What are Telomeres?

Telomeres are like the plastic tips at the end of the shoelaces; they are the caps at the end of each strand of DNA and they protect our DNA from becoming damaged.

Telomeres were first distinguished in 1933 by Dr. Barbara McClintock. Recent research lead Dr. Carol Greider, and Dr. Jack Szostak to be awarded the 2009 Nobel Prize in Physiology or Medicine for the discovery of how chromosomes are protected by the enzyme telomerase and telomeres.

Diagram of Chromosome Showing Telomeres in Green Credit: Beauty Black Book

Telomeres Shorten as We Age

Each cell in our bodies replicates DNA and divides. DNA polymerase is the enzyme in charge of DNA replication, but it is incapable of replicating the entire chromosome strand.  Telomeres serve as a “scape goat” of dispensable DNA not needed for vital functions, so when DNA polymerase is ready to fall off the chromosome some of this dispensable DNA is lost.

How Much Telomeres Do We Lose in a Lifetime?

To put it in perspective, we are born with about 11 kb of telomeres, that’s 11,000 base pairs of DNA. By old age, we have approximately 4 kb or 4,000 base pairs.

This significant decrease in telomeres suggests that each cell has a maximum number of cell divisions before it must induce its own cell death. Dr. Leonard Hayflick extensively studied this phenomenon and concluded that each cell can only divide up to 60 times. The maximum number of cell divisions is now known as The Hayflick Limit.

Diagram Showing Decrease of Telomere Length with Age Credit: Defytime

Promising Study on Progeria Cells

Scientist are in hot pursuit to find the fountain of youth. Dr. John Cook and his team conducted an experiment with promising results and with the intentions of helping children with progeria, a rare genetic condition which speeds up aging.

In the study, the participants, aged 1 to 14 years-old, had telomeres lengths of a 69-year-old. Telomeres length was significantly increased in progeria cells as measured by expression of telomerase.

Video on Study on Progeria Cells by Dr. John Cook Credit:  Vimeo

Although this study is very promising, other scientists believe delaying the natural decline of telomere length could be harmful. Dr. Peter Lansdorp from the University of British Columbia explains that telomere shortening is a defense mechanism built within our cells to decrease the chances of developing cancers. Shortening telomere length of cancerous cells causes them to die. Halting this mechanism would allow cancer cells to continue to divide to create tumors.

What Speeds Up and Slows Down Aging?

Studies have shown that following a healthy diet, regular exercise, managing stress, and increase sleep is associated with longer telomeres, whereas higher body mass index, high stress, and smoking are associated with shorter telomeres.

Table of Factors that Affect Telomere Length Credit:  Indian Journal of Medical Research

https://soundcloud.com/sciencetoday/telomere

Podcast on Telomeres as Marker of Aging Credit: US Science Today SOUNDCLOUD

Stress Less Live longer!

Studies suggest that any type of stress will have an effect on your telomeres and will in turn speed-up the aging process. It also shows that taking good care of yourself will  delay the aging process. So next time you feel stressed out, take a second to breath. Your biological clock will thank you.

Video of The Science of Aging Credit: ASAP Science YouTube

Maria-Fernanda Arcila