Also called clusterbean and Calcutta lucern.
This gummy substance, obtained from the ground endosperm of the seeds of the Cyamopsis tetragonoloba tree in India (C. psoraloides), is used mainly as a thickener and stabiliser in commercial food processing. Three or four species of guar are found in regions of Africa, Arabia, India, Pakistan, the USA, and northern Australia. (Steger 2000 ref.3599 4)
Guar gum, available as a yellowish-white powder, has 5-8 times the thickening power of starch, and the unique ability among gums to hydrate rapidly in cold water. (But it is insoluble in oils, grease, hydrocarbons, ketones, and esters.)
Guar gum is an emulsifier, a firming agent, a formulation aid, stabiliser, and a thickener. It is used in baked goods and baking mixes, cereals, beverages, cheese and other milk products, dairy product analogues, fats, oils, gravies, jams, jellies, sauces, soup mixes and soups, syrups, toppings, vegetable juices, processed vegetables and deep-frozen foods. The gum functions synergistically with xanthan gum by increasing the viscosity of a product. Guar gum is also common in the fat-reduced or fatless spreads.
Guar gum increases viscosity in the gut, which causes a slower absorption rate of carbohydrates and stimulates bile production. This initiates cholesterol reduction and increases intestinal tract motility. It can also function as a slimming aid, since it swells in the stomach and gives a feeling of satiety.
May not be used to produce dehydrated foodstuffs intended to rehydrate on ingestion. Guar gum readily absorbs water and swells, and should thus not be ingested as a dry powder. There is a limit on the use of Guar gum in slimming capsules, since it could cause esophageal obstruction as a result of swelling up in the oesophagus, rather than the stomach, causing choking obstruction, or rupture the oesophagus.
Has been used as a laxative in folk medicine, an appetite suppressant, and to treat ulcers!
Mainly used in the paper, food, cosmetic, pharmaceutic, textile, printing, polishing and atomic metal processing industries. Also used as a thickener and emulsion stabiliser. Suspending agent. Bulking agent. Binder for meats, cheese spreads, etc. Keeps tablets bound. Used in toiletries. It is a fixing agent for colors and is used in carpet manufacturing to adhere the dye to fibere. In the process of making carpets, the guar gum can be easily aerosolised. (Malo 1990 ref.7053 4)
IGE AND IMMUNE:
Guar gum is a high-molecular-weight agent that can cause occupational rhinitis and asthma. (Malo 1990 ref.7053 4)
More than 15 allergens were responsible for food-induced anaphylaxis in this French study: egg (11.6%), fish (10.4%), crustaceans (10.4%), milk (6.5%), fruit-latex group (6.5%), peanut and other legumes (soy, peas, lentils, guar gum, etc.), celery, garlic, etc. The food allergen still remained unknown in 25% of cases (Moneret-Vautrin 1995 ref.2153 7) (Moneret-Vautrin 1995 ref.2430 7)
Carpet manufacturing, cosmetics, fireworks manufacturer, food industry, hairdresser, printers, mining, pharmaceutical industry, textile workers
Occupational asthma. (Lagier 1990 ref. 28 129)
Reversible obstructive sleep apnea caused by occupational exposure to guar gum powder, in a pet food plant employee. Severe cough, rhinitis, and conjunctivitis was also experienced. (Leznoff 1986 ref.265 23)
Three cases of allergic rhinitis (rhinitis, palateal oedema) from guar gum are reported. Two subjects were exposed to fine guar gum powder, an insulator in rubber cables, when opening cables in a power cable laboratory. After 1-2 years' exposure the patients developed rhinitis. A third subject developed allergic rhinitis from another guar gum product after 2 years' exposure in a paper factory. Diagnosis were made with positive skin tests and nasal provocation tests. (Kanerva 1987 ref.30 039)
Three subjects who developed symptoms of rhinitis and asthma after the onset of exposure to guar gum are reported in a study. The first subject worked for a pharmaceutical company; the second and third subjects worked at a carpet-manufacturing plant. Specific IgE was demonstrated on skin prick tests and high levels were determined in their serum to guar gum. Specific inhalation challenges in which the three subjects were exposed to powder of guar gum elicited isolated immediate bronchospastic reactions in two subjects and a dual reaction in the other subject. (Lagier 1990 ref.28 143)
Malo et al. found 14 of 162 employees at a carpet-manufacturing plant using guar gum to be sensitized to this gum, of which two had occupational asthma. Eight subjects (5%) demonstrated immediate skin reactivity to guar gum. Eleven subjects (8.3%) had serum IgE antibodies to guar gum.(Malo 1990 ref.7053 4)
Occupational asthma in printers and carpet manufactures (Quirce 1998 ref.2386 2)
Sixteen workers with normal nonspecific bronchial reactivity (NSBR) who had been previously diagnosed with occupational asthma caused by high-molecular-weight agents, flour in seven workers, psyllium in five, and guar gum in four, were rechallenged after removal from exposure to these agents for a mean of 5.7 yr, and who no longer showed evidence of persisting asthma, and had a normal lung function. The authors conclude that specific bronchial reactivity to high-molecular-weight agents persists in most cases despite a normalization of NSBR, and that this persistence is associated with a persistence of specific immunization to the agent. (Lemiere 2000 ref.7332 5)
In a study of 15 subjects with occupational asthma (eight due to high-molecular-weight agents--flour and guar gum--and seven due to isocyanates), inhaling occupational agents of high or low molecular weight, including isocyanates, whether through the mouth or nose, resulted in asthmatic responses, caused a significant nasal symptoms and an increase in nasal resistance, and resulted in significant changes in inflammatory cells and mediators. (Desrosiers 1998 ref.7333 2)
Excess intake: nausea, flatulence, abdominal cramps, diarrhoea.
Potentially dangerous when used as slimming agent, since may swell up in the gullet, rather than the stomach, causing choking obstruction, or rupture the oesophagus.
Guar gum is used as a thickener in foods and infant foods. The ingestion of carob bean gum caused a significant reduction in the absorption and bioavailability of calcium, iron, and zinc. (Bosscher 2001 ref.7155 5)
Pharmacobezoars, bezoars comprised of medications, are unusual entities. Guar gum is a medication reported to cause bezoars. (Stack 1995 ref.7334 1)
This study concludes that guar is fermented in the human colon, producing rises in breath methane and serum acetate but not hydrogen. Although psyllium had no effect on hydrogen, methane, or acetate, this does not prove that it is not fermented. (Wolever 1992 ref.7335 3)
Information supplied from an abridged section of:
Allergy Advisor - Zing Solutions
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