Protocol
Oat beta-glucan (3 g/day or more) for LDL-C
Oat beta-glucan at 3 g/day or more lowers LDL Low-density lipoprotein cholesterol, the cholesterol fraction most closely tied to plaque in the arteries. cholesterol by about 0.25 mmol/L (about 10 mg/dL) in a meta-analysis A study that pools the numbers from several trials into one combined estimate. of 28 randomized trials, with later pools of 58 trials and of 13 trials in people with raised cholesterol agreeing.
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How this letter has changedLatest: October 2026 · First graded.
Meta-analyses of randomized trials, 28 trials (Whitehead et al., Am J Clin Nutr, 2014; PMID PubMed ID: the permanent number the US National Library of Medicine gives a published paper. Each one links to that paper's record on PubMed. 25411276), 58 trials (Ho et al., Br J Nutr, 2016; PMID 27724985) and 13 trials in adults with raised cholesterol (Yu et al., Nutrients, 2022; PMID 35631184), find 3 g/day or more of oat beta-glucan lowers LDL cholesterol, and a randomized trial found the effect depends on molecular weight (Wolever et al., Am J Clin Nutr, 2010; PMID 20660224). LDL is a surrogate, so B is the ceiling. The high-cholesterol condition page previously listed oats under a soluble-fiber row whose evidence was psyllium only; oats now have their own row.PMID 25411276 PMID 27724985 PMID 35631184 PMID 20660224
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Oat beta-glucan is the thick, gel-forming fiber in oats. In dozens of trials, about 3 grams a day lowered LDL cholesterol by about 10 points (mg/dL) compared with foods without it. That is roughly the beta-glucan in a large bowl and a half of oatmeal. The fiber only works when it stays thick: a broken-down form in one trial did not lower LDL. No oat trial has tested whether it prevents heart attacks or deaths.
Oat beta-glucan at 3 g/day or more lowers LDL cholesterol by about 0.25 mmol/L (about 10 mg/dL) in a meta-analysis of 28 randomized trials, with later pools of 58 trials and of 13 trials in people with raised cholesterol agreeing. The effect depends on the beta-glucan staying viscous: in a 345-person trial, high- and medium-molecular-weight oat beta-glucan lowered LDL and a low-molecular-weight form at 4 g/day did not. A 2026 trial in metabolic syndrome found 80 g of oats a day (about 3.5 g of beta-glucan) did not significantly lower LDL over 6 weeks, while a 2-day diet of 300 g a day did. Surrogate endpoint A lab value or measurement used in place of the outcome that matters, such as LDL cholesterol standing in for heart attacks. Moving a surrogate does not always move the outcome., so B is the ceiling.
Why this gradeThe reasoning, and what the grade does not cover.
Grade B on LDL cholesterol. Three meta-analyses of randomized trials find oat beta-glucan lowers LDL cholesterol: 28 trials at 3 g/day or more, LDL 0.25 mmol/L lower (Whitehead et al., 2014; PMID 25411276), and 58 trials at a median 3.5 g/day, with non-HDL cholesterol and apolipoprotein B also lower (Ho et al., 2016; PMID 27724985), and 13 trials in adults with raised cholesterol from an independent group, LDL 0.27 mmol/L lower (Yu et al., 2022; PMID 35631184). A randomized trial that varied only molecular weight found the effect depends on it: high- and medium-molecular-weight forms lowered LDL and a low-molecular-weight form did not (Wolever et al., 2010; PMID 20660224). One 2026 trial found an everyday portion of whole oats, about 3.5 g of beta-glucan, did not significantly lower LDL over 6 weeks (Klümpen et al., 2026; PMID 41535271). A single small trial does not outweigh three pooled analyses of randomized trials, so the grade holds at B (Rules 01 to 06: pooled randomized evidence on a surrogate endpoint The outcome a trial measures to decide whether the treatment worked, such as heart attacks, blood pressure or a symptom score.).
WHY NOT ALDL cholesterol is a surrogate marker, and no oat beta-glucan trial has tested heart attacks or deaths.
WHAT THIS GRADE DOES NOT COVERyeast beta-1,3/1,6-glucan, a different molecule graded separately for upper respiratory infections; low-molecular-weight oat beta-glucan; barley beta-glucan, which these pools did not test; cardiovascular events; and any claim about clearing PFAS or other chemicals, which rests on a mouse study and one exploratory human analysis.
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The evidence, in fullFive papers, each linked to its PubMed record.
Whitehead et al. (Am J Clin Nutr, 2014; PMID 25411276): meta-analysis of 28 randomized controlled trials People are assigned to the treatment or a comparison by chance, so the groups differ only in what they received. It is the design that can show cause and effect. of 3 g/day or more of oat beta-glucan; LDL cholesterol lower than control by 0.25 mmol/L (95% CI 0.20 to 0.30) and total cholesterol by 0.30 mmol/L, HDL cholesterol and triglycerides unchanged, larger falls at higher baseline LDL, dose range 3.0 to 12.4 g/day over 2 to 12 weeks. Ho et al. (Br J Nutr, 2016; PMID 27724985): systematic review A review that searches for every study on a question using a method set in advance, then assesses them together. and meta-analysis of 58 randomized trials, 3,974 participants, median 3.5 g/day; LDL cholesterol lower by 0.19 mmol/L, non-HDL cholesterol by 0.20 mmol/L and apolipoprotein B by 0.03 g/L, with considerable unexplained heterogeneity How much the results of the pooled trials differ from each other. High heterogeneity makes a combined estimate less reliable.. Yu et al. (Nutrients, 2022; PMID 35631184): systematic review and meta-analysis of 13 randomized trials in 927 adults with raised cholesterol, from an independent group declaring no conflicts; LDL cholesterol lower by 0.27 mmol/L (95% CI 0.20 to 0.35) and total cholesterol by 0.24 mmol/L, triglycerides and HDL unchanged. Wolever et al. (Am J Clin Nutr, 2010; PMID 20660224): double-blind Neither the participants nor the people assessing them know who received the real treatment until the trial ends. multicenter randomized trial, 367 enrolled and 345 completed, adults with LDL cholesterol 3.0 to 5.0 mmol/L, 4 weeks; cereal with 3 g high-molecular-weight, 4 g medium-molecular-weight or 3 g medium-molecular-weight oat beta-glucan lowered LDL by about 0.2 mmol/L (about 5 percent) against wheat fiber, while 4 g of low-molecular-weight oat beta-glucan did not significantly lower it. Klümpen et al. (Nat Commun, 2026; PMID 41535271): two parallel randomized trials in adults aged 45 to 70 with metabolic syndrome; a 2-day diet of 300 g/day of oats (13.5 g beta-glucan) at 1,100 to 1,200 kcal/day lowered LDL by 16.3 mg/dL more than a calorie-matched, high-fiber oat-free control (32 completers), while replacing one meal a day with 80 g of oats (3.5 g beta-glucan) for 6 weeks left LDL and total cholesterol largely unchanged against a usual-diet control (34 completers). Grade B (surrogate lipid endpoint).
Fasting LDL cholesterol and total cholesterol at baseline and after 4 to 12 weeks, the durations of the pooled trials: the pooled effect at 3 g/day or more is an LDL fall of about 0.25 mmol/L (about 10 mg/dL). Products rarely state the molecular weight of their beta-glucan, which the cited trial found decides whether LDL falls.
Evidence notes: randomized trial, meta-analysis
Endpoint graded: LDL cholesterol (surrogate)
Last reviewed: October 2026
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("oat beta-glucan"[tiab] OR "oat β-glucan"[tiab] OR "oat beta glucan"[tiab]) AND (LDL[tiab] OR cholesterol[tiab]) AND (meta-analysis[pt] OR randomized controlled trial[pt])Grades move when new trials publish. A free monthly email lists every grade EBL moved, with the reason and the trial behind it: the sign-up is on the Evidence Log →