Think only zombies eat brains? Think again. A normal human could chow down on the bloody organ pictured above—because it’s cake! If you find yourself both nauseated and fascinated by this grotesque baked good, you’re not alone.

According to scientists, the feeling of disgust evolved to keep people away from things that could make them sick. “It’s a way of protecting ourselves,” says Tara Cepon-Robins. She’s an anthropologist—a scientist who studies humans—at the University of Colorado in Colorado Springs. Things like poop, vomit, and rotting food gross us out, because “these are things that carry threats of infection,” says Cepon-Robins.

If disgust is such an important response, why might someone be tempted to try a slice of this gory cake? Scientists aren’t entirely sure. Cepon-Robins says that eating something that looks dangerous—but really isn’t—may allow us to safely test the limits of our disgust. It helps people learn to distinguish between things we perceive as revolting and those that could truly harm us.

This distinction is important. Avoiding every object or place we associate with being germy, like mud or the bathroom floor, can end up hurting us in the long run. Our bodies need some exposure to microbes in our environment to develop a healthy disease-fighting immune system. So if someone presents you with a realistic-looking cake shaped like a brain, maybe try a bite. Even though it looks revolting, it might just leave you saying, “Yum!”