What’s your cellular age?
Control how well you’re aging by improving your telomere health.
Have you wondered why some sixty-year-olds look and feel like forty-year-olds and why some forty-year-olds look and feel like sixty-year-olds? While many factors contribute to aging and illness, Dr. Elizabeth Blackburn discovered a biological indicator called telomerase, the enzyme that replenishes telomeres, which protect our genetic heritage.
Are Telomeres the Key to Aging and Cancer
You may recall from your high school or college biology class, your unique genetic code is carried by the DNA found in nearly every cell of your body, 46 chromosomes arranged in 23 pairs.
You may have heard DNA referred to as the building block of life, as it is found in small packages called chromosomes in nearly every cell of all living beings.
Telomeres are the protective caps found at the ends of your chromosomes that protect our genetic information during cellular division. For our bodies to heal and function properly, cells must divide to product new cells to replace old, worn-out cells. Telomeres allow our cells to divide without damaging or scrambling the cells’ genetic information. A great analogy for telomeres is the plastic tips on shoelaces as they keep chromosome ends from tangling and fraying.
Telomeres have been compared with the plastic tips on shoelaces, because they keep chromosome ends from fraying and sticking to each other, which would destroy or scramble an organism’s genetic information.
Yet, each time a cell divides, the telomeres get shorter. When they get too short, the cell can no longer divide; it becomes inactive or “senescent” or it dies. This shortening process is associated with aging, cancer, and a higher risk of death. So telomeres also have been compared with a bomb fuse.
Dr. Blackburn and Dr. Elissa Epel’s research shows that the length and health of one’s telomeres are a biological underpinning of the long-hypothesized mind-body connection. They and other scientists have found that changes we can make to our daily habits can protect our telomeres and increase our health spans (the number of years we remain healthy, active, and disease-free).
Why do telomeres get shorter each time a cell divides?
Before a cell can divide, it makes copies of its chromosomes so that both new cells will have identical genetic material. To be copied, a chromosome’s two DNA strands must unwind and separate. An enzyme (DNA polymerase) then reads the existing strands to build two new strands. It begins the process with the help of short pieces of RNA. When each new matching strand is complete, it is a bit shorter than the original strand because of the room needed at the end for this small piece of RNA. It is like someone who paints himself into a corner and cannot paint the corner.
Telomerase counteracts telomere shortening.
An enzyme named telomerase adds bases to the ends of telomeres. In young cells, telomerase keeps telomeres from wearing down too much. But as cells divide repeatedly, there is not enough telomerase, so the telomeres grow shorter and the cells age.
Telomerase remains active in sperm and eggs, which are passed from one generation to the next. If reproductive cells did not have telomerase to maintain the length of their telomeres, any organism with such cells would soon go extinct.
Telomeres and cancer
As a cell begins to become cancerous, it divides more often, and its telomeres become very short. If its telomeres get too short, the cell may die. Often times, these cells escape death by making more telomerase enzyme, which prevents the telomeres from getting even shorter.
Many cancers have shortened telomeres, including pancreatic, bone, prostate, bladder, lung, kidney, and head and neck.
Human lifespan has increased.
Human lifespan has increased considerably since the 1600s, when the average lifespan was 30 years. By 2012, the average US life expectancy was nearly 79.
Some scientists predict average life expectancy will continue to increase, although many doubt the average will ever be much higher than 90. But a few say vastly longer lifespans are possible.
Cawthon says that if all processes of aging could be eliminated and oxidative stress damage could be repaired, “one estimate is people could live 1,000 years.”