It’s taken me a couple months to get over life’s many sucker punches but I’m dusting off the spidey webs on my blog with a much requested (er Yuri, only one person requested this – pipe down!) post on epigenetics and the link to generational trauma.
So before we get into the heavy stuff, let’s break it down simply. Who we are, is encoded in our DNA, a unique code (unless you have an identical twin) that tells whether you will have the musical talent of a blocked nose or be the next Mozart. Since the father of genetics, Gregor Mendel first played around with his pea plants, things have become slightly more complicated, leading to the field of epigenetics in the last 50 years. Epigenetics refers to which bits of your code will be switched on, or to be more exact, the changes in expression of your genes.
Epigenetics is the study of heritable changes in gene expression without changes to the genetic code which in turn affects how cells read the genes.
Your DNA stays constant throughout your life but how your cells read the genes changes. These can be natural and regular occurrences, but it can also be affected by factors like age, the environment/lifestyle, and disease state. These can turn the activity of the genes up or down and can tell your cells what they should grow up to be – skin cells, liver cells or brain cells. In more serious instances, epigenetic changes result in diseases like cancer.
Epigenetics and trauma
The 1944-45 Dutch famine provides an interesting and unexpected experiment on epigenetics. Children born during this period ended up being influenced by the famine throughout their lives, even though they only experienced the effects in the womb. As adults, they were slightly more overweight than average with higher rates of high cholesterol, diabetes and schizophrenia.
Researchers attribute obesity in these adults to a small change, a specific methyl group (pictured) on a gene, PIM3. Basically, the Dutch famine added a methyl group to foetuses born to starving mothers, which made the PIM3 gene less active –> thus leading to a slow metabolism. Now, this explanation makes sense to me, if your body thinks you’re in starvation mode (low-calorie diets included) – it’s likely to pile on the weight, polar bear pre-hibernation style.
Other epigenetic studies have tried to understand the trauma that seems to be passed on at a biological level, that perpetuates the experience in a trans-generational manner. The first researcher to make headway on this topic showed that when plants were traumatised with ultraviolet light, the mother plant was able to produce seedlings with exactly the same DNA. Although there were no physical changes to the appearance of the seedlings, they were highly sensitive to ultraviolet light that lasted three to four generations.
More interestingly (IMO) is the concept of inheriting nightmares from your ancestors. This paper described how survivors of the Holocaust went on to have children that have a biological memory of what their parents experienced. This either gave these children a greater resilience to stress or predisposed them to stress.
“It seems that these individuals, who are now adults, somehow have absorbed the repressed and insufficiently worked-through Holocaust trauma of their parents, as if they have actually inherited the unconscious minds of their parents.”
This phenomenon is not exclusive to Holocaust survivors, offspring of other PTSD parents are also vulnerable; including descendants of war veterans, survivors of war trauma and childhood sexual abuse, refugees and torture victims. Not only that, but the transmission may continue down the lineages for many generations. Mothers who were pregnant during the 9/11 event gave birth to babies who had elevated levels of stress agents in their saliva.
The exciting field of epigenetics is only starting up, with further research we may be able to detect the changes that would lead to health problems later in life. Further studies in animal models would help predict how a pregnant mother’s food supply affects the epigenetics of her offspring. Epigenetics could also help tailor treatment of transgenerational transmission of trauma.
Want to know about another sciencey topic? Let me know!