Genetics and Lifestyle Play a Role
Jones’s concern is well founded. Research suggests that having a parent with type 2 diabetes increases your risk of developing the disease by as much as fourfold, and even more if both parents are affected. “We know that if both parents have type 2 diabetes, there’s about a 50 percent risk that you and your siblings could have the genes passed on,” says Edward Hess, MD, an endocrinologist who leads the diabetes program at Kaiser Permanente in Fontana, California.
It’s clear that there’s a strong genetic component to type 2 diabetes, and that’s why we see greater prevalence in some ethnic groups, like Native Americans and African Americans. But it’s an incredibly complex disease. “There are literally dozens of genes and sites on the DNA that are associated with type 2 diabetes,” Dr. Hess says.
It’s hard to tease out how much of our risk comes from genetics and how much comes from lifestyle factors, like eating and exercise patterns. “It's a combination of inheriting that really strong type of diabetes from your parents,” says Hess, “and you can inherit bad habits from your parents, too.”
Understand Your Individual Risk
Family history is just one of many risk factors for type 2 diabetes, so it’s worth talking with your doctor about your overall risk. If you have a parent or sibling affected and you’re overweight or obese, the American Diabetes Association recommends getting tested for diabetes. If you have a normal BMI, they recommend routine testing starting at age 45. This is done with a blood test for blood sugar, or A1C, a measure of your average blood sugar over the last two to three months. If you have more risk factors or your test results indicate that you have prediabetes, your doctor will probably want to keep tabs on you with an annual test.
With your family history, you and your doctor should also keep an eye out for signs of diabetes complications, like vision problems or nerve damage, Hess says.
Avoid Hereditary Diabetes
While you can’t change your family tree, there is a lot you can do to cut your chances of developing diabetes. A study published in August 2017 in Primary Care Diabetes found that diet and exercise can help lead to lasting health benefits in relatives of people with type 2 diabetes. More generally, a study published in November 2009 in The Lancet showed that the Diabetes Prevention Program, which helped high-risk adults lose 7 percent of body weight and start doing about 30 minutes of moderate-intensity physical activity — like brisk walking — each day, decreased participants’ risk of diabetes even 10 years later.
Having regular, balanced meals can help even out your blood sugar so your body doesn’t have to work so hard to keep it in check, says Sandra Arevalo, RDN, CDE, the director of nutrition services and outreach programs at Montefiore Health System’s Community Programs in the Bronx, New York. She recommends three meals per day using the MyPlate eating pattern, with fruits and vegetables making up about half of each meal and a modest serving of carbohydrates, preferably whole grains.
Regular exercise is just as important. “When you are exercising, it's like the cells open the doors to receive all the sugars in the blood, so it's like a natural medicine for diabetes and prediabetes,” says Arevalo. She says that a registered dietitian or diabetes educator can help people make a diabetes prevention plan that will work for them.
It’s best if diabetes prevention becomes a family affair, says Hess. “Go to your brothers and sisters and say, ‘Hey, you'd better get involved in this, too, because if I've got this risk of diabetes, you do too.’”