Nattokinase Supplementation and Cardiovascular Risk Factors: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Most nattokinase reviews are enthusiastic narratives. This one is different — a meta-analysis that actually pools the randomized trials and reports what the numbers say.

Across six randomized controlled trials, nattokinase produced a statistically significant reduction in both systolic and diastolic blood pressure. The lipid story was weaker: low doses did little for cholesterol, and there was a mild, unexpected rise in blood glucose. The safety profile was reassuring throughout.

The practical takeaway is appropriately narrow: nattokinase has a real, measurable role as an adjunct for blood pressure, while its much-touted lipid benefits likely require higher doses and its glucose effect warrants a watchful eye. It supplements, rather than replaces, standard antihypertensives.

We rate the evidence moderate-to-solid in method but limited in scope: Cochrane-standard meta-analytic technique with low bias and no conflicts, but only six trials and a small total sample. Its clinical significance is modest — a genuine blood-pressure signal that needs larger confirmatory trials before nattokinase earns a defined place in therapy. Notably, this is the most rigorous nattokinase source in our library, and its measured conclusions sit well below the sweeping claims of the narrative reviews on the same supplement.