Biological versus Chronological Age Assessment
Rationale & Instructions
Biological age is a concept that reflects the
physiological state of an organism, rather than the chronological age.
Biological age can vary significantly among individuals of the same
chronological age, depending on their genetic background, lifestyle,
environmental factors, and health status. Therefore, it can be a more accurate
indicator of the risk of age-related diseases and mortality than chronological
age.
One of the challenges in measuring biological age is
to find reliable biomarkers that can capture the complex and dynamic processes
of aging. Biomarkers are objective and quantifiable characteristics that
reflect the biological or functional state of an organism. Ideally, biomarkers
of aging should be predictive, reproducible, non-invasive, and easy to measure.
Among the various biomarkers of aging that have been
proposed, three of them have received considerable attention: epigenetic tools,
telomere length, and immune parameters. Epigenetic tools refer to methods that
measure the changes in DNA methylation patterns that occur during aging. DNA
methylation is a chemical modification that regulates gene expression without
altering the DNA sequence. Epigenetic tools can estimate the biological age of
an individual by comparing their DNA methylation profile with a reference
dataset derived from a large population of individuals with known chronological
ages. One of the most widely used epigenetic tools is the epigenetic clock,
which is based on a mathematical algorithm that calculates the biological age
from the methylation levels of 353 CpG sites (regions of DNA where a cytosine
nucleotide is followed by a guanine nucleotide) across the genome1.
Telomere length is another biomarker of aging that
measures the length of the protective caps at the ends of chromosomes.
Telomeres protect the chromosomes from damage and degradation during cell
division. However, telomeres shorten with each cell division and with exposure
to oxidative stress and inflammation. Telomere length reflects the cumulative
history of cell division and cellular senescence, which are key aspects of
aging. Telomere length can be measured in various tissues, such as blood cells,
buccal cells, or saliva samples2.
Immune parameters are biomarkers of aging that reflect
the changes in the immune system that occur during aging. The immune system is
responsible for defending the body against pathogens and foreign substances, as
well as eliminating damaged or abnormal cells. However, the immune system
declines with age, resulting in increased susceptibility to infections, chronic
inflammation, autoimmune diseases, and cancer. Immune
parameters include measures of immune cell counts, subsets, functions, and
cytokine levels3.
Biological age based on these biomarkers can be
effectively used in health management for several reasons. First, biological
age can provide a more accurate assessment of the health status and disease
risk of an individual than chronological age. For example, individuals with shorter telomeres or higher epigenetic age
have been shown to have higher mortality rates and higher risks of
cardiovascular disease, diabetes, cancer, and neurodegenerative diseases4,5.
Second, biological age can help monitor the effects of interventions that aim
to slow down or reverse aging. For example,
lifestyle modifications such as exercise, diet, stress management, and smoking
cessation have been shown to improve biological age by increasing telomere
length or decreasing epigenetic age1 .
Third, it can help personalize medicine and optimize treatment outcomes by
considering the individual variability in aging processes. For example, it can
help determine the optimal dose and timing of drugs or vaccines for different
patients based on their immune status.
In conclusion, biological age based on epigenetic
tools, telomere length, and immune parameters can be a valuable tool for health
management. Biological age can provide a more comprehensive and precise measure
of aging than chronological age and can help guide preventive and therapeutic
strategies for improving health span and lifespan.
1 Vaiserman, A. and Krasnienkov, D.
Telomere Length as a Marker of Biological Age: State-of-the-Art, Open Issues,
and Future Perspectives. Front Genet 11, 630186 (2021).
https://doi.org/10.3389/fgene.2020.630186
2 Colloca,
G., Di Capua, B., Bellieni,
A. et al. Biological and
Functional Biomarkers of Aging: Definition, Characteristics, and How They Can
Impact Everyday Cancer Treatment. Curr Oncol
Rep 22, 115 (2020). https://doi.org/10.1007/s11912-020-00977-w
3 Ledda, C.; Loreto, C.; Rapisarda, V.
Telomere Length as a Biomarker of Biological Aging in Shift Workers. Appl. Sci.
10, 2764 (2020). https://doi.org/10.3390/app10082764
4 Mather,
K.A., Jorm, A.F., Parslow, R.A. and Christensen, H.
Is Telomere Length a Biomarker of Aging? A Review, J Geront
A Biol Sci Med Sci, 66A, 202–213 (2011). https://doi.org/10.1093/gerona/glq180
5 Banszerus, V.L.; Vetter, V.M.; Salewsky, B.; König, M.;
Demuth, I. Exploring the Relationship of Relative Telomere Length and the
Epigenetic Clock in the LipidCardio Cohort. Int
J Mol Sci 20, 3032 (2019). https://doi.org/10.3390/ijms20123032
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Biological versus chronological age
from epigenome & telomere profiling |
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Dataset from direct-to-consumers (DTC) epigenome profiling companies |
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Other |
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Dataset from telomere
profiling companies |
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Other |
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Dataset from comprehensive
telomere & epigenetic testing companies |
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If you are already engaged with
one or more of the above epigenome or telomere profiling companies and know
that your biological age is equal to or less than your chronological age,
score 0. If not, score 1. |
Reminder:
Accumulated score of zero requires no further action. The user is encouraged to
discuss with a healthcare provider any line items scored as 1 and proceed with
remedial actions as appropriate. Save or print the table. All forms will reset
to blank state once the user exits the website.
"Prevention is better than cure" Desiderius Erasmus