Thank goodness I was made redundant! Part 2, – “What do we mean by Epigenetics?”

It is now a couple of years since I wrote a blog entitled “Thank goodness I was made redundant”. This redundancy coincided with my starting a family.

In 2020, my colleagues at What About The Children?, Sir Denis Pereira Grey, and Philip and Diana Dean had two papers published in reviewed Journals. These dealt with what, in many ways, has become a taboo subject – how society views childcare for the under-threes. Parents opting for childcare for their babies and toddlers has been a growing situation through the second half of the 20th century in the context of the positive social movement to include women across all areas of society, though better educational and employment opportunities. The Government lends support through policy, including the provision of Childcare allowances – not least because The Treasury benefits from the tax from women’s wages and child-carers’ wages. The two Pereira Grey papers, mentioned above, reviewed research on the effects of early life stress in infants on long-term changes in their DNA.

Is this immense positive social change, towards women achieving greater equality of opportunity, really a bonus, therefore? Or can it be a loss to their children’s health and happiness? There is a negative effect from stress on perhaps up to 40% of children who spend long hours in day-nursery, away from their home. The strongest effects are not only changing their hormones, affecting brain development, but also affecting the control (on/off) mechanisms of the genes controlling proteins and these can be passed on to the next generation through epigenetic processes.

Epigenetic means “on – top – of” genes.  What does this mean in the reality of children’s experiences? In the context of my life at the time I returned to work part-time (15 hours a week) my son at age two and a half was taken to a friendly small nursery of 8 children, or to a village playgroup, and collected by either myself, or one of three other mothers. Life was stressful in the mornings, trying to get everyone out on time, and often there were raised voices. As on some occasions, I wasn’t back in time to collect him, I now reflect that he might have been stressed when he had to go with another mother. In contrast, his older sister had started school.

My son’s adrenal glands were making cortisol and this was rushing through his brain and being picked up by the hormone receptors in his hypothalamus and pituitary. But because his blood line from his father and grandmother carried genes for susceptibility to stress, and a difficulty in dealing with stress, it was now triggered. We didn’t notice any effect at that time, and he didn’t say anything, because this was just normal life for him, but once he reached puberty, when testosterone floods the body and changes so many things, this sensitivity to stress popped up again. It is still with him now, in his 20s, but, thankfully, the effect decreases as he gets older. This is an example of intergenerational transmission of stress as reviewed by Bowers and Yehuda in 2016 (see for a short summary of this research).

We don’t know what happened in the young lives of our ancestors, but their hormone receptor genes can have been chemically modified, so they work at different speeds. It is the inheritance of these genes with “control modifications” or chemical methylation, which is dependent on luck: the gamete from one parent might carry it, from the other parent, it might not.

Going back to the stressed children in the Nursery… Only some children may carry “susceptibility” genes, so a stressful environment may trigger a change in one child but not in the next. My daughter, who is two years older, was lucky enough not to be susceptible to stress in the same way as my son.

In my earlier Blog, the last sentence read:

‘If I had known, back then, what you can now read on the research pages of What About The Children? website, – that boys’ brains are slower to develop and are more sensitive to stress, particularly in the three periods of testosterone surges (All our Sons by Allan N. Schore, 2017), I would have waited just a little longer before I changed my son’s daily pattern of life. If these research findings had been available when my son was small, I would have begged, scrimped and saved rather than have gone back to work so soon’.

I wouldn’t disagree now, but I would add that he may have been an anxious adolescent in any case, as another event later in his life may have triggered the change, whether or not he had been stressed early in his life.

I do also know that sensitive parenting does help, and all through his teenage years, as he was discovering his disability, I continued to try to be a sensitive mother.

I wonder what epigenetic changes occurred in the babies and children of mothers living through the wars, or the industrial revolution, working in horrible conditions in factories, or as a result of being taken as a slave to the West Indies. Some children’s health and happiness may still be reeling from the effects of such experiences.

Dr Elizabeth Bland