Feeling stressed and anxious? You’re not alone. Last year, stress, depression and anxiety accounted for 57% of all ‘sick days’ in the UK. And while we may think that the effects of stress are temporary, new research shows that ‘scarred for life’ may not just be a metaphor. In fact, we could be leaving permanent epigenetic marks on our DNA.
What is epigenetics? Across our lifetime, specific genes may switch themselves on or off, making us more susceptible to serious illness, weight gain and much more. In this relatively new field of study, researchers have found that what we eat, drink, how often we exercise, how stressed we are and the environments we expose ourselves to can affect how our genes are read. In some cases, epigenetic changes are reversible but recent studies have found that extreme stress and anxiety can actually have long lasting effects, which could potentially be passed on to our offspring, this is known as transgenerational epigenetics.
An experiment by researchers from the Brain Researcher Institute, found removing mice from their mother’s early on, recreating what would be major childhood trauma in humans, heightened their fear and anxiety as adults. In addition to this, they also had altered DNA methylation patterns on stress-response genes. What the researchers found particularly interesting, was that these traits were passed down to the next two generations of offspring, despite never being separated from their mothers.
Though the existence of true transgenerational epigenetic inheritance in humans is still debated, this explanation could be used to help us better understand lasting effects on Holocaust survivors and their offspring. A defining and terrible period of mass trauma, descendants of those who survived the Holocaust have been found to have altered chronic stress levels to their peers, which Rachel Yehuda, researcher of epigenetics and intergenerational effects of trauma, says could predispose them to anxiety disorders and other health risks.
Yehuda and her team found that survivors faced a lifetime of complications including having lower levels of cortisol, a hormone that helps the body return to normal after trauma. They also had lower levels of a particular enzyme that breaks down cortisol. The children of survivors were also found to have lower cortisol levels, but higher levels of the enzyme that breaks it down. With this in mind, Yehuda is able to theorise that if pregnant survivors had low levels of the enzyme in the placenta, a greater amount of cortisol could make its way to the fetus, which would then develop high levels of the enzyme to protect itself. Because of this, it is thought that children of Holocaust survivors have a higher sensitivity to stress.
In our day-to-day lives, we come up against different stresses all the time, be it work, money, pressure to succeed, sleep deprivation - these are all add up to cumulative stress exposure, which sits apart from acute 'fight or flight' stress. Chronic stress can embed itself in us in many different ways, eliciting both immediate and long-lasting psychological, physical and emotional strains.
In the past year, 74% of people have felt so stressed and overwhelmed they’ve been unable to cope. As a result of this 46% reported they overate or ate unhealthily, 29% said they started drinking or drank too much alcohol, and 16% started smoking or increased their smoking, further fuelling stress and anxiety. Over stress is said to cost the US economy over $300 billion a year.
While tasty food, smoking and drinking can offer short term comfort, the long term effects can be much more serious. Professor Subhash C. Pandey, director of the Alcohol Research Center at the University of Illinois, Chicago, says, “adolescent binge drinking can disrupt epigenetic programming in key brain regions by changing certain key molecular targets within the epigenome.” Ultimately, this can lead to changes in gene functions - switching on unrequited genes - and predispose an individual to ‘adult psychopathology.’
However, the good news is, not many of us are stressed to the point of no return, there is hope. The day-to-day stresses described here commonly result in an ‘acute reaction’, most of which are temporary and reversible. “Reviewing our basic lifestyle choices and habits can go a long way to improving our mental health,” says Dr. Tom Stubbs, Chronomics CEO. “It may sound simple but many of us create stress by not giving ourselves enough time to relax, leading to bad habits like too much caffeine, alcohol, lack of exercise, sleep deprivation and unhealthy or irregular eating, all of which have the potential to affect the epigenetic regulation of our health.”
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3. Rodriguez T. Descendants of Holocaust Survivors Have Altered Stress Hormones, Scientific American, 1 March 2015
4. American Psychological Association, 2018
5. Research Society on Alcoholism. "Anxiety study shows genes are not fixed: Experience and exposure can change them." ScienceDaily. ScienceDaily, 26 June 2017.