Type 2 diabetes has been increasing in incidence, largely due to the obesity epidemic. But type 1 diabetes is also on the increase worldwide – and experts aren’t sure why.
It seems every day, there’s another headline about the diabetes epidemic. But while the growing numbers of people worldwide with type 2 diabetes has been largely tied to obesity and lifestyle issues, the incidence of type 1 diabetes is also on the rise, and experts are puzzled about the reasons why.
Both forms of diabetes are related to problems with insulin, a hormone used to process blood sugar. People with type 2 diabetes still produce insulin, although their bodies can’t use it properly. But in type 1 diabetes, the immune system attacks and destroys the insulin-producing beta cells of the pancreas, meaning that people with this disorder must take insulin and keep careful track of their blood sugar levels in order to stay healthy.
Type 1 diabetes is usually first diagnosed in children and teens, which is why it used to be known as juvenile diabetes. It’s also much less common than type 2: The World Health Organization (WHO) estimates that about 90 percent of diabetes cases worldwide are attributable to type 2 diabetes.
But as an article in Scientific American points out, the incidence of type 1 diabetes has been increasing by 3 to 5 percent a year. In 2006, a WHO project called DIAMOND, which reviewed 10 years’ worth of records from 57 countries, found that type 1 rates had risen an average of 5.3 percent a year in North America, 4 percent in Asia and 3.2 percent in Europe. And a study published in the June 2009 issue of The Lancet found that the incidence of type 1 diabetes across 17 European countries was rising by nearly 4 percent a year, increasing most quickly in children under age five.
So far, the reasons for the uptick are still largely a mystery, but experts believe that the underlying cause is likely to be environmental, not genetic. According to Scientific American, here’s what researchers are focusing on as possibilities:
- Gluten: An increase in consumption of highly processed foods means more exposure to gluten, a protein found in wheat that many people with type 1 diabetes seem to be sensitive to. The JDRFestimates that about 1 in 10 Americans with type 1 diabetes have celiac disease (gluten intolerance), compared with about 1 in 100 in the general U.S. population.
- Bacteria: The “hygiene hypothesis” states that a lack of early exposure to infections and allergens doesn’t allow the immune system to learn how to handle these and other stressors, which can lead to autoimmune attacks like that which precipitates type 1 diabetes. The article cites the fact that diabetes is less common in children who are in day care.
- Obesity: Type 1 diabetes isn’t normally linked to being overweight or obese. But some experts believe that extra weight, which leads to more insulin production, can overload the pancreatic beta cells to the point of failure and “push a child whose beta cells are already under attack into developing type 1 diabetes.”
Whatever the cause, public health researchers hope to find an answer soon to help prevent or reverse this trend. Although there’s great optimism about the development of artificial pancreas systems — a breakthrough that is expected to significantly improve the lives of many people with type 1 diabetes — there is currently no cure for this condition.