Nattokinase for Hypertension
Nattokinase shows only a small, inconsistent blood-pressure signal that is not strong enough to recommend it for hypertension, and no major health authority or clinical body endorses such use. It should not replace proven treatments like diet, exercise, or prescribed antihypertensive medication.
Why this grade7-layer evidence engine
This earns a weak (Tier C) grade because the evidence is small and pulls in different directions. A 2023 meta-analysis of 6 randomized trials (546 participants; PMID 39076715) found nattokinase modestly lowered systolic blood pressure by about 3.5 mmHg and diastolic by about 2.3 mmHg, and two small 8-week trials echoed this: a 2008 South Korean study (n=86; PMID 18971533) and a 2016 North American study (n=79; PMID 27785095), though the latter's systolic drop was not statistically significant.
Crucially, the largest and longest trial undercuts that signal. The 3-year NAPS study (n=265; PMID 33843667), conducted in healthy low-risk adults, found no significant effect on blood pressure. Most individual trials had fewer than 90 participants, skewed toward East-Asian populations, and had largely undisclosed funding, so manufacturer conflict of interest cannot be ruled out. The effect, where seen, was small and limited to pre/hypertensive people.
No regulator or clinic backs this use. The US FDA issued a 2020 warning letter against nattokinase circulation and clot-dissolving claims, the EU's EFSA authorizes no blood-pressure or cardiovascular claim, and the NHS and WHO do not address it. Mayo Clinic, Cleveland Clinic, Harvard Health, and hypertension specialty societies are silent rather than supportive. Nattokinase also carries a real bleeding-risk caveat due to its fibrinolytic and antiplatelet activity, especially alongside anticoagulants or before surgery.
Scoring transparency
All scores computed by a 7-layer evidence engine — fully auditable▸View the full decision path (audit trail)
- compute_raw_score — 加權公式: L2×0.30 + L3×0.25 + L5×0.25 + L11×0.10 + L1×0.10 = 0.472
- tier_from_score — 依分數區間映射至 tier letter
- apply_hec_rules — 高品質 SR/MA 顯示 positive (1 篇 > 0 negative)
- tier_strict_requirement_check — Tier 條件達標，未降階
- detect_disputes — 偵測到 0 個 hard + 0 個 soft dispute
- decide_status — 依 tier + dispute 結果決定 status