Ecklonia is a genus of brown seaweed, most notably represented by Ecklonia cava, which has drawn attention for its potential metabolic health benefits. Scientific interest stems primarily from its high content of phlorotannins, a class of polyphenolic compounds unique to brown algae. Several preclinical studies (in vitro and animal models) have reported that extracts from Ecklonia cava may help improve various aspects of metabolic syndrome, including glucose metabolism, lipid profiles, and inflammation. Mechanisms proposed include inhibition of carbohydrate-hydrolyzing enzymes (such as α-glucosidase), antioxidant activity, and modulation of lipid metabolism pathways. For example, a few small clinical trials have suggested that Ecklonia cava phlorotannin-rich extracts can modestly lower fasting blood glucose and improve cholesterol profiles in humans with metabolic risk factors.

However, the clinical evidence is limited and preliminary. Most human studies have been small, short-term, and sometimes industry-sponsored. There is insufficient high-quality evidence from large, well-controlled randomized trials to support routine use of Ecklonia extracts for metabolic syndrome. While traditional use of brown seaweeds for general health exists in East Asian cultures, the specific use of Ecklonia for metabolic syndrome is a recent development and is largely driven by scientific investigation rather than long-standing traditional practice. Overall, while there is scientific rationale and early data, the evidence base remains weak (rating: 2/5).