Telomere length reductions due to stressors
Economic problems in an increasingly unequal society, an excessive workload, caring for a sick relative are increasingly common pressures that make stress an important part of modern life.
A number of studies have linked stress to shorter telomeresa chromosomal component that has been associated with cellular ageing and the risk of heart disease, diabetes and cancer.
How do personality and environment influence this phenomenon? Elissa Epel, PhD, has been researching this question for more than a decade at the University of California, San Francisco, where she directs the Center for Aging, Metabolism and Emotion. She works frequently with Elizabeth Blackburn, PhD, who won a Nobel Prize in 2009 for her research on telomeres.
What are telomeres and how do they relate to ageing and disease?
Telomeres are a protective sheath at the end of a strand of DNA. Each time a cell divides, it loses some of its telomeres. An enzyme called telomerase can replenish it, but chronic stress and exposure to cortisol decrease its supply. When the telomere is too short, the cell often dies or becomes pro-inflammatory. This leads to the ageing process, along with the associated health risks.
How is stress classified in terms of factors affecting telomere length?
The two most important factors are chronological ageing and genetics.but stress is now on the map as one of the most consistent predictors of shorter telomere length. The type of stress determines how great its effect is. It appears that exposures to multiple early life adversities, such as childhood neglect, have the greatest effects, as they track into late adulthood, or establish persistent mechanisms that keep telomeres short throughout life, such as exaggerated stress reactivity and poor health behaviours. . Stress factors such as late-life care also have an effect. So we can see the relationship between stress and cellular ageing across a lifespan, and it is fundamental to the way we are built. Our brains are constantly looking for threats to our survival. When we expose our bodies to years of chronic stress excitation, we see effects that override normal ageing, making our telomeres look like they belong to a significantly older person.. When we look at groups of people with psychiatric disorders related to dysregulated emotional responses, especially depression, and compare them to people who have never experienced these disorders, they consistently have shorter telomeres.
How early in life do the negative effects of stress begin?
To be literal in this regard, it should be said that begin before conception. An infant's intrauterine environment is shaped by a mother's pre-existing physical health. There have also been several studies on maternal health and telomeres in offspring. So far, we found in a small study that the greater a mother's prenatal anxiety, the shorter the baby's telomere length, as seen in the work of Sonja Entringer, PhD, Pathik Wadhwa, PhD, et al.. This scenario is setting the stage for an accelerated trajectory of ageing. In fact, it may be one of the most critical periods in time affecting cellular ageing. Transgenerational transmission of risks must be taken into account to understand and improve public health.
Another consistent pattern that emerges in clinical case histories is that early-life adversity is associated with shorter telomeres. This relationship was first observed in adults when early adversity was assessed retrospectively, but has now been observed in young children prospectively. Maltreatment, abuse, severe neglect and exposure to violence appear to take up a stretch of telomeres.
The good news is that there are buffers to early adversity, such as high-quality, warm and interactive parents, or possibly the luck of having a more stress-resistant genotype.according to a small study by Colter Mitchell, PhD, and colleagues.
One of his recent studies has the intriguing conclusion that stress can alter the way we metabolise high-fat and sugary foodsWhat's behind it?
Chronic stress wreaks havoc on neuron-driven compulsive eating patterns. It can cause neuroplastic changes that alter the way we perceive and react to the world in ways that may be good for short-term survival, but not for longevity mechanisms. Stress impairs our executive functionwhich hampers our ability to resist impulses. Chronic stress can increase the reward response in our brains. So if we're prone to addiction, it's going to make us crave even tastier foods or drugs.
Risk factors for chronic stress
Our social environment.
Is your social fabric rich and are you connected to the people in your social circle? starting with your family? A strong social network is probably the biggest buffer against toxic stress, next to exercise.. However, we often lack the quality of long-term social connections. There is frequent loneliness among high-risk groups such as the elderly, who may be more isolated. For those on low incomes, many are working long and inflexible hours. Part of the problem is that there are limited minutes in the day, and if you are working excessively, you are low on affection for your social network and yourself.
One thing to remember about chronic stress is that it is only our thoughts that make it seem that way. Viewed consciously, no situation is truly chronic - there are always quiet moments to be alive and present. Moments that can be enjoyed with ease and enthusiasm.
Finally and fortunately, other studies suggest ways to prevent or reduce premature telomere shortening. For example, avoiding chronic stress and work-related fatigue, eating a healthier diet, etc. (according to a December 2012 study, the Mediterranean diet is preventive), reducing exposure to air pollution, regular sport, moderating alcohol consumption and dealing with stressful situations as challenges rather than threats.