The Ice-Craving Mystery: Pagophagia in Iron-Deficiency Anemia

 

Iron deficiency anemia is one of the most common nutritional deficiencies in children and adolescents in the United States, affecting the body’s ability to transport oxygen effectively due to insufficient iron in red blood cells. As iron plays a critical role in binding oxygen inhaled by the lungs, its deficiency can lead to a range of physical and cognitive symptoms, including fatigue, pallor, tachycardia, and difficulty concentrating. This diminished oxygen delivery can limit both mental and physical performance, significantly reducing a patient's overall activity and alertness. Interestingly, one striking clinical manifestation of iron-deficiency anemia is pica, a condition in which individuals develop a compulsion to eat non-food substances, most notably in the form of pagophagia—compulsive ice chewing.

Pagophagia, the consumption of ice, is the most common form of pica seen in anemic patients, and it is so strongly associated with iron deficiency that many physicians consider it a specific indicator of anemia. The reasons for this behavior, however, remain a medical mystery. Several hypotheses have been put forward to explain why individuals with iron-deficiency anemia may be driven to chew ice, including the micronutrient deficiency hypothesis. This hypothesis maintains that patients consume non-food items due to iron, zinc, calcium, or some other micronutrient deficiencies. Pica consumption can therefore be classified as an attempt to increase levels of micronutrient intake. However, this hypothesis cannot explain the onset of pagophagia, as ice typically contains few trace minerals and almost no iron. Anecdotal reports from anemic individuals suggest that chewing ice may improve alertness or concentration, likening the sensation to a cup of coffee that boosts focus and energy throughout the day.

Another intriguing hypothesis is that ice chewing could trigger vascular changes in the body, possibly through the dive reflex (a series of physiological responses that happen when air-breathing vertebrates, including humans, hold their breath under cold water) or sympathetic nervous system activation, leading to enhanced blood flow to the brain. This effect might increase alertness and cognitive performance in anemic patients, who are more prone to these symptoms due to their reduced oxygen levels. If this hypothesis holds, chewing ice could have measurable effects on attention, concentration, and reaction time in anemic individuals, potentially improving their neurocognitive function during daily activities. Exploring the connection between pagophagia and brain function in anemic patients could provide new insights into both the physiology of iron-deficiency anemia and the unusual behaviors that accompany it.

REFERENCES:

Hunt, M. G., Belfer, S., & Atuahene, B. (2014). Pagophagia improves neuropsychological processing speed in iron-deficiency anemia. Medical Hypotheses, 83(4), 473–476. doi:10.1016/j.mehy.2014.07.016