This white paper synthesises insights and experiences from four EU-funded Horizon Europe projects, SmartCHANGE, AI-PROGNOSIS, TRUSTroke, and UMBRELLA, united by a shared focus on trustworthy artificial intelligence in healthcare. Published by the StayHealthy Cluster in September 2026, the paper explores common challenges and solutions across three thematic areas: personalised risk modelling across the lifespan, explainable AI and clinical decision support, and data privacy, ethics, and regulation. Each project contributes a distinct perspective, from AI-driven NCD prevention in children and adolescents (SmartCHANGE) to Parkinson's disease prognosis (AI-PROGNOSIS), stroke management (TRUSTroke and UMBRELLA), yet all converge on the critical importance of building AI systems that are not only accurate, but transparent, ethical, and aligned with the needs of clinicians, patients, and families. The paper also includes a market overview of the AI healthcare landscape, an analysis of barriers to entry, and reflections on strategic positioning for scaling trustworthy AI tools across diverse European healthcare systems. This is the first of two white papers authored by the Cluster. The second will focus on results, experiences, recommendations, and impact.