23 September 2013
ByAppeared in BioNews 723
Switching to a healthier lifestyle may reverse the signs of ageing at the genetic level in men with low-risk prostate cancer, a small study has found.
The length of telomeres - caps that protect the stability of chromosomes - grew longer in men who adopted a healthy lifestyle, whereas they became shorter in men who made no lifestyle changes. Telomeres shorten naturally with each cell division; short telomeres are linked to ageing and earlier onset of illnesses such as heart disease and some cancers, including prostate cancer.
Professor Dean Ornish, who led the study at the Preventive Medicine Research Institute at the University of California, San Francisco, said: 'The implications of this relatively small pilot study may go beyond men with prostate cancer. If validated by large-scale randomised 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'.
The study, published in the journal Lancet Oncology, followed 35 men with low-risk prostate cancer over five years: ten men who undertook major changes to their diet, exercise, stress management and social support, and 25 men who were not given lifestyle advice.
Researchers measured the telomere length of the participants at the beginning of the study and five years later. They found that telomeres had increased in relative length in the group that had adopted a healthy lifestyle, but had decreased in length in the group that did not. The researchers concluded that improvements in lifestyle were statistically associated with increases in telomere length.
There was no difference seen in levels of prostate-specific antigen (PSA), or in the activity of telomerase (an enzyme that is involved in telomere lengthening) between the two groups of men.
Larger scale studies are needed to further investigate the link between the lifestyle changes and lengthened telomeres, and whether this would lead to improved outcomes in prostate cancer patients.
Dr Lynne Cox from the University of Oxford, who was not involved in the study, said: 'The authors are very careful to point out that their sample sizes are small and that all the men they studied had cancer so they cannot draw conclusions about the effect of similar lifestyle changes for telomere length and ageing in healthy people'.
'Overall, though, the findings of this paper that changes in lifestyle can have a positive effect on markers of ageing support the calls for adoption of and adherence to healthier lifestyles'.
The lifestyle changes that the men made included adopting a diet high in fruits and vegetables and low in fat and sugar; walking 30 minutes per day on six days of the week; one hour of meditation and yoga per day; one hour of social support per week; and training from dieticians and stress management specialists.
Telomeres are repeating DNA sequences found at the ends of chromosomes. They enhance the stability of chromosomes and protect against their degradation during cell division. The enzyme telomerase is involved in the lengthening of telomeres, but is also active in most cancer cells.