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Fiber for high cholesterol

Goal: What trials of soluble fiber used to lower LDL cholesterol, and how large the fall was.

Each protocol describes what studies used, for one goal or for one group of people. It is not advice for you: talk to a doctor before you start a supplement.

Updated 4 Nov 2026
Dose

Medians in reviews: about 10.2 g of psyllium a day in 28 trials, 3.5 g of oat beta-glucan in 58 trials and 6.5 g of barley beta-glucan in 14 trials. Konjac glucomannan: about 3 g in 12 trials.[1][2][3][4] The claim of EFSA, the EU food safety authority, needs at least 3 g of oat beta-glucan a day.[5] The European Medicines Agency (EMA) gives 7 to 20 g of psyllium husk a day.[6]

Form

Psyllium, or foods enriched with oat or barley beta-glucan.[1][2][3] In one oat trial, low molecular weight beta-glucan had half of the effect.[7]

When to take

In 1 to 3 doses during the day, with at least 30 ml of liquid per 1 g of psyllium husk.[6] The oat trial divided the dose into 2 a day.[7]

How long

At least 3 weeks in reviews, with a median of 4 weeks for barley.[1][3] Few trials lasted more than 12 weeks.[8]

What studies found

A 2023 review of 181 trials with 14,505 people found LDL 8.28 mg/dL lower, and 5.57 mg/dL lower for each extra 5 g a day.[9] Psyllium lowered LDL by 0.33 mmol/L, oat beta-glucan by 0.19 mmol/L, barley beta-glucan by 0.25 mmol/L and konjac by 0.35 mmol/L.[1][2][3][4] None of the 23 trials in a Cochrane review reported deaths or heart events.[8]

Ask a doctor first

Psyllium can delay the absorption of medicines, and it can block the throat or gut if taken with too little liquid.[6] The EMA says its use for high cholesterol needs medical supervision.[6]

People with diabetes, people who take a daily medicine, and people with trouble swallowing should ask a doctor or pharmacist first.[6][10]

References

  1. Effect of psyllium (Plantago ovata) fiber on LDL cholesterol and alternative lipid targets, non-HDL cholesterol and apolipoprotein B: a systematic review and meta-analysis of randomized controlled trials. Jovanovski E, Yashpal S, Komishon A, Zurbau A, Blanco Mejia S, Ho HVT, et al. Am J Clin Nutr, 2018. PMID 30239559
  2. The effect of oat β-glucan on LDL-cholesterol, non-HDL-cholesterol and apoB for CVD risk reduction: a systematic review and meta-analysis of randomised-controlled trials. Ho HV, Sievenpiper JL, Zurbau A, Blanco Mejia S, Jovanovski E, Au-Yeung F, et al. Br J Nutr, 2016. PMID 27724985
  3. A systematic review and meta-analysis of randomized controlled trials of the effect of barley β-glucan on LDL-C, non-HDL-C and apoB for cardiovascular disease risk reduction(i-iv). Ho HV, Sievenpiper JL, Zurbau A, Blanco Mejia S, Jovanovski E, Au-Yeung F, et al. Eur J Clin Nutr, 2016. PMID 27273067
  4. A systematic review and meta-analysis of randomized controlled trials of the effect of konjac glucomannan, a viscous soluble fiber, on LDL cholesterol and the new lipid targets non-HDL cholesterol and apolipoprotein B. Ho HVT, Jovanovski E, Zurbau A, Blanco Mejia S, Sievenpiper JL, Au-Yeung F, et al. Am J Clin Nutr, 2017. PMID 28356275
  5. Scientific Opinion on the substantiation of a health claim related to oat beta glucan and lowering blood cholesterol and reduced risk of (coronary) heart disease. European Food Safety Authority, 2010. efsa.onlinelibrary.wiley.com
  6. Community herbal monograph on Plantago ovata Forssk., seminis tegumentum. European Medicines Agency, HMPC, 2013. www.ema.europa.eu
  7. Physicochemical properties of oat β-glucan influence its ability to reduce serum LDL cholesterol in humans: a randomized clinical trial. Wolever TM, Tosh SM, Gibbs AL, Brand-Miller J, Duncan AM, Hart V, et al. Am J Clin Nutr, 2010. PMID 20660224
  8. Dietary fibre for the primary prevention of cardiovascular disease. Hartley L, May MD, Loveman E, Colquitt JL, Rees K Cochrane Database Syst Rev, 2016. PMID 26758499
  9. Soluble Fiber Supplementation and Serum Lipid Profile: A Systematic Review and Dose-Response Meta-Analysis of Randomized Controlled Trials. Ghavami A, Ziaei R, Talebi S, Barghchi H, Nattagh-Eshtivani E, Moradi S, et al. Adv Nutr, 2023. PMID 36796439
  10. Psyllium: MedlinePlus Drug Information. MedlinePlus, US National Library of Medicine, 2024. medlineplus.gov