Safety of medicinal and edible herbs from seed sources for human consumption: A systematic review

Plant seeds constitute an important category of medicinal and edible herbs. However, assessments regarding their safety for human consumption remain insufficient. This systematic review comprehensively evaluates human safety for 21 medicinal and edible seeds.

Two independent reviewers screened the titles, abstracts, and fulltexts of the retrieved literature against the inclusion and exclusion criteria to identify eligible AE reports in both English (PubMed, Embase, CENTRAL) and Chinese (CNKI, Wanfang, VIP, SinoMed) databases. Search strategies were constructed using the scientific names, common names, and frequent aliases of the medicinal and edible seeds combined with safety evaluation keywords such as "adverse reaction," "toxicity," and "side effect." Any studies describing adverse event (AE) after human intake of specific seeds were included. AE characteristics were summarized. Causality between seed consumption and AEs was assessed.

We identified 703 AEs involving eight medicinal and edible seeds. Ginkgo semen and Armeniacae semen amarum caused the most AEs, followed by Persicae semen, Myristicae semen, Sterculiae lychnophorae semen, Canavaliae semen, Cassiae semen, and Ziziphi spinosae semen. Among the AEs, 70.8% occurred in children, and 68.9% were associated with excessive intake. Most AEs manifested as gastrointestinal and/or neurological symptoms. Ninety-six were classified as serious; these were caused by Ginkgo semen (29 cases), Armeniacae semen amarum (60 cases), Persicae semen (4 cases), Canavaliae semen (2 cases), and Myristicae semen (1 case). These SAEs resulted in 15 fatalities and 3 cases of permanent functional impairment. Causality with seed consumption was determined to be "certain" for 239 AEs, "probable" for 449, and "possible" for 15. No AE reports were found for thirteen seeds.

Consuming specific medicinal and edible seeds, particularly Ginkgo semen, Armeniacae semen amarum, Persicae semen, Myristicae semen, and Canavaliae semen, poses potential risks, including fatal cases. Excessive dosages, consumption by children, and inappropriate processing were primary causes. Therefore, strengthening safety management for these is warranted.

PROSPERO (No. CRD42023426497).