Epigenetics and pregnancy part II
From last week’s discussion, we have shown that a mother’s offspring can have its DNA read or silenced by environmental inputs during pregnancy. The research has been exploding over the last decade and it is clear that almost any environmental signal can potentially have an effect on our genetic codes interpretation at the cellular level.
Let’s take a look at the work of Dr. Moshe Szyf from McGill University in Canada. He has been studying the effects of environmental triggers on the genome for decades and his group, along with the work of Michael Meaney, has proven that the behaviors and traits that we see as newborns and children are dictated in large part by environmental and lifestyle experiences. He has also shown that the DNA can be affected after conception well into childhood. (Szyf et. al. 2012)
From a transcript: “So we can’t do experiments. We can administer adversity to humans. But God does experiments with humans. And it’s called natural disasters. So one of the natural disasters – the hardest natural disaster in Canadian history happened in my province of Quebec. It’s the ice storm of 1998. We lost our entire electrical grid because of an ice storm when the temperatures were in the dead of winter of Quebec – minus 20 to minus 30 – and there were pregnant mothers during that time.
“And my colleague, Suzanne King, followed the children of these mothers for 15 years. And what happened was that as the stress increased – and here we had objective measures of stress. How long you were without power? Where did you spend your time? Was it in your mother-in-law’s apartment or in some posh country home? So all these added up to a social stress scale. And you can ask the question, how did the children look like? And it appears that as stress increases, the children develop more autism. They develop more metabolic diseases. And they develop more autoimmune diseases.” (Szyf transcript 2017)
Epidemiological research from Overkalix, Sweden and The Dutch Hunger Winter study have also shown that periods of feast and famine during pregnancy can have an effect on the offspring of the mother regardless of other factors or confounders like socioeconomic status that are usually used to debunk data points. (Bygren et. al. 2014 and Schulz 2010)
Whether these stressful events happened to a child in utero or after birth, the epigenetic marks causing disease worsened with increasing stress. Taking it a step further, it is clear from the collective research to date in the field of epigenetics that there are exponential ways to alter gene expression. They are called daily life. The research has identified some that are clearly detrimental and some that are beneficial to the offspring. The trick is to understand what helps and what harms.
Dr. Szyf goes on to state: “So on one hand, we have an old genome – right? – that’s millions of years old that’s fixed. On the other hand, we have a changing world that is talking to our DNA. And this balance, probably, was selected by many, many millions of years of evolution to provide with us with this amazing, what we call, plasticity on one hand and fixed characters on the other hand, right? So we need both. We need the immutable and mutable operating together. And that’s the amazing paradox and challenge of life.”
What he is saying is that this epigenetic changeability is evolutionarily protective in an ever-changing environment. However, if our DNA can be read in many different ways depending on the changing world, then why are we falling apart as a species? This question is related in large part to modern society.
The answer is likely related to the fact that humans have altered the environment at such a torrid pace in the last 100 years compared to the previous thousands of years. We are inundated with chemical exposure, increased mental stress and poor quality food driving the majority of the poor epigenetic signals that our children are receiving and processing. We no longer have the historical stresses of food scarcity, temperature swings in a non-climate controlled environment and microbial friend exposures of the recent past. In other words, we have a whole new set of lifestyle challenges and we are not evolving fast enough to combat them.

Next week – fathers and genes?

Dr. Chris Magryta is a physician at Salisbury Pediatric Associates. Contact him at newsletter@salisburypediatrics.com