Nuclear factor kappa B (NF-κB) plays a central role in the inflammatory process, and activation of Keap1-Nrf2 system counteracts with NF-κB by upregulating various genes such as superoxide dismutase (SOD), catalase, and heme oxygenase-1 (HO-1). Recently, plant-derived various phytochemicals such as sulforaphane, resveratrol, and curcumin and animal-derived substances such as L-carnitine, L-acetyl-carnitine, and carnosine activate Keap1-Nrf2 system and enhance anti-inflammatory, antioxidant, and anti-apoptotic response of the body. This new nutritional genomics dealing research and clinical application of these so-called “healthy substances” is in the spotlight. Carnitine is one of them and there are many basic and clinical studies. Inflammation, oxidative stress, and apoptosis are related to various pathophysiology, such as cardiovascular diseases, neurodegenerative diseases, frailty, and sarcopenia. The newly discovered actions of carnitine might have therapeutic potential in these area and are discussed in end of this chapter.