Biological age

Warning

Although genetic testing can provide important information for the diagnosis, treatment, and prevention of health conditions, there are limitations. For example, if you are a healthy person, a positive genetic test result does not mean that you will develop a health condition other than your current one. On the other hand, in some situations, a negative result does not guarantee that you will not have a certain disorder. Test results are intended for educational purposes only and not for diagnostic use. Any results from the analysis of genome sequence information that may be considered medically relevant must be confirmed using other tests (analysis). If you have questions or concerns about what you learn from these informative genome sequence tests, you should talk to your doctor or a licensed genetic counselor.

Biological age

Genomic DNA is under constant attack from both, endogenous and exogenous, damaging agents. Without proper repair, the ensuing DNA damages would lead to the alteration of genomic structure thus affecting the faithful transmission of genetic information. During the process of evolution, organisms have acquired a series of mechanisms responding to and repairing DNA damage, assuring the maintenance of genome stability and the faithful transmission of genetic information. In 1930 it was first proposed that chromosome ends play an important role in ensuring genomic stability. Chromosomal ends were noted to have special features and were named telomeres by Muller from the Greek words telos (end) and meros (part) as shown here below.

In 1986 Cooke and Smith associated telomeres directly to aging by noticing that the length of telomere repeats, capping sex chromosomes in sperm cells, was longer than in adult sperm. In humans, telomeres consist of thousands of repetitive TTAGGG DNA non-coding sequences that cap both ends of linear chromosomes. Telomeres shorten with age and with each round of mitosis because of the inability of the DNA replication machinery to read and copy up to the ends of linear chromosomes. In this perspective, telomeres act as an expendable DNA to prevent the loss of coding DNA. When telomere lengths drop below a certain threshold, the cell decreases the proliferative potential and may undergo cellular senescence. Telomere length is influenced by a complex interplay of genetic, environmental, and lifestyle factors. While hereditary factors set the baseline for telomere dynamics, external influences such as chronic stress, poor diet, smoking, lack of physical activity, and exposure to oxidative stress can accelerate telomere shortening. Chronic psychological stress, smoking, obesity, sedentary behavior, and exposure to pollutants are all associated with accelerated telomere shortening (Epel et al., 2004; Valdes et al., 2005; Du et al., 2012). In contrast, regular physical activity, healthy dietary patterns (e.g., Mediterranean diet), and effective stress-reduction practices (e.g., yoga, mindfulness) have been linked to longer telomeres and reduced cellular aging (Puterman et al., 2010; Boccardi & Boccardi, 2019).

Measuring telomere length gives a measure of your biological age, which is different from the chronological age because of the interplay between genetic and epigenetic factors that modulate telomere length and gives you an idea of your real biological age and how to act to lower it through improvement in lifestyle factors.

Scientific literature

• Harley, C.B., Futcher, A.B., and Greider, C.W. (1990). Telomeres shorten during ageing of human fibroblasts. Nature 345, 458–460.
• Epel, E. S., et al. (2004). Accelerated telomere shortening in response to life stress. PNAS, 101(49), 17312–17315.
• Valdes, A. M., et al. (2005). Obesity, cigarette smoking, and telomere length in women. The Lancet, 366(9486), 662–664.
• Du, M., et al. (2012). Environmental exposure to polycyclic aromatic hydrocarbons and telomere length in a Chinese population. Occupational and Environmental Medicine, 69, 769–77.
• Puterman, E., et al. (2010). The power of exercise: buffering the effect of chronic stress on telomere length. PLoS ONE, 5(5), e10837.
• Boccardi, V., & Boccardi, M. (2019). Telomeric aging: Lifestyle modification and nutrition influence. Current Pharmaceutical Design, 25 (34), 3777–3781.