The ends of chromosomes are protected by specific DNA sequences called telomeres, visualized here in red. This image shows that some chromosomes are depleted of telomeres, which can result in abnormal cell division and cancer. (NIH)
Have you ever envied a friend who looks 20 years younger than their age?
How do they do it?
The secret could lie in their telomeres, the tiny caps on the ends of their chromosomes—kind of like the plastic wraps at the end of shoelaces. Nobel Laureate Elizabeth Blackburn, thepresident of the Salk Institute for Biological Studies, used this metaphor recently when she was a guest on KQED's Forum, along with UCSF psychologist Elissa Epel. The two, who have researched telomeres, discussed their new book, "The Telomere Effect: A Revolutionary Approach to Living Younger, Healthier, Longer."
"Picture a shoelace and remember the little plastic tips at the end," said Blackburn. "If you don't have those at the end of your shoelace, they will start fraying away, and the shoelaces will stop working well. Now imagine the shoelaces are actually the chromosomes that carry our genetic material. ... When those telomeres wear down, which they do over the many, many decades of human life, then the consequences are severe. Cells will stop in their tracks and start malfunctioning, and they start becoming inflammatory. "
The good news, Blackburn says, is that minimizing stress will keep your shoelace tips (telomeres) in better shape, helping to prevent disease and maybe even the effects of aging.
Below are excerpts from the conversation, edited for length and clarity. Answers from both authors are combined.
Telomeres Connected to the Big Killers
When telomeres fray at the tips, the DNA inside a cell is no longer able to protect its genetic material, because the telomeres don't work well. Again, think of shoelaces. When the tips are frayed, it's difficult to thread them through your shoes. The same is true if your telomeres wear down.
When chromosomes are no longer protected by the telomeres, it sets off alarm signals inside the cells. Over the years, this process of deterioration is what leads to the major diseases of aging like cardiovascular disease, dementia and cancer, because the body isn't protecting itself well.
Telomere attrition—causing negative damage to the cells—is one of the contributors that lead to these major killers. So the more we stave off attrition of telomeres, the more we extend both our lifespan and our healthspan (the years in which we enjoy a high quality of life where our health is concerned.)
A Mystery Solved
We knew that telomeres gradually wear down over the years. We also knew these protective tips build back up, but we didn't know how.
Then we discovered a biological indicator, an enzyme called telomerase, which protects our genetic heritage. The enzyme is one of many factors that helps the telomeres build back up again and pass DNA successfully from generation to generation.
Telomere Length Depends on Mind-Body Connection
There is a well-established correlation between chronic stress and our health, not only in accelerating chronic diseases but also the short-term effects on the immune system. We wanted to find out how stress affects telomeres, and the results surprised us.
We found a strong relationship between perceived stress—the feeling that you can't cope with all that's on your plate—and shorter telomeres, and in turn we found lower levels of telomerase in patients who were in a state of overwhelm.
Active exercise, good nutrition and deep sleep all play a role in helping to lower stress, but we also found that our community, our neighborhood and our social and psychological lives are also shaping our telomere length throughout our lifespan. For example, the trust we feel or don't feel in our neighbors are all related to telomeres.
Any time you get a group of people together, you have social connection and support, which is powerful. And, we are starting to see that emotional support groups can reduce stress just as well as meditation and mindfulness training. For example, the research on knitting , Christian prayer and other repetitive behaviors like chanting look pretty darn good when you study their mind-body effects.
So what's very interesting about telomeres is how much control one has over the net attrition rate, which is the sum of many, many influences. You can quantify it and then say, "Wow this statistically relates to a lot of these things."
Telomeres: A Key Pathway in Aging
Part of the reason we know so much about telomeres is that we can now study human DNA so easily. The number of studies that have been done on large populations all over the world is phenomenal. Granted, telomere research is only one factor of aging, but it is a pathway that is illuminated and that we know a lot about.
There are other discoveries that are gaining scientists' attention, like the epigenetic clock, which is another predictor of our longevity and our health. But it's a totally different, independent pathway. Our goal in focusing on telomeres is to empower people to see all the ways they can improve their health on their own. You can do a lot to improve your DNA without having to buy expensive genetic tests, like changing the way you eat, relax and sleep.
Don't Fall For Pills that Make Big Promises
Don't take supplements promising to improve your telomeres. They are completely unproven. The creams you put on the outside of the body are really not going to seep down to the deeper layers and change the cell aging system. We suggest changes in small daily habits that add up over time. For example, nutrition is a powerful way to reduce oxidative stress, reduce inflammation and possibly boost telomerase. New studies will likely show that changes in diet eventually affect the skin and beyond.
Blackburn and Epel offer a list of practices to strengthen the health of your telomeres.
Get the best of KQED’s science coverage in your inbox weekly.