Stress doesn’t change your genes. It changes how they speak.

How trauma leaves lasting marks on the body — shaping health, aging and even physical traits.

Trauma and stress may not rewrite the physical code of you, but it can permanently alter how genes are expressed. Through epigenetic mechanisms like DNA Methylation and Histone Modification, stressors can influence everything from immune function to physical traits like pigmentation or hair texture. I want to discuss this, how it happens, and how the body can remember trauma in this way, and what it means for health and healing.

I know what you’re thinking: “How can our genes speak?” Conceptually, our genetic code, our hard A's, G's, C's and T’s seem like very strict and unchanging markers of our biology. Aside from the rare genetic mutations, we can’t seem to escape them. Inside our cells, DNA is tightly wrapped into compact chromosomes that protect it from environmental damage. 

However, in the past few decades, a new field of research has emerged that expands on our previous notions of genetic inheritance and expression called epigenetics. This field of research studies the heritable and stable changes in gene expression that occur resulting from alteration to chromosome structure rather than DNA sequence. See, our chromosomes, unlike our genetic code, aren't completely static. Epigenetic tags such as methylation markers can change how tightly or loosely our chromosomes are wrapped, which in turn changes what and how chemical signals such as hormones or transcription factors can interact with it.         

If your genome is the blueprint to build the house that is you, your epigenome is the instruction manual that distinguishes where, how, and when that blueprint is used. Our DNA codes for all of the proteins that are responsible for our body’s functions, and therefore this instruction manual is a vital part of the way that the house is built. 

So what causes these epigenetic changes?

While our genetics and inheritance have a role to play in it, research has shown that your environment, and experiences are equally powerful influences. Environmental factors like air quality, pollutant exposure and occupation, along with lifestyle factors such as diet, exercise, and very importantly — stress — all have significant impacts on our epigenome.

Stress in particular is associated with various epigenetic changes, some creating lasting marks on DNA expression. In mice models, various researchers have found that acute and chronic stress can cause various histone modifications, down-regulating various mRNA expression levels in brain regions like the hippocampus and amygdala, responsible for things like emotion and memory. 

Epigenetic modifications are very dynamic, and as they are influenced by the environment, there’s less research about their implications when tracing these tags across generations. However, researchers have found specific loci in the human genome in which these epigenetic modifications can be inherited. This has led to growing interest around transgenerational epigenetic inheritance: the idea that stress-induced changes in one's epigenome can impact not only themselves but also successive generations. 

This idea was first explored in psychiatric patients after the Holocaust, where the many children of Holocaust survivors displayed severe psychiatric symptomatology in subsequent generations. Continued research in this field is incredibly important when analyzing adverse health outcomes for different groups of people, where events such as slavery, colonization, displacement and genocide can carry biological effects across generations. Increased attention to this area has been pivotal in developing longitudinal studies designed to determine the mechanisms behind this phenomenon.

In animal models, many stress-related epigenetic changes have already been found to persist into offspring. In humans, while the evidence is still developing, this provides an important direction in understanding how these dynamic changes can impact inheritance, and how trauma can have implications across generations.

In our evolutionary history, epigenetic modifications pose a unique way for us as organisms to be able to adapt to our environment while maintaining the stability of our genetic code. We inherit DNA from our parents, but we also inherit context. Stress can change how our genes “speak,” but the same epigenetic mechanisms behind that can also allow healing and recovery. Epigenetics reminds us that health is not completely individual, but also shaped by our environment, history and lifestyle.

These articles are not intended to serve as medical advice. If you have specific medical concerns, please reach out to your provider.