In the past few years, doctors have identified compulsive cravings for ice as a surprising sign of the blood disorder anemia. The most common form of anemia, iron deficiency anemia, causes fatigue and weakness by reducing the number of oxygen-carrying red blood cells in the body. Fortunately, doctors have found that treating the underlying cause of the anemia -- often heavy periods, a history of childhood trauma or neglect, certain cancers, or surgery like the Roux-en-Y gastric bypass operation -- usually cures the ice cravings.
In one study, scientists gave people with low iron levels a math test and then had them chew on some ice while taking the test again. The researchers found that people who chewed ice did better on the test retake than those who didn’t chew the ice. They think this is because chewing the ice alerts the brain, giving them an extra boost of energy and focus.
Another reason why ice could make you feel more alert is because chewing ice releases small amounts of oxygen into the bloodstream, which can help people feel more awake. This effect is similar to the way coffee makes people feel.
In addition to addressing the underlying cause of anemia, doctors often prescribe iron supplements for people who have ice cravings. It’s important to note, though, that ice is not a good source of nutrients, and people should not use it to replace other healthy foods in their diet. Also, the habit of eating and chewing a lot of ice can damage tooth enamel over time.