1. Men with biopsy-verified, benign prostate cancer who underwent healthy lifestyle changes over a five-year period had longer telomeres than men who did not.
2. There was a positive correlation between the degree of adherence to the regimen and the amount of change in telomere length from baseline.
Evidence Rating Level: 2 (Good)
Study Rundown: Studies suggest that people with shorter telomeres are at an increased risk for many diseases, including several types of cancer. While it is known that differences in the length of our telomeres are partially attributable to genetic variation, the role played by environmental factors is decidedly less clear. This study presented a correlation between lifestyle modifications and telomere length in men diagnosed with low-risk prostate cancer. The authors compared men who received active surveillance plus lifestyle changes to a control group that underwent active surveillance only. After five years, telomere length and telomerase activity were measured and patients who had followed the healthy lifestyle regimen had longer telomeres compared to those who had not (p=0.03). However, there was no significant difference in telomerase activity between the two groups (p=0.64). Interestingly, when data from all participants were analyzed together, a positive correlation was observed between the degree of healthy lifestyle change and relative telomere length. This study had small sample sizes in both groups, which limits the generalizability of the authors’ findings. Further, this was not a randomized study, thus raising important questions about the influence of bias at multiple steps in the study’s progression. Ultimately, as correlation does not equate causation, studies on possible mechanisms behind the observed effects are needed. It is also clear that larger, randomized controlled trials are needed to provide stronger evidence in favor of the authors’ conclusions.
Study co-author, Professor Dean Ornish, M.D., of the University of California San Francisco talks to 2 Minute Medicine:
“The implications of this relatively small pilot study may go beyond men with prostate cancer. 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. Our genes, and our telomeres, are a predisposition, but they are not necessarily our fate.”
In-Depth [prospective cohort study]: 64 patients with pathology-confirmed prostate cancer plus a Gleason score of 6 or lower, a PSA of 10 µg/L or lower and a stage T1 or T2a tumor (on a TNM staging system) were included in this study. 30 patients underwent active surveillance plus life style changes consisting of four components: a low-fat, low-carbohydrate diet, regular aerobic exercise, stress reduction activities, and social support group sessions. The amount of participation in each of these activities was used to compute lifestyle index scores for each patient. 34 patients underwent active surveillance only. Telomere length was measured via qPCR relative to a standard DNA sequence, reported as telomere to single-copy gene ratio (T/S). Telomerase activity was measured in patients’ PBMCs and compared to HEK 293T cells (positive control). Out of the initial population, the baseline PBMC samples of 10 men in the intervention group and 25 men in the control group were sufficient enough to merit inclusion in the follow-up analysis.
The authors found that the intervention group’s telomere length increased by a median of 0.06 T/S units (IQR -0.05 to 0.11), while the control group’s telomere length decreased by a median of -0.03 T/S units (IQR -0.05 to 0.03) after five years (p=0.03). The median lifestyle index score was predictably higher in the intervention group (increase of 0.22 units, IQR 0.13 to 0.36) than in the control group (decrease of 0.06 units, IQR -0.17 to 0.08) after five years (p=0.02). When the telomere lengths and lifestyle scores of both groups were analyzed together, a positive correlation between the two measures was observed; for every percentage point increase in lifestyle score, the average telomere length increased by 0.07 T/S units (p=0.005). However, the median change in telomerase activity after five years was not significantly different between the two groups (p=0.64).
By Nick Woolf and Mimmie Kwong
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