Research

Hormonal

Pharmacological doses of isolated viscous soluble fiber (e.g., guar gum) improve insulin sensitivity, reduce LDL-cholesterol, and lower clotting factors, whereas isolated insoluble cereal fiber (e.g., wheat bran) does not directly act on these risk factors when consumed in refined forms.

To improve insulin sensitivity and lower LDL cholesterol, focus on viscous soluble fiber sources like oats, barley, or supplements like guar gum, taken in significant amounts (e.g., 10g+ per dose). Simply eating 'high fiber' refined grains (like white flour with added bran) may not provide these specific metabolic benefits.

GoodQualifiesHIGH confidence
Many beneficial effects are seen with pharmacological doses of isolated viscous soluble fibre, including improved insulin sensitivity, decreased LDL-cholesterol levels and decreased clotting factors. In contrast, insoluble non-viscous cereal fibre is not seen to act directly on risk factors when taken in refined foods such as in milled flour.
David J.A. Jenkins et al. · British Journal Of Nutrition · 2000

Why this rating

Supported by multiple controlled studies and meta-analyses cited (e.g., Brown et al. 1999, Landin et al. 1992), though epidemiological data for isolated fiber is less clear.

Source

Dietary fibre, lente carbohydrates and the insulin-resistant diseases

David J.A. Jenkins et al. · British Journal Of Nutrition · 2000

DOI 10.1017/s0007114500001100

narrative_reviewCited 218×
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DOI resolved against Crossref · corpus check 2026-06-10

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