What causes type 1 diabetes?
Type 1 diabetes is caused by an autoimmune reaction (meaning the body attacks itself by mistake) that destroys the cells in the pancreas that make insulin, Katherine Araque, M.D., director of endocrinology of the Pacific Neuroscience Institute at Providence Saint John's Health Center in Santa Monica, Calif., tells Health. What actually causes that autoimmune reaction in the first place isn't completely known at this time.
This process can go on for months or even years before someone develops symptoms, the CDC says. Unlike type 2 diabetes, diet and lifestyle factors don't cause type 1 diabetes. But beyond that, there are some factors that put someone at a greater risk of developing type 1 diabetes:
A family history of the disease
Having a parent, brother, or sister with type 1 diabetes, raises a person's risk of also developing the disease—but it's not a given. "There certainly is an inherited tendency but that alone is not sufficient," Dr. Dungan says, noting that plenty of people have the disease with no immediate relatives who also have it. "It's not like type 2 diabetes, where almost everyone has a close relative with it," she says.
A younger age
Type 1 diabetes usually starts when someone is a child or young adult but, the CDC points out, you can technically develop the disease at any age. "It's not that there's an absence of risk as one gets older; It's just that the incidence of type 2 diabetes goes up with age," Dr. Dungan says.
It's possible that environmental factors might be involved in the development of type 1 diabetes, like patients having a virus, like enterovirus, or being exposed to certain things before they develop the disease, but it's more of a theory at this point. "It hasn't really been well understood," Dr. Dungan says.
Given that the cause of type 1 diabetes isn't completely understood, scientists haven't figured out a set way to prevent the disease. "There are multiple ongoing trials right now to try to figure out how to prevent type 1 diabetes, but we haven't extrapolated anything yet," Dr. Araque says.