Abstract
Now that it's accepted that people age differently, it's critical to know why. Aging is such a holistic process that we might suppose that no simple answer about why we age differently will ever emerge. However, that may not be true at the cellular level. Cells have their own lifespan, ranging from the early stages, marked by rapid division and fresh renewal every time a cell divides—this is the period molecular biologist Elizabeth Blackburn, PhD, calls luxuriant growth—ending with a stage in which no more divisions occur and the cell is tired and unreliable in performing its basic functions—this is the period known as senescence.
A senescent cell breaks down on several fronts. It sends out faulty chemical messages and fails to interpret incoming messages correctly. Its ability to heal itself slows down and eventually comes to a halt. Pro-inflammatory substances can start to leak out through the cell membrane into surrounding tissue and the bloodstream. It seems more and more possible that when our cells age, so do we.
The most striking support for this theory comes from research into our genes and specifically a section of DNA known as a telomere, which caps the end of each chromosome like a period ending a sentence. Telomeres are “noncoding” DNA, meaning that they have no specified function in building cells, but they are far from passive. Their function seems to be to preserve cells. Every time a cell divides, which happens constantly somewhere in the body, its telomeres are shortened. Longer telomeres are typical of young cells in the stage of luxuriant growth; shortened or frayed telomeres are typical of weary senescent cells.
Blackburn, leading researcher on the subject, who shared the 2008 Nobel Prize in Physiology or Medicine with Carol Greider of Johns Hopkins and Jack Szostak of Harvard for their discovery of telomerase (the enzyme that replenishes telomeres), and now the head of the Salk Institute in La Jolla, California, covers every aspect of cell aging and renewal in her book, The Telomere Effect, 1 coauthored with her close research colleague of 15 years, health psychologist Elissa Epel, PhD. They convincingly describe telomeres and levels of telomerase in the cell as our best marker yet for the mysterious and multifold process of aging. This also implies that by increasing one's telomerase levels and thereby causing telomeres to grow longer, a healthy lifespan can be founded on cells that keep renewing themselves for decades.
In their book, Blackburn and Epel cite a startling actuarial prediction. There are currently around 300,000 centenarians existing around the world, a number that is rapidly increasing. According to one estimate, reaching age one hundred is about to become so commonplace that one-third of children born in the United Kingdom will live to be centenarians. The issue of protecting our cells is suddenly more urgent than ever. The bottom line is to understand what puts our telomeres at high risk and low risk.
The book's survey of all the pertinent research dovetails with everything we've been discussing under a healing lifestyle, as follows:
Your telomeres are at low risk if you: Have no exposure to severe stress. Have never been diagnosed with a mood disorder. Enjoy good social support, including a close confidant who gives good advice, friends who listen to you and with whom you can unburden yourself, and relationships in which love and affection are shown. Exercise moderately or vigorously at least three times a week, preferably more. Get good-quality sleep for at least seven hours a night. Consume omega-3-rich food three times a week while avoiding processed meats, sugary sodas, and processed food in general. A whole-food diet is best. Are not exposed to cigarette smoke, pesticides, and insecticides.
The opposite is also true.
Your telomeres are at high risk if you: Are being exposed to severe stress in your life. Have a history of being medically treated for anxiety or depression. Lack social support from friends and family. Lead a completely sedentary lifestyle with no regular exercise, even light activity like walking. Suffer from chronic insomnia or cut your sleep shorter than seven hours a night. Consume a diet high in fat, processed foods, and sugary sodas, with no attention to sufficient fiber and omega-3 fatty acids. Are exposed to cigarette smoke, pesticides, insecticides, and other chemical toxins.
These points summarize the research-supported risk factors presented by Blackburn, and as with any risk-based program, some people are more affected than others. Severe stress is one of the most thoroughly damaging factors—in one study, caregivers who tended Alzheimer's patients had shortened telomeres that predicted a shortened lifespan of between five and eight years. 2 Blackburn also lists a number of commercial labs where people can pay to have their telomerase level analyzed.
It's also significant that the lifestyle choices known to decrease the risk of heart disease, particularly the intensive program devised by Dean Ornish, MD, have a beneficial effect on telomere length. Extending the program to cancer, Ornish had another impressive finding. A group of men with low-risk prostate cancer were selected for study. 3 (Low risk means that their cancer was at an early stage and slow growing. Prostate cancer can take decades to advance, and the current recommendation advises balancing the risk and reward of doing any active treatments, a change from the era when any cancer was immediately treated and usually aggressively.)
The men were put on a variant of the heart-disease protocol: they ate a low-fat, high-fiber diet; walked for thirty minutes a day; and attended regular support group meetings. Stress management was included, and there was training in meditation, mild yoga stretching, and breathing. At the end of three months the group that was on the program had higher telomerase levels than the control group, which meant that their cells were aging better. Stress seemed to play a key role, because the greatest increase in telomerase occurred among the men who reported having fewer distressing thoughts about prostate cancer. Ornish followed some of the men for five years, and those who stuck with the program showed telomeres that had increased by 10 percent, reversing the usual expectation as cells age. 4
If stress levels determine how well or badly our cells age, this should show up in meditation studies, and it has. 5,6 Blackburn cites two studies conducted at meditation retreats that were three weeks and three months long. At the end of the three-month retreat, meditators had higher telomerase levels compared to the control group. In the three-week retreat, meditators showed longer telomeres in their white blood cells than the control group, which showed no change.
How long would it take for these effects to appear, and how intensive does one's dedication to meditation have to be? There is no definitive answer, but probably the best clues come from a collaborative study in which Blackburn and other leading researchers participated, conducted at the Chopra Center in Carlsbad, California. 7 Women in good health were divided into two groups. One group enjoyed a spa vacation without other interventions. The other group went through a program led by Deepak Chopra, MD, that included meditation and a variety of Ayurvedic treatments. At the end of the week everyone reported feeling better, which attests to the likelihood that most people are in sympathetic overdrive, because simply going on a week's vacation improved their sense of well-being.
In the same vein, there were improvements in gene expression (activity) in both groups, including the chemical pathways that trigger inflammation and the stress response. There also appeared to be a meditation effect on telomeres and telomere-protective genes. These occurred in the meditation group among experienced meditators. The fact that it took only a week to produce results that started to be significant points to the conclusion that we are doing our cells some good almost as soon as we take up meditation and that the practice needs to be regular and long lasting.
We are encouraged by how strongly telomere research validates a healing lifestyle. It also underlines the conviction that cells benefit directly, at the genetic level, from conscious lifestyle choices. Blackburn ends her book with a visionary Telomere Manifesto that would prioritize protecting our cells as a part of parenting, social relations, the fight against income inequality, and global outreach for the planet. Like all visions, this one depends upon individual decisions, and one comes away from The Telomere Effect even more persuaded that anti-aging begins by keeping our cells in a state of renewal. If there are no new startling things to do, becoming more optimistic about our own aging is valuable in itself. ■