If you need coffee as a morning pick-me-up, you're not alone. If you need to chomp through a cup of ice, you're also not alone—but there are fewer people like you. Such ice-eaters may suffer from pagophagia (a compulsive craving for ice) that could be caused by an iron deficiency, the Washington Post reports. In a study published in Medical Hypotheses, researchers asked both healthy and anemic participants to consume either a glass of lukewarm water or a cup of ice before taking a 22-minute test designed to help diagnose ADHD. They found that iron-deficient subjects who drank the water performed "far more sluggishly" than healthy subjects, but those who crunched on ice did as well as the controls.
As the Post explains, pagophagia is a type of pica, a disorder that makes people crave and eat nonfoods (like dirt and clay, which the Learning Channel has turned into reality TV shows). Study author Melissa Hunt says this cognitive boost may be related to the "mammalian diving reflex," a trigger that causes blood-flow to the brain when a vertebrate is exposed to cold water. At least two hematologists say the study has possible flaws—having iron deficiency doesn't necessarily mean you have anemia, for example—but at least one admits he can't discount the power ice holds over his patients: "I had one patient tell me: 'I love ice. It's better than sex,'" he says. (Eating ice is also the newest diet trend.)