Eating 40 grams of a special starch every day for a month can lower bad cholesterol and a waste product called urea nitrogen in the blood of people who are a healthy weight.
See the scientific wording
Consuming 40 grams of resistant starch type 2 daily for 4 weeks reduces LDL cholesterol and blood urea nitrogen levels in normal-weight adults.
Very strong evidence
Randomized trialsOne high-quality study supports this claim.
What the research says
1 study reviewedSupporting (1)
Randomized Controlled TrialHuman2019
The study gave healthy-weight people the exact same 40g special starch every day for 4 weeks and found that both their bad cholesterol (LDL) and a waste product (BUN) went down, showing the claim is true.
Contradicting (0)
No contradicting studies found yet
That doesn't mean it's settled — it just means no study has tested the opposite.
Quality-weighted scoring: we follow the GRADE framework — each study is rated High, Moderate, Low, or Very Low based on study design, methodology rigor, and risk of bias. A single high-quality RCT can outweigh several weaker observational studies.
Scores reflect study quality, not just count.
Resistant starch is a type of fiber that our body cannot digest, so it travels to the large intestine. There, the good bacteria feed on it and produce short-chain fatty acids. These fatty acids signal the gut to release a hormone that helps the pancreas release more insulin. Insulin helps the body to use sugar for energy and also reduces the amount of waste (urea) in the blood. Additionally, the fatty acids and insulin tell the liver to stop making too much 'bad' cholesterol. So the levels of bad cholesterol and urea in the blood go down.
Score breakdown, mechanism chain, raw evidence, ideal studies needed & 1 supporting study
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Eating 40 grams of a special starch every day for a month can lower bad cholesterol and a waste product called urea nitrogen in the blood of people who are a healthy weight.
Mechanism
1 studyResistant starch feeds the good bacteria in the gut, making fatty acids. These fatty acids cause the body to release a hormone that increases insulin, and together they lower bad cholesterol and a waste product in the blood. The specific bacteria you already have affect how well this works.
Resistant starch is a type of fiber that our body cannot digest, so it travels to the large intestine. There, the good bacteria feed on it and produce short-chain fatty acids. These fatty acids signal the gut to release a hormone that helps the pancreas release more insulin. Insulin helps the body to use sugar for energy and also reduces the amount of waste (urea) in the blood. Additionally, the fatty acids and insulin tell the liver to stop making too much 'bad' cholesterol. So the levels of bad cholesterol and urea in the blood go down.
Consumed resistant starch type 2 escapes digestion in the small intestine and reaches the large intestine intact.
Gut bacteria ferment the resistant starch, producing short-chain fatty acids, particularly acetate. The composition of the gut microbiota influences the rate of fermentation, with certain beneficial bacteria (e.g., Ruminococcaceae_UCG-005) increasing in abundance after starch consumption.
Short-chain fatty acids, especially acetate, stimulate L-cells in the gut lining to release glucagon-like peptide-1 (GLP-1).
GLP-1 acts on pancreatic beta-cells to enhance glucose-stimulated insulin secretion.
The increased insulin and short-chain fatty acids modify hepatic metabolism, reducing cholesterol synthesis and decreasing protein breakdown, which lowers LDL cholesterol and blood urea nitrogen.
Evidence from Studies
Supporting (1)
Community contributions welcome
Metabolic phenotypes and the gut microbiota in response to dietary resistant starch type 2 in normal-weight subjects: a randomized crossover trial
The study gave healthy-weight people the exact same 40g special starch every day for 4 weeks and found that both their bad cholesterol (LDL) and a waste product (BUN) went down, showing the claim is true.
Contradicting (0)
Community contributions welcome
Score Breakdown
No multi-axis breakdown available yet. The overall Pro / Against score above is the best signal.
- No clinical evidence is available; the score reflects mechanistic plausibility only.
What Would Prove This
Per GRADE and EBM methodology, here is what ideal scientific evidence would look like to definitively prove or disprove this claim, ordered from strongest to weakest.
Systematic Review and Meta-Analysis of Resistant Starch Type 2 on LDL Cholesterol and Blood Urea Nitrogen in Adults
Comprehensive search of databases for RCTs and quasi-experimental studies that administer resistant starch type 2 to adults, with outcomes including LDL cholesterol and blood urea nitrogen. Meta-analysis with subgroup analysis by dosage and duration.
Randomized Controlled Trial of 40g Resistant Starch Type 2 Daily for 4 Weeks on Lipid Profile and Renal Function in Normal-Weight Adults
Double-blind, placebo-controlled trial with normal-weight adults (BMI 18.5-24.9) randomly assigned to receive 40g/day of resistant starch type 2 or an isocaloric placebo for 4 weeks. Baseline and post-intervention measurements of LDL cholesterol and blood urea nitrogen.
Prospective Cohort Study of Resistant Starch Intake and Cardiovascular Risk Markers in Normal-Weight Adults
Prospective observational study with a large cohort of normal-weight adults, assessing dietary intake of resistant starch via food frequency questionnaires and tracking LDL cholesterol and blood urea nitrogen over several years, adjusting for known confounders.
Cross-Sectional Study of Dietary Resistant Starch Intake and Serum Lipid and Urea Levels in Normal-Weight Adults
Survey a representative sample of normal-weight adults, measure their habitual dietary intake of resistant starch, and simultaneously measure fasting LDL cholesterol and blood urea nitrogen. Use regression analysis to assess the association.