The Role of Olive Oil Polyphenols in Osteosarcopenic Obesity-Related Biological Domains: A Systematic Review of Current Evidence

Background: Osteosarcopenic obesity (OSO) is an emerging syndrome characterized by the coexistence of obesity, sarcopenia, and osteoporosis, primarily affecting aging populations. Nutrition, especially polyphenol-rich foods like extra virgin olive oil (EVOO), may play a preventive or therapeutic role in OSO. This review aims to critically examine evidence from in vitro, in vivo, and human studies on the effects of olive oil polyphenols on OSO-related biological domains. Methods: This systematic review followed PRISMA guidelines. Studies were identified from PubMed and Google Scholar using MeSH terms related to olive oil, polyphenols, and OSO-associated conditions. In vitro and in vivo studies (both in animal and human models) published in the last ten years were included. The study protocol was registered with PROSPERO (CRD420251077836). Results: Fifteen studies were included: eight in vitro, four in vivo on animal models, and three human trials. Phenolic compounds such as hydroxytyrosol, oleuropein, oleocanthal, and oleacein demonstrated antioxidant, anti-inflammatory, anti-adipogenic, and osteo-/myo-protective effects. These compounds modulated key metabolic pathways and gene expression related to adipogenesis, bone metabolism, and muscle integrity. Conclusions: Olive oil polyphenols exhibit promising biological effects on the tissues involved in OSO. Although evidence is mostly preclinical, selected compounds (notably hydroxytyrosol and oleuropein) may serve as adjuncts in nutritional strategies for OSO prevention.