of diabetes and alcohol intake.
This isn't the first time a person's neighbourhood has been linked to poorer health. Earlier this year, a study from the University of Alberta suggested that your "Retail Food Environment Index" (RFEI) is a good predictor of whether you will end up obese.
To calculate your RFEI, add up the number of fast-food restaurants and convenience stores within 800 metres (half a mile) in any direction from your home. Think McDonald's, KFC, Wendy's, 7-Eleven, gas-station food marts and so on.
Then, divide that number by the number of grocery stores and produce vendors in your neighbourhood. (The RFEI of my home in Toronto is 1.0.) The study revealed that among 2,900 Edmonton residents, the odds of being obese was significantly lower if they lived in an area with the lowest RFEI (below 3), and greater if they lived in a neighbourhood with a RFEI of 5 or higher.
Researchers from the University of Utah also found that residents of Salt Lake City who lived in neighbourhoods built before 1950 were leaner than people who lived in more modern communities.
Older neighbourhoods were thought to protect from obesity because they were built with pedestrians - not cars - in mind. They had more trees, more sidewalks, more intersections, and offered a pleasant walking environment.
Such findings suggest it may be possible to halt and reverse the epidemics of obesity and Type 2 diabetes by modifying the environment in which we live. This is a good long-term public-health strategy, but it won't protect you in the meantime.
If you live in a so-called "obesogenic" neighbourhood, Type 2 diabetes is not inevitable. While the temptation of fast food at every corner might threaten your willpower, the following strategies can help guard against diabetes.
Eat at home
Commit to eating more meals at home where you have control. Plan meals in advance to avoid relying on take-out and restaurant meals. On the weekend batch cook soups, casseroles, pasta sauce or chili and freeze for busy weeknights.
Choose low glycemic
Studies suggest that a diet based on foods that raise blood glucose slowly, ( low glycemic foods) reduce the risk of Type 2 diabetes.
At meals, include low-glycemic carbohydrates such as beans, lentils, nuts, brown rice, sweet potatoes, steel-cut or large-flake oatmeal, oat bran, Red River cereal and psyllium-enriched cereal (e.g. Kellogg's All Bran Buds). Low GI fruits include apples, oranges, peaches, pears and berries.
Processed and refined foods such as white bread, instant rice, refined breakfast cereals, cereal bars and sweets have a high GI and cause sharp rises in blood sugar and insulin.
Lose excess weight
Excess body fat around the abdomen is linked with insulin resistance, a risk factor for diabetes.
Large studies conducted in people with impaired fasting glucose have demonstrated that losing as little as 7 to 10 per cent of body weight - along with walking - can dramatically reduce the risk of developing full-blown diabetes. (Impaired fasting glucose occurs when your fasting glucose is higher than normal but not high enough to be diagnosed as diabetes.) Get moving. If possible, walk whenever you can - get off the bus early, park at the back of the lot, walk part way to work, or take the dog for a long stroll. Use a pedometer - aim for 10,000 steps a day.
If your neighbourhood isn't walking-friendly, consider other ways to be active daily. Use the stairs instead of the elevator, even if only part way. Ride a stationary bicycle while watching TV or consider joining a sports team.
Leslie Beck, a Toronto-based dietitian at the Medcan Clinic, is on CTV's Canada AM every Wednesday. Her website is lesliebeck.com .
Leslie Beck