Two newly published studies involving thousands of nurses show that lifestyle and attitude might influence the age of your cells.
Telomeres are special “end caps” on chromosomes that keep them from unwinding. Cells begin with a number of caps; each time a cell divides, a cap is lost (although the telomerase enzyme can add new telomeres). Much remains to be learned about telomeres, but they seem to be implicated with aging. When a chromosome runs out of telomeres, it can no longer divide, and the cell dies.
Can lifestyle and attitude influence telomeres? This is largely unknown territory. Starting in 1976, thousands of female nurses participated in a Nurses Health Study (NHS) by filling out questionnaires on their health habits and anxiety levels and following up every 2–3 years. In 1988–1990, thousands submitting blood samples. This data has now been correlated with telomere counts in the leukocytes (white blood cells), important cells in the immune system.
One study by Qi Sun et. al, published in May in PLoS ONE, found a correlation between telomere shortness and unhealthy lifestyles. Another study by Okereke et al., just published July 11 in PLoS ONE, found a possible connection between “phobic anxiety” and telomere shortness. This study was summarized on Science Daily.
The authors of these papers realize that correlation is not causation, and even correlation is difficult to measure, due to errors and omissions such as inconsistencies in questionnaire responses, lack of follow-up blood samples, evaluation of a single cell type, and evaluations of one gender only. Nevertheless, the researchers found statistically significant correlations that remained stable even after cross-checking their data various ways. These studies had the advantage of large data sets involving thousands of participants.
If the correlations remain robust in similar studies, it would indicate that mental states and lifestyle choices can produce epigenetic effects on our genes. Most of us realize that poor lifestyle choices and anxieties are unhealthy, but these studies suggest a detailed physical connection between mind and body about which many of us were unaware.
Since it’s very difficult to have high confidence in correlation studies like this, we’ll mark this as interesting and potentially valuable to know. It fits well with what biologists are learning about the “mysterious epigenome” (see 07/04/2012 entry). Wouldn’t it be something if your fears or choices have a tangible effect on the action of the telomerase enzymes in your cells? Don’t make your telomerase say, “What’s the use? My owner doesn’t care about all the work I do.”