4 Surprising Facts About Your Genes and Diabetes

For starters, sugar's not the only culprit

family portrait

If you’ve heard of the old “nature versus nurture” debate, forget it. When it comes to diabetes, it’s both.

Advertising Policy

Cleveland Clinic is a non-profit academic medical center. Advertising on our site helps support our mission. We do not endorse non-Cleveland Clinic products or services. Policy

When I say that, I mean that both your genes and your behavior likely play a part in developing diabetes. That’s true for type 1 and type 2 diabetes — just in different ways.

Below, I explore this and other surprising facts about the genetics of diabetes.

In diabetes, your genes and environment interact

Developing diabetes often comes down to a mix of your genes, your environment and how they act together.

Certain genetic mutations make you more predisposed to the disease than other people. But it takes factors in the environment to actually lead to disease. Those factors can be things you’re exposed to — or things you expose yourself to.

Take type 2 diabetes, for example. Your genes may predispose you to higher risk for the disease. But eating habits — such as a long-term diet that includes high amounts of sugar — ultimately play a role in whether you actually get type 2 diabetes.

Sugar isn’t the only factor in the disease

Type 2 diabetes is heavily linked to how your body processes glucose. So it makes sense that exposure to sugar ends up being one of the major triggers for disease.

Type 1 diabetes is different, though. Variations in genes called HLA lead to a higher predisposition for the disease. There are different variations on HLA for different groups of people, but they all boil down to affecting how your immune system works.

Advertising Policy

That leads to some surprising connections. Strange as it may seem, type 1 diabetes symptoms may show up after you’ve had a cold, flu or other virus. Bacteria can have a similar effect. Trends even suggest cold weather affects type 1 diabetes.

RELATED: How You Can Create a Powerful Diabetes Game Plan

Type 2 diabetes is actually “more genetic” than type 1

Most people assume type 1 diabetes is tied more closely to genetics than type 2. There may be a couple of reasons. First, type 1 comes on frequently in childhood, which suggests an inherited connection. Second, type 2 has so much to do with long-term dietary habits.

But studies in twins have shown the family connection is even stronger in type 2 diabetes. If one twin has type 1 diabetes, there’s a 50 percent chance the other twin will, too. But if one twin has type 2 diabetes, there’s a 75 percent chance the other one will.

If either type of diabetes runs in your family, keep a detailed family history and share that information with your doctor. But even more important, act on it. The connection may be stronger for type 2, but it’s there for both.

For example, if you know type 2 diabetes is common in your family, that’s one more reason to carefully watch what you eat.

RELATED: 8 Tips for a Better Family Health History

Advertising Policy

Family history matters in more ways than one

Genetic factors are the obvious connection between family and disease.

For example, a mom with type 1 diabetes has a 1 in 25 to 1 in 100 chance of having a child with the condition, depending on age. For type 2 diabetes, the ratio is anywhere from 1 in 7 to 1 in 13 in general, again depending on age.

But keep in mind that a mom and dad who both have type 1 diabetes have a 1 in 10 to 1 in 4 chance of having a child with the same condition.

However, people learn culture and behavior from family, too. You might inherit your risk of diabetes from your family, but you also often learn your eating and exercising habits from them, too.

A good family history goes beyond just diseases and includes these types of cultural issues. The more info you compile to discuss with your doctor, the more info you have to lead you to action.

avatar

Charis Eng, MD, PhD

Charis Eng, MD, PhD is founding chairwoman of the Genomic Medicine Institute and founding director of its Center for Personalized Genetic Healthcare. Dr. Eng is a global leader in cancer genetics and cancer genomic medicine.
Advertising Policy