Whole grain instead of refined
Swap bread, rice and pasta for the whole-grain version. Moves HbA1c and LDL most.
Order of magnitude
Most grain portions as whole grain.
The pooled effects are reported as standardised mean differences, which cannot be turned back into percentage points of HbA1c or mg/dL of cholesterol without the underlying standard deviations, so this database records the direction and not the size.
Effects in detail
Each row is a directed edge from our database, with range, latency, evidence grade and the condition under which it applies at all.
| Marker | Effect | Latency | Mode of action | Outcome | Evidence | Condition | Sources |
|---|---|---|---|---|---|---|---|
| Apolipoprotein B | helps. Lowers Direction known, size not established Across 22 meta-analysed randomised trials, whole-grain oats improved total cholesterol (standardised mean difference -0.54, 95 % CI -0.95 to -0.12) and LDL-C (-0.57, -0.84 to -0.31). marker_proxy is ldl_c: the trials measured LDL-C, not apolipoprotein B. Trial proxy: ldl_c. | not specified | chronic | unclear | Evidence grade B | applies regardless of the starting value | |
| HbA1c | helps. Lowers Effect size, not in the marker's unit confidence interval of the estimate, not the range one person can expect Twenty-five randomised trials replacing refined grains with whole grains improved HbA1c with a standardised mean difference of -0.33 (95 % CI -0.61 to -0.04) and C-reactive protein with -0.22. No effect size in percentage points is entered because the result is a standardised mean difference and the underlying standard deviations are not available. | 2–2 weeks | chronic | unclear | Evidence grade A | applies regardless of the starting value | |
| Triglycerides | helps. Lowers Direction known, size not established In the same review, whole-grain rice improved triglycerides, while oats moved cholesterol and LDL-C instead. Grade C: a single grain type within one review, with no effect size quoted in the abstract for this outcome (gaps_batch2.md G-QC1). | not specified | chronic | unclear | Evidence grade C | applies regardless of the starting value |
What this measure costs
Counteracting effects of the same measure.
No counteracting effect is on file for this measure. That does not mean there is none, only that we found no defensible edge.
Moves without implying progress
Informational or no established effect: the marker moves or was checked, and that is not progress.
| Marker | Effect | Latency | Mode of action | Outcome | Evidence | Condition | Sources |
|---|---|---|---|---|---|---|---|
| high-sensitivity CRP | moves, and does not count. Lowers Effect size, not in the marker's unit confidence interval of the estimate, not the range one person can expect Across 22 meta-analysed randomised trials, whole grains of all types improved C-reactive protein with a standardised mean difference of -0.22 (95 % CI -0.44 to -0.00). The interval reaches zero, so this is a weak positive. | not specified | chronic | unclear | Evidence grade B | applies regardless of the starting value |
Sources
Full details of every study the rows above rely on.
The Effect of Replacing Refined Grains with Whole Grains on Cardiovascular Risk Factors: A Systematic Review and Meta-Analysis of Randomized Controlled Trials with GRADE Clinical Recommendation
Marshall et al. · Journal of the Academy of Nutrition and Dietetics · 2020 · Meta-analysis