Guar Gum Supplements
Description
This focus of this entry is the dietary fiber benefits of guar gum supplements. For a discussion of guar gum as an herbal remedy, see Guar Gum Plant.
Guar gum is a galactomannan storage polysaccharide obtained from the cluster bean (Cyamopsis tetragonolobus). This dietary fiber has been found to have many therapeutic uses in recent years, based on carefully controlled clinical studies. Guar gum reduces serum cholesterol in normal volunteers and in patients with elevated levels of serum cholesterol or triglycerides. Guar gum reduces insulin requirements in normal subjects, non-insulin dependent type 2 diabetics, insulin-dependent type 1diabetics. This fiber has also been found to be of benefit in the treatment of hypertension, duodenal ulcers and obesity.
In a dilute aqueous solution, guar gum powder forms an extremely viscous gel. Ingested raw, hydrated or otherwise, guar gum is usually quite unpalatable and may induce nausea and vomiting. However, a considerable number of studies conducted over the past 15 years have shown that, if baked into crispbread, bread or pasta products, guar gum can be edible, palatable and virtually free from side effects.
Method of Action
The beta-glycosidic linkages in guar gum are not subject to cleavage by human digestive enzymes. Thus, guar gel reaches the large intestine essentially unchanged. During transit through the digestive tract, guar gum reduces the absorption of dietary cholesterol. This decreased absorption may explain guar gum's hypercholesterolemic (serum cholesterol-lowering) effect.
Guar gum may also reduce the absorption of bile salts from the terminal ileum and/or interrupt the enterohepatic circulation of bile salts. In this manner, it would act like cholestyramine resin. However, some researchers have found excretion of fecal bile acids increases by only about 30% during guar gum treatment. This finding suggests guar gum's effect on bile acids could not be the the major mechanism for its cholesterol-lowering action.
The reduction in blood glucose is at least partly due to delayed gastric empyting and a retardation of the intestinal absorption of glucose, although the reduction has been attributed to attenuated secretion of glucose-dependent insulinotropic polypeptide (GIP) by guar gum supplementation.
The new guar-rich pasta products contain a natural proprietary inhibitor which prevents gelation from occuring until the guar reaches the acid environment of the stomach. The inhibitor temporarily prevents gelation, by inhibiting hydrogen bonding between guar molecules.
Therapeutic Approaches
Clinicians recommending long-term use of a high fiber diet or fiber supplementation with guar gum have been advised to make sure patients are receiving adequate calcium, iron, magnesium and zinc in the diet, since fiber can interfere with the absorption of these minerals. This may concern clinicians since guar gum has been recommended as an effective aid in the treatment of non-insulin dependent diabetes.
Metabolic studies of guar gum's effects on mineral balance in patients with non-insulin dependent diabetes, reported in 1989, have shown such concerns may be unwarranted.
In this study, 16 patients were given granola bars without or without guar gum, providing an average of 31.7 grams of guar gum a day for six months. No differences in mineral levels were found between those receiving guar gum and those who did not, when feces, urine or blood were examined. This suggests guar gum may be be used over an extended period without causing trace mineral imbalances. However, attention should be given to potential selenium losses, based on another 1989 study. In this study 15 healthy subjects were given meals over seven day periods with no supplements, with selenium supplementation only, and with selenium supplementation combined with guar gum. This controlled diet study continued for 61 days. During the period guar gum was given to subjects, both selenium balance and glutathione peroxidase activity decreased, regardless of the selenium content of the diet. These findings suggest selenium status should be monitored since selenium bio-utilization may be affected by guar gum supplementation.
Diabetes (Type 2)
There is considerable evidence guar gum enriched diets reduce postprandial blood glucose response in both healthy subjects and type 2 diabetic patients, but possibly not in type 2 obese diabetics. The beneficial effects of guar gum have even been demonstrated in randomized, double-blind, placebo-controlled studies of type 2 diabetics whose disease is poorly managed through diet alone. The reduction in blood glucose, seen with guar gum supplementation, is at least partly due to delayed gastric emptying and a retardation of intestinal absorption of glucose. However, the insulin-sparing effect of guar gum increases with the carbohydrate content of the diet, particularly, complex carbohydrates.
Guar gum biscuits, bread rolls or crispbreads have been shown to be effective in improving glycemic control in the diabetic diet for type 2 (non-insulin dependent) diabetics. These benefits have been shown in type 2 diabetics by double-blind, placebo-controlled trials. Four bread rolls provide 15 grams of guar gum. However, in a 1988 study, breadcrisp, with as little as 3 grams of guar flour, produced significant insulin-sparing effects in non-diabetic subjects. These studies have produced a model showing a reduction of 209 mU/min/l in the integrated insulin can be achieved for every 1 gram of guar incorporated into a biscuit.
Diabetes (type 1)
The effect of guar gum on glucose and lipid metabolism has been studied in type 1 diabetics, using a double-blind, randomized, cross-over design. It was shown from this study guar gum can reduce postprandial blood glucose, insulin requirements, and serum total cholesterol levels.
Cholesterol
Reductions in cholesterol levels have been achieved with guar gum therapy, even in severe cases of hypercholesterolemia. In one study, cholesterol levels were reduced an average of 14% in diabetics following three weeks' treatment with guar gum. The higher the initial cholesterol level, the greater the reduction in cholesterol; 26% reduction was achieved in 4 patients with initial levels above 7 mM. Alpha-lipoprotein levels did not change, thus the increase in alpha-lipoprotein cholesterol/total serum cholesterol ratio was obtained. These findings have been supported by double-blind placebo studies.
In 1989, a well designed double-blind study has shown guar gum may even help patients not benefitting from cholesterol-lowering medications if the gum was used in combination with drug therapy. This was clearly seen with the use of gemfibrozil, a relatively new lipid-lowering drug that can normally lower LDL- and VLDL-cholesterol levels while raising HDL-cholesterol. However, in some patients that drug is not effective until 5 grams of guar gum, taken three times a day, is added to the drug regimen. When gemfibrozil was given with guar gum at these levels there was a "remarkably higher (95%)" HDL/LDL ratio at the end of the study period.
Hypertriglyceridemia
Patients requiring a high-carbohydrate but low-fiber diet have few options for handling the hypertriglyceridemic effects of such diets. Guar gum offers one such option.
Duodenal gastric ulcer
A double-blind, placebo-controlled study of guar gum showed decreases in the total acid load, gastric juice acidity, and rates of emptying of gastric contents between 60 and 120 minutes postprandially. This was probably because of guar gum's viscosity and ability to neutralize gastric acidity. Guar gum supplementation may therefore be beneficial for duodenal ulcer patients.
Obesity
Obese subjects were given 10 grams of palatable guar gum twice daily to determine if a reduction in hunger would result. Not only did guar gum supplementation produce a reduction in body weight, but it reduced hunger significantly better than commercially-prepared bran products. These findings have been supported in other studies.
Hypertension
Blood pressure measured at standing, supine and sitting positions decreased 9.8% (systolic) and 9% (diastolic) in moderately obese men given 7 grams of guar gum three times a day. This effect was derived after just two weeks of supplementation. Furthermore, in these same patients, an 8% (systolic) and 7% (diastolic) reduction in blood pressure was maintained during exercise on an ergometer bicycle doing submaximal work load. The improved blood pressure readings did not revert to pre-treatment values for three weeks after guar gum supplementation was discontinued.
Toxicity Factors
Apart from reports of transient diarrhea or flatulence, there appears to be little evidence of acute or medium-term toxicity with guar gum. Long-term treatment requires further study to discern if the absorption of fat-soluble vitamins is impaired with guar gum therapy.
Except in the case of calcium, there is no evidence guar gum therapy impairs absorption from the intestinal tract, or alters plasma levels, of trace metal levels in users. In an absorption study using humans, guar gum was found to delay the initial rise of the radioactive calcium isotope (45Ca) in plasma and reduce the initial fractional absorption of that mineral.
Raw guar gum contains a globulin which can be denaturated and made non-toxic through cooking. Another toxic compound found in raw guar is fluoroacetic acid. Chemical analysis of samples has shown this acid is present in very low concentrations (0.07-1.42 micrograms/gram). Such low levels should dispel any concerns about the potential toxicity of guar gum due to its fluoroacetate content.
Guar gum has been determined to be non-teratogenic.
The only reported cases of allergic reaction to guar gum have been in subjects who experienced repeated occupational exposure to fine guar gum powder. Four such cases have been reported.
Guar gum can interfere with the absorption of drugs, such as digoxin or phenoxymethyl penicillin. Guar gum therapy can significantly reduce serum levels of these drugs.
References
Beattie, V.A., C.A. Edwards, J.P. Hosker, D.R. Cullen, J.D. Ward & N.W. Read. Does adding fibre to a low energy, high carbohydrate, low fat diet confer any benefit to the management of newly diagnosed overweight type II diabetics? Br Med J. 1988. 296(6630); 1147-1149.
Behall, K., D. Scholfield, M. McIvor, et al. Effect of guar gum on mineral balance in NIDDM adults. Diab Care. 1989. 12; 357-364.
Collins, T.F., J.J. Welsh, T.N. Black, S.L. Graham, M.W. O'Donnell, Jr. Study of the teratogenic potential of guar gum. Food Chem Toxicol. 1987. 25(11); 807-814.
Ebeling, P., H. Yki-Jarvinen, A. Aro, E. Helve, M. Sinisalo & V. Koivisto. Glucose and lipid metabolism and insulin sensitivity in type 1 diabetes - the effect of guar gum. Am J Clin Nutr. 1988. 48(1); 98-103.
Ellis, P.R., T. Kamalanathan, F.M. Dawoud, R.N. Strange & T.P. Coultate. Evaluation of guar biscuits for use in the management of diabetes - tests of physiological effects and palatability in non-diabetic volunteers. Eur J Clin Nutr. 1988. 42(5); 425-435.
Frick, M.H., O. Elo, K. Haapa, O.P. Heinonen, P. Heinosalmi, et al. Helskink Heart Study: primary-prevention trial with gemfibrozil in middle-aged men with dyslipidemia. N Eng J Med. 1987. 20; 1237.
Fuessl, H., G. Williams, T. Adrian & S. Bloom. Guar sprinkled on food - effect on glycemic control, plasma lipids and gut hormones in non-insulin dependent diabetic patients. Diabetic Med. 1987. 4(5); 463-468.
Groop, P.H., L. Groop, K.J. Totterman & F. Fyhrquist. Relationship between changes in GIP concentrations and changes in insulin and C-peptide concentrations after guar gum therapy. Scand J Clin Lab Invest. 1986. 46; 505-510.
Gulliford, M., G. Pover, E. Bicknell & J. Scarpello. Guar delays intestinal calcium absorption in man. Eur J Clin Nutr. 1988. 42(5); 451.
Harju, E. Guar gum benefits duodenal ulcer patients by decreasing gastric acidity and rate of emptying of gastric contents 60 to 120 minutes postprandially. Am Surg. 1984. 50(12); 668-672.
Hill, M., S. French, M. Sunman & C. Sutton. The preparation and use of guar bread in diet therapy. Hum Nutr Appl Nutr. 1984. 38(3); 227-228.
Holt, S., R.C. Heading, D.C. Carter, L.F. Prescott & P. Tothill. Effect of gel fibre on gastric empyting and absorption of glucose and paracetamol. Lancet. 1979. I; 636-639.
Huupponen, R., P. Seppala & E. Iisalo. Effect of guar gum, a fibre preparation, on digoxin and penicillin absorption in man. Eur J Clin Pharmacol. 1984. 26(2); 279-281.
Jenkins, D.J.A. Dietary fibre, diabetes and hyperlipidemia. Progress and prospects. Lancet. 1979. II; 1287-1290.
Jenkins, Leeds, Gassull, Houston, Goff & Hill. The cholesterol-lowering properties of guar and pectin. Clin Sci. Molec Med. 1976. 51; 8-12.
Jenkins, D.J., A.R. Leeds, B. Slavin, J. Mann & E.M. Jepson. Dietary fiber and blood lipids: reduction of serum cholesterol in type II hyperlipidemia by guar gum. Am J Clin Nutr. 1979. 32; 16-20.
Jenkins, D.J., D. Reynolds, B. Slavin, A.R. Leeds, A.L. Jenkins & E.M. Jepson. Dietary fiber and blood lipids, treatment of hypercholesterolemia with guar crispbread. AJCN. 1980. 33; 575-581.
Jenkins, D.J., T.M. Wolever, T.D. Hockaday, A.R. Leeds, R. Haworth, S. Bacon, E.C. Apling & J. Dilawari. Treatment of diabetes with guar gum: reduction of urinary glucose loss in diabetics. Lancet. 1977. II.
Jenkins, D.J.A., T.M.S. Wolever, R. Nineham, et al. Guar crispbread in the diabetic diet. Br Med J. 1978. 2; 1744-1746.
Jenkins, D.J., T.M. Wolever, S. Bacon, R. Nineham, R. Lees, R. Rowden, M. Love & D.R. Hockaday. Diabetic diets - high carbohydrate combined with high fiber. Am J Clin Nutr. 1980. 33; 1729-1733.
Jenkins, D.J.A., C. Newton, A.R. Leedes. Effect of pectin, guar gum, and wheat fiber on serum-cholesterol. Lancet. 1975. I; 1116-1117.
Jenkins, D.J.A., A.R. Leeds, M.A. Gassull, B. Cochet & K.G. Alberti. Decrease in postprandial insulin and glucose concentrations by guar and pectin. Ann Intern Med. 1977. 86; 20-24.
Kanerva, L., O. Tupasela, R. Jolanki, E. Vaheri, T. Estlander & H. Keskinen. Occupational allergic rhinitis from guar gum. Clin Allergy. 1988. 18(3); 245-252.
Krotkiewski, M. Effect of guar gum on body-weight, hunger ratings and metabolism in obese subjects. Br J Nutr. 1984. 52(1); 97-105.
Krotkiewski, M. Effect of guar gum on the arterial blood pressure. Acta Med Scand. 1987. 222(1); 43-49.
Manninen, V., M. Malkonen, A. Eisalo, J. Virtamo, J. Tuomilehto & P. Kuusisto. Gemfibrozil in the treatment of dyslipidaemia. A 5-year follow-up study. Acta Med Scand. Supplemental. 1982. 668; 82.
Morgan, L.M., T.J. Goulder, D. Trolakis, V. Marks & K.G. Alberti. The effect of unabsorbable carbohydrate on gut hormones. Diabetologia. 1979. 17; 85-89.
Niemi, M.K., K. Keinanen & P.I. Salmela. Long-term effects of guar gum and microcrystalline cellulose on glycemic control and serum lipids in type 2 diabetes. Eur J Clin Pharmacol. 1988. 34(4); 427-429.
Simons, Gayst, Balasubramaniam, & Ruys. Long-term treatment of hypercholesterolemia with a new palatable formulation of guar gum. Atherosclerosis. 1982. 45; 101-108.
Smith, C.J., M.S. Rosman, N.S. Levitt & W.P. Jackson. Guar biscuits in the diabetic diet. S Afr Med J. 1982. 61(6); 196-198.
Smith, U. & G. Holm. Effect of modified guar gum preparation on glucose and lipid levels in diabetics and healthy volunteers. Atherosclerosis. 1982. 45; 1-10.
Superko, H.R., W.L. Haskell, L. Sawrey-Kubicek & J.W. Farguhar. Effects of solid and liquid guar gum on plasma cholesterol and triglyceride concentrations in moderate hyper-cholesterolemia. Am J Cardiol. 1988. 62(1); 51-55.
Tognarelli, M., R. Miccoli, O. Giampietro, M. Cerri & R. Navalesi. Guar pasta - a new diet for obese subjects? Acta Diabetol Lat. 1986. 23; 77-80.
Tuomilehto, J., M. Silvasti, A. Aro, A. Koistinen, P. Karttunen, C.S. Gref, C. Ehnholm & M. Uusitupa. Long term treatment of severe hypercholesterolemia with guar gum. Atherosclerosis. 1988. 72(2-3); 157-162.
Tuomilehto, J., M. Silvasti, V. Manninen, M. Uusitupa & A. Aro. Guar gum and gemfibrozil-an effective combination in the treatment of hypercholesterolaemia. Atherosclerosis. 1989. 76; 71-77.
Uusitupa, M., J. Tuomilehto, P. Karttunen & E. Wolfe. Long term effects of guar gum on metabolic control, serum cholesterol and blood pressure levels in type 2 (non-insulin dependent) diabetic patients with high blood pressure. Ann Clin Res. 1984. 16 Suppl 43; 126-131.
Vartiainen, T. & J. Gynther. Fluoroacetic acid in guar gum. Food Chem Toxicol. 1984. 22(4); 307-308.
Vinik, A.I. & D.J.A. Jenkins. Dietary fiber in management of diabetes. Diabetes Care. 1988. 11(2); 160-173.
Weintraub, M.S., S. Eisenberg & J.L. Breslow. Different patterns of postprandial lipoprotein metabolism in normal, type III and type IV hyperlipoproteinemic individuals - effects of treatment with cholestyramine and gemfibrozil. J Clin Invest. 1987. 79; 1110.
| Signup Free Applied Health Journal |
||||
|
FREE Sample Issue Your email address is all we need to start you on a better path to health. We respect your privacy.
|
