Aloe Vera for Type 2 Diabetes
Pooled trials suggest oral aloe vera modestly lowers HbA1c and fasting glucose in type 2 diabetes and prediabetes, but the evidence rests on small, low-quality studies and is contradicted by major clinical guidelines, so it cannot be recommended as a treatment.
Why this grade7-layer evidence engine
Four pooled analyses point the same way, which is what earns a Preliminary (B) grade. Three meta-analyses (PMID 27009750, n=470; PMID 27152917, n=283; PMID 27347994, n=415) and one umbrella review (PMID 34563809) consistently found oral aloe vera lowered HbA1c by roughly 0.4% to 1.05%, with the largest effect in poorly-controlled patients. That cross-study agreement is a genuine signal rather than noise.
The grade is Disputed because that signal is fragile. Every underlying trial is small and low-quality, the aloe preparations and doses were never standardized, heterogeneity was high, and several author teams called their own results inconclusive (PMID 27347994). One meta-analysis statistically detected publication bias for fasting-glucose results (PMID 27152917, p=0.010), and in established diabetes the fasting-glucose effect was only borderline (PMID 27009750, p=0.05). No large, rigorous trial exists.
Authorities lean cautious to negative. The American Diabetes Association does not recommend aloe vera for glycemic benefit, and Mayo Clinic warns it can cause hypoglycemia when combined with diabetes medicines. On safety, the US FDA found aloe stimulant-laxative ingredients not generally recognized as safe and effective, and the WHO's IARC classifies aloe whole-leaf extract as possibly carcinogenic (Group 2B). Treat it as an unproven adjunct, not a substitute for established care.
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 = 0.557
- tier_from_score — 依分數區間映射至 tier letter
- apply_hec_rules — 高品質 SR/MA 顯示 positive (4 篇 > 0 negative)
- tier_strict_requirement_check — Tier 條件達標，未降階
- detect_disputes — 偵測到 1 個 hard + 0 個 soft dispute
- decide_status — 依 tier + dispute 結果決定 status