Gums: the cholesterol effect comes from daily supplements

These are the seed gums that thicken ice cream and salad dressing, guar and locust bean, and not the chewing kind. Pooled across 19 randomized placebo-controlled trials, guar gum supplementation lowered total cholesterol in adults by 19.34 mg/dl (95% CI -26.18 to -12.49) and LDL by 16.19 mg/dl (95% CI -25.54 to -6.83), with no change in triglycerides or HDL. That is a real effect of a real size, and the authors of the meta-analysis still ask for large trials in varied populations before anyone turns it into clinical advice. The catch is the amount, and the form. Every trial above dosed guar gum as a supplement, and EU law lets a food carry the guar gum cholesterol claim only if it provides a daily intake of 10 g of guar gum, with that condition spelled out to the shopper. We hold no portion record for how much gum a jar of sauce or a tub of ice cream contains, so this page cannot say how far an ordinary food falls short of 10 g. There is no official upper limit. EFSA found adults tolerated 0.32 to 1.1 oz (9 to 30 g) of guar gum a day, with some abdominal discomfort from about 15 g, and set no numerical limit. Taken as a supplement, the dry gum needs plenty of liquid: swallowed as granules or pills without enough, it has blocked the esophagus and caused choking. EU product information says to take other medicines 2 hours before or after it, and people with diabetes may need their drug doses changed.

The numbers, per 3.5 oz (100 g)

What your body absorbs

• Across 32 studies of dietary fiber including guar gum, 9 of them in people, no significant correlation was found between fiber consumption and iron absorption or iron status. — 32 studies of dietary fiber including guar gum, pectin and inulin, of which 9 were clinical and 23 in vivo (n = 32 studies) Evidence C source
  No significant correlations between dietary fiber consumption and iron absorption or iron status-related biomarkers

What it does to your health

• Pooling 19 randomized placebo-controlled trials, guar gum supplementation lowered total cholesterol by 19.34 mg/dl and LDL by 16.19 mg/dl in adults, with no change in triglycerides or HDL. — adults in 19 randomized placebo-controlled trials (n = 19 trials) Evidence A source
  Total cholesterol WMD -19.34 mg/dl (95% CI -26.18 to -12.49, P < 0.001), LDL WMD -16.19 mg/dl (95% CI -25.54 to -6.83, P = 0.001), no effect on triglycerides or HDL
• For blood sugar the picture is narrower: across 14 randomized trials guar gum supplementation lowered HbA1c by 0.47 units and did nothing to fasting blood sugar, blood pressure or body mass. — adults in 14 randomized controlled trials, with a subgroup of patients with type 2 diabetes (n = 14 trials) Evidence A source
  HbA1c WMD -0.47 (95% CI -0.75 to -0.18, p = 0.001); no effect on fasting blood sugar, systolic or diastolic blood pressure or body mass; fasting glucose reduced only in type 2 diabetes at doses above 15 g/d
• When 16 soluble fibers were ranked against each other in 46 trials covering 2685 patients with type 2 diabetes, the galactomannans, which is what guar and locust bean gum are, came first for lowering HbA1c and LDL cholesterol. — 2685 adults with type 2 diabetes in 46 randomized controlled trials of 16 fiber types (n = 2685) Evidence A source
  Galactomannans ranked first for HbA1c (SUCRA 92.33%), fasting glucose (85.92%), triglycerides (82.77%) and LDL cholesterol (86.56%); gum arabic ranked first for HDL cholesterol (89.06%)

Safety, limits and interactions

• In 631 patients fed through a tube for five days after gastrointestinal surgery, a formula with 15 g/L of partially hydrolyzed guar gum gave diarrhea in 9.6% against 10.1% on fiber-free formula. — 631 patients receiving enteral nutrition after gastrointestinal surgery, randomized for 5 days (n = 631) Evidence B source
  Diarrhea 9.6% (95% CI 6.3 to 12.8) with PHGG versus 10.1% (95% CI 6.8 to 13.4) without, difference -0.5 (95% CI -5.1 to 4.2), non-inferior; in patients taking at least 4500 calories over 5 days diarrhea 10.4% versus 24.7% and abdominal distension 19.4% versus 38.4%
• In a randomized crossover study in 12 adults, trimethoprim taken with food, with or without guar gum, reached a lower peak and about 22% less total exposure than taken fasting, so guar added nothing beyond the meal. — healthy adult volunteers given trimethoprim suspension 3 mg/kg fasting, with food, or with food and guar (n = 12) Evidence B source
  Peak 2.35 (fasting) vs 1.84 (food) vs 1.97 (food + guar) ug/ml. AUC down 22.2% with food and with food + guar
• In 2024 EFSA concluded that the data submitted were not sufficient to support the safe use of guar gum in infant formula and special medical foods for infants and young children. — infants below and above 16 weeks and young children (infant formula and foods for special medical purposes) Evidence E source
  Submitted data not sufficient to support safe use of E 412 in foods for infants and young children in these categories
• EU product information summarized by EFSA says guar gum must be taken with plenty of liquid and other medicines 2 hours before or after it. Gas and diarrhea affect 1 in 10 or more users at the start, and people with diabetes may need their drug doses changed. — users of guar gum medicinal products in the EU (product information summarized by EFSA) Evidence E source
  Take other medicines 2 h before or after. Flatulence and diarrhea very common (1 in 10 or more) at the start. Antidiabetic doses may need changing
• EFSA notes human cases of severe harm, such as a blocked esophagus or choking, after guar gum or similar gums were swallowed as granules or pills without enough liquid. — people taking guar gum or similar gums as granules or pills without enough liquid Evidence E source
  Severe adverse effects such as esophageal obstruction or asphyxiation reported
• An analysis of 26 FDA reports on a guar gum diet pill found 18 blocked esophagi and 7 small bowel obstructions. The gum can swell 10 to 20 times, and the product was withdrawn in the US and banned in Australia. — US reports of suspected reactions to the guar gum diet pill Cal-Ban 3000 (n = 26) Evidence D source
  18 esophageal obstructions, 7 small bowel obstructions, 1 death of uncertain cause. Half of esophageal cases had prior esophageal or gastric disorders
• In 10 healthy volunteers, guar gum lowered early blood levels of digoxin without changing the total absorbed, and significantly reduced peak level and total exposure of penicillin V. — healthy volunteers given digoxin and phenoxymethyl penicillin with or without guar gum (n = 10) Evidence C source
  Early digoxin levels lower, 24 h urinary digoxin unchanged. Peak penicillin and AUC significantly reduced
• In 6 healthy volunteers, taking guar gum with 1700 mg of metformin slowed its absorption over the first 6 hours, which the authors say may weaken its glucose-lowering action. — healthy subjects given 1700 mg metformin with a standardized meal (n = 6) Evidence C source
  Slower metformin absorption over the first 6 hours with guar
• In a 4-week randomized crossover trial in 9 people with type 2 diabetes, 15 g of guar gum a day did not change absorption of glibenclamide and lowered fasting blood glucose to 10.5 from 204 mg/dL (11.3 mmol/l) on placebo. — patients with type 2 diabetes on glibenclamide 3.5 mg twice daily, guar gum 5 g three times daily with meals (n = 9) Evidence B source
  Glibenclamide Cmax 223 vs 184 ng/ml and AUC0-6 729 vs 560, both NS. Fasting glucose 189 vs 204 mg/dL (10.5 vs 11.3 mmol/l) (p<0.05)
• In 10 healthy volunteers, 4.75 g of guar gum taken with or 30 minutes after glipizide did not significantly change how much of the drug was absorbed. — healthy volunteers given 2.5 mg glipizide with 4.75 g guar gum and a standard breakfast (n = 10) Evidence C source
  Glipizide AUC to 8 h not significantly different. No substantial deleterious effect on absorption

What people believe that the data does not support

• Guar gum holds one of the rare authorized health claims in the EU register, for maintaining normal blood cholesterol, while 29 other claims made for it were rejected. — EU register of nutrition and health claims, snapshot of 2026-09-21 (n = 1 authorized, 29 rejected) Evidence E source
  Claim POL-HC-6382 authorized for maintenance of normal blood cholesterol levels
• The threshold behind that claim is 10 g of guar gum a day, and EU law requires that condition to be stated to the consumer. — foods sold in the EU bearing the guar gum cholesterol claim Evidence E source
  Claim permitted only for food providing a daily intake of 10 g of guar gum, with that condition to be communicated to the consumer
• A meta-analysis of 20 randomized trials found guar gum did not lower body weight (-0.09 lb (95% CI -4.9 to 4.6; metric: -0.04 kg, -2.2 to 2.1)), while abdominal pain, gas, diarrhea and cramps were common and 3% of patients dropped out because of them. — adults in randomized trials of guar gum monopreparations reporting body weight (n = 20 trials) Evidence A source
  Weight WMD -0.09 lb (95% CI -4.9 to 4.6; metric: -0.04 kg, -2.2 to 2.1). 11 patients (3%) dropped out for adverse events

Who this works differently for

• EFSA found that adults tolerated 0.32 to 1.1 oz (9 to 30 g) of guar gum a day, but some had abdominal discomfort from about 15 g a day, and in one study 5 of 22 children with diabetes given 13.5 g a day reported abdominal discomfort. — adults in guar gum intervention studies, and 22 children with diabetes in one study Evidence E source
  9 to 30 g a day well tolerated in adults. Some abdominal discomfort from about 15 g a day. 5 of 22 children with discomfort at 13.5 g a day
• EU product information summarized by EFSA says guar gum medicines are mostly not meant for children and adolescents, and can be used in pregnancy and breastfeeding if medically needed. — children, adolescents, pregnant and breastfeeding women using guar gum medicinal products Evidence E source
  Use in children and adolescents mostly not foreseen (some products from 15 years). Pregnancy and lactation: possible if medically needed
• In a randomized trial in 48 pregnant women with cholestasis of pregnancy, guar gum taken until delivery eased itching and stopped the rise in bile acids seen on placebo, without side effects. — pregnant women with intrahepatic cholestasis of pregnancy (n = 48) Evidence B source
  Pruritus eased or did not worsen with guar (worsened on placebo, p<0.05). Serum bile acids unchanged vs rose on placebo. No side effects

What is still unknown

• Even after 14 pooled trials the authors of the glycemic meta-analysis say the extant clinical trials are not sufficient to form guidelines for clinical practice. — adults in 14 randomized controlled trials of guar gum supplementation (n = 14 trials) Evidence A source
  Existing trials judged insufficient to form guidelines for clinical practice

The bottom line

For blood sugar the effect is smaller and narrower. Across 14 randomized controlled trials guar gum supplementation lowered HbA1c by 0.47 (95% CI -0.75 to -0.18) in adults and did nothing to fasting blood sugar, blood pressure or body mass. Fasting glucose moved only in the type 2 diabetes subgroup, at doses above 15 g a day, and that subgroup rests on fewer trials than the headline figure. When 16 soluble fibers were ranked against each other in 46 randomized trials covering 2685 patients with type 2 diabetes, the galactomannans came first for HbA1c (SUCRA 92.33%) and for LDL cholesterol (86.56%). Galactomannan is the family guar and locust bean gum belong to. A ranking tells you which fiber came out on top and not by how much it beat the next one, and most comparisons in that network carried low or moderate certainty. The old worry that gums strip minerals out of a meal was not confirmed. A systematic review of 32 studies of dietary fiber, 9 of them in people and 23 in vivo, found no significant correlation between fiber intake and iron absorption or iron status biomarkers. The review adds that its own evidence base is not substantial enough to close the question, and most of what it pooled was animal work. The one tolerance measurement we hold is a hospital one. Among 631 patients tube fed for five days after gastrointestinal surgery, a formula with 15 g/L of partially hydrolyzed guar gum produced diarrhea in 9.6% (95% CI 6.3 to 12.8) against 10.1% (95% CI 6.8 to 13.4) on the fiber-free formula, which met the trial non-inferiority mark. It ran open label, for five days, in post-surgical patients, on a partially hydrolyzed gum delivered through a tube in liquid. That is not the same thing as swallowing 10 g of gum powder daily. Outside hospital, EFSA sums up that adults tolerated 9 to 30 g a day, some with abdominal discomfort from about 15 g, and in one study 5 of 22 children with diabetes given 13.5 g a day reported abdominal discomfort. Across 20 weight-loss trials, guar gum did not lower body weight, abdominal pain, gas, diarrhea and cramps were common, and 3% of patients dropped out because of them. The serious harm is mechanical. The gum can swell 10 to 20 times, and 26 FDA reports on a guar gum diet pill counted 18 blocked esophagi and 7 small bowel obstructions. The product was withdrawn in the US and banned in Australia. EFSA notes cases of a blocked esophagus or choking when guar or similar gums were swallowed as granules or pills without enough liquid, and EU product information says to take it with plenty of liquid. Gums can also change how medicines arrive. In small studies, guar slowed metformin absorption in 6 healthy people and cut peak and total penicillin V levels, while it did not change glibenclamide or glipizide absorption. In 9 people with type 2 diabetes on glibenclamide, 15 g a day lowered fasting blood glucose further, to 10.5 from 204 mg/dL (11.3 mmol/l), which matters for anyone at risk of low blood sugar. EU product information says to take other medicines 2 hours before or after guar gum and that people with diabetes may need their drug doses changed. For babies, EFSA found the data not sufficient to support guar gum in infant formula and special medical foods for infants and young children. EU product information says guar gum medicines are mostly not meant for children and adolescents and can be used in pregnancy and breastfeeding if medically needed, a label statement with no pregnancy outcome data behind it. Guar gum holds one authorized EU health claim, for maintaining normal blood cholesterol, and 29 other claims made for it were rejected. The authors of the glycemic meta-analysis put the rest plainly: the trials so far are not sufficient to form guidelines for clinical practice.

Sources

1. gumx-r4-06 · systematic review
   The results showed no significant correlations between consumption of dietary fiber to iron absorption/status-related biomarkers.
   Crit Rev Food Sci Nutr, 2023 · checked 2026-09-24
2. gumx-r4-01 · systematic review and meta-analysis
   Pooled analysis of nineteen randomised controlled trials (RCT) revealed that guar gum supplementation led to significant reductions in TC (WMD: -19·34 mg/dl, 95 % CI -26·18, -12·49, P < 0·001) and LDL (WMD: -16·19 mg/dl, 95 % CI -25·54, -6·83, P = 0·001).
   Br J Nutr, 2023 · checked 2026-09-24
3. gumx-r4-02 · systematic review and meta-analysis
   Pooled analysis of 14 randomized controlled trials (RCTs) revealed that guar gum supplementation led to significant reductions in hemoglobin A1c (HbA1c) (WMD: -0.47 mg/dL, 95% CI: -0.75, -0.18, p = 0.001). However, there was no effect on fasting blood sugar (FBS), systolic and diastolic blood pressure, and body mass among adults in comparison with the control group.
   Diabetes Res Clin Pract, 2023 · checked 2026-09-24
4. gumx-r4-03 · systematic review and network meta-analysis
   Galactomannans had the highest effect on reducing the levels of HbA1c (SUCRA: 92.33%) and fasting blood glucose (SUCRA: 85.92%)...Galactomannans were ranked first in reducing the levels of triglycerides (SUCRA: 82.77%) and LDL cholesterol (SUCRA: 86.56%).
   Am J Clin Nutr, 2023 · checked 2026-09-24
5. gumx-r4-07 · randomized controlled trial
   The incidence of diarrhea was 9.6 % (95 % confidence interval [CI]: 6.3 to 12.8) in the experimental group and 10.1 % (95 % CI: 6.8 to 13.4) in the control group, with an absolute difference of -0.5 (95 % CI: -5.1 to 4.2) confirming non-inferiority (P < 0.001).
   Clin Nutr, 2026 · checked 2026-09-24
6. hf2-gum-10 · randomized controlled trial
   The mean peak serum concentration was higher when fasting subjects were treated (mean: 2.35, 1.84 and 1.97 micrograms/ml for the fasting, food and food + guar groups, respectively; ANOVA p less than 0.001 for the difference between fasting and non-fasting values). The times of the peak serum concentrations did not differ. Food ingestion decreased the area under the curve by 22.2%, as did food + guar.
   Eur J Clin Pharmacol, 1987 · checked 2026-10-08
7. hf2-gum-12 · EFSA scientific opinion
   The Panel concluded that the submitted data are not sufficient to support the safe use of guar gum (E 412) in food for infants (below and above 16 weeks of age) and young children under FC 13.1.1, 13.1.5.1 and 13.1.5.2.
   EFSA FAF Panel, Re-evaluation of guar gum (E 412) as a food additive in foods for infants below 16 weeks of age and follow-up of its re-evaluation as a food additive for uses in foods for all population groups, EFSA Journal 2024;22(5):e8748 · checked 2026-10-08
8. hf2-gum-2 · EFSA scientific opinion
   Contraindications warn that the blood glucose level might change and in the case of diabetic patients there might be need to change the doses of other antidiabetic drugs (especially oral antidiabetics). Guar gum must be administered with ample volumes of liquid, avoiding alcoholic liquids and other medication should be consumed 2 h before or after intake of guar gum, since guar gum might influence absorption of other substances. Adverse effects reported after consumption of guar gum are gastrointestinal discomforts including gas in the intestine (flatulence) and diarrhoea, especially in the beginning of the use, with a frequency of very common (≥ 1/10)
   EFSA ANS Panel, Re-evaluation of guar gum (E 412) as a food additive, EFSA Journal 2017;15(2):4669 · checked 2026-10-08
9. hf2-gum-3 · EFSA scientific opinion
   The Panel noted that these restrictions have to be seen against the background of human cases on severe adverse effects, such as oesophageal obstruction or asphyxiation, after oral intake of guar gum or other gums/hydrocolloids with similar physicochemical properties as guar gum in the form of granules or pills without enough liquid
   EFSA ANS Panel, Re-evaluation of guar gum (E 412) as a food additive, EFSA Journal 2017;15(2):4669 · checked 2026-10-08
10. hf2-gum-4 · case series
    There were 18 instances of esophageal obstruction, seven instances of small bowel obstruction, and one individual who was reported to have died after ingestion of Cal-Ban 3000, but for whom insufficient details were provided to assess causation. ... The water-holding capacity and gel-forming tendency of guar gum permits it to swell in size 10- to 20-fold, and may lead to luminal obstruction, especially when an anatomic predisposition exists. Such products have been banned in Australia, and Cal-Ban 3000 has recently been removed from the market in the United States.
    Am J Gastroenterol, 1992 · checked 2026-10-08
11. hf2-gum-6 · controlled crossover study
    Guar gum reduced serum digoxin concentration during the early absorption period, but a similar amount of digoxin was found in 24 h urine whether given with or without guar gum. Both the peak penicillin concentration and the area under the serum curve were significantly reduced by the gum.
    Eur J Clin Pharmacol, 1984 · checked 2026-10-08
12. hf2-gum-7 · controlled drug absorption study
    The effect of Guar gum on the digestive absorption of metformin was tested in 6 healthy subjects given 1700 mg of metformin with a standardised meal. Metformin blood levels showed that when given together with Guar there was a reduction in the absorption rate over the first 6 hours. These findings suggest that combination therapy may diminish the anti-hyperglycaemic action of metformin.
    Horm Metab Res, 1989 · checked 2026-10-08
13. hf2-gum-8 · randomized crossover trial
    The fasting blood glucose (10.5 +/- 3.4 mmol/l on guar gum vs 11.3 +/- 3.7 mmol/l on placebo, p less than 0.05) and serum total cholesterol (5.9 +/- 1.4 mmol/l on guar gum vs 6.6 +/- 1.6 mmol/l on placebo; p less than 0.05) levels were lower after the treatment with guar gum than placebo. ... The administration of guar gum together with glibenclamide did not change significantly the maximum concentration (223 +/- 196 ng/ml on guar gum vs 184 +/- 138 ng/ml on placebo; n = 7, NS) or area under the curve (AUC0-6) [729 +/- 813 (ng/ml) X h on guar gum vs 560 +/- 513 (ng/ml) X h on placebo; NS] of glibenclamide.
    Int J Clin Pharmacol Ther Toxicol, 1990 · checked 2026-10-08
14. hf2-gum-9 · controlled drug absorption study
    The AUCs for glipizide were calculated up to 8 hours. They did not differ significantly between the treatment, although there was a non-significant trend to lower values during Treatment 3. ... According to this single dose study, guar gum does not have any substantial deleterious effect on the absorption of glipizide.
    Eur J Clin Pharmacol, 1985 · checked 2026-10-08
15. gumx-r4-04 · claims register
    POL-HC-6382 Guar Gum Guar gum contributes to the maintenance of normal blood cholesterol levels Authorised
    EU Register on nutrition and health claims, claim POL-HC-6382, snapshot 2026-09-21 · checked 2026-09-24
16. gumx-r4-05 · regulation
    The claim may be used only for food which provides a daily intake of 10 g of guar gum. In order to bear the claim, information shall be given to the consumer that the beneficial effect is obtained with a daily intake of 10 g of guar gum.
    Commission Regulation (EU) No 432/2012, consolidated text, annex of permitted health claims · checked 2026-09-24
17. hf2-gum-5 · meta-analysis
    The meta-analysis indicated a nonsignificant difference in patients receiving guar gum compared with patients receiving placebo (weighted mean difference -0.04 kg; 95% confidence interval (CI): -2.2 to 2.1). ... Adverse events most frequently reported were abdominal pain, flatulence, diarrhea, and cramps. Overall, 11 patients (3%) dropped out owing to adverse events.
    Am J Med, 2001 · checked 2026-10-08
18. hf2-gum-1 · EFSA scientific opinion
    Oral intake of large amount of guar gum (9,000–30,000 mg/person corresponding to 128–429 mg/kg bw per day) was well tolerated in humans. In general, in most studies after consumption of around 15,000 mg per day corresponding to 214 mg/kg bw per day, some individuals experienced abdominal discomfort (Pittler and Ernst, 2001 ). In one interventional study with diabetic children, abdominal discomforts were reported in 5 out of 22 children given 13,500 mg guar gum per day corresponding to 314 mg/kg bw per day
    EFSA ANS Panel, Re-evaluation of guar gum (E 412) as a food additive, EFSA Journal 2017;15(2):4669 · checked 2026-10-08
19. hf2-gum-11 · EFSA scientific opinion
    In most cases, the usage in children and adolescent is not foreseen, while some products would include adolescents of 15 years of age and older. Usage in pregnancy and lactation is possible if medically needed.
    EFSA ANS Panel, Re-evaluation of guar gum (E 412) as a food additive, EFSA Journal 2017;15(2):4669 · checked 2026-10-08
20. hf2-gum-13 · randomized controlled trial
    Forty-eight patients with intrahepatic cholestasis of pregnancy were randomized double-blind to receive either guar gum or placebo until delivery. ... Guar gum relieved the intensity of pruritus without any side effects and prevented the rise in serum bile acid concentration in this placebo-controlled and double-blind study of patients with intrahepatic cholestasis of pregnancy.
    Acta Obstet Gynecol Scand, 2000 · checked 2026-10-08
21. gumx-r4-08 · systematic review and meta-analysis
    However, the extant clinical trials, thus far, are not sufficient enough to form guidelines for clinical practice.
    Diabetes Res Clin Pract, 2023 · checked 2026-09-24