For thousands of years, farmers in India and elsewhere have harvested guar beans, the source of guar gum, for both human consumption and cattle feed. Since the 1950s, the gum has been used to make processed foods, in which it acts as a thickener and prevents the formation of ice crystals – essential if you like your ice cream to be, well, creamy.
But if you like your ice cream to be inexpensive as well, prepare for bad news: guar gum now sells for almost 20 times its 2010 price, and some of that cost increase is being passed on to consumers. The culprit: hydraulic fracturing, also known as hydrofracking, a rapidly expanding natural gas extraction technique.
Each hydrofracking well uses 10 tons of guar gum, and 35,000 new hydrofracking wells were drilled last year in the United States alone, dramatically increasing demand for guar, and causing a spike in its price. As a result, guar bean farmers in India and Pakistan are smiling all the way to the bank, while food manufacturers are asking their own bean counters for a second opinion.
In hydrofracking, guar gum is used to thicken water, which allows it to move grains of sand underground more effectively than water alone would.
In the human digestive system, it does something similar: the gum can function as a laxative by forming a bulky gel that moves the contents of the intestines along. For this reason, doctors will sometimes prescribe the stuff to alleviate symptoms of irritable bowel syndrome or Crohn's disease. Another benefit: guar gum is also one example of soluble fiber, which decreases the body's levels of LDL, or "bad," cholesterol.
Apparently taking advantage of the laxative effects of guar gum (and because large quantities of it can produce a feeling of satiety), companies manufactured guar gum weight-loss pills in the 1980s. These were as ineffective as they were dangerous – too much guar gum taken with too little water can swell up and block the esophagus. The Food and Drug Administration banned guar weight-loss pills in 1992.
In the smaller quantities used in food, however, guar gum is more healthy than problematic, although rare allergies to the substance do occur. Still, for most consumers, guar gum is a safe food additive.