A nutritious diet, exercise, and a good night’s sleep are the fundamental rules to follow for a happy and healthy life. A new study from the University of California, San Francisco, has shown that these factors can also help slow down the process of cellular aging that result due to accumulation of life’s stressors over time.

The study looks into the role of shortened telomeres in age-related diseases. "The study participants who exercised, slept well, and ate well had less telomere shortening than the ones who didn't maintain healthy lifestyles, even when they had similar levels of stress," said lead author Dr. Eli Puterman, assistant professor in the department of psychiatry at UCSF, in a press release. "It's very important that we promote healthy living, especially under circumstances of typical experiences of life stressors like death, caregiving and job loss." The paper appears in the journal Molecular Psychiatry.

How Do Telomeres Affect Aging?

The repetitive stretches of DNA at the ends of chromosomes are called telomeres. They are compared to the plastic tips at the end of shoe laces, since they prevent the chromosomal ends from fusing with neighboring chromosomes. The telomeres keep getting shorter each time the cell divides, and when they become too short the cell can no longer divide and it dies. Telomeres also get shorter with age.

But in this study the researchers proved that a healthy lifestyle that includes physical activity, controled diet, and adequate sleep could reduce telomere shortening and thereby ageing. They did this by examining the effect of these behaviors in 239 post-menopausal, non-smoking women, over the course of one year. The women provided blood samples at the beginning and end of the year, which were checked for telomere measurements.

The women also reported of any stressful events that had occurred in their lives over the course of the year. In women who engaged in lower levels of healthy behaviors, there was a significantly greater decline in telomere length in their immune cells for every major life stressor that occurred during the year. Conversely, women who followed a healthy lifestyle, in spite of experiencing life stressors were found to have lesser shortening. 

"This is the first study that supports the idea, at least observationally, that stressful events can accelerate immune cell aging in adults, even in the short period of one year," Puterman said. "Exciting, though, is that these results further suggest that keeping active, and eating and sleeping well during periods of high stress are particularly important to attenuate the accelerated aging of our immune cells."

Apart from aging, the shortening length of the telomeres is also associated with cancer of the prostate, bladder, lung, and kidney. These cancer cells also produce more of the enzyme telomerase to prevent shortening of the telomeres and continue growing. So a measure of telomerase can be used to detect cancer.

Other age-related diseases associated with shortening telomeres are stroke, vascular dementia, cardiovascular disease, obesity, and osteoporosis diabetes. 

The discovery of telomeres and the enzyme telomerase earned Nobel prizes for three Americans, including UCSF molecular biologist and co-author Elizabeth Blackburn.

"These new results are exciting yet observational at this point. They do provide the impetus to move forward with interventions to modify lifestyle in those experiencing a lot of stress, to test whether telomere attrition can truly be slowed," Blackburn said.

Source: Puterman E, Blackburn E, Epel E, Lin J, Krauss J. Determinants of telomere attrition over 1 year in healthy older women: stress and health behaviors matt. Molecular Psychiatry. 2014.