Researchers can’t say for certain that any individual environmental factor directly causes type 2 diabetes, but studies have found links that suggest some factors play a role in its development.
Read on to learn about how environmental factors such as pollution, infrastructure, and access to healthy food may contribute to the development of type 2 diabetes.
How Does the Environment Influence Diabetes?
Type 2 diabetes is believed to result from an interaction of biological, behavioral, and environmental risk factors. Someone’s environment can influence other risk factors. For example, some biological risk factors for type 2 diabetes are abdominal obesity and high blood pressure. Behavioral risk factors include lack of physical activity and regularly eating a diet that contributes to raised blood sugar. Environmental factors such as the layout of a city or the availability of good quality food can contribute to these other risk factors.
On they other hand, an environment that supports healthy lifestyle choices can lessen some of the biological and behavioral risk factors.
Environmental Risk Factors
The measurable totality of environmental (non-genetic) drivers of disease is called “the exposome.” Environmental factors that contribute to the development of health conditions can be divided into classifications such as:
The built environment: The physical space in which we live and work. The social environment: The context in which groups of people live, interact, and form relationships, including socioeconomic position. The physico-chemical environment: Which chemicals or physical agents are present in our local area. The lifestyle/food environment: Includes how accessible, affordable, and available food and food retailers are in the area.
Within these environmental groups, more specific factors can be examined in terms of how they may contribute to type 2 diabetes.
Pollution
There is some evidence that suggests higher air pollution, particularly exposure to nitrogen dioxide (NO2) and particle matter (PM2.5), may contribute to an increased risk for type 2 diabetes.
Air pollution has been shown to change endothelial (cells that line the blood vessels) function, elevate adipose (body fat) and systemic inflammation, and trigger insulin resistance. It is also associated with obesity and high blood pressure. This can contribute to type 2 diabetes risk.
Several meta-analyses have found associations between chemical pollutants (such as persistent organic pollutants, pesticides, and heavy metals) and an increased risk of type 2 diabetes.
Geography
Rates of type 2 diabetes are rising world-wide but are increasing particularly quickly in low and middle-income countries.
Over 60% of the global cases of diabetes are in Asia. The number of people aged 20 to 79 in Asia living with diabetes is expected to increase to approximately 180 million in 2025, compared to approximately 114 million in 2007.
Weather/Climate
Climate change negatively affects people with diabetes in a number of ways, including:
Increased morbidity and mortality, particularly for those with cardiovascular problems Increased dehydration during extreme heat events (people with diabetes are more prone to dehydration) Extreme weather events such as hurricanes and flooding can disrupt food supply (thus limiting healthy food choices) and access to medical care and supplies, including medication production facilities
Access to Healthy Food
When discussing a location’s access to healthy food, two terms are often mentioned:
Food desert: An area without access to healthy food where a person lives Food swamp: An area in which unhealthy food options are more available and accessible than healthy food options
The availability, accessibility, and affordability of healthy food influences dietary habits. One cohort study found that the risk of type 2 diabetes decreased by 37% among those with the highest access to healthy food compared with those with the least access.
Design and Infrastructure
The physical design of the environment in which a person spends the majority of their time can influence factors that impact type 2 diabetes risk.
Walkability
Walkability refers to how conducive and supportive for walking the location is. Some research has found a connection between living in an area with a higher level of walkability and a lower risk of type 2 diabetes. There is currently not enough data to show whether this lowered risk is caused by increased walkability or only associated with it. For instance, people who are more physically active may choose to live in areas with high walkability rather than walkability promoting physical activity.
Green Space
“Green space” describes outdoor areas, such as forests, parks, and nature spots, that have lots of vegetation and are accessible for physical activities like walking.
Three cross-sectional studies found that neighborhoods with more green space had a lower risk for type 2 diabetes. These studies used the quantity of green space rather than quality to assess. One study found the largest benefit was within areas with 40% to 60% green space land use.
Green space is also associated with stress reduction, which benefits blood glucose management.
Active Transportation
Active transportation consists of walking, biking, and other forms of physical activity used to get from point A to point B. Public transportation is sometimes included under active transportation because there is often walking or other physical activity before and after the ride.
People living in areas with higher levels of active transportation exhibit a reduced risk of cardiovascular disease, hypertension, and type 2 diabetes.
One cohort study that followed 8,576 men for four years found a 27% reduction in risk of developing type 2 diabetes in those who walked approximately twenty minutes to work than those who walked for under ten minutes.
Safety, Neighborhood Conditions, and Social Environment
Neighborhoods in which residents feel safe and socially supported, and that are aesthetically pleasing, encourage physical activity.
Research on the specifics of how housing and neighborhood conditions impact the risk for type 2 diabetes has been less clear-cut. More research is needed to determine how factors such as real estate value, population density, crime rates, and physical conditions influence type 2 diabetes risk.
Other Risk Factors
There is no one cause of type 2 diabetes. It is believed to develop from an interaction of genetic and environmental factors.
Risk factors for type 2 diabetes include:
Having family members, particularly a parent or sibling, with type 2 diabetes Being older than age 40 Having extra weight or obesity (particularly around the middle) Being physically inactive Being of African, Asian, Arab, Latino, Hispanic, Indigenous, Pacific Islander, or South Asian descent Having experienced gestational diabetes (diabetes during pregnancy) and/or given birth to a baby who weighed more than nine pounds at birth
Some health conditions can also increase the risk of developing type 2 diabetes, such as:
Prediabetes Insulin resistance High blood pressure High blood levels of cholesterol or other fats Non-alcoholic fatty liver disease Polycystic ovary syndrome (PCOS) Psychiatric disorders (depression, schizophrenia, bipolar disorder) Obstructive sleep apnea Acanthosis nigricans (darkened patches of skin) Being on glucocorticoid medication
Preventable Risk Factors
Many of the risk factors for type 2 diabetes are preventable or modifiable, but that doesn’t mean that avoiding them is easy.
Eating a balanced, diabetes-friendly diet, staying physically active, and achieving/maintaining a weight that is healthy for you are measures you can take that go a long way to lowering your risk of developing type 2 diabetes.
Environmental factors such as income, built environment, etc., are considered modifiable risk factors as well, but they are harder to change on an individual level. Getting involved in diabetes advocacy is one way to help improve the circumstances that lead to these risk factors.
Summary
Type 2 diabetes is believed to be caused by a combination of biological/genetic factors and environmental factors. Aspects of the environment in which we live can affect our risk of developing type 2 diabetes. This includes factors such as pollution, climate, the planning and infrastructure of our neighborhood, and our access to nutritious food options.
Stress can also prompt people to engage in unhealthy lifestyle habits such as smoking or being less thoughtful with their nutrition. This also contributes to an increased risk of type 2 diabetes.
People who experience a lower socioeconomic status often have higher stress levels, making them more vulnerable to existing risk factors associated with socioeconomic status.
A Word From Verywell
While it’s difficult to prevent exposure to all factors that can increase your risk of developing type 2 diabetes, there are some aspects of your environment that may be within your control. If you are choosing a neighborhood to move to, consider the design of the neighborhood, the walkability and amount of green space it offers, and how it may foster or hinder your ability to practice healthy lifestyle habits.
