Comprehensive Guide to Psyllium
(Psyllium husk fiber or Psyllium seed)

Psyllium (Psyllium husk fiber or Psyllium seed)Dr. James Meschino DC, MS, ND
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General Features
Psyllium is native to Iran and India. It is currently cultivated all over the world and the seed husks are used medicinally. The seed husks are unique in that they contain a high level of mucilage content and soluble fiber, which provide a health-promoting effect on the function of the large bowel, reduce high cholesterol levels, and help regulate blood sugar levels in diabetics. Psyllium seeds have been used for many years in traditional herbal medicine.
Principle Active Constituents
Mucilage and Soluble Fiber - Psyllium seed husks are high in both mucilage (10 – 30% by weight) and soluble fiber. The laxative effect is due to swelling of the husk when it comes into contact with water, creating a gelatinous fecal mass that stimulates peristalsis (movement of fecal content through the intestinal tract) and voiding of the bowel (bowel movements). 3 The soluble fiber is responsible for its ability to lower cholesterol and regulate blood sugar.
Clinical Application and Mechanism of Action
1. Laxative
The laxative properties of Psyllium are due to the ability of the mucilage portion of the seed husk to absorb water, in a similar fashion as a sponge. This swelling creates a large gelatinous mass that applies pressure to the bowel wall and thereby, stimulates more frequent contractions of the muscles that rhythmically contract to propel fecal matter through the large intestine. Due to the high water content of this gelatinous fecal mass, the developing fecal matter is softened, and hydrated, provided sufficient water is ingested to allow this to occur. Thus, as a bulk-forming laxative, Psyllium supplementation encourages more rapid movement of fecal contents through the large bowel, softens the stool for easier elimination, and by absorbing water it may help to dilute the effects of bowel carcinogens; a means proposed to reduce risk of colon and rectal cancers. 3,6
Studies show that Psyllium is highly effective in relieving lifestyle-related and functional constipation, but not in cases caused by diseases of the intestinal tract. 7
In functional cases, Psyllium has been shown to be better than, or at least as effective as, standard laxative medications (e.g., docusate sodium). Psyllium also has fewer side effects than most other laxative medications and offers better stool consistency. 6
2. Diarrhea
Psyllium has been used successfully to control diarrhea due to its ability to increase the thickness of stools. 8,9 This also has important application for HIV patients, taking Protease Inhibitor drugs, which commonly produce diarrhea and thereby further contribute to malnutrition, weight loss, and immunosuppression, often seen in these patients. Psyllium is one of the interventions that is shown to reduce diarrhea in these patients.
3. High Cholesterol
Based upon substantial clinical and scientific evidence, the United States Food and Drug Administration (FDA) has approved a health claim for Psyllium in regards to its ability to reduce cardiovascular disease risk. 4 This is primarily attributable to the ability of the soluble fiber fraction of Psyllium seed husk to drag cholesterol and bile acids (bile acids may otherwise be re-absorbed and converted into cholesterol within the liver) through the intestinal tract and eliminate them from the body in the stool. 4,11 It may also stimulate the liver to convert cholesterol to bile acids, lowering the total cholesterol load on the body. 11,13 Through these mechanisms, Psyllium supplementation has been shown to reduce blood cholesterol levels to a modest degree in patients with high cholesterol and in patients whose cholesterol levels fall within the normal range. Numerous double-blind studies have shown that Psyllium supplementation can lower total cholesterol and LDL-cholesterol (bad cholesterol), with no significant effect on HDL-cholesterol levels (good cholesterol). 12,14 Studies involving children have also shown a significant cholesterol lowering effect in subjects with elevated cholesterol levels. 15
In the Lipid Assessment Treatment Project (L-TAP), the success rates for lipid-regulating therapies and treatments according to the National Cholesterol Education Program (NCEP) Adult Treatment Panel II (ATP II) were reported to be a 43% reduction in LDL-cholesterol for bile acid sequestrant drugs, 39% for high-dose niacin, 32% for gemfibrozil, 28% for Psyllium fiber, 40% for statin drugs (e.g., lovastatin), and 40% for combination therapies. 25
A meta-analysis conducted to evaluate the hypolipidemic effects of Psyllium fiber (which pooled eight controlled studies, involving 384 and 272 subjects with mild to moderate hypercholesterolemia receiving Psyllium or cellulose placebo, respectively), revealed that Psyllium supplementation (10.2 gm per day), as an adjunct to a low fat diet, lowered total cholesterol by 4%, LDL-cholesterol by 7% and the ratio of apolipoprotein (apo) B to apo A-1 by 6%, relative to the placebo. The researchers concluded that Psyllium is well tolerated and safe when used as an adjunct to a low-fat diet in individuals with mild-to-moderate hypercholesterolemia. 26
A study involving 34 hypercholesterolemic men with type II diabetes showed that men receiving 5.1 gm of Psyllium 20-30 minutes prior to breakfast and evening meals for eight weeks, reduced their total cholesterol levels on average by 8.9% and LDL-cholesterol levels by 13%, compared to the placebo group. As well, their post-lunch glucose levels dropped by 4.2%, compared with a 12.7% increase in the placebo group.
4. Diabetics and Blood Sugar
The soluble portion of Psyllium has been shown to improve blood glucose regulation in both insulin-dependent and non-insulin dependent diabetic patients. 16,17,18 Soluble fiber is known to slow the absorption of simple sugars (monosaccharides) from the intestinal tract, helping to prevent a hyperglycemic response following a meal containing carbohydrate foods. Challenge studies have shown that Psyllium supplementation can significantly lower the glycemic response to a carbohydrate test meal in these patients, producing lower, more controlled blood glucose levels, postprandially. 12
5. Ulcerative Colitis
A double-blind trial involving patients with ulcerative colitis showed that Psyllium supplementation significantly reduced symptoms such as bleeding, and helped patients remain in remission longer (upon ingesting 20 gm of ground Psyllium seeds, twice daily with water), compared to the use of the medication mesalamine alone. However, the combined effects of mesalamine and Psyllium produced the best overall outcomes in this study. 19
6. Irritable Bowel Syndrome (IBS)
Some studies suggest that Psyllium supplementation may be helpful in the management of IBS. An illuminating study by J. Holtz, et al, showed that both Psyllium and wheat bran supplementation improved stool frequency and consistency in a 6-week trial of thirty IBS patients. However, the Psyllium group demonstrated superior outcomes with respect to stool frequency and degree of abdominal distension, making it the preferred intervention, according to the researchers involved in this trial. 20 As there are few effective interventions in the treatment of IBS, it is worth noting that well-designed trials support the use of Psyllium supplementation in these cases, although outcomes may vary greatly from patient to patient.
7. Blood Pressure
There is some evidence to suggest that Psyllium supplementation can help reduce high blood pressure by enhancing the fecal excretion of sodium absorbed in the intestinal tract. Although this evidence comes mostly from animal studies, a trial involving sixty-eight hypercholesterolemic patients demonstrated a small reduction in blood pressure in patients receiving 8 gm of Psyllium supplementation each day for four weeks. Their cholesterol levels were also reduced, providing a desirable synergistic effect in reducing cardiovascular disease risk.
Dosage and Standardized Grade
1. Constipation (from non organic disease), Diarrhea, IBS and Non-insulin Dependent Diabetes and Insulin-Dependent Diabetes: 5 gm (one teaspoon), three times per day, or 10 to 30 gm of whole seeds per day, taken in three evenly divided doses. This should be stirred into a large glass of water or fruit juice and ingested as a beverage (before it thickens in the glass). 1,5,6,20
2. Cholesterol-lowering: 5 gm (one teaspoon), two or three times per day. Follow instructions above. 1,2,11,25,26,27
3. Ulcerative Colitis: 5 gm (one teaspoon), twice per day; or 10 gm whole seed, twice per day. Follow instructions above.
Adverse Side Effects, Toxicity and Contraindications
Psyllium supplementation has been shown to be safe when taken at recommended doses. 1 Some patients with IBS may see a worsening of their condition upon supplementation with Psyllium as has been reported in some cases. 1,21 Patients with bowel obstruction and diabetics with extreme blood sugar sensitivities should not use Psyllium. 21 Allergic skin reactions from Psyllium are primarily limited to people working in factories manufacturing Psyllium products.
Drug-Nutrient Interactions
Psyllium supplementation may potentiate the action of the following medications and thereby lower the required dosages of these medications:
1. Hypoglycemic Medications (e.g., glyburide, glipizide, metformin, rosiglitazone, glimepiride, tolbutamide, acarbose, chlorpropamide etc.) 18
2. Insulin 18
3. Cholesterol-lowering drugs.
Pregnancy and Lactation
During pregnancy and lactation, the only supplements that are considered safe include standard prenatal vitamin and mineral supplements. All other supplements or dose alterations may pose a threat to the developing fetus and there is generally insufficient evidence at this time to determine an absolute level of safety for most dietary supplements other than a prenatal supplement. Any supplementation practices beyond a prenatal supplement should involve the cooperation of the attending physician (e.g., magnesium and the treatment of preeclampsia.)

References: Pregnancy and Lactation
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2. Reavley NM. The New Encyclopedia of Vitamins, Minerals, Supplements, and Herbs. Evans and Company Inc. 1998.
3. The Healing Power of Herbs (2nd edition). Murray M. Prima Publishing 1995.
4. Boon H and Smith M. Health Care Professional Training Program in Complementary Medicine. Institute of Applied Complementary Medicine Inc. 1997.
1. Healthnotes, Inc. 2001. Psyllium
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3. Leung AY, Foster S. Encyclopedia of Common Natural Ingredients Used in Food, Drugs, and Cosmetics, 2nd ed. New York:John Wiley & sons 1996:427-9
4. Jenkins, DJ, Kendall CW, Vuksan V, Vidgen E, Parker T, Faulkner D, et al. Soluble fiber intake at a dose approved by the US Food and Drug Administration for a claim of health benefits: serum lipid risk factors for cardiovascular disease assessed in a randomized controlled crossover trial. Am J Clin Nutr May 2002;75(5):834-9
5. Frati Muari AC, et al. Lowering glycemic index of food by acarbose and Plantago psyllium mucilage. Arc Med Res Jun1998;29(2):137-41
6. McRorie JW et al. Psyllium is superior to docusate sodium for treatment of chronic constipation. Aliment Pharmacol Ther May1998;12(5):491-7
7. Voderholzer WA, Schatke W, Mühldorfer BE, et al. Clinical response to dietary fiber treatment of chronic constipation. Am J Gastroenterol 1997;92:95-8
8. Washington N et al. Moderation of lactulose-induced diarrhea by psyllium: effects on motility and fermentation. Am J Clin Nutr Feb1998:;67(2):317-21
9. Leib MS. Treatment of chronic idiopathic large-bowel diarrhea in dogs with a highly digestible diet and soluble fiber: a retrospective review of 37 cases. J Vet Intern Med Jan2000;14(1):27-32
10. Sherman DS, Fish DN. Management of Protease Inhibitor-associated Diarrhea. Clin Infect Dis Jun2000;30(6):908-14
11. Davidson MH, et al. Long-term effects of consuming foods containing psyllium seed husk on serum lipids in subjects with hypercholesterolemia. Am j Clin Nutr Mar1998;67(3):367-76
12. Anderson JW, Aligood LD, Turner J, et al. Effects of psyllium on glucose and serum lipid response in men with type 2 diabetes and hypercholesterolemia. Am J Clin Nutr 1999;70:466-73
13. Schwesinger WH, et al. Soluble dietary fiber protects against cholesterol gallstone formation. Am J Surg Apr1999;177(4):307-10
14. Oson 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 1997;127:1973-80
15. Davidson MH, Dugan LD, Burns JH, et al. A psyllium-enriched cereal for the treatment of hypercholesterolemia in children: A controlled, double-blind, crossover study. Am J Clin Nutr 1996;63:96-102
16. Florholmen J, Arvidsson-Lenner R, Jorde R, Burhol PG. The effect of Metamucil on postprandial blood glucose and plasma gastric inhibitory peptide in insulin-dependent diabetics. Acta Med Scand 1982;212:237-9
17. Rodriguez-Moran M, Guerrero-Romero F, Lazcano-Burciaga G. Lipid- and glucose-lowering efficacy of plantago psyllium in type II diabetes. J Diabetes Complicaitons 1998;12:273-8
18. Anderson JW, Allgood LD, Turner J et al. Effects of psyllium on glucose and serum lipid response in men with type 2 diabetes and hypercholesterolemia. Am J Clin Nutr 1999;70:466-73
19. Fernandez-Banares F, Hinojosa J, Sanchez-Lombrana JL, et al., Randomized clinical trial of Plantago ovata seeds (dietary fiber as compared with mesalamine in maintaining remission in ulcerative colitis. Am J Gastroenterol 1999;94:427-33
20. Hotz J et al. Effectiveness of plantago seed husks in comparison with wheat brain on stool frequency and manifestations of irritable colon syndrome with constipation. Med Klin Dec1994;89(12):645-51
21. Blumenthal M, Busse WR, Goldberg A, et al. (eds). The Complete Commission E Monographs: Therapeutic Guide to herbal medicines, Boston, MA: Integrative Medicine Communication 1998:190-2
22. Obata K et al. Dietary fiber, psyllium, attenuates salt-accelerted hypertension in stroke-prone spontaneously hypertensive rats. J Hypertens Dec1998;16(12 Pt 2):1959-64
23. Brown L et al. Cholesterol-lowering effects of dietary fiber: a meta-analysis. Am J Clin Nutr Jan1999;69(1):30-42
24. Anderson JW et al. Long-term cholesterol-lowering effects of psyllium as an adjunct to diet therapy in the treatment of hypercholesterolemia. Am J Clin Nutr Jun2000;71(6):1433-8
25. Gaw A. A new reality: achieving cholesterol-lowering goals in clinical practice. Atheroscler Suppl 2002Apr;2(4):5-11
26. Anderson JW, Allgood LD, Lawrence A, Altringer LA, Jerdack GR, Hengehold DA et al. Cholesterol-lowering effects of psyllium intake adjunctive to diet therapy in men and women with hypercholesterolemia: meta-analysis of 8 controlled trials.
27. Larsen HR. Psyllium decreases cholesterol. Alive: Canadian journal of Health & Nutrition 0228586X Feb2000;208