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Home , Guar gum, Psyllium

A SPECIAL ARTICLE

Psyllium versus Gum: Facts and Comparisons

by T.S. Dharmarajan

INTRODUCTION stool mass, which floats in the toilet rather than sink- ietary fiber is a term that denotes components of ing while the unfermented from psyllium functions plant origin that are resistant to digestion by gas- as an emollient and lubricant. Dtrointestinal in humans. Based on its Guar gum is extracted from the seeds of the shrub solubility in water, fiber may be classified as soluble Cyamopsis tetragonolobus wherein it acts as a food or insoluble. Soluble fiber, the basis for discussion and water store. The annual plant, which flourishes in here, is a plant ingredient that stores water. Besides , and the West, is drought resistant and storing water, its properties include the ability to fer- thrives in sandy soil. Guar gum is an economical ment and to increase (1,2). thickener, emulsifier and stabilizer that hydrates Psyllium and guar gum are two forms of soluble rapidly in cold and hot water to give solutions high fiber that make an interesting comparison. Psyllium, viscosity. It retards ice crystal growth and is resistant mainly cultivated in Iran and India, is used in the man- to oils and solvents. reactivity is in question. agement of several medical disorders and also as an Guar gum is approved for use in foods, pharmaceuti- herbal remedy. Psyllium is a member of the plant fam- cals and cosmetics. In the , examples ily Plantaginaceae. Its common names include flea include bakeries and . It is a common ingredient seed and ispaghula while the botanical names are for dressings and and as a stabilizer for drinks ovato and Plantago ispaghula. Psyllium and juices. Guar gum serves as a thickener for sham- seeds contain up to 30% mucilage; swelling of the poos and . It is also used in the and occurs in contact with water, resulting in a gelati- industries (Table 1). nous mass and an increase in bulk that keeps feces hydrated and soft (3). Psyllium are pure dietary BENEFITS IN HEALTH AND DISEASE fiber that is mainly composed of . This component of fiber is not digested in the small intes- Hyperlipidemia tine, but instead it is broken down in the colon where In numerous studies, psyllium has been found to be it acts as a food source for the intestinal flora. The bac- beneficial in lowering total and LDL (“bad”) choles- terial mass and water contribute to an increase in stool terol (4). However, HDL (“good”) does not weight. The husks absorb water to form a soft bulky appear to be affected (5). The benefits of psyllium in hyperlipidemia are secondary to its soluble component. T.S. Dharmarajan, M.D., FACP, AGSF, Chief, Divi- In a meta-analysis of 8 controlled trials, psyllium sup- sion of Geriatrics, Director, Geriatric Medicine Fellow- plements caused significant reductions in total and LDL ship Program, Our Lady of Mercy Medical Center, cholesterol in subjects on a low-fat diet (6). Other solu- Bronx, New York, Professor of Medicine, New York ble fibers, such as guar gum (besides pectin and oat Medical College, Valhalla, NY. ), also decrease total and LDL cholesterol. How-

72 PRACTICAL GASTROENTEROLOGY • FEBRUARY 2005 Psyllium Versus Guar Gum

A SPECIAL ARTICLE

ever, practical use of many of the latter Table 1 forms of fiber is limited by the lack of Properties of Psyllium and Guar Gum palatable preparations (7). In a study in rats comparing 10 different fibers, psyl- Property Psyllium Guar Gum lium use was associated with the lowest serum cholesterol levels (8). The Food Botanical name P. ovato, P. ispaghula C. tetragonolobus and Drug Administration has authorized Structure Non starch Non starch polysaccharide the use of “the association of psyllium Solubility Soluble Soluble and a reduced risk of coronary heart dis- ease” on health labels. This health claim Component Mucilage, hemicellulose Gum was attributed to a lowering of choles- Thickening effect Effective Very effective terol levels, based on the assumption Palatability Several choices Limited that 4 servings of per day would reduce cardiovascular risk (9). Gas, bloating Less problematic More problematic

Diabetes also been demonstrated is the regulation of stool fre- In type 2 , addition of psyllium to dietary mea- quency in . Aside from these sures has been shown to improve glycemic control (4). examples of relief in transit disorders, in ventilator- The benefit appears to result from a slowing of glucose dependent septic patients, soluble fiber in the form absorption from the small intestine. Psyllium treatment of guar gum added to enteral feeding reduced the should be individualized for maximum effect (10). In a incidence of (16). The addition of guar gum study comparing ispaghula husk (psyllium) with guar (7 g daily) to a standard tube feeding formula gum, mean serum postprandial insulin levels decreased stool frequency and helped normalize stool decreased for both, but the area under the glucose flora (17). The relief of and resultant curve was reduced significantly for psyllium but not long-term regular bowel habits with soft stools from for guar gum (11). the use of fiber provides relief to individuals suffering from hemorrhoids. Constipation and Other Gastrointestinal Transit Disorders Hunger, Food Intake and Many studies have revealed the benefit of psyllium in Psyllium reduces the feeling of hunger and thereby alleviating constipation by speeding the transit of stool energy intake. The mechanism of action may entail through the intestines. Its use is standard practice for increasing the time for intestinal absorption and flat- constipation. Psyllium increases stool mass more than tening of glucose, insulin and triglyceride curves with- common fiber sources such as oat bran and wheat bran out altering gastric emptying for solids or liquids (18). (12,13). A comparison of psyllium as ispaghula husk Hence, it is conceivable that psyllium may help in with other revealed that ispaghula use was weight loss, inducing a feeling of stomach fullness associated with a higher percentage of well-formed without providing calories. The addition of guar gum and less hard stools, as well as less soiling, diarrhea to meals has also been shown to prevent an increase in and abdominal discomfort (14). As a bulk-forming appetite, hunger and desire to eat (19). agent, psyllium also helps manage mild diarrhea by providing a stool firmer that slows transit time. In ulcerative colitis, psyllium seeds (10 grams twice daily) were as effective as mesalamine in maintaining Soluble fiber administered as psyllium (12 g/d) remission in one trial (15). Another benefit that has reduced 24-hour and awake systolic blood pressure.

PRACTICAL GASTROENTEROLOGY • FEBRUARY 2005 73 Psyllium Versus Guar Gum A SPECIAL ARTICLE

Table 2 ADMINISTRATION Psyllium and Guar Gum in Health Care Fiber is an important dietary ingredi- ent, but the precise dietary require- Disorder Psyllium Guar Gum ments for protective benefits are not Lowers LDLC, TC Lowers LDLC, TC clear. In general, it is advisable to con- sume fiber from natural sources before Diabetes Significant benefit Significant benefit resorting to supplements. The Ameri- Constipation Significant benefit Some benefit can Dietetic Association recommends Diarrhea Some benefit Some benefit the consumption of 20 to 35 grams of fiber per day. A combination of solu- Irritable bowel syndrome Some benefit Role not clear ble and insoluble fiber is recom- Ulcerative colitis Some benefit Role not clear mended (1,2). Where the dietary intake of fiber is inadequate, commer- Weight loss May be helpful May be helpful cial preparations supplement fiber Blood pressure Beneficial in Benefit in post-prandial intake to match the recommended hypertension? hypotension? amounts. Standard forms of psyllium are This finding may have implications in long-term treat- available in dry seed and husk form. Psyllium is taken ment of hypertension (20). In quite the opposite set- one to three times a day with plenty of water a half ting, through a slowing of gastric emptying and glu- hour before or at least an hour after meals. Husks can cose absorption, guar gum reduced the magnitude of a be added to soups or sauces as a thickener. Psyllium drop in blood pressure after an oral glucose load. This should be taken with a full 8 oz glass of water, and it finding may provide a novel approach to the manage- ment of post-prandial hypotension (21). (continued on page 76)

Table 3 Miscellaneous Considerations A Comparison of Two Forms of Soluble Fiber In one study, the consumption of fiber (as P. ovata) has been associated with a reduced risk Konsyl Benefiber of colon cancer (22). However, the data from Ingredient Psyllium Hydrolyzed guar gum numerous trials evaluating the relationship Serving Size 1 teaspoon 1 tablespoon between dietary fiber and colorectal cancer are at best conflicting (1,23). Fiber, particu- Serving Size (grams) 6 g/teaspoon 4 g/tablespoon larly the insoluble component, has been asso- Fiber (g/serving) 5 grams 3 grams ciated with a decreased risk of diverticular disease. In patients in whom adequate intake Calories 3 per serving 16 per serving of insoluble fiber is not possible, preparations Sodium 4.1 mg 15 mg such as psyllium may be helpful. Potassium 42 mg 15 mg Psyllium use is not habit forming. As a pure fiber, the husks contain only trace calo- 48 mg none ries, vitamins and minerals. Unlike wheat Carbohydrate 0.05 g 4.0 g bran and some other fiber, excessive bloating Protein 5.3% none attributable to gas formation is less likely to occur with psyllium. Gastrointestinal side Fat 2.7% none effects appear to be more common with guar none none gum (2) (Table 2).

74 PRACTICAL GASTROENTEROLOGY • FEBRUARY 2005 Psyllium Versus Guar Gum A SPECIAL ARTICLE

(continued from page 74) is essential that at least 6 to 8 glasses of water be con- and women with hypercholesterolemia: meta-analysis of 8 con- trolled trials. Am J Clin Nutr, 2000; 71(2): 472-479. sumed over the day to avoid constipation. Excessive 7. Anderson JW, Riddell-Mason S, Gustafson NJ, et al. Cholesterol- fiber intake to the tune of 50 to 60 grams daily may lowering effects of psyllium-enriched cereal as an adjunct to a pru- dent diet in the treatment of mild to moderate hypercholesterolemia. result in gastrointestinal side effects and malabsorption Am J Clin Nutr, 1992; 56: 93-98. of nutrients and drugs. intake is best 8. Anderson JW, Jones AE, Riddell-Mason S. Ten different dietary avoided at the same time as fiber to minimize a delay fibers have significantly different effects on serum and liver lipids of cholesterol-fed rats. J Nutr, 1994; 124: 78-83. or malabsorption of drugs. 9. Jenkins DJ, Kendall CW, Vuksan V, et al. Soluble fiber intake at a Hydrolyzed guar gum is added to foods and bev- dose approved by the US Food and Drug Administration for a claim of health benefits: serum lipid risk factors for erages as a fiber supplement to regulate bowel move- assessed in a randomized controlled crossover trial. Am J Clin Nutr, ments. It may be mixed with water or juices and soft 2002; 75(5): 834-839. 10. Sierra M, Garcia JJ, Fernandez N, et al. Therapeutic effects of psyl- foods. In particular, it may be supplemented with tube lium in type 2 diabetic patients. Eur J Clin Nutr, 2002; 56 (9): 830- feedings on an individualized basis for the purpose of 842. 11. Sierra M, Garcia JJ, Fernandez N, et al. Effects of ispaghula husk regulating bowel function (Table 3). and guar gum on postprandial glucose and insulin concentrations in healthy subjects. Eur J Clin Nutr, 2001; 55(4); 235-243. 12. Cummings JH. The effect of dietary fiber on fecal weight and com- position. In: Spiller GA ed. Dietary Fiber in Human Nutrition. Boca SUMMARY Raton, CRC Press. 1993: 263-350. 13. Chen HL, Haack VS, Janecky CW, et al. Mechanisms by which Psyllium and guar gum are two forms of soluble fiber wheat bran and oat bran increase stool weight in humans. Am J Clin that are available as commercial preparations, but they Nutr, 1998; 68: 711-719. have somewhat different properties. While both forms 14. Dettmar PW, Sykes J. A multi-center, general practice comparison of ispaghula husk with and other laxatives in the treatment of fiber are helpful in the management of hyperlipi- of simple constipation. Curr Med Res Opin, 1998; 14(4): 227-233. demia, psyllium appears to be more suitable in the 15. Fernandez-Banares F, Hinojosa J, Sanchez-Lombrana JL, et al. Randomized clinical trial of Plantago ovato seeds (dietary fiber) as management of motility disorders, such as constipation compared to mesalamine in maintaining remission in ulcerative col- and irritable bowel syndrome. Psyllium (as in Konsyl) itis. Spanish Group for the Study of Crohn’s Disease and Ulcerative Colitis (GETECCU). Am J Gastroenterol, 1999; 94: 427-433. offers a higher concentration of fiber per serving, in 16. Spapen H, Diltoer M, Van Malderen C, et al. Soluble fiber reduces addition to fewer calories and lower sodium and carbo- the incidence of diarrhea in septic patients receiving total enteral nutrition: a prospective, double-blind, randomized, and controlled hydrate content. These properties are significant in the trial. Clin Nutr, 2001; 20(4): 301-305. management of coexisting hypertension and diabetes. 17. Nakao M, Ogura Y, Satake S, et al. Usefulness of soluble dietary Fewer gastrointestinal side effects seem to be encoun- fiber for the treatment of diarrhea during enteral nutrition in elderly patients. Nutrition, 2002; 18: 35-39. tered with psyllium. On the other hand, guar gum (as in 18. Rigaud D, Paycha F, Meulemans A, et al. Effect of psyllium on gas- Benefiber) may have better utility as a thickener, par- tric emptying, hunger feeling and food intake in normal volunteers: a double blind study. Eur J Clin Nutr, 1998; 52(4): 239-245. ticularly in the food and textile industry. I 19. Kovacs EM, Westerterp-Plantenga MS, Saris WH, et al. The effect of addition of modified guar gum to a low-energy semisolid meal on appetite and body weight loss. Int J Obes Relat Metab Disord, 2001; References 25(3): 307-315. 1. Dharmarajan TS, Ravunniarath J, Pitchumoni CS. Dietary fiber: 20. Burke V, Hodgson JM, Beilin LJ, et al. Dietary protein and soluble its role in older adults. Practical Gastroenterology, 2003; 27(2): fiber reduce ambulatory blood pressure in treated hypertensives. 43-58. Hypertension, 2001; 38(4): 821-826. 2. Van Horn L. Fiber, lipids, and coronary heart disease. A state- 21. Jones KL, MacIntosh C, Su YC, et al. Guar gum reduces postpran- ment for healthcare professionals from the Nutrition Committee, dial hypotension in older people. J Am Geriatr Soc, 2001; 49(2): American Heart Association. Circulation, 1997; 95: 2701-2704. 162-167. 3. Leung AY, Foster S. Encyclopedia of Common Natural Ingredi- 22. Juarranz M, Calle-Puron ME, Gonzales-Navarro A, et al. Physical ents Used in Food, Drugs and Cosmetics. 2nd ed. NewP York,G exercise, use of Plantago ovato and aspirin, and reduced risk of 28TH colon cancer. Eur J Cancer Prev, 2002; 11 (5): 465-472. John Wiley and Sons. 1996: 427-429. YEAR 4. Anderson JW, Allgood LD, Turner J, et al. Effects of psyllium on 23. O’Keefe SJ, Kidd M, Espitalier-Noel G, et al. Rarity of colon can- glucose and serum lipid responses in men with cer in Africans is associated with low animal product consumption, and hypercholesterolemia. Am J Clin Nutr, 1999; 70: 466-473. not fiber. Am J Gastroenterol, 1999; 94: 1373-1380. 5. Olson BH, Anderson SM, Becker MP, et al. Psyllium-enriched cereals lower blood total cholesterol and LDL cholesterol, but not HDL cholesterol, in hypercholesterolemic adults: results of a meta-analysis. J Nutr, 1997; 127: 1973-1980. 6. Anderson JW, Allgood LD, Lawrence A, et al. Cholesterol-low- 29THTH ering effects of psyllium intake adjunctive to diet therapy in men PG YEARYEAR 05 76 PRACTICAL GASTROENTEROLOGY • FEBRUARYP 2005G 28TH YEAR