The Role of Calorie Restriction in Modifying the Ageing Process through the Regulation of SIRT1 Expression

Calorie restriction (CR), as a dietary approach of reducing caloric intake while maintaining nutritional adequacy, has gained significant attention due to its potential role in promoting longevity and enhancing health. Central to the beneficial effects of CR is SIRT1. SIRT1 belongs to a family of NAD+ dependent deacetylases and plays an important role in regulating various cellular processes, including histone deacetylation, oxidative stress response, and mitochondrial biogenesis. This chapter reviews the evidence regarding the effect of CR on SIRT1 expression and mitochondrial biogenesis. Both pre-clinical and human studies have consistently demonstrated that CR promotes an increase in SIRT1 expression and activity in different tissues. This is also associated with other favourable health outcomes, such as delayed neurodegeneration and improved cognitive function. Moderate CR (25% restriction) has shown an impact on promoting mitochondrial biogenesis, reflected in markers such as mitochondrial DNA and transcription factors. However, this is reviewed in light of some methodological limitations, as data varied in response to different CR regimens. Herein, we highlight the potential of CR in up-regulating SIRT1 and promoting mitochondrial biogenesis, which can have significant implications for developing strategies to manage and promote healthy ageing.