Psyllium Seed Husks

Common Names: Psyllium seed husks; Effer-syllium, Fiberall, Hydrocil Instant, Konsyl, Metamucil, Modane Bulk, Perdiem Fiber, Reguloid, Serutan®, Siblin, Syllact, V-Lax, and Others

Clinical Names: Plantago psyllium, Plantago ovata

Summary

botanical names: Plantago psyllium, Plantago ovata

commercial/common names: Flea seed, plantago seed; Psyllium seed husks.

trade names: Effer-syllium®, Fiberall®, Hydrocil Instant®, Konsyl®, Metamucil®, Modane® Bulk, Perdiem Fiber®, Reguloid®, Serutan®, Siblin®, Syllact®, V-Lax®, and others

overview of interactions:
• nutrient affecting drug performance: Digoxin

• food/herb affecting drug performance: Insulin

• foods/herbs affecting drug performance: Lithium

known or potential therapeutic uses: Atherosclerosis, (non-pathological) constipation, diabetes mellitus, diarrhea, diverticular disease, elevated cholesterol levels, elevated triglycerides levels, hemorrhoids, irritable bowel syndrome, obesity, psoriasis, skin irritations (topically).

mechanism: Psyllium is a bulk-forming laxative, high in both fiber and mucilage, with the seeds containing 10-30% mucilage. Upon coming in contact with water the husks swell and form a gelatinous mass. The effect is to keep the feces moist and soft, and produce bulk which will stimulate a reflex contraction in the smooth muscles of the intestines and facilitate emptying.

maintenance dose: Usually not necessary with balanced diet, regular consumption of water, and adequate exercise. Optimal levels of intake have not been established.

therapeutic dose: Psyllium husks are typically used as powdered seeds with typical dosages in the range of 4-20 grams (1 U.S. teaspoon) or 10-20 grams (up to 2 U.S. teaspoons). Once mixed into water the material needs to be consumed before thickening, accompanied by generous fluid intake.

side effects: Psyllium is generally considered extremely safe when used in recommended dosages with adequate fluid intake and lacking the presence of underlying pathological factors, most notably intestinal obstruction. Reported side effects, such as respiratory and skin allergic reactions, have primarily been limited to supplement manufacturing situations where workers have been exposed to high levels of psyllium dust. Some individuals with irritable bowel syndrome may be aggravated by psyllium and other forms on non-soluble fiber; fruit or other dietary forms of soluble fiber may be better tolerated and more effective.

toxicity: No toxicities have been reported or suspected as being associated with psyllium.

contraindications:
• Intestinal obstruction.
• Individuals with disorders of the esophagus should avoid, or at least exercise caution with the use of, psyllium or other forms of fiber in pill form as it may be liable to expand in the esophagus which could potentially could lead to intestinal obstruction.
• Individuals with diabetes mellitus for whom blood glucose levels are unstable should only use psyllium after consulting with their physician or other healthcare professional trained in nutritional therapies.
• Individuals with chronic constipation not improved by dietary changes, increased fluid intake, increased exercise and use of adequate fiber. Further investigation by a healthcare professional may be warranted.



Interactions

nutrient affecting drug performance: Digoxin

• mechanism: hydrophilic fiber, such as psyllium, slows absorption of oral drugs and specifically reduces absorption of digoxin; most studies thus far have indicated that the clinical implications of this reduced absorption may be negligent
(Johnson BF, et al. J Clin Pharmacol 1987 Jul;27(7):487-490.)

food/herb affecting drug performance: Insulin

• mechanism: Diets containing large quantities of some hydrocolloidal fiber sources can delay gastric emptying and reduce the rate of absorption of dietary carbohydrates.

• nutritional concerns: Insulin requirements for diabetics using such fiber sources need to be closely monitored and dosages may need to be modified due to changes in glucose absorption.

foods/herbs affecting drug performance: Lithium

• mechanism: Hydrophilic fiber such as Psyllium can reduce absorption of lithium taken orally.

• reports: There have been reports of individuals taking lithium who experienced decreased lithium levels after they started consuming psyllium husk, in one case two times per day; lithium levels increased to therapeutic levels after stopping the psyllium.
(Toutoungi M, et al. Therapie. 1990 Jul-Aug;45(4):358-60; Perlman BB. Lancet. 1990 Feb 17;335(8686):416.)

• nutritional concerns: Adverse effects from this interaction can usually be avoided by taking the lithium at least one hour before the psyllium.


Please read the disclaimer concerning the intent and limitations of the information provided here.
Do not rely solely on the information in this article.

The information presented in Interactions is for informational and educational purposes only. It is based on scientific studies (human, animal, or in vitro), clinical experience, case reports, and/or traditional usage with sources as cited in each topic. The results reported may not necessarily occur in all individuals and different individuals with the same medical conditions with the same symptoms will often require differing treatments. For many of the conditions discussed, treatment with conventional medical therapies, including prescription drugs or over-the-counter medications, is also available. Consult your physician, an appropriately trained healthcare practitioner, and/or pharmacist for any health concern or medical problem before using any herbal products or nutritional supplements or before making any changes in prescribed medications and/or before attempting to independently treat a medical condition using supplements, herbs, remedies, or other forms of self-care.



References

Blumenthal M, Busse WR, Goldberg A, et al, eds. The Complete Commission E Monographs: Therapeutic Guide to Herbal Medicines. Boston, MA: Integrative Medicine Communications, 1998, 190-192.

Bruttomesso D, Biolo G, Inchiostro S, Fongher C, Briani G, Duner E, Marescotti MC, Iori E, Tiengo A, Tessari P. No effects of high-fiber diets on metabolic control and insulin-sensitivity in type 1 diabetic subjects. Diabetes Res Clin Pract 1991 Aug;13(1-2):15-21.
Abstract: The metabolic effects of a three-month treatment with a high-fiber diet (15 grams of guar-gum added to a standard diet) were investigated in seven type 1 diabetic subjects, with a moderately poor metabolic control. HbA1c levels, daily insulin requirement, cholesterol, triglyceride, amino acid and intermediate metabolite concentrations were evaluated before and following the high fiber diet, both in the postabsorptive state at euglycemia and during a euglycemic, hyperinsulinemic, hyperaminoacidemic clamp. Insulin-mediated glucose utilization, an index of insulin-sensitivity, was also measured during the clamp. Following the diet, no differences in HbA1c levels (7.6 +/- 0.7%----7.3 +/- 0.6%), daily insulin requirement (50 +/- 5----51 +/- 3 U/d), triglyceride, amino acid and intermediary metabolite concentrations in the basal, euglycemic state, were observed. Only cholesterol concentrations decreased significantly (from 165 +/- 12 to 142 +/- 12 mg/dl, P less than 0.01) after the diet. During the clamp, the concentrations of all measured substrates were comparable before and after high fiber treatment. Insulin-mediated glucose disposal was also unchanged by guar-gum treatment. Patients' body weights were not modified by the diet. In conclusion, our study shows that a high fiber diet, obtained with the addition of 15 grams of guar-gum to a standard diet, is of no benefit to IDDM either as regards the metabolic control or insulin sensitivity. Only cholesterol levels were decreased. Therefore, the costs and benefits of these diets in the treatment of IDDM should be reconsidered.

Davidson MH, Dugan LD, Burns JH, Sugimoto D, Story K, Drennan K. A psyllium-enriched cereal for the treatment of hypercholesterolemia in children: A controlled, double-blind, crossover study. Am J Clin Nutr 1996 Jan;63(1):96-102.
Abstract: Psyllium, a water-soluble fiber, has been shown to lower total serum and low-density-lipoprotein (LDL)-cholesterol concentrations in adult hypercholesterolemic subjects and may be effective in the treatment of hypercholesterolemia in children. The effects of a psyllium-enriched cereal were compared with a matched control cereal in a double-blind, crossover fashion in 25 children, 6-18 y old, with hypercholesterolemia. After an 8-wk diet-stabilization period, the subjects were randomly assigned to receive the active or control cereals for 6 wk, followed by a 6-wk washout period and a 6-wk crossover treatment period. Whereas no changes were noted in total and LDL-cholesterol concentrations during consumption of the control cereal, significant changes were seen during the psyllium-cereal periods [0.31 mmol/L (12.1 mg/dL) and 0.28 mmol/L (10.9 mg/dL); P = 0.03 and 0.01, respectively]. The psyllium-enriched cereal was well tolerated throughout the trial. Consumption of the psyllium-enriched cereal resulted in a modest 7% reduction in LDL-cholesterol concentrations compared with the control cereal when used in this pediatric hypercholesterolemic sample. Psyllium offers a potential adjunct to a low-fat diet for the treatment of hypercholesterolemia in the pediatric population because of its ease of incorporation into various foods.

Davidson MH, Maki KC, Kong JC, Dugan LD, Torri SA, Hall HA, Drennan KB, Anderson SM, Fulgoni VL, Saldanha LG, Olson BH. Long-term effects of consuming foods containing psyllium seed husk on serum lipids in subjects with hypercholesterolemia. Am J Clin Nutr. 1998 Mar;67(3):367-376.
Abstract: The effects of consuming foods containing 0 (control), 3.4, 6.8, or 10.2 g psyllium seed husk (PSH)/d for 24 wk on the serum lipid profile were assessed in this randomized, double-blind controlled study. Men and women (n = 286) with LDL-cholesterol concentrations between 3.36 and 5.68 mmol/L (130 and 220 mg/dL) were randomly assigned to one of four treatment groups after following a low-fat diet for > or = 8 wk. At week 24, LDL cholesterol was 3% above baseline in the control group. In the group consuming 10.2 g PSH/d, LDL cholesterol remained below baseline during treatment, with a value 5.3% below that of the control group at week 24 (P < 0.05 compared with the control group). No significant differences were observed in HDL cholesterol or triacylglycerol. Although modest, the effect of 10.2 g PSH/d on LDL cholesterol (relative to the control) persisted throughout the 24-wk treatment period, indicating potential for long-term benefit.

Foster S. Herbs for Your Health. Loveland, CO: Interweave Press, 1996, 74-75.

Johnson BF, Rodin SM, Hoch K, Shekar V. The effect of dietary fiber on the bioavailability of digoxin in capsules. J Clin Pharmacol 1987 Jul;27(7):487-490.
Abstract: Sixteen healthy volunteers were regularly given 0.4 mg of digoxin daily as two capsules with breakfast. After ten days during which breakfast was supplemented with 11 g of bran fiber, steady-state predose mean serum digoxin was lower (0.89 +/- 0.19 versus 0.84 +/- 0.18 ng/mL, P less than .05) and mean 24-hour area under curve determination was lower (30.5 +/- 6.1 versus 28.4 +/- 6.0 ng X hr/mL, P less than .05) than during the control period without bran. Height and time of peak serum digoxin, and 24-hour urinary digoxin were not significantly different. The 6 to 7% reduction in digoxin absorption from capsules is less than that reported from tablets and is probably clinically unimportant.

Leung AY, Foster S. Encyclopedia of Common Natural Ingredients Used in Food, Drugs, and Cosmetics, 2d ed. New York: John Wiley & Sons, 1996, 427-429.

Olson BH, Anderson SM, Becker MP, Anderson JW, Hunninghake DB, Jenkins DJ, LaRosa JC, Rippe JM, Roberts DC, Stoy DB, Summerbell CD, Truswell AS, Wolever TMS, Morris DH, Fulgoni VL 3rd. 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 Oct;127(10):1973-1980.
Note: Study funded by Kellog Company.
Abstract: We conducted a meta-analysis to determine the effect of consumption of psyllium-enriched cereal products on blood total cholesterol (TC), LDL cholesterol (LDL-C) and HDL cholesterol (HDL-C) levels and to estimate the magnitude of the effect among 404 adults with mild to moderate hypercholesterolemia (TC of 5.17-7.8 mmol/L) who consumed a low fat diet. Studies of psyllium cereals were identified by a computerized search of MEDLINE and Current Contents and by contacting United States-based food companies involved in psyllium research. Published and unpublished studies were reviewed by one author and considered eligible for inclusion in the meta-analysis if they were conducted in humans, were randomized, controlled experiments, and included a control group that ate cereal providing </=3 g soluble fiber/d. Eight published and four unpublished studies, conducted in four countries, met the criteria. Analysis of a linear model was performed, controlling for sex and age. Female subjects were divided into two groups to provide a rough estimate of the effect of menopausal status (premenopausal = <50 y, postmenopausal = >/=50 y) on blood lipids. The meta-analysis showed that subjects who consumed a psyllium cereal had lower TC and LDL-C concentrations [differences of 0.31 mmol/L (5%) and 0.35 mmol/L (9%), respectively] than subjects who ate a control cereal; HDL-C concentrations were unaffected in subjects eating psyllium cereal. There was no effect of sex, age or menopausal status on blood lipids. Results indicate that consuming a psyllium-enriched cereal as part of a low fat diet improves the blood lipid profile of hypercholesterolemic adults over that which can be achieved with a low fat diet alone.

Perlman BB. Interaction between lithium salts and ispaghula husk. Lancet 1990 Feb 17;335(8686):416. (Letter)

Spence JD, Huff MW, Heidenheim P, Viswanatha A, Munoz C, Lindsay R, Wolfe B, Mills D. Combination therapy with colestipol and psyllium mucilloid in patients with hyperlipidemia. Ann Intern Med 1995 Oct 1;123(7):493-499.
Abstract: OBJECTIVE: To test whether combining psyllium mucilloid with half the usual dose of colestipol reduces the adverse effects associated with colestipol and maintains or increases its efficacy in the treatment of hyperlipidemia. This strategy might make bile acid sequestrants, which are seldom used because they cause adverse effects such as bloating and constipation, more tolerable and less expensive. DESIGN: A randomized, parallel-group, double-blind, controlled trial. SETTING: An outpatient clinic in a tertiary care hospital. PATIENTS: 121 patients who had moderate primary hypercholesterolemia (total cholesterol level > 6 mmol/L and < 8 mmol/L; triglyceride level < 3 mmol/L) after following a low-fat diet for 1 year (National Cholesterol Education Program Step Two diet). INTERVENTION: 5 g of cellulose placebo; 5 g of colestipol; 2.5 g of colestipol plus 2.5 g of psyllium; or 5 g of psyllium three times daily before meals for 10 weeks. MAIN OUTCOME MEASURES: At baseline and at weeks 4 and 10, fasting blood lipid levels and apoprotein concentrations were measured and a quality-of-life instrument was completed. RESULTS: A combination of 2.5 g of psyllium and 2.5 g of colestipol was better tolerated than and as effective as either 5 g of colestipol alone or 5 g of psyllium alone. The combination therapy and colestipol alone did not differ significantly with respect to changes in individual lipid values. The ratio of total cholesterol to high-density lipoprotein cholesterol (HDL) was reduced by 18.2% (95% CI, 12.3% to 24%) with the combination therapy; by 10.6% (CI, 2.0% to 15.4%) with colestipol alone; by 6.1% (CI, 1.5% to 10.6%) with psyllium alone; and by 0.1% (CI, -4.8% to 7%) with placebo (P = 0.0002). Combination therapy reduced the ratio of total cholesterol to HDL significantly more than did colestipol alone or psyllium alone (P < 0.05). CONCLUSIONS: These findings suggest that adding psyllium to half the usual dose of bile acid sequestrant resins maintains the efficacy and improves the tolerability of these resins.

Toutoungi M, Schulz P, Widmer J, Tissot R. [Probable interaction of psyllium and lithium]. Therapie 1990 Jul-Aug;45(4):358-360. [Article in French] (Letter)

Voderholzer WA, Schatke W, Muhldorfer BE, Klauser AG, Birkner B, Muller-Lissner SA. Clinical response to dietary fiber treatment of chronic constipation. Am J Gastroenterol. 1997 Jan;92(1):95-98.
Abstract: OBJECTIVES: To determine the clinical outcome of dietary fiber therapy in patients with chronic constipation. METHODS: One hundred, forty-nine patients with chronic constipation (age 53 yr, range 18-81 yr, 84% women) at two gastroenterology departments in Munich, Germany, were treated with Plantago ovata seeds, 15-30 g/day, for a period of at least 6 wk. Repeated symptom evaluation, oroanal transit time measurement (radiopaque markers), and functional rectoanal evaluation (proctoscopy, manometry, defecography) were performed. Patients were classified on the basis of the result of dietary fiber treatment: no effect, n = 84; improved, n = 33; and symptom free, n = 32. RESULTS: Eighty percent of patients with slow transit and 63% of patients with a disorder of defecation did not respond to dietary fiber treatment, whereas 85% of patients without a pathological finding improved or became symptom free. CONCLUSION: Slow GI transit and/or a disorder of defecation may explain a poor outcome of dietary fiber therapy in patients with chronic constipation. A dietary fiber trial should be conducted before technical investigations, which are indicated only if the dietary fiber trial fails.

Werbach MR. Foundations of Nutritional Medicine. Tarzana, CA: Third Line Press, 1997. (Review).

Zilly W, Kuhlmann J, Kasper H, Richter E. [Effect of a fiber-rich diet on digoxin resorption]. Med Klin [Prax] 1982 Sep 10;77(19):42-48. [Article in German]
Abstract: In five female healthy volunteers the influence of dietary fiber (wheat bran or carob seed flour) on absorption of digoxin was investigated. Five minutes after ingestion of a formula diet alone or in combination with wheat bran or carob seed flour 0,8 mg beta-acetyldigoxin was given per os. The plasmaconcentration-time curve over eight hours, the area under curve and the cumulative urinary excretion were not changed significantly. It was concluded that there is no influence of dietary fiber on rate or degree of digoxin-absorption.