Seaweed proteins are nutritionally valuable components in the human diet

The global population is expected to reach 11 billion people by the year 2100 and will require sustainable sources of dietary protein. Most dietary protein originates from animal and terrestrial plant agriculture, which leads to deforestation, water pollution, and greenhouse gas emissions. Discovering alternative protein sources that are nutritionally adequate for the human diet without harmful environmental effects is imperative. Seaweeds are a promising option as they produce abundant protein with a low carbon footprint. Experimental evidence shows that seaweeds contain high concentrations of the essential amino acids (EAAs) necessary for human consumption, but seaweeds have yet to be evaluated with standardized metrics to compare their nutritional value to other protein sources. In this technical note, independent literature describing the EAA content and protein digestibility of 3 commonly consumed species of seaweeds was evaluated alongside traditional protein sources using a novel hybrid protein quality (HPQ) metric. HPQ is derived from the protein digestibility-corrected amino acid score and digestibility indispensable amino acid score but includes modifications to address the lack of in vivo digestibility data for seaweeds. Seaweed proteins are similar in quality to common plant protein sources such as peas, soy, and tree nuts. Furthermore, seaweed proteins from different species have complementary EAA profiles and can be mixed to form protein blends that are nutritionally on par with animal products such as milk and whey. Thus, seaweeds may be viable protein sources with a reduced footprint that provide beneficial ecosystem services.