Barley, beta-glucan and what the trials actually measured

Barley is sold on cholesterol, and the evidence for that splits in two depending on what was in the spoon. Pooling 17 randomised trials in 916 people with high cholesterol, beta-glucan from oats or barley lowered LDL by 0.21 mmol/L and total cholesterol by 0.26 mmol/L. Those trials were counted by the beta-glucan, with oats and barley pooled together, so the number describes the fibre and says nothing about a bowl of barley on its own. When 55 trials covering 3900 people compared whole foods, barley as a whole grain moved blood lipids nowhere at all, while oat bran lowered LDL by 0.32 mmol/L. Europe still authorises the cholesterol claim for barley beta-glucan, on condition the label says 3 g a day and the food carries at least 1 g per portion. What barley does consistently is flatten the glucose curve inside a meal, not across the day. A 2026 meta-analysis of 31 controlled trials, 1325 people, found blood glucose 10.48 mg/dL lower at 30 minutes and 12.38 mg/dL lower at 60 minutes. Fasting glucose and HbA1c stayed put, so the effect lives inside the meal and is gone by the next morning. Barley contains gluten: the American College of Gastroenterology guideline names it with wheat and rye as the grains that people with celiac disease exclude, so for them this grain is off the table whatever the rest of this page says. Form decides much of the rest. Eaten as whole kernels barley scored 26 to 53 on the glycemic index across nine cultivars, while the same grains ground into pasta scored 61 to 72.

The numbers, per 100 g

How much is actually in it

• Glycemic index of barley ranged from 26 to 53 between cultivars, and pearling raised it from 26 to 35 in 10 healthy adults. — 10 healthy adults per experiment, 9 cultivars (n = 10) Evidence B source
  GI CDC Fibar 26 ± 3 vs AC Parkhill 53 ± 4 (P < 0.05); whole grain 26 ± 4 vs white pearled 35 ± 3 (P < 0.05); GI correlated with total fiber r = -0.75

What a real portion looks like

• In 68 adults fed 4 daily servings of whole grain barley per 2000 kcal for 6 weeks, LDL fell 8.9 mg/dL versus control (trend, p = 0.0638) and diastolic blood pressure fell significantly. — 68 adults, 6-week double-blind parallel controlled feeding trial (n = 68) Evidence B source
  LDL -8.9 mg/dL (barley) and -11.2 mg/dL (oats) vs control, p = 0.0638; diastolic BP lowered p = 0.0388; VCAM lowered p = 0.0320
• In 30 overweight Korean adults, daily barley cereal (about 50 g available carbohydrate in 190 mL milk) for 6 weeks changed body weight by -1.18 kg relative to corn cereal. — 30 overweight Korean adults, mean age 43, 15 per arm, 6 weeks (n = 30) Evidence B source
  Body weight difference -1.18 kg (p = 0.027); BMI difference -0.17 kg/m2 (p = 0.014); glycated albumin difference -0.87% (p = 0.032)
• In 68 young Japanese women eating about 40 g/day of waxy barley for 4 weeks, defecation days, frequency and stool amount increased in both cultivar groups, with 6.3 to 10.7 g/day fibre from the barley. — 68 young Japanese women, 4 weeks, two waxy barley cultivars (n = 68) Evidence B source
  Both groups: more defecation days, frequency and stool amount, no between-group difference; fibre 6.3 g (Kirarimochi) vs 10.7 g (Fukumi Fiber) per day

What your body absorbs

• Hydrothermal treatment that cut barley phytate from 111 to 28 mg P raised zinc absorption from 11.0% to 25.2% in 12 healthy adults, with no change in calcium absorption. — 12 healthy adults (porridge) and 10 (malted cereal), single meals with 65Zn and 47Ca labels (n = 22) Evidence B source
  Zinc absorption 25.2 ± 6.9% vs 11.0 ± 2.5% (P < 0.001); malted barley 22.9 ± 5.8% vs 14.8 ± 4.6% (P < 0.05); calcium unchanged

What cooking and storage change

• Grinding barley into wet pasta raised its glycemic index to 61 to 72, versus 26 to 35 for the same cultivars eaten as whole kernels. — 10 healthy adults, 2 cultivars, kernel vs pasta form (n = 10) Evidence B source
  Pasta GI 69 ± 3 (AC Parkhill), 64 ± 4 (Celebrity); white pearled pasta 61 ± 3 vs whole grain pasta 72 ± 4 (P < 0.05)

What it does to your health

• In 16 healthy adults, whole grain barley breakfasts with about 4, 5 or 6 g beta-glucan produced progressively lower blood glucose peaks and iAUC than white glutinous rice. — 16 healthy fasted adults, crossover, 4 to 8 test occasions (n = 16) Evidence B source
  Higher beta-glucan content associated with lower glucose peak and iAUC; effect attenuated when 50 g HFCS added

Safety, limits and interactions

• The American College of Gastroenterology guideline defines celiac disease as an immune reaction to gluten, the storage protein of wheat, barley and rye, treated by excluding gluten. — people with celiac disease Evidence E source
  Barley is a gluten-containing grain; excluded on a gluten-free diet
• Under Regulation (EU) No 1048/2012 the cholesterol claim for barley beta-glucan requires telling consumers the effect is obtained with 3 g per day, and the food must supply at least 1 g per portion. — EU food labelling Evidence E source
  Condition of use: 3 g barley beta-glucan per day; at least 1 g per quantified portion

What people believe that the data does not support

• In a network meta-analysis of 55 trials (3900 participants), barley as a whole grain did not improve blood lipids versus control, while oat bran lowered LDL by 0.32 mmol/L. — adults in 55 whole-grain and bran trials, 3900 participants (n = 3900) Evidence A source
  Barley: no significant lipid change; oat bran TC -0.35 mmol/L (95% CI -0.47, -0.23), LDL -0.32 mmol/L (95% CI -0.44, -0.19)
• A systematic review of 48 crossover trials found barley fibre had only a weak effect on appetite and ad libitum energy intake, while rye and oat fibres showed stronger satiety effects. — healthy adults in 48 randomised crossover studies (n = 48 studies) Evidence A source
  Cereal fibre overall favourable for satiety, limited effect on energy intake; barley and wheat fibres weak
• The EU register authorises the claim that barley beta-glucans lower blood cholesterol (POL-HC-6226). — EU food labelling Evidence E source
  Authorised disease-risk-reduction claim
• The EU register rejected the claim that barley grain fibre helps with weight control and gives a long-lasting sense of satiety (POL-HC-6678). — EU food labelling Evidence E source
  Non-authorised claim
• FDA allows the soluble-fibre heart-disease claim only for whole grain barley with at least 4 percent beta-glucan and 10 percent total dietary fibre by dry weight. — US food labelling Evidence E source
  Eligibility threshold: 4% beta-glucan (dwb), 10% total dietary fibre (dwb) for whole grain; 8% fibre for dry milled products

Who this works differently for

• In hypercholesterolemic adults, beta-glucan from oats or barley lowered total cholesterol by 0.26 mmol/L and LDL cholesterol by 0.21 mmol/L across 17 randomised trials (916 people). — hypercholesterolemic adults, 17 RCTs, 916 subjects (n = 916) Evidence A source
  TC MD -0.26 mmol/L (95% CI -0.33 to -0.18); LDL MD -0.21 mmol/L (95% CI -0.27 to -0.14); no change in HDL, TG or glucose
• In 20 adults with type 2 diabetes, bread made with 75% hulless barley flour lowered the 4-hour postprandial glucose response by 11% versus 100% wheat bread. — 20 adults with type 2 diabetes, four breads at four visits (n = 20) Evidence B source
  75% hulless barley: glucose iAUC -11% (P < 0.05); 50% amylose-only barley: -34% vs wheat; insulin iAUC also reduced
• For keeping ulcerative colitis in remission, germinated barley foodstuff showed a relative relapse risk of 0.40 (95% CI 0.15 to 1.03) in 59 patients, not statistically significant and with very low certainty. — 59 patients with ulcerative colitis in remission (n = 59) Evidence A source
  RR of clinical relapse 0.40 (95% CI 0.15-1.03); very low certainty of evidence

What is still unknown

• Across 12 randomised trials (603 hypercholesterolemic people), beta-glucan from oats or barley did not change fasting glucose (WMD 0.05 mmol/L) or fasting insulin. — hypercholesterolemic adults, 12 RCTs, 603 subjects (n = 603) Evidence A source
  Fasting glucose WMD 0.05 mmol/L (95% CI -0.11, 0.02); fasting insulin 0.75 pmol/L (-1.82, 3.32); not significant
• A 2026 meta-analysis of 31 controlled trials found barley lowered postprandial glucose by 10.48 mg/dL at 30 min and 12.38 mg/dL at 60 min, with no effect on fasting glucose or HbA1c. — adults in 31 controlled trials, 34 arms, 660 barley and 665 control participants (n = 1325) Evidence A source
  Postprandial glucose -10.48 mg/dL (30 min), -12.38 mg/dL (60 min), -6.95 mg/dL (120 min); fasting glucose and HbA1c not significant

The bottom line

Whole kernels are the form the evidence likes. Eaten whole, barley scored between 26 and 53 on the glycemic index across nine cultivars. Pearling took one cultivar from 26 to 35. Grinding the same grains into pasta took them to between 61 and 72. Flour still buys something: in 20 adults with type 2 diabetes, bread made with 75 percent hulless barley flour cut the four-hour glucose response by 11 percent against wheat bread. Cooking also changes what you absorb. A hydrothermal treatment that cut phytate from 111 to 28 mg of phytate phosphorus raised zinc absorption from 11.0 to 25.2 percent in 12 adults, and calcium absorption did not move. Malting, which is sprouting the grain, did something similar in the same study, 22.9 against 14.8 percent. The everyday promises are weaker than the packaging. In 68 adults eating four servings of whole grain barley per 2000 kcal for six weeks, LDL fell 8.9 mg/dL, which is about 0.23 mmol/L on the scale the trials above use, against control, a trend that missed significance, while diastolic blood pressure did fall. In 30 overweight Korean adults, a daily barley cereal for six weeks came out 1.18 kg lighter than the corn cereal arm. One small trial. Satiety has failed twice over: the EU register rejected the claim that barley grain fibre gives lasting fullness, and a review of 48 crossover trials put barley fibre among the weak ones for appetite, behind rye and oat. Bowels are where barley delivered cleanly. In 68 young Japanese women eating about 40 g of waxy barley a day for four weeks, defecation days, frequency and stool amount all rose, on 6.3 to 10.7 g of extra fibre a day. Barley contains gluten. The American College of Gastroenterology guideline names it with wheat and rye as a grain that people with celiac disease exclude, and that is not a portion question. Past that point our safety evidence is thin, and you should know it. We hold no upper limit for barley, nothing on interactions with medicines, and nothing on how that much fibre behaves in a gut that is already irritated. Germinated barley foodstuff, a manufactured preparation rather than the grain, was tested in 59 people for holding ulcerative colitis in remission: relapse risk 0.40, confidence interval 0.15 to 1.03, which crosses no effect, at very low certainty. That one belongs with the doctor treating you.

Sources

1. bar-c2-07 · RCT
   GI varied by cultivar (CDC Fibar vs. AC Parkhill, [mean ± SEM]: 26 ± 3 vs. 53 ± 4, respectively; P < 0.05) and pearling (WG vs. WP: 26 ± 4 vs. 35 ± 3, respectively; P < 0.05) with no cultivar × pearling interaction.
   J Nutr, 2012 · checked 2026-09-23
2. bar-c2-05 · RCT
   A 6-week, double-blind, parallel-design, randomized, controlled feeding trial was conducted with 68 adults...LDL cholesterol concentrations show a trend of statistical significance across diets (p = 0.0638), with a lowering of 8.9 mg/dL (barley) and 11.2 mg/dL (oats) compared to the control...The barley diet significantly lowered diastolic blood pressure (p = 0.0388) and vascular cell adhesion molecule concentrations (p = 0.0320).
   Nutrients, 2026 · checked 2026-09-23
3. bar-c2-06 · RCT
   overweight adults (n = 30; mean age of 43 ± 10.89 years; 36.7% female) were randomly assigned to consume either barley (n = 15) or corn cereal (n = 15) daily for 6 weeks. Participants consumed approximately 50 g of available carbohydrates (either barley or corn cereal) in 190 mL milk...After 6 weeks, between-group comparisons revealed significant differences favoring the barley group in body weight (barley: -0.33 kg vs. corn: +0.85 kg; difference: -1.18 kg, p = 0.027)
   Nutrients, 2025 · checked 2026-09-23
4. bar-c2-11 · RCT
   A randomized double-blind parallel-group comparison study was conducted on 68 young Japanese women...Both groups consumed about 40 g/day of WB. DF and β-G intakes from barley were 6.3 g/2.5 g in Group K and 10.7 g/4.3 g in Group F. Regarding defecation, both groups showed increases defecation days, defecation frequency and stool amount, with no differences between groups.
   J Physiol Anthropol, 2025 · checked 2026-09-23
5. bar-c2-09 · RCT
   Zinc absorption from hydrothermally treated barley porridge, containing 28 mg P as inositol tri- to hexaphosphates (InsP(3)-InsP(6)), was significantly higher (P<0.001) than from control porridge containing 111 mg P as InsP(3)-InsP(6), 25.2+/-6.9 vs 11.0+/-2.5% (n=12). Calcium absorption did not differ (P>0.05), 21.1+/-6.8 vs 19.5+/-4.7% (n=12).
   Eur J Clin Nutr, 2003 · checked 2026-09-23
6. bar-c2-08 · RCT
   The GI of AC Parkhill pasta (69 ± 3) was similar to that of Celebrity pasta (64 ± 4) but, unlike in Expt. 1, the GI of WP pasta (61 ± 3) was less than that of WG pasta (72 ± 4) (P < 0.05).
   J Nutr, 2012 · checked 2026-09-23
7. bar-c2-12 · RCT
   Sixteen healthy, over-night fasted participants were studied on four or eight separate occasions. Participants consumed an unsweetened preload condition (n = 16): white glutinous rice (WR; 0 g β-glucan), low β-glucan barley (LB; ~4 g), medium β-glucan barley (MB; ~5 g), or high β-glucan barley (HB; ~6 g)...In both sweetened and unsweetened conditions, higher β-glucan content was associated with lower blood glucose peak response and incremental area under the curve estimates (iAUC).
   Nutrients, 2025 · checked 2026-09-23
8. bar-c2-15 · guideline
   Celiac disease is an immune-based reaction to dietary gluten (storage protein for wheat, barley, and rye) that primarily affects the small intestine in those with a genetic predisposition and resolves with exclusion of gluten from the diet.
   Am J Gastroenterol, 2013 · checked 2026-09-23
9. bar-c2-18 · regulation
   Information shall be given to the consumer that the beneficial effect is obtained with a daily intake of 3 g of barley beta-glucan. The claim can be used for foods which provide at least 1 g of barley beta-glucan per quantified portion.
   Commission Regulation (EU) No 1048/2012, EUR-Lex · checked 2026-09-23
10. bar-c2-02 · network meta-analysis
    Fifty-five eligible trials with a total of 3900 participants were included...Barley, brown rice, wheat and wheat bran were shown to be ineffective in improving blood lipid compared with control.
    Eur J Nutr, 2019 · checked 2026-09-23
11. bar-c2-13 · systematic review
    Evidence from 48 studies indicated that cereal fiber intake was associated with favorable effects on satiety and other measures of appetite but limited effects on ad libitum energy intake...Wheat and barley fibers as well as functional fibers, resistant starch, and soluble corn fiber, showed a weak effect on appetite sensations and ad libitum energy intake.
    Nutr Rev, 2026 · checked 2026-09-23
12. bar-c2-16 · register
    POL-HC-6226 Barley beta-glucans Barley beta-glucans has been shown to lower/reduce blood cholesterol. High cholesterol is a risk factor in the development of coronary heart disease. -/- Authorised
    EU Register on nutrition and health claims, claim POL-HC-6226, snapshot 2026-09-21 · checked 2026-09-23
13. bar-c2-17 · register
    POL-HC-6678 Barley grain fibre Helps with weight control. For long-lasting sense of satiety. Frees energy slowly Non-authorised
    EU Register on nutrition and health claims, claim POL-HC-6678, snapshot 2026-09-21 · checked 2026-09-23
14. bar-c2-19 · regulation
    Dehulled and hull-less whole grain barley with a β-glucan soluble fiber content of at least 4 percent (dwb) and a total dietary fiber content of at least 10 percent (dwb).
    21 CFR 101.81, Health claims: Soluble fiber from certain foods and risk of coronary heart disease · checked 2026-09-23
15. bar-c2-01 · meta-analysis
    Seventeen eligible RCTs with 916 subjects were included in the meta-analysis. The pooled result showed that beta-glucan consumption in hypercholesterolemic population significantly lowered the total cholesterol (TC) (MD, -0.26 mmol/L; 95% CI, -0.33 to -0.18; P < 0.00001) and low-density lipoprotein (LDL)-cholesterol concentration (MD, -0.21 mmol/L; 95% CI, -0.27 to -0.14; P < 0.00001).
    Nutr Metab Cardiovasc Dis, 2015 · checked 2026-09-23
16. bar-c2-10 · RCT
    Twenty adults with T2D were randomly allocated to one of four breads at four separate visits...Bread made from 75% hulless barley reduced the postprandial glucose response (iAUC) by 11% (P < 0.05) compared to 100% wheat bread.
    Eur J Clin Nutr, 2024 · checked 2026-09-23
17. bar-c2-14 · meta-analysis
    For maintenance of remission in UC, germinated barley foodstuff trended toward preventing clinical relapse (relative risk, 0.40; 95% confidence interval, 0.15-1.03; n = 59), but OF-IN, oat bran, and Plantago ovata did not...The overall certainty of evidence was very low.
    Inflamm Bowel Dis, 2025 · checked 2026-09-23
18. bar-c2-03 · meta-analysis
    Twelve trials with a total of 603 subjects were included in the meta-analysis. Beta-glucan consumption did not significantly affect measures of glycemic control. Summary estimates of weighted mean differences (WMD) and 95% confidence interval was 0.05 mmol/L (-0.11, 0.02) for fasting glucose concentration
    Int J Food Sci Nutr, 2015 · checked 2026-09-23
19. bar-c2-04 · meta-analysis
    Barley supplementation significantly reduced postprandial glucose levels at 30 (−10.48 mg dL–1), 60 (−12.38 mg dL–1), and 120 (−6.95 mg dL–1) minutes...In the long term, barley intake did not significantly affect fasting glucose or hemoglobin A1c levels.
    Nutrition Reviews, 2026 (advance article, 6 February 2026) · checked 2026-09-23