Nature or Nurture? Is Diabetes Hereditary or Acquired?

The latest statistics from the Centers for Disease Control (CDC) indicate that 38.4 million people in the United States have diabetes. The figure represents 11.6 percent of the US population. The figure includes 8.7 million adults aged 18 or older who met laboratory criteria for the condition but were either not aware of or did not report having it. [1]

As cases of diabetes increase annually – 1.2 million Americans are diagnosed with diabetes each year [2] – it stands to reason many with a family history of the disease want to know is diabetes hereditary, if they are not already living with it. Those with diabetes also may be wondering if they can trace the disease solely to their family or if there are other factors. Of concern is the possibility of passing diabetes on to their children.

The answer to the question is diabetes hereditary is not a simple one. According to the American Diabetes Association, “you inherit a predisposition to the disease, then something in your environment triggers it.”  To validate their assertion, the ADA points to statistics regarding identical twins, who have the same genetic material. However, when one twin has Type 1 diabetes, the other twin gets the disease, at most, only half the time. In the case of Type 2 diabetes, when one twin has it, the risk to the other twin is at most three in four.[3]  (It should be noted regarding these statistics that a 2021 study found that an estimated 15 percent of identical twins have a specific number of genetic mutations specific to one of them.[4] )

How Type 1 diabetes develops

Type 1 diabetes is an autoimmune disease in which the body’s immune system attacks healthy cells. When examining whether Type 1 diabetes is hereditary or acquired, the disease originally was attributed to genetics. However, although genetic features may predispose someone to the disease, other factors play a role.

Scientists have found there are certain variants of specific genes – known as HLA genes - that provide instructions for making proteins that play a critical role in the immune system. For reasons not yet understood, in people with Type 1 diabetes, the immune system damages the insulin-producing beta cells in the pancreas. Damage to these cells impairs insulin production and leads to symptoms of Type 1 diabetes. HLA genes have many variations and individuals have a certain combination of these variations. Among these variations, certain ones are associated with a greater risk of developing Type 1 diabetes.[5]

A predisposition to develop Type 1 diabetes is hereditary, but the inheritance pattern is unknown. Certain factors that can trigger the condition include:[6]

·         Cold weather: Type 1 diabetes is more likely to appear in winter than summer and is more common in colder climates

·         Viruses: Researchers think some viruses may activate Type 1 diabetes in people who are more susceptible, including measles and mumps

·         Early diet: Being breastfed as a baby may lower the chances of getting Type 1 diabetes later in life.

Children’s risk factors for Type 1 diabetes

Is Type 1 diabetes hereditary or acquired naturally is a concern for parents with the disease in their family.  A child's risk of diabetes increases in the following situations:[7]

• If the father has Type 1 diabetes, the risk of the child developing diabetes is 1 in 17.
• If the mother has Type 1 diabetes and:
• If the child was born before she is 25 years old, then the risk is 1 in 25.
• The child was born after she was 25 years old, the child's risk is 1 in 100.
• If the father and mother develop diabetes before the age of 11 years, the child's risk is between 1 in 10 and 1 in 4, respectively.
• If the person has diabetes along with thyroid disease, a poorly working adrenal gland, and an immune system disorder, the child's risk of developing Type 1 diabetes is 1 in 2.

Is Type 2 diabetes hereditary?

Type 2 diabetes is the most common of all types of diabetes, accounting for 90-95 percent of all diagnosed cases of diabetes, reports the CDC. [8] Genetics is a factor, as it is with Type 1 diabetes, -- people with Type 2 often have a close family member with the disease.  However, other lifestyle factors, including diet and exercise, influence whether someone develops the disease.

CDC says you are at risk for Type 2 diabetes if you: [9]

·         Have prediabetes.

• Are overweight.
• Are 45 or older.
• Have a parent, brother, or sister with Type 2 diabetes.
• Are physically active less than 3 times a week.
• Have ever had gestational diabetes (diabetes during pregnancy) or given birth to a baby who weighed 9 pounds or more.
• Are an African American, Hispanic or Latino, American Indian, or Alaska Native person. Some Pacific Islander people and Asian American people are also at higher risk.

·         If you have non-alcoholic fatty liver disease you may also be at risk for Type 2 diabetes.

Changes in lifestyle including losing weight if you are overweight and eating a healthy diet and getting proper exercise can prevent and even delay getting Type 2 diabetes.

A child’s hereditary risk for Type 2 diabetes[10]

·         If the father has type 2 diabetes, the risk factor is about 30 percent

• If the mother has type 2 diabetes, the risk factor is slightly higher.
• If both parents have diabetes, the risk factor increases to about 70 percent.

Whether the concern is Type 1 or Type 2 diabetes, there is a risk of inheriting the disease if it runs in your family. However, as with other diseases nature and nurture both play a role in developing the condition.