Duckweed (Wolffia globosa, Wolffia arrhiza, and Lemna minor) as novel therapeutic food for acute malnutrition and famine alleviation in low- and middle-income countries and humanitarian crisis settings

Acute malnutrition remains a leading cause of under-five mortality in low- and middle-income countries (LMICs), particularly in humanitarian crisis settings where conventional therapeutic food supply chains are frequently disrupted. There is an urgent need for locally cultivable, affordable, and nutritionally adequate alternatives to imported ready-to-use therapeutic foods (RUTFs). In this review, we examine the nutritional composition, food safety, and production scalability of three duckweed species, namely: Wolffia globosa , Wolffia arrhiza , and Lemna minor , as candidate therapeutic foods in famine-affected regions. Compositional analyses indicated that these species consist of a high protein content (up to 48.2, 50.9, and 39.1% dry weight for W. globosa , W. arrhiza , and L. minor , respectively), a comprehensive essential amino acid profile, and an array of micronutrients and immunomodulatory compounds. As indicated by a Protein Digestibility-Corrected Amino Acid Score (PDCAAS) of 89% for W. globosa and the Digestible Indispensable Amino Acid Score (DIAAS) of 0.75 for W. arrhiza , the protein quality of duckweed is considered high. Furthermore, as one of the fastest-growing plants on earth, duckweed can double their biomass in only 4–5 days, reach harvest size within 2–5 days, and produce up to ∼177 g of biomass per square meter per day, with water requirements up to 90% lower per kilogram of protein produced as compared to conventional crops. Although antinutritional factor levels are comparable to common vegetables and pathogen risks are manageable via solar drying and boiling, two primary limitations restrict their immediate application. First, a low-fat content (0.5%–9.6% DW) that confines energy density relative to standard RUTFs and, second, a susceptibility to accumulating heavy metals from growth medium. Additionally, the current evidence base may be constrained by absence of data regarding cultivation failures or adverse implementation outcomes. Consequently, rigorous, context-specific risk-benefic assessments are required. Controlled cultivation trials in LMICs, integrated with randomized controlled trials in malnourished cohorts, are necessary to objectively determine the feasibility of these species for acute malnutrition management.