Telomere shortening has been discovered to be the primary cause of human ageing.
The DNA is the genetic code that contains the information for the structuring and functioning of the human body. It’ s like the hard disk in a computer that provides all the data for the programs that run within a network. Our DNA is a long thread of the double helix that is packaged in the form of the chromosomes. There are 23 pairs of chromosomes in human cells.
The end parts of the chromosomes are called telomeres. Their name derives from Greek telos- that means ‘end’ and -meros that means ‘part’, and they are literally ‘the end part’ of chromosomes. Telomere ends serve to protect the DNA. They are often compared to the plastic protective tips in shoelaces that protect a lace from unravelling. At the same way, telomeres play an important role in protecting the DNA and keeping it stable.
Human cells at 20 years of age have an average telomere length is around 8.000 bases pairs. Around 35-150 base pairs are lost every year until we reach a level of less than 4500 base pairs of telomeres.
What is really important in ageing is the rate in which those telomeres shorten. A person who loses 35 instead of 150 base pairs per year, ages at a five times slower pace.
Cells have internal mechanisms that repair and can re-lengthen telomeres.
Multiple factors activate this mechanism: vitamins, antioxidants, a healthy diet, omega 3 fatty acids and exercise.
Cellular ageing
Cells have a limited amount of divisions available through a lifetime. This number is around 50 times and is regulated through the length of telomeres. The lifestyle determines how much those cellular divisions are going to last or how often they will divide.
Smoking, lack of sleep, unhealthy nutritional habits, deficiencies, consumption of too much alcohol, obesity lack of exercise, dehydration force cells to divide faster to repair damaged tissues so consequently ageing is rapid.
The faster cells divide the faster telomeres shrink.
Two individuals can have the same chronological age but are in a completely different biological condition and thus have a younger biological age. Telomere length is an accurate index of the biological versus the chronological age of a person.
The longer the telomeres, the younger the biological age of the body.
Research suggests that preserving telomeres length has the potential to prevent ageing and treat diseases associated with ageing and possibly allow humans to increase their longevity beyond the current theoretical maximum of 125 years.
Telomeres, lifestyle, cancer, and aging. Curr Opin Clin Nutr Metab Care. 2011 Jan; 14(1): 28–34. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3370421/
Telomere length predicts replicative capacity of human fibroblasts. Proc Natl Acad Sci U S A. 1992 Nov 1;89(21):10114-8. http://www.ncbi.nlm.nih.gov/pubmed/1438199
The nature of telomere fusion and a definition of the critical telomere length in human cells. Genes Dev. 2007 Oct 1;21(19):2495-508. http://www.ncbi.nlm.nih.gov/pubmed/17908935
Potential therapeutic applications of telomere biology. http://www.sierrasci.com/?p=proof_of_concept
Watts, Geoff (2011). “Leonard Hayflick and the limits of ageing”. The Lancet 377 (9783): 2075
Healthy living is the best revenge: findings from the European Prospective Investigation Into Cancer and Nutrition-Potsdam study. Arch Intern Med. 2009 Aug 10;169(15):1355-62. http://www.ncbi.nlm.nih.gov/pubmed/19667296
Peripheral Blood Leukocyte Telomere Length and Mortality Among 64 637 Individuals From the General Population. J Natl Cancer Inst (2015) 107 (6):
Telomere Length in the Newborn. Nature. Pediatric Research (2002) 52, 377–381
Are Telomeres The Key To Aging And Cancer? http://learn.genetics.utah.edu/content/chromosomes/telomeres/
What is a telomere? Yourgenome www.yourgenome.org/facts/what-is-a-telomere
Telomere Dysfunction, Autoimmunity and Aging. Aging and Disease 2011 Dec; 2(6): 524–537. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3295061/
Diet, nutrition and telomere length.J Nutr Biochem. 2011 Oct;22(10):895-901. http://www.ncbi.nlm.nih.gov/pubmed/21429730
Telomeres and aging. Physiol Rev. 2008 Apr;88(2):557-79. http://www.ncbi.nlm.nih.gov/pubmed/18391173
Reduction of leucocyte telomere length in radiographic hand osteoarthritis: a population-based study. Ann Rheum Dis 65(11): 1444-8. Zhai, G., A. Aviv, et al. (2006).
Premature telomeric loss in rheumatoid arthritis is genetically determined and involves both myeloid and lymphoid cell lineages. Proc Natl Acad Sci U S A. 100(23):13471-6 Schanland SO, Lopez C, et. al (2003).
Telomere length in leukocytes correlates with bone mineral density and is shorter in women with osteoporosis. Osteoporos Int 18(9): 1203-10. Valdes, A. M., J. B. Richards, et al. (2007).
Prematurely senescent ARPE-19 cells display features of age-related macular degeneration. Free Radic Biol Med. 44(7):1348-61. Glotin AL, Debacq-Chainiaux F, et. al. (2008).
Telomere shortening in the damaged small bile ducts in primary biliary cirrhosis reflects ongoing cellular senescence. Hepatology 48(1):186-95. Sasaki M, Ikeda H, et. al. (2008).
Short telomeres are a risk factor for idiopathic pulmonary fibrosis. Proc Natl Acad Sci U S A. 105(35):13051-6. Epub 2008 Aug 27. Alder JK, Chen JJ, et. al. (2008).
Mechanism of telomere shortening by oxidative stress. www.ncbi.nlm.nih.gov/pubmed/15247029. Ann N Y Acad Sci. 2004 Jun;1019:278-84. S Kawanishi – 2004.
Stress and telomere biology: a lifespan perspective. Psychoneuroendocrinology. 2013 Sep;38(9):1835-42. http://www.ncbi.nlm.nih.gov/pubmed/23639252
How “reversible” is telomeric aging? Cancer Prevention Research (Philadelphia, Pa.). 2012 Oct;5(10):1163-8. http://www.ncbi.nlm.nih.gov/pubmed/23639252
The rate of increase of short telomeres predicts longevity in mammals. Cell Rep. 2012 Oct 25;2(4):732-7. http://www.ncbi.nlm.nih.gov/pubmed/23022483
Telomerase reverse transcriptase synergizes with calorie restriction to increase health span and extend mouse longevity. PLoS One. 2013;8(1):e53760. http://www.ncbi.nlm.nih.gov/pubmed/23349740