Dr's Casebook: The strange habit of crunching ice

Some people with anemia may crave ice as a result of an iron deficiency. Photo: AdobeStock

The really hot weather lately must have been a real boon for ice cream sellers. I enjoy both ice cream and ice lollies, but I am always wary about eating them too quickly. And one thing I always avoid is actually crunching the ice.

Dr Keith Souter writes: The reason that I avoid ice crunching is that I have in the past experienced the so-called ‘ice-cream headaches’ after doing so. I am not alone in this, as about a third of people get it, only for a few seconds, but long enough to make one notice it.

The scientific name for this phenomenon is sphenopalatine ganglioneuralgia, or Cold Stimulus Headache. It comes about when the weather is hot and the sudden cold stimulation to the palate causes instant waves of constriction and then dilation of blood vessels, which trigger headache.

Some people, however, crave ice and crunch it quite happily. Indeed, people who do this to an excessive degree may be experiencing ‘pagophagia,’ or ‘ice pica.’

Pica is the name for a desire for types of food that have no nutritional value at all. Ice is, after all, just frozen water.

Strangely, a study published in the Japanese Journal of Haematology in 2014 suggests that there can be a link between this pagophagia and iron deficiency anaemia. In their study of 81 patients with diagnosed iron deficiency anaemia, they asked all about their eating habits. Rather surprisingly, they discovered that 16 per cent of the people described pagophagy, or the craving and desire to crunch ice.

All 81 patients were then treated with iron tablets and carefully followed up with blood tests to monitor improvement. They found that the iron therapy cured the ice craving in all of the patients who had reported it. Very surprisingly, they found that this cure of the craving occurred sooner than the improvement in their blood

readings.

There may be a biochemical explanation for this strange association. Iron deficiency anaemia occurs if there is not enough iron in the diet or if there is blood loss from somewhere. It often creeps up on people and they are not aware of it. The desire to crunch ice may be a symptom, especially if one is lacking in energy.