Type 2 Diabetes Causes
Genetics and Lifestyle Choices Play a Role
Type 2 diabetes has several causes: genetics and lifestyle are the most important ones. A combination of these factors can cause insulin resistance, when your body doesn’t use insulin as well as it should. Insulin resistance is the most common cause of type 2 diabetes.
Genetics Play a Role in Type 2 Diabetes
Type 2 diabetes can be hereditary. That doesn’t mean that if your mother or father has (or had) type 2 diabetes, you’re guaranteed to develop it; instead, it means that you have a greater chance of developing type 2.
Researchers know that you can inherit a risk for type 2 diabetes, but it’s difficult to pinpoint which genes carry the risk. The medical community is hard at work trying to figure out the certain genetic mutations that lead to a risk of type 2.
Lifestyle Is Very Important, Too
Genes do play a role in type 2 diabetes, but lifestyle choices are also important. You can, for example, have a genetic mutation that may make you susceptible to type 2, but if you take good care of your body, you may not develop diabetes.
Say that two people have the same genetic mutation. One of them eats well, watches their cholesterol, and stays physically fit, and the other is overweight (BMI greater than 25) and inactive. The person who is overweight and inactive is much more likely to develop type 2 diabetes because certain lifestyle choices greatly influence how well your body uses insulin.
Lifestyle choices that affect the development of type 2 diabetes include:
- Lack of exercise: Physical activity has many benefits—one of them being that it can help you avoid type 2 diabetes, if you’re susceptible.
- Unhealthy meal planning choices: A meal plan filled with high-fat foods and lacking in fiber (which you can get from grains, vegetables, and fruits) increases the likelihood of type 2.
- Overweight/Obesity: Lack of exercise and unhealthy meal planning choices can lead to obesity, or make it worse. Being overweight makes it more likely that you’ll become insulin resistant and can also lead to many other health conditions.
That combination of factors—genetic susceptibility and lifestyle choices—leads to insulin resistance. If your body is insulin resistant, it doesn’t use insulin properly.
Your body may produce enough insulin to transport the glucose to the cells (you can read more about how insulin works in our article on insulin
), but unfortunately, the body resists that insulin.
Glucose builds up in the blood when you are insulin resistant, leading to the symptoms associated with type 2 diabetes.
In type 2 diabetes, genetics and lifestyle play a role in causing your body to become insulin resistant.
Type 2 Diabetes Isn’t Always Caused by Insulin Resistance
Insulin resistance is the most common cause of type 2 diabetes, but it is possible to have type 2 and not be insulin resistant. You can have a form of type 2 where you body simply doesn’t produce enough insulin; that’s not as common. Researchers aren’t sure what exactly keeps some people from producing enough insulin, but that’s another thing they’re working hard to figure out.
Type 2 Risk Factors
- American Diabetes Association. Standards of Medical Care in Diabetes—2009. Diabetes Care. 2009;32:S13-61.
- Becker G. Type 2 Diabetes: An Essential Guide for the newly Diagnosed. 2nd ed. New York, NY: Marlowe & Company; 2007.
- McCulloch D. Patient information: Diabetes type 2: Overview. UpToDate Web site. January 30, 2009. Available at: http://www.uptodate.com/patients/content/topic.do?topicKey=~n0K0MIfI1iZs.&selectedTitle=5~150&source=search_result. Accessed April 20, 2009.
- McCulloch D. Patient information: Diabetes mellitus type 2: Overview. UpToDate Web site. December 4, 2008. Available at: http://www.uptodate.com/patients/content/topic.do?topicKey=~X0jjLnBn4._ko&selectedTitle=4~150&source=search_result. Accessed April 20, 2009.