Spiritual practices may seem like a distant world from biomedical research, with its focus on molecular processes and repeatable results. However, off the coast of the University of California, San Francisco (UCSF), a team led by a Nobel Prize-winning biochemist is investing in a territory where few conventional scientists would dare to move forward. While Western biomedicine has traditionally avoided the study of personal experiences and emotions concerning physical health, these scientists are putting the state of mind at the center of their work. They are involved in serious studies suggesting that meditation can - as Eastern traditions have long claimed - delay aging and prolong life.
Elizabeth Blackburn has always been fascinated by how life works. Born in 1948, she grew up by the sea in a remote Tasmanian city in Australia, collecting ants from her garden and jellyfish from the beach. When she started her scientific career, she went on to dissect molecules from living systems by molecule. She was attracted to biochemistry, she says because it offered a complete and accurate understanding "in the form of a deep understanding of the smallest possible subunit of a process".
Working with biologist Joe Gall at Yale in the 1970s, Blackburn sequenced the chromosome tips of a single-celled freshwater creature called Tetrahymena (“scum pond,” as she describes it) and discovered a repetitive DNA motif that works like a cap protective. The capsules, dubbed telomeres, were later found on human chromosomes as well. They protect the ends of our chromosomes every time our cells divide and DNA is copied, but they wear out with each division. In the 1980s, working with graduate student Carol Greider of the University of California, Berkeley, Blackburn discovered an enzyme called telomerase that can protect and rebuild telomeres. Even so, our telomeres decrease over time. And when they get too short, our cells start to malfunction and lose the ability to divide - a phenomenon that is now recognized as a key process in aging. This work finally won Blackburn the 2009 Nobel Prize in Physiology or Medicine.
In 2000, she received a visit that changed the course of her research. The caller was Elissa Epel, a postdoc at the UCSF psychiatry department. Psychiatrists and biochemists generally don't have much to talk about, but Epel was interested in the damage done to the body by chronic stress, and she had a radical proposition. Epel, now director of the UCSF Aging, Metabolism, and Emotion Center, has a longstanding interest in how mind and body relate. She cites as an influence both holistic health guru Deepak Chopra and pioneering biologist Hans Selye, who first described in the 1930s how rats subjected to long-term stress become chronically ill. "Each stress leaves an indelible scar, and the body pays for its survival after a stressful situation, becoming a little older," said Selye.
In 2000, Epel wanted to find that scar. "I was interested in the idea that if we look deeply into cells, we can measure the stress and stress of everyday life," she says. With some fear of approaching such an experienced scientist, the postdoctoral fellow asked Blackburn for help with a study of mothers who were going through one of the most stressful situations she could think of - caring for a chronically ill child. Epel's plan was to ask women how they felt stressed and then look for a relationship between their mental state and the state of their telomeres. University of Utah collaborators measured telomere length, while Blackburn's team measured telomerase levels.
Blackburn's research to this point involved precisely controlled experiments in the laboratory. Epel's work, on the other hand, focused on real people, living complicated lives. "It was another world, as much as I expected," says Blackburn. At first, she doubted that it was possible to see any significant connection between stress and telomeres. Genes were seen as the most important factor in determining telomere length, and the idea that it would be possible to measure environmental influences, let alone psychological influences, was highly controversial. But as a mother, Blackburn was drawn to the idea of studying the situation of these stressed women. "I just thought, how interesting," she says. "You cannot avoid empathy."
It took four years before they were finally ready to collect blood samples from 58 women. This would be a small pilot study. To give the greatest chance of a significant result, women in both groups - stressed and controlled mothers - had to match as closely as possible, with similar ages, lifestyles, and backgrounds. Epel recruited his patients with meticulous care. Still, says Blackburn, she saw the trial as nothing more than an exercise in viability. Until Epel called her and said, "You won't believe it."
The results were clear. The more stressed the mothers said they were, the shorter their telomeres and the lower their telomerase levels. The most exhausted women in the study had telomeres that translated into a decade or more of aging compared to those who were less stressed, while telomerase levels were cut in half. "I was thrilled," says Blackburn. She and Epel connected real lives and experiences to molecular mechanics within cells.
Many telomer researchers were cautious at first. They pointed out that the study was small and questioned the accuracy of the telomere length test used. "That was a risky idea at the time and, in the eyes of some people, unlikely," explains Epel. “Everyone is born with very different telomere lengths and thinks we can measure something psychological or behavioral, not genetic, and does that predict the length of our telomeres? This is not really where this field was ten years ago. ”
The role triggered an explosion of research. Researchers have since linked perceived stress to shorter telomeres in healthy women, as well as in Alzheimer's caregivers, victims of domestic abuse, early trauma, people with severe depression, and post-traumatic stress disorder. "Ten years later, there is no doubt that the environment has a bearing on the duration of telomeres," says Mary Armanios, a physician and geneticist at the Johns Hopkins School of Medicine, a specialist in telomer disorders.
There is also progress towards this mechanism. Laboratory studies show that the stress hormone, cortisol, reduce telomerase activity, while oxidative stress and inflammation - the physiological consequences of psychological stress - appear to corrode telomeres directly. This appears to have devastating consequences for our health. Age-related conditions, from osteoarthritis, diabetes, and obesity to heart disease, Alzheimer's disease, and stroke, have been linked to short telomeres.
The big question for researchers now is whether telomeres are simply a harmless marker of age-related damage (like gray hair, say) or whether they play a role in causing the health problems that plague us as we age. People with genetic mutations that affect the telomerase enzyme, who have many shorter-than-normal telomeres, suffer from accelerated aging syndromes and their organs fail progressively. But Armanios questions whether the smallest telomere length reductions caused by stress are relevant to health, especially since telomere lengths are so variable in the first place.
However, as evidence of the damage caused by the decrease in telomeres accumulates, research is embarking on a new question: how to protect them. "Ten years ago, if you had told me that I would be thinking seriously about meditation, I would have said that one of us is crazy," Blackburn told the New York Times in 2007. Yet, this is where her work on telomeres brought her. Since their initial study with Epel, the pair has been involved in collaborations with teams from around the world - up to 50 or 60, she calculates, spinning in "wonderful directions". Many of them focus on ways to protect telomeres from the effects of stress; trials suggest that exercise, healthy eating, and social support help. But one of the most effective interventions, apparently capable of slowing telomere erosion - and perhaps even increasing it again - is meditation.
Theories differ on how meditation can boost telomeres and telomerase, but most likely reduce stress. The practice involves slow, regular breathing, which can physically relax us by calming the fight or flight response. It probably has a psychological anti-stress effect. Being able to move away from negative or stressful thoughts can allow us to realize that these are not necessarily accurate reflections of reality, but transient and ephemeral events. It also helps us to appreciate the present instead of continually worrying about the past or planning for the future.
Inevitably, when a Nobel Prize-winner starts talking about meditation, he irritates some people. In general, Blackburn's methodical approach to the subject gained reluctant admiration, even among those who expressed concern about the health claims made for alternative medicine. "She takes care of her business in a cautious and systematic way," says Edzard Ernst, from the University of Exeter, UK, who specializes in testing complementary therapies in rigorous controlled tests. Oncologist James Coyne of the University of Pennsylvania, Philadelphia, who is skeptical of this field in general and describes some of the research on positive psychology and health as "morally offensive" and "science of tooth fairy", admits that some of the data of Blackburn are “promising”.
But in a new study of 239 healthy women, Blackburn found that women whose minds wandered less (the main purpose of mindfulness meditation) had significantly longer telomeres than those whose thoughts went crazy. "Although we report only one association here, it is possible that a greater presence of spirit promotes a healthy biochemical environment and, in turn, the longevity of cells," concluded the researchers.
The contemplative traditions from Buddhism to Taoism believe that the presence of the mind promotes health and longevity; Blackburn and his colleagues now suggest that ancient wisdom may be right.