Ashitaba May Prevent Blood Clots - Review Analysis

Key Findings

This 2018 narrative review synthesizes evidence suggesting Ashitaba (Angelica keiskei) exhibits antithrombotic properties primarily through its bioactive chalcones (e.g., xanthoangelol and 4-hydroxyderricin). The review reports these compounds inhibit platelet aggregation in vitro and in animal models, with xanthoangelol showing an IC₅₀ of 10 μM for collagen-induced platelet aggregation. The authors conclude Ashitaba consumption may reduce thrombosis risk but emphasize human clinical data are lacking. No quantitative efficacy metrics for humans were provided.

Study Design

This is a narrative review (not an original study), analyzing prior in vitro, animal, and limited human observational data published up to 2018. It synthesizes findings from 48 referenced studies but does not conduct new experiments. No original sample size, participant demographics, or trial duration are reported, as the work aggregates existing literature. The methodology involves qualitative discussion of mechanisms (e.g., COX-1 inhibition, reduced thromboxane B₂ production) without systematic literature screening criteria.

Dosage & Administration

The review does not specify doses used in human contexts. It notes traditional Japanese consumption of Ashitaba as fresh leaves, juice, or dried powder in dietary amounts but provides no standardized dosing protocols. Animal and in vitro studies cited used isolated chalcones at concentrations like 10–50 μM, which are not translatable to human oral intake.

Results & Efficacy

The review highlights:
- Xanthoangelol reduced platelet aggregation by ~40% at 10 μM in vitro (p<0.01 vs. controls).
- In rat models, Ashitaba extract (dose unspecified) prolonged bleeding time and reduced thrombus formation.
- Statistical significance (p<0.05) was noted for key in vitro and animal outcomes in cited studies, but no human efficacy data, effect sizes, or confidence intervals were presented. Results are mechanistic (e.g., inhibited COX-1 activity by 60–80% at 30 μM), not clinical.

Limitations

Major limitations include:
1. No human trials analyzed: Evidence relies on preclinical data; relevance to humans is unproven.
2. Dose uncertainty: No established effective human dose; in vitro concentrations may not reflect achievable blood levels.
3. Review methodology: Lacks systematic search strategy, risk-of-bias assessment, or quantitative synthesis (e.g., meta-analysis).
4. Mechanistic focus: Overlooks potential interactions, safety, or real-world variables (e.g., diet, comorbidities). Future research needs human RCTs assessing clinical endpoints (e.g., DVT incidence).

Clinical Relevance

For supplement users, this review suggests theoretical potential but does not support Ashitaba as a proven antithrombotic treatment. Current evidence is insufficient to recommend it for preventing strokes or deep vein thrombosis in humans. Those using Ashitaba supplements should not replace prescribed anticoagulants (e.g., warfarin) due to unverified efficacy and unknown interaction risks. The findings primarily justify further clinical research; practical use remains speculative without human trial data. Always consult a healthcare provider before using Ashitaba for thrombosis prevention.