Seaweed bioactives: A comprehensive review of their nutritional, medicinal, and functional roles

Seaweeds contain a rich nutritional composition and various bioactive components including polysaccharides, proteins, pigments, fatty acids, polyphenols, and phlorotannins. Recent studies have highlighted the therapeutic potential of seaweed bioactives, demonstrating their functional efficacy as anti-oxidant, anti-inflammatory, anti-microbial, anti-cancer, anti-obesity, and anti-diabetic agents in different models. Owing to those bioactive properties, the integration of seaweeds into food, feed, pharmaceutical and nutraceutical industries is expanding rapidly. However, the lack of robust large-scale processing technologies and limited understanding of biocompatibility and bioavailability remain significant barriers to their wider utilization. This review delivers a comprehensive overview of the nutritional, bioactive, and therapeutic potentials of seaweeds and their major bioactive compounds and further highlights how molecular structure, processing, and food matrix influence their bioactivity and absorption. It also examines downstream processing strategies and evaluates their impact on product quality, safety, and scalability. Finally, the review discusses future research directions, including the development of multiproduct biorefineries, optimization of bioactive delivery in functional foods, and the need for human pharmacokinetic studies. Collectively, these developments position seaweeds as sustainable foundation in health and wellness, with vast potential to address global nutritional and therapeutic needs through innovative, technology-driven approaches.