Healthy Living May Keep Cells Young
Published: Sep 16, 2013, By John Gever, Deputy Managing Editor, MedPage Today, Reviewed by Robert Jasmer, MD; Associate Clinical Professor of Medicine, University of California, San Francisco
Men with low-risk prostate tumors who participated in a multifaceted lifestyle improvement program showed an increase in mean telomere length after 5 years, contrary to findings in a control group, a small study found.
Among 10 patients who volunteered for the intervention, the ratio of telomere to single-copy human beta-globin gene length increased from baseline by a median of 0.06 (interquartile range -0.05-0.11), whereas in 25 similar patients who underwent active surveillance for cancer and no other particular intervention, the ratio decreased by a median of 0.03 (IQR -0.05-0.03, P=0.03), reported Dean Ornish, MD, of the University of California San Francisco and the Preventive Medicine Research Institute (PMRI) in Sausalito, Calif., and colleagues.
Increases in telomere length were found in nine of the control patients (36%), compared with seven (70%) of the patients undergoing the intervention, Ornish and colleagues reported online in The Lancet Oncology.
Telomeres are the end-caps on chromosomes that, under normal circumstances, grow shorter with each round of cell division. When they reach a certain critical length, cells stop dividing and eventually senesce and die.
The intervention was comprised of a plant-based diet low in fats and refined carbohydrates, moderate walking-based exercise, weekly group meetings to build social support, and daily hour-long stress reduction exercises including stretching, breathing, meditation, and progressive relaxation.
The three patients in the intervention group who had decreased telomere length showed less adherence to the intervention. With adherence to the intervention's components measured with a scale ranging from 0 to 1, the median change from baseline in the three with decreased telomere length was 0.13 units (IQR 0.03-0.34) versus 0.29 units in the seven with increased length (IQR 0.21-0.56, P-value not reported.
The same lifestyle interventions were also assessed in the control patients, some of whom undertook their own efforts at improvement. Across both groups, Ornish and colleagues found a significant association between adherence to such efforts, with an increase from 0 to 1 in adherence score correlated with a 0.07-point increase in telomere length (P=0.005). As expected, age was significantly associated with telomere shortening, with each additional year at the end of the study correlated with a decrease of 0.005 in telomere length (P=0.007).
Ornish and colleagues indicated that the findings were consistent with several previous studies, although they also acknowledged that the small sample size and the nonrandomized design were important limitations. It also did not address clinical outcomes such as mortality or new-onset diseases of aging.
But the researchers described the study as important because it was the first longitudinal, controlled study to link a specific intervention to increased telomere length.
'Simple Changes in Lifestyle'
In an interview with Medpage Today, Ornish argued in favor of a three-way association between healthy lifestyle factors, reduced incidence or progression of chronic conditions such as heart disease, and increased telomere length. Earlier studies had established associations between the last two and between the last two. The current study, Ornish said, now provides a connection between the first and the third.
"These findings are yet another example of how, although we tend to think of advances in medicine as a new drug or laser, something high-tech and expensive, that these simple changes in lifestyle can make such a powerful difference, and now help to explain on a cellular level how we may be able to reverse aging," he said.
But he also cautioned that this was a pilot study and the findings "need to be replicated in large randomized trials."
Patricia Opresko, PhD, a telomere biologist at the University of Pittsburgh, told MedPage Today that it remained unclear "what telomere length means for an individual."
She noted that not everyone in the study who practiced the interventions showed increases in telomere length. "It's hard to say whether, in the individuals without telomere lengthening, the intervention did not work for them or would not be beneficial for them. We're really still at the point where telomere length measurements are better interpreted in the context of population-type studies," she said.
The patients in the intervention and control groups were participants in two separate studies of men with early-stage, low-risk prostate cancer who were choosing active surveillance as the management strategy. Selection criteria were the same in order to facilitate comparing outcomes. Tumors were no more advanced than stage T2a, with Gleason scores no greater than 6, and limits of 33% for biopsy core width and 50% of the length positive for adenocarcinoma.
The 10 members of the intervention group had volunteered to undergo the program of lifestyle changes. The weekly support sessions lasted 4 hours, included 1 hour each of physical and stress management exercises plus an additional hour of group discussion and a fourth hour with a dinner lecture from a health professional. Meetings were compulsory for the first 3 months, during which the investigators provided all food for meals, but participants were encouraged to meet on their own for two 4-hour self-directed sessions each month.
Participants in the control group also had chosen active surveillance for cancer management as the sole treatment approach, although those patients received standard medical advice on diet and lifestyle according to their clinicians' judgment. All participants in both groups completed questionnaires at baseline and after 5 years about diet, exercise, stress reduction, and social support, from which the lifestyle adherence scores were calculated.
Mean baseline ages in the intervention and control groups were 62 and 63, respectively, and body mass index values averaged 25 kg/m2 and 27 kg/m2, respectively. Mean systolic blood pressure was 140 and 137 mm Hg, respectively.
Three patients in the intervention group and two in the control group eventually underwent more aggressive prostate cancer therapies including brachytherapy, hormonal treatments, or prostatectomy. Omitting those patients from the analysis did not alter the findings markedly, Ornish and colleagues indicated.
The study was funded by the U.S. Department of Defense, the National Cancer Institute, Furlotti Family Foundation, Bahna Foundation, DeJoria Foundation, Walton Family Foundation, Resnick Foundation, Greenbaum Foundation, Natwin Foundation, Safeway Foundation, and Prostate Cancer Foundation.
Three study authors reported co-founding a company, Telomere Health Inc., to develop telomere length diagnostics. Ornish and another author reported working with Healthways to educate and support people in improving health behaviors.
Primary source: Lancet Oncology
Source reference: Ornish D, et al "Effect of comprehensive lifestyle changes on telomerase activity and telomere length in men with biopsy-proven low-risk prostate cancer: 5-year follow-up of a descriptive pilot study" Lancet Oncol 2013; DOI: 10.1016/S1470-2045(13)70366-8.