This method to measure aging and physiological age measures the many physical and biological characteristics that were definitely linked to the aging process (cholesterol levels, unipedal stance test, central obesity…)
This method follows the decline of many organic systems (cardiovascular, lungs, kidneys, liver, teeth, and immune system) by quantifying 18 markers for chronic diseases linked to aging. This technique was developed by a research team from Duke University, under the supervision of Dr. Daniel Belsky.
DNA methylation levels grow with the number of divisions a cell undergoes. The number of cell divisions grows with time. Therefore, measuring the methylation of DNA helps to quantify aging. Treating DNA with bisulfites allows to convert non-methylated cytosines into uraciles, so the methylated cytosines can easily be identified. We deduce a physiological age from their numbers.
Telomeres can be found at the end of our chromosomes, and get shorter with age. There are many techniques to measure their length (TRFs, Q-Fish, qPCR, STELA…) based on the Southern Blot principle, PCR and in situ hybridization.