By all measures and estimates, the world has been gripped by a terrifying epidemic. One that sneaks up on us and kills slowly and silently. It happens without us knowing, and by 2020, nearly half of the U.S. population could be affected. But this isn’t a terrifying virus like bird flu or measles or HIV.

It’s diabetes.

Over 3 million people die from diabetes every year, and worldwide, more than 170 million people are affected. In the U.S. alone, around 2 millions cases are diagnosed every year.

As most people know, there are two types of diabetes, type I, which occurs as a genetic autoimmune disorder, and type II, which arises because of lifestyle choices, diet, and exercise. For many years, type I was referred to as juvenile diabetes, and type II was called adult-onset diabetes. But over the past few years, researchers and doctors have realized those terms no longer apply as more and more children and teenagers are presenting with type II diabetes caused by obesity.

Now it seems there may be one more name-change in order. You know about type I and type II, but what about type III diabetes? Chances are, you haven’t heard this term used very often, and its target population is neither children nor average adults. You probably know it by its more common name: Alzheimer’s.

While researchers have speculated about the link between Alzheimer’s and insulin for years, earlier this year, several convincing articles made the scientific community take notice. Type III diabetes, also called brain diabetes, had already been identified, but evidence for the link to Alzheimer’s only recently appeared.

While people with Alzheimer’s may not have diabetes, they often have reduced insulin production and fewer insulin receptors in the brain (much like people with type II diabetes). Studies have also shown that this decreased brain function may be due to an increase in fat and sugar intake. (Other studies confirm the role a healthy diet plays in protection as people with healthy diets rich in vitamins and omega-3 fatty acids (such as the Mediterranean diet) have less brain shrinkage.)

Although most of the studies on the effects of bad diets have been done in animals (it would be unethical to do the same in humans), decreased insulin function has already been established in many people with Alzheimer’s. In addition, studies show that people with type II diabetes are twice as likely to get Alzheimer’s, and people with high cholesterol have a higher rate of brain plaques (which contribute to dementia).

The links identified between obesity- or diet-related diseases and Alzheimer’s may have very immediate and shocking implications, particularly as a generation of baby boomers (many of whom already have type II diabetes) grows older and older. These findings may mean rising healthcare costs, lower quality of life, and decreased autonomy for millions of people in the coming years. All because of their current dietary habits.

Unfortunately, trying to prevent Alzheimer’s means the same uphill battle against the modern American diet and way of life already presented in trying to tackle obesity or diabetes. For many people, the promise of stopping diseases that don’t strike until later in life provides very little motivation for changing their diet and activity in the present. And unlike diabetes and heart disease which develop in young or middle adulthood, type III diabetes may not crop up for many decades down the line.

To get started on protecting your health, check out MyPlate Mondays for tips on healthy eating, and learn more about the signs and treatments for prediabetes and diabetes.