- Genetics are a significant risk factor in determining whether you develop type 2 diabetes
- Environmental factors, however, are also significant—with factors like your age, weight, and your activity impacting how high your risk is
- Understanding which environmental factors can increase your risk of type 2 diabetes will help you understand which positive behaviours can help you to stay healthy
If you’re attempting to understand more about the risk of developing type 2 diabetes, the internet may be your first port of call. But as much as it can help you diagnose type 2 diabetes, the tangled web of information online can mean it’s easy to get mixed up in the myths and misnomers around the condition, and what causes it.
One of the main questions many people ask is—is type 2 diabetes genetic?
The truth is that genetics is a significant factor, but they are just one of many factors that can increase or decrease your risk of developing type 2 diabetes. Understanding the risk factors that lead to type 2 diabetes can be critical to understanding the condition, and how the decisions you make can drastically reduce its threat.
Can you inherit type 2 diabetes?
When considering the risk factors for type 2 diabetes, you can segment these into two categories: genetic factors and environmental factors.
So is type 2 diabetes genetic? Well, genetic factors do play a significant role. Ultimately, you are at a higher risk of developing type 2 diabetes if someone else in your family has it.
The strong link between genetics and type 2 diabetes was underlined in a 2018 study, which examined over 20 trillion data points to understand which particular changes in your DNA sequence can lead to a higher risk of type 2 diabetes.
What does this mean in reality? To break down the numbers:
- If either parent has type 2 diabetes, the risk of inheritance of type 2 diabetes is 15%
- If both parents have type 2 diabetes, the risk of inheritance is 75%
The other significant genetic factor that impacts your risk of type 2 diabetes is ethnicity. Type 2 diabetes is between two and four times as prevalent in people of South Asian, Black African, or Afro-Caribbean descent.
Why do genetic factors play a significant role? Type 2 diabetes occurs when your body cannot make enough insulin, or the insulin you make is not effective at breaking down glucose. Certain gene mutations, in particular those involved in controlling glucose levels, have been found to be linked with type 2 diabetes.
While the link is small, people carrying more of these gene mutations are at a higher risk.
What about environmental factors?
It’s not all genetics though—while important, they aren’t the only contributing factor to your risk of type 2 diabetes. Not everyone who has a family history of diabetes, or carries these specific gene mutations, will develop type 2 diabetes.
There are a number of environmental factors (factors outside of your genetic makeup) that can contribute to your chances of developing this condition.
For one, your age. People over the age of 40 face a much more considerable risk of developing type 2 diabetes. People of South Asian, Black African, or Afro-Caribbean descent face this greater risk over the age of 25.
Lifestyle factors, however, play a much more significant role.
Your diet is a strong contributor. Being overweight or obese poses a considerable risk, as do connected factors like having an unhealthy diet, being physically inactive, having high blood pressure. Other unhealthy lifestyle choices, like smoking or drinking alcohol excessively, will also contribute.
Having a sedentary lifestyle (spending much of your time sitting—not the same as being physically inactive) will also increase your risk. Whether this is working at a desk throughout the day without moving, sitting or lying down while watching TV or playing video games for hours at a time, or even spending long hours of the day driving.
Other medical conditions may place you at higher risk of type 2 diabetes. Women are at greater risk if they develop gestational diabetes (a type of diabetes that affects pregnant women around the second or third trimester), or Polycystic Ovary Syndrome (PCOS), a condition associated with insulin resistance. There are also a number of mental health conditions that increase your risk, including schizophrenia, bipolar disorder, and depression.
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Tackling the environmental factors
When you get into the details, it can be tricky to distinguish between genetic factors and environmental factors. Often, your family has the biggest impact on your environment—such as your choice of food, the likelihood of you smoking or drinking excessively, or your access to physical exercise—and so it can be hard to separate the two. At the same time, genetics often can play a big factor in determining your overall health, so it’s not always easy to just bin the bad behaviours.
But understanding which environmental risks lead to type 2 diabetes can be a good place to start when considering how to limit your own likelihood of developing the condition. This will help you implement good behaviours towards a healthier lifestyle, which in turn will decrease your risk of type 2 diabetes.
Start by implementing a healthier diet. Swap processed foods for whole fruits and vegetables, choose complex (whole grains, etc) over simple carbohydrates (sugary foods), and keep well hydrated. All these things will have a huge impact on your weight and overall well being.
Staying active will also help you lower your risk of type 2 diabetes. Put a regular exercise routine in place, whether that’s going for runs, gym workouts, bike rides, or playing team sports. This can also help tackle the risk of a sedentary lifestyle—something many of us have got accustomed to when working from home. If you need to, set reminders to go out for a walk at lunchtime, or to do a workout before or after you finish your day.
The difference between type 1 and type 2 diabetes—and why it matters
Type 1 diabetes and type 2 diabetes have a number of different traits—but there are two main differences that are worth knowing when considering how to limit your risk of type 2 diabetes.
Firstly, while we don't really know the causes of type 1 diabetes, we do know the causes of type 2 diabetes. That it's a combination of genetics and environmental factors (over which you can have an influence) means that you can be proactive about limiting your personal risk to type 2.
Secondly, the treatment differs. Type 1 is treated using managed insulin shots to regulate your glucose levels. Type 2, however, can be treated using medication, or more impactfully through your diet and lifestyle decisions.
So if you’re asking the question, “Is type 2 diabetes genetic?”, then the answer is that genetics play a significant, but not determining role. The most important takeaway, however, is that when it comes to effectively treating it, that’s not left up to your DNA or genetic code—the power is in your hands! Read our full guide to implementing a good type 2 diabetes management routine.
 Mahajan, A., Taliun, D., Thurner, M., et al. (2018). Fine-mapping type 2 diabetes loci to single-variant resolution using high-density imputation and islet-specific epigenome maps. Nat Gen 50:1505-1513. Accessible here.
 Type 2 Diabetes. Diabetes.co.uk. Retrieved 11 February 2022. Accessible here.
 Diabetes Risk Factors. Diabetes UK. Retrieved 11 February 2022. Accessible here.