Grapefruit Seed Extract for Immune Function

Research suggests that grape seed extract (GSE) may support immune function through several mechanisms, including anti-inflammatory, immunomodulatory, and antiviral activities, with the available evidence pointing consistently in a supportive direction. Studies indicate that GSE can reduce inflammatory cytokine production, suppress pro-inflammatory immune cell populations such as Th1 and Th17 cells, and attenuate inflammatory infiltration in tissue models of lung injury and autoimmune neurological disease, with one mouse study showing meaningful reductions in symptoms of an MS-like condition. Two laboratory-based studies also found antiviral activity against norovirus and Aichi enteric virus, suggesting a potential role in defending against viral pathogens. However, the current body of evidence consists primarily of animal studies, cell-based experiments, and one general review, with no human clinical trials identified among the linked research, which represents a significant limitation in drawing conclusions about real-world immune benefits in people.