Fiber

How does fiber lower cholesterol?

Updated 4 Nov 2026

Short answer

Probably in part by making the body lose bile acids. Soluble fiber binds bile acids in the gut, so more of them leave in stool.[1] The liver makes bile acids from cholesterol, so it may use more cholesterol and take more LDL cholesterol from the blood.[2]

Two other ideas exist. Less insulin after a meal may lower the cholesterol the liver makes. Propionate from fermentation may also play a part, but the evidence for it is not conclusive.[1] Parts of this picture come from animal studies.[2]

Sources (2)

  1. Mechanisms underlying the cholesterol-lowering properties of soluble dietary fibre polysaccharides. Gunness P, Gidley MJ Food Funct, 2010. PMID 21776465
  2. Guar gum and similar soluble fibers in the regulation of cholesterol metabolism: current understandings and future research priorities. Rideout TC, Harding SV, Jones PJ, Fan MZ Vasc Health Risk Manag, 2008. PMID 19183750

More about fiber

What is fiber?How much fiber do you need per day?What is fiber used for?How long does fiber take to lower cholesterol?Is fiber safe?Is fiber from food better than a fiber supplement?

For education; not medical advice. Talk to a doctor before you start, stop or change a supplement.