The pale brown biscuits, known by locals simply as "terre", have traditionally been eaten by pregnant Haitians and children as an antacid and source of calcium. However, for some Haitians unable to afford even a plate of rice, terre has become their staple diet.
The Food and Agriculture Organisation of the United Nations has expressed concern over food prices in the Caribbean, recently declaring a state of emergency in Haiti and several other countries. The agency estimates prices have rocketed by as much as 40 per cent due to floods and crop damage caused by the 2007 hurricane season. At the market in Haiti's La Salines slum, two cups of rice now sell for 60 US cents, up 10 cents since December and 50 per cent from a year ago.
Beans, condensed milk and fruit have gone up at a similar rate. Even the price of the clay used in the biscuits has increased considerably though, at five cents each, they are still relatively cheap. The biscuits reportedly taste smooth but suck out the moisture from the mouth as soon as they touch the tongue, leaving an unpleasant earthy aftertaste which lingers for hours.
Gerald Callahan, an immunology professor at Colorado State University who has studied geophagy, the scientific name for dirt-eating, said mud can contain dangerous parasits or toxins. But it can also strengthen the immunity of unborn babies to certain diseases, he said.
Haiti is the poorest country in the western hemisphere. Seventy-six per cent of the population lives on less than $2.25 a day. Malnutrition is widespread and diarrhoea kills one in five children under the age of five. Haitian doctors say that people who depend on the biscuits for sustenance risk malnutrition. Dr Gabriel Thimothee, executive director of Haiti's health ministry, said: "Trust me, if I see someone eating those cookies, I will discourage it."