Chicory: what the trials actually tested

The chicory on our data table is witloof, the pale salad head you braise or eat raw. Almost every trial on this page tested something else, a powder of inulin-type fructans pulled out of chicory root and eaten at 3 to 20 g a day, stirred into a drink or baked into a bar. Hold that gap in mind while you read the numbers. Across 32 randomised trials, in people who were healthy and in people with health problems, the powder lowered body weight by 0.97 kg against placebo, so close to one kilogram on average. The trials disagreed with each other badly, 73 percent of the variation sits between studies rather than within them, and neither the dose nor how long people took it explains much of that. Pooling 50 trials in 2525 people aged 0 to 83, it raised gut Bifidobacterium by a standardised mean difference of 0.83. In 197 people with fatty liver disease across 5 trials, alanine transaminase fell by 17.53 U/L and the blood lipids did not move. Those are the three strongest results we hold, and all three are about an extract. One trial did feed the vegetable itself: 100 g of Brussels chicory a day for a week stretched time to exhaustion by 8.3 percent in men and 12.2 percent in women, in 32 untrained students, single-blind, and the researchers call it a pilot.

The numbers, per 100 g

What a real portion looks like

• Adding 7 g a day of chicory root fructans to snack bars raised Bifidobacterium from 5.3 to 18.7 percent of gut bacteria in adults who normally eat little fibre. — 50 healthy adults with habitually low fibre intake, two 4-week placebo-controlled double-blind crossover trials, 7 g/d and 3 g/d (n = 50) Evidence B source
  Bifidobacterium relative abundance 5.3 ± 5.9 to 18.7 ± 15.0 percent at the moderate dose, no difference in gastrointestinal symptoms

What your body absorbs

• Six weeks of chicory oligofructose and long-chain inulin raised fractional absorption of both calcium and magnesium in 15 postmenopausal women. — 15 postmenopausal women aged about 72 years, double-blind placebo-controlled crossover, 6 weeks per arm (n = 15) Evidence B source
  Fractional calcium and magnesium absorption higher than placebo (P < 0.05), with about two thirds of women responding

What it does to your health

• Across 32 randomised trials in healthy people and people with health impairments, chicory inulin-type fructans lowered body weight by 0.97 kg against placebo, an average of less than a kilogram with 73 percent heterogeneity between trials. — participants of 32 randomised controlled trials, healthy and with health impairments, n=1184 for body weight (n = 1184) Evidence A source
  Body weight -0.97 kg (95% CI -1.34 to -0.59), BMI -0.39 kg/m2, waist -1.03 cm, fat mass -0.37 kg
• Pooling 50 randomised trials with 2525 people, 3 to 20 g a day of chicory inulin-type fructans raised gut Bifidobacterium by a standardised mean difference of 0.83. — 2525 participants aged 0 to 83 years in 50 randomised controlled trials, minimum 7 days of supplementation (n = 2525) Evidence A source
  Standardised mean difference 0.83 (95% CI 0.58 to 1.08) for Bifidobacterium abundance at 3 to 20 g a day
• In 197 patients with fatty liver disease across 5 trials, chicory supplementation lowered alanine transaminase by 17.53 U/L and left the lipid profile unchanged. — 197 patients with non-alcoholic fatty liver disease in 5 randomised clinical trials (n = 197) Evidence A source
  Alanine transaminase -17.53 U/L (95% CI -32.64 to -2.42), aspartate transaminase -7.07 U/L (95% CI -13.82 to -0.32), no effect on lipids, ALP or GGT
• Four weeks of 12 g of chicory inulin a day raised stool frequency from a median of 3.0 to 4.0 per week in adults with constipation. — 44 healthy volunteers with constipation, randomised double-blind placebo-controlled crossover, 3 doses of 4 g a day for 4 weeks (n = 44) Evidence B source
  Median 4.0 stools per week (IQR 2.5 to 4.5) versus 3.0 (IQR 2.5 to 4.0) on placebo, P = 0.038, with softer stools
• Seven days of Brussels chicory juice lengthened time to exhaustion by 8.3 percent in men and 12.2 percent in women. — 32 untrained college students, 18 men, single-blind placebo-controlled two-way crossover, 100 g Brussels chicory a day for 7 days (n = 32) Evidence B source
  Time to exhaustion +8.3 percent in men and +12.2 percent in women, blood lactate lower by 14.5 and 10.6 percent

Safety, limits and interactions

• At 8 g a day for 4 weeks, chicory inulin cut measured gas retention by 22 percent in people with gas complaints, and the difference against placebo was not significant. — 36 adults with abdominal symptoms and reduced tolerance of intestinal gas, 18 on inulin and 18 on maltodextrin, 4 weeks (n = 36) Evidence B source
  Gas retention -22 percent versus own baseline (P = 0.035), between-group P = 0.343, bifidobacteria higher than placebo (P = 0.01)
• A worker in a chicory inulin factory developed rhinoconjunctivitis and asthma from dry chicory root dust, with specific IgE to a 17 kDa birch-related protein. — one adult male worker in a factory producing inulin from chicory (n = 1) Evidence D source
  Provocation test with dry chicory induced acute rhinoconjunctivitis and an immediate asthmatic response, skin prick positive to fresh and dry chicory and negative to inulin

What people believe that the data does not support

• The EU register lists the wording that inulin and oligofructose enhance calcium absorption as non-authorised, even though a randomised trial measured higher calcium absorption. — EU health claim application for inulin and oligofructose Evidence E source
  Status Non-authorised in the EU Register on nutrition and health claims
• A claim that a leaf mix containing red and green chicory protects blood lipids from oxidative damage is listed as non-authorised in the EU register. — EU health claim application for a mix of spinach, chicory and chard leaves Evidence E source
  Status Non-authorised in the EU Register on nutrition and health claims

What is still unknown

• In 12 rat studies, inulin cut aberrant crypt foci, an early marker of colon tumours, by a standardised mean difference of 3.805. — rats in 12 animal studies selected from 114 articles (n = 12 studies) Evidence D source
  Aberrant crypt foci SMD -3.805 (95% CI -7.348 to -0.262), butyrate SMD 4.471 (95% CI 2.464 to 6.478)

The bottom line

If you buy chicory root fibre, you are buying the thing that was tested. Doses in the trials ran from 3 to 20 g a day. Seven grams a day added to snack bars took Bifidobacterium from 5.3 to 18.7 percent of gut bacteria in 50 adults who normally eat little fibre, with no more gut complaints than on placebo. For constipation, 12 g a day for four weeks moved stool frequency from a median of 3 a week to 4. That is one extra stool, so decide for yourself whether it is worth the cost and the taste. One caveat belongs right here. In the pooled trials the gain in bowel function showed up in healthy people and was absent in people with gastrointestinal disorders, so if a bowel problem is the reason you are reading this, that is the line that concerns you. On weight, read the number slowly. Across 32 trials, in healthy people and in people with health problems, chicory fructans took off 0.97 kg against placebo. That is an average of less than a kilogram, spread over everyone who was pooled. The trials pulled in different directions, 73 percent heterogeneity, and dose and duration explain little of it. Call it a small average shift. It is no way to lose weight. The liver result needs the same kind of care. It comes from 5 small trials in 197 people already diagnosed with fatty liver disease, and the authors ask for longer studies before anyone recommends chicory for it. It says nothing about readers in general. Two findings sit in an awkward middle. Six weeks of chicory oligofructose and long-chain inulin raised how much calcium and magnesium 15 postmenopausal women absorbed, and about two thirds of them responded. The EU register lists the wording that inulin and oligofructose enhance calcium absorption as non-authorised, so the trial and the regulator disagree, and 15 women is a small room to settle that in. A leaf mix containing red and green chicory carries a non-authorised claim too, about protecting blood lipids from oxidative damage. On gas the honest reading is thin. At 8 g a day for four weeks, gas retention fell 22 percent against people's own baseline in 36 adults who tolerate intestinal gas badly, and against placebo the difference did not reach significance. The comparison that reached significance is the weaker one. The only other safety record we hold is a case report of a factory worker who breathed dry chicory root dust and developed rhinoconjunctivitis and asthma. He reacted to a chicory protein and not to inulin, and breathing dust at work is a different exposure from eating a salad. Two details in that report reach further than the factory. His skin prick test was positive to fresh chicory as well as dry, and his IgE was to a 17 kDa chicory protein related to a birch one. If you react to birch pollen, that part is about you. Colon cancer comes up whenever inulin does, and here the data is rat data. Twelve rat studies show inulin cutting aberrant crypt foci, an early marker of tumours. No human trial has tested that, so it stays a hypothesis and we are not going to write it as anything else. What we could not find matters as much as what we did. We hold nothing on who should be careful. No trial here covers chicory in pregnancy, in children, in kidney disease or alongside a medicine, and our drug interaction layer is organised by nutrient, so for a food it is empty by construction. That silence is our shelf being bare, and you should not read it as a clean safety record. We also have no measured range for how chicory composition varies between samples, and no figure for what cooking does to it, because dietary fibre is absent from the USDA retention tables. If you are pregnant, take regular medication, or live with a gut condition, ask the person treating you before you start on concentrated fructans.

Sources

1. chy-r5-05 · RCT
   Compared with the control group, the moderate-dose group showed significant differences across multiple microbial taxa, most notably an increased relative abundance of the Bifidobacterium genus from (mean ± SEM) 5.3% ± 5.9% to 18.7% ± 15.0%.
   Am J Clin Nutr, 2020 · checked 2026-09-23
2. chy-r5-04 · RCT
   Fractional absorption of Ca and Mg increased following SYN1 compared with placebo (P < 0.05).
   Br J Nutr, 2007 · checked 2026-09-23
3. chy-r5-01 · systematic review and meta-analysis of RCTs
   Chicory ITF significantly reduced body weight [mean difference (MD): -0.97 kg; 95% CI: -1.34, -0.59); n = 1184] compared with placebo.
   Am J Clin Nutr, 2024 · checked 2026-09-23
4. chy-r5-02 · systematic review and meta-analysis of RCTs
   Chicory-derived inulin-type fructans at a dose of 3-20 g/day significantly increased Bifidobacterium abundance in participants with an age range from 0 to 83 years (standardized mean difference: 0.83, 95% CI: 0.58-1.08; p < 0.01; 50 studies; 2525 participants).
   Crit Rev Food Sci Nutr, 2023 · checked 2026-09-23
5. chy-r5-03 · systematic review and meta-analysis of RCTs
   The study showed that chicory significantly decreased the levels of both aspartate transaminase (WMD: -7.07 U/L, 95%CI: -13.82 to -0.32) and alanine transaminase (WMD: -17.53 U/L, 95%CI: -32.64 to -2.42).
   Clin Nutr ESPEN, 2023 · checked 2026-09-23
6. chy-r5-06 · RCT
   Consumption of Orafti® Inulin significantly increased stool frequency compared to placebo (median 4.0 [IQR 2.5-4.5] versus 3.0 [IQR 2.5-4.0] stools/week, p = 0.038).
   Int J Food Sci Nutr, 2017 · checked 2026-09-23
7. chy-r5-08 · RCT
   Brussels chicory consumption increased time to exhaustion by 8.3% and 12.2% for men and women participants, respectively.
   Nutrients, 2025 · checked 2026-09-23
8. chy-r5-07 · RCT
   Inulin decreased gas retention during the gas challenge test (by 22%; P=0.035 vs. baseline), while the placebo did not, but the intergroup difference was not statistically significant (P=0.343).
   J Clin Gastroenterol, 2017 · checked 2026-09-23
9. chy-r5-10 · case report
   A provocation test with dry chicory induced acute rhinoconjunctivitis and an immediate asthmatic response with no further clinical symptoms.
   J Investig Allergol Clin Immunol, 2009 · checked 2026-09-23
10. chy-r5-11 · regulatory register entry
    POL-HC-7292 Inulin/oligofructose Inulin/oligofructose enhances calcium absorption Non-authorised
    EU Register on nutrition and health claims, claim POL-HC-7292, snapshot 2026-09-21 · checked 2026-09-23
11. chy-r5-12 · regulatory register entry
    POL-HC-8442 A combination of red spinach, green spinach, red chicory, green chicory, green leaf chard, red leaf chard, red Swiss chard, golden Swiss chard and white Swiss chard Contributes to the protection of blood lipids from oxidative damage -/- Non-authorised
    EU Register on nutrition and health claims, claim POL-HC-8442, snapshot 2026-09-21 · checked 2026-09-23
12. chy-r5-09 · animal meta-analysis
    Results indicate that inulin supplementation significantly reduced aberrant crypt foci count in rats (SMD = -3.805, 95% CI, -7.348 to -0.262, p < 0.001)
    J Food Sci, 2025 · checked 2026-09-23