Elizabeth Blackburn speaks at TED2017 in Vancouver.Bret Hartman
Nobel Prize laureate Elizabeth Blackburn discovered that a tiny piece of our chromosomes holds the secret to why we age.
It's a special region on the ends of our chromosomes that becomes shorter every time it replicates inside our body. Stopping or reversing that process – which scientists already know how to do – could reverse the process of aging.
But Dr. Blackburn warns taking a sip from the fountain of youth could cause more harm than good, protecting us from some diseases while opening up new risks for others.
"Human genetics have taught us that humans live on a knife edge," Dr. Blackburn said Thursday during her lecture at the TED Conference in Vancouver.
Dr. Blackburn explained that telomeres, a region at the ends of our chromosomes, become shorter every time our cells replicate. She compared telomeres to the protective wax capping on the end of a shoelace, protecting our chromosomes from fraying. When it becomes too short, the DNA is no longer being protected and the telomeres sends a signal to the cell that it's "time to die."
She said the shortening of telomeres produces the signs of aging.
"My skin cells begin to die and you see fine lines and wrinkles," she said. "Hair pigment cells die and you start to see grey. Your immune system cells die and you increase your risks of getting sick.
Research in the past 20 years has made it clear that the shortening of this protective cap is contributing to our risk of some cancers, cardiovascular disease, diabetes and Alzheimer's. These diseases are ranked one, two, six and seven out of the top 10 killers of Canadians.
On the other hand, she said, there are websites where you can purchase bottles of pills that are "proven through independent testing to increase the length of the telomeres caps on your DNA."
But Dr. Blackburn warns against such tampering – at least for now.
"Yes, nudging up [telomeres] does decrease the risk of some diseases, but it also increases the risk of some nasty cancers."
Our cells have a natural life cycle, and when they are no longer needed, or when they accumulate too much damage, they die off in a process called apoptosis.
This natural cell death is important, she said – we don't want cells with bad mutations to replicate and spread. But if our telomeres never shrank, and our cells never died naturally, they could replicate indefinitely, passing on harmful mutations and complications. This unchecked replication of cells would increase the risk of cancer, she said.
Dr. Blackburn doesn't want to focus on living forever.
"It's not about immortality, it's about health span," she said. "The number of years that you're free of disease and healthy and doing things."
She said we can also control our telomeres just by controlling the amount of stress we experience. Studies have shown that people who have that "worn down" look to them have experienced high levels of stress for long periods of time – such as taking care of a parent with dementia. These people had one thing in common: shortened telomeres. And this was irrespective of their age.
"The more chronic stress you're under, the more likely you were to fall victim to an early disease and an untimely death," Dr. Blackburn says.
She was among dozens of lecturers at the annual TED Conference in Vancouver, where speakers talk about big ideas (TED is an acronym for technology, entertainment and design). Former U.S. vice-president Al Gore and the Pope (via video) made surprise appearances this week, and Tesla founder Elon Musk is on the schedule for Friday.