In this review, we present clinical studies on mindfulness-based therapy (MBT) with a focus on mediating mechanisms for its health promoting effects. These constitute awareness, self-compassion, regulation of dysfunctional patterns of thoughts and emotions, neural network and cellular processes. Among cellular processes are inflammation, oxidative stress, mitochondrial dysfunction and telomere shortening, which all contribute to the molecular pathophysiology of several of today's lifestyle diseases. Finally, we address applications, where strong evidence exists for the clinical impact of MBT.