Ginger Supplementation and Blood Pressure in Adults: A GRADE-Based Systematic Review and Dose-Response Meta-Analysis of Randomized Controlled Trials

Why they ran it

Ginger contains bioactive compounds with vasodilatory properties that the authors say may matter for blood pressure regulation, but findings across studies have stayed inconsistent.

The team set out to pool the randomised trials in adults and to test whether the amount of ginger used explains some of that inconsistency.

Drawn from the paper's abstract.

The team searched three databases, from the start of each through 1 May 2026, for randomised controlled trials of ginger supplementation that measured blood pressure in adults. Twelve unique trials qualified, contributing 13 effect estimates for systolic pressure and 12 for diastolic. Results were pooled as weighted mean differences using a random effects model, with subgroup, sensitivity and both linear and nonlinear dose response analyses layered on top. Risk of bias was scored with RoB 2, and the overall certainty of evidence with the GRADE framework.

Pooled across trials, systolic pressure was 5.03 mmHg lower with ginger, with a 95 percent confidence interval from 8.49 to 1.57 lower, and diastolic 2.03 mmHg lower, interval 3.90 to 0.15 lower. Notice how close that diastolic interval sits to zero: the systolic result is the sturdier of the two. Bigger reductions turned up in trials enrolling people with elevated baseline blood pressure or obesity, trials including both sexes, and trials testing 2000 mg a day or more. Nonlinear dose response analysis found the same inverse relationship, while trial length made no meaningful difference.

Then the authors mark their own work down. GRADE certainty came out low, downgraded solely for inconsistency, meaning the trials disagree on magnitude more than chance comfortably explains. Results held in sensitivity analyses and no publication bias was detected, so the problem is not a missing literature or one trial dragging the average. It is short trial durations, substantial heterogeneity, and diastolic findings the authors describe as limited in robustness. They close by calling for high quality long term trials before any definitive conclusions are drawn.

The numbers

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Why this might happen

Proposed by the authors This is the explanation the authors offer in their discussion. This study did not test it.

The authors attribute any possible effect to bioactive compounds in ginger that have vasodilatory properties, which they say may benefit blood pressure regulation.

No further mechanistic account is given in what the paper makes available here, and the dose response modelling is presented as a statistical pattern across trials rather than as a biological explanation.

Drawn from the paper's abstract, since the PMC record returned an empty body.

What this does not show

It cannot establish a dose threshold. The 2000 mg a day figure comes from comparing subgroups of trials against each other, not from randomising people to different doses within a trial. Trials at higher doses may differ in population and design as well as dose.
The diastolic result cannot be treated as reliable. The pooled diastolic interval stretches to just 0.15 mmHg below zero, and the authors themselves describe the limited robustness of the diastolic findings as a reason to hold confidence back.
It cannot show effects on heart attacks, strokes or any clinical outcome. The only outcomes pooled were systolic and diastolic readings taken during the trials. No study followed participants for cardiovascular events.
It cannot say the pooled figure applies to a general adult population. Subgroup reductions clustered in trials enrolling people with elevated baseline blood pressure or obesity, so the average is weighted by who happened to be studied.

Where this leaves us

Pooling twelve randomised trials makes it more likely that ginger supplementation is associated with a small average reduction in measured blood pressure rather than with nothing at all. That refines a scattered prior literature rather than confirming it, and the authors themselves grade the certainty of the evidence as low, downgraded for inconsistency.

Adults enrolled in the twelve included randomised controlled trials, with the clearest subgroup signals in trials enrolling people with elevated baseline blood pressure and people with obesity. Trial durations were short, and duration had no meaningful influence in the dose response analyses.

The authors say further high quality, long term randomised controlled trials are needed before any definitive clinical or dosing conclusions can be drawn.

Caveats worth holding

Trial durations were short, so nothing here speaks to what sustained use over months or years would look like.
Heterogeneity was substantial: the pooled figures are averages across trials that do not agree, which is exactly why the authors graded certainty as low.
The abstract does not report which ginger preparations, extracts or formulations the individual trials used, so the products sitting behind the dose figures are not described.
The record carries a month level publication date of August 2026 with no day, so the exact publication date could not be pinned down.