A massive study has revealed molecular changes that occur in human bodies as they age.
From the Research Abstract:
Disease incidences increase with age, but the molecular characteristics of ageing that lead to increased disease susceptibility remain inadequately understood. Here we perform a whole-blood gene expression meta-analysis in 14,983 individuals…and identify 1,497 genes that are differentially expressed with chronological age. … We further used the gene expression profiles to calculate the ‘transcriptomic age’ of an individual, and show that differences between transcriptomic age and chronological age are associated with biological features linked to aging, such as blood pressure, cholesterol levels, fasting glucose, and body mass index. …
Additionally, the work revealed a connection between these genes and factors such as diet, smoking and exercise.
Links to articles about the study as well as the study itself have been placed in Aging:
The transcriptional landscape of age in human peripheral blood