Life Expectancy – It’s Written in Your DNA

Want to know how close you are to death’s door? Unnerving as it sounds, researchers have recently shown that DNA can better predict life expectancy than chronological age. Furthermore, they’ve shown that the rate of aging differs between individuals. The key lies in the internal clock we’re all born with – telomeres.
Photo by Julián Ignacio Gomez Lorenzonon Flickr
So what are these? They’re protective sequences that prevent our DNA from unraveling. The catch?  Whenever our cells divide, our telomeres irreversibly shorten. Shorter telomeres = less DNA protection and faster aging. Scientists have known about this connection for decades. However, this is the first study to prove the link outside of a lab. Researchers from the University of East Anglia (U.K.) analyzed the DNA of over 300 birds (Seychelles Warblers) for their entire lifespan. The twenty-year study found that the rate of telomere shortening better predicted a bird’s life expectancy than chronological age. 
The surprising part was that individuals aged at different rates. So, what can cause some telomeres to shrink faster than others? Though researchers are not 100% sure, what they do know is that stress is key – any kind of stress. Everything from mental to physical strain causes oxidants to attack and destroy our DNA’s protection (think smoking, a poor diet, or even an angry boss). Ironically, if you’d like to increase your odds of a longer life, it’s probably best not to worry about your shrinking telomeres.

About the author

Melissa Carmen Cheung, PhD

Passionate about sharing science with the public in a fun and accessible way, Melissa is a Medical Communications professional who earned her Ph.D. in Pharmaceutical Sciences from the University of Toronto. Though her research focused on the design of novel cancer therapeutics, Melissa is intrigued by all facets of science. Her goal in life is to captivate people with the same excitement she feels for science.