You heard us: arsenic—that potent poison worthy of murder mysteries. So what’s going on? Evidently, the alcohol in beer can impair the body’s ability to metabolize the arsenic that’s naturally present in the grains used in brewing. Believe it or not, researchers discovered this by testing toenail clippings—markers of prolonged exposure to arsenic—and found that other foods, including fish, rice, and brussels sprouts, are culprits, too. MORE: The Incredibly Awesome Way Beer Can Lower Your Cancer Risk Arsenic occurs naturally in the environment, so it can end up in groundwater, which is how it works its way into your brussels sprouts and beer. While you won’t get arsenic poisoning from overindulging in a few IPAs or eating sushi occasionally, regularly consuming foods high in the stuff could cause it to accumulate in your system over time. The World Health Organization estimates that a prolonged exposure of 5 years or more can cause serious side effects, such as kidney failure, skin lesions, and various types of cancers, according to the EPA.   MORE: Gluten-Removed Beer: Best Thing Ever? Keep your system clean by eating a varied, healthy diet, and don’t rely too much on any one specific type of food, suggests lead researcher Kathryn Cottingham. And stock up on antioxidants—a Columbia University study found that vitamins A, B, C, and E, as well as riboflavin and folic acid, can help reduce the risk of arsenic-related skin lesions by up to 68%. The article “The Dark Side Of Your Brew” originally ran on MensHealth.com.