Beetroot / Beet juice for Hypertension
Beetroot juice provides a real but small reduction in systolic blood pressure (roughly 3.5 to 5 mmHg in pooled trials), with a weaker and less consistent effect on diastolic pressure. It is a supportive food, not a substitute for proven antihypertensive therapy, and it appears to add little for people already on blood-pressure medication.
Why this grade7-layer evidence engine
This earns a Preliminary (B) grade because three independent meta-analyses agree on a modest, statistically significant systolic effect: -4.95 mmHg in hypertensive patients (PMID 35369064), -3.55 mmHg across 22 trials (PMID 29141968), and -4.4 mmHg across 16 RCTs (PMID 23596162), all p<0.001, with a dose- and duration-dependent trend. The mechanism is well established (dietary nitrate raises nitric oxide and relaxes blood vessels), which supports the signal.
The grade stops short of higher because the effect is small and the diastolic reduction is weak or non-significant (PMID 29141968: -1.32 mmHg; PMID 23596162: -1.1 mmHg, p=0.06). Most trials ran under two weeks, so durability is unproven, and a 2024 double-blind RCT (PMID 38546454) found no blood-pressure benefit in already-medicated older hypertensives, suggesting a ceiling effect once drugs are on board.
Regulators and clinics reinforce caution rather than endorsement. The FDA lists beet juice only as a permitted food color with no health claim, the WHO/JECFA addresses nitrate intake limits only, and the NHS notes harmless pink urine (beeturia). Mayo Clinic confirms the nitrate effect but stresses it is mostly systolic, while major bodies do not back beet juice as a standalone hypertension therapy. Those on nitrate drugs or antihypertensives should consult a clinician before high-dose use.
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 = 0.595
- tier_from_score — 依分數區間映射至 tier letter
- apply_hec_rules — 高品質 SR/MA 顯示 positive (2 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