Chromosomes grew stronger as everyday habits improved, but number of participants in project was small
MONDAY, Sept. 16, 2013 (HealthDay News) -- Healthy behaviors such as exercise, good diet and stress management have the potential to reverse aging on a molecular level and partly restore the vitality of a person's cells, according to a new pilot study.
Healthy lifestyle choices can increase the length of DNA sequences found at the end of a person's chromosomes, said lead author Dr. Dean Ornish, founder and president of the nonprofit Preventive Medicine Research Institute in Sausalito, Calif.
What's more, the healthier you live, the stronger your chromosomes become, the researchers said in the Sept. 17 online issue of the journal The Lancet Oncology.
"We may be able to reverse aging on a cellular level," said Ornish, a best-selling author who advocates a lifestyle-driven approach to improve health and combat disease. "Our bodies are much more dynamic than we had once recognized, and the more you change at any age the more you can improve."
But one geneticist cautioned that the study findings are preliminary, and raised several unanswered questions
The DNA sequences, known as telomeres, directly affect how cells age and have been associated with an increased risk of premature death and age-related diseases. As telomeres become shorter and their structural integrity weakens, cells age and die faster.
Shorter telomere length has been tied to unhealthy behaviors such as cigarette smoking, chronic emotional stress and poor diet, Ornish said, as well as diseases including cancer, cardiovascular disease, dementia, obesity, stroke, osteoporosis, infectious diseases and diabetes.
"They're sometimes likened to the plastic tips on the end of shoelaces that keep your laces from unraveling," Ornish said of telomeres. "In this case, they keep your chromosomes from unraveling."
Previous research has shown that adopting a healthy lifestyle can provide many medical benefits, including reversal of heart disease progression. The researchers said, however, that this is the first study to show that the benefits of healthy living may extend down to a person's cellular genetics.
"If validated by large-scale randomized controlled trials, these comprehensive lifestyle changes may significantly reduce the risk of a wide variety of diseases and premature mortality," Ornish said. "Our genes -- and our telomeres -- are a predisposition, but they are not necessarily our fate."
The five-year study focused on two small groups of men diagnosed with low-risk prostate cancer that had not been treated. Ten men were asked to make comprehensive lifestyle changes, while a control group of 25 men maintained their personal status quo.
The lifestyle changes focused on four main areas, Ornish said:
- Eating right. Adoption of a whole-food, plant-based diet that was low in fat and processed carbohydrates.
- Moderate exercise. Thirty-minute walks six days a week.
- Stress management. Participation in meditation, yoga and other relaxation techniques for an hour a day.
- Social support. Attendance at an hour-long support-group meeting once a week.
The researchers took blood samples and measured the length of the participants' telomeres at the start of the study, and again after five years.
The men who made comprehensive lifestyle changes experienced an average 10 percent increase in their telomere length. Men in the control group had their telomeres shrink an average of 3 percent.
Further, there appeared to be a relationship between the "dose" of lifestyle change and the body's response -- the more positive lifestyle choices someone made, the longer their telomeres grew.
"Our bodies in general have a remarkable ability to heal if we simply stop what we're doing," Ornish said. "I've been impressed by how dynamic these mechanisms are and how quickly people can get better."
The pilot study's results are promising, but need to be replicated in a large, randomized trial, said Joseph Lee, a human geneticist and associate professor of clinical epidemiology at the Columbia University Mailman School of Public Health in New York City.
"The participants in the intervention group were highly motivated, as they maintained the intervention regimen for more than five years and they continued to attend meetings when the meetings were not required," Lee said. "One needs to be cautious as to how effective lifestyle changes will be in a large general population where the level of motivation may not be so high."
Lee also regretted that the researchers didn't check health traits such as weight, body-mass index or blood pressure along with the length of the patients' telomeres.
"For example, if the participants in the intervention group with longer telomere length had lower blood pressure, it would have been far more interesting," Lee said. "Even though it may not have been significant statistically due to small sample size, it would have been informative."
The study was not intended to gauge whether lifestyle changes slowed progression of prostate cancer.
For more information on telomeres, visit the University of Utah (http://learn.genetics.utah.edu/content/begin/traits/telomeres/ ).
SOURCES: Dean Ornish, M.D., founder and president, Preventive Medicine Research Institute, and clinical professor, medicine, University of California, San Francisco; Joseph Lee, Ph.D., human geneticist, and associate professor, clinical epidemiology, Columbia University Mailman School of Public Health, New York City; Sept. 17, 2013, The Lancet Oncology, online