Lifestyle Choices, Psychological Stress and Their Impact on Ageing: The Role of Telomeres

Telomeres are the heterochromatic repeat regions at the ends of eukaryotic chromosomes that maintain the genomic integrity of a cell. Telomere shortening with increasing age is a part of the normal ageing process. However, factors such as inflammation, oxidative stress and other genotoxic stressors may also increase the rate of telomere attrition, leading to telomere dysfunction-mediated cellular senescence and accelerating the ageing process. Once telomeres shorten to a critical length, the cell encounters a proliferation block where it either ceases to divide or undergoes programmed cell death. Thus, telomere length is considered a biological clock that limits the lifespan of a cell and an organism: people with short telomeres often have reduced lifespan. Certain lifestyle factors such as smoking, body mass index and psychological stress have been found to correlate with accelerated telomere shortening, likely because they increase DNA damage through oxidative stress. Recently, studies have identified lifestyle factors that can potentially protect telomeres. For example, people who lead a healthy lifestyle by increasing their physical activity, practising meditation, adhering to the Mediterranean diet and using multivitamins have been shown to have longer telomeres than those who do not adhere to such lifestyle changes. This chapter highlights the influence of lifestyle factors on key biological mechanisms associated with telomere maintenance.