genetics

Parents often wonder why their children are contending with learning problems or attentional issues, or suffer from emotional difficulties, and if they could have done something different in their parenting to have spared their child. Alternatively, they assume their own genes are condemning their child to these difficulties and challenges. This is the nature-nurture debate, but beyond contributing to parental sleepless nights, this either-or construction is overly simplistic—and overly deterministic. A  better way to think about this problem is provided by the study of epigenetics, or the  interaction between genetics and environment (genetics x environment).

The word “epigenetic” refers to  any process that alters gene activity (“turning on“ or “turning off” genes) without changing the underlying DNA sequence. These changes are sometimes referred to as “mutations.”  Some of these mutations will be “reset” in the next generation, but some continue to influence gene expression for several generations. Nessa Carey, author of “Epigenetics Revolution,”  uses the analogy of a movie to help understand this process. If a person’s life were a movie, their DNA would be the script, and certain blocks of the DNA sequence (genes) would instruct key actions or events to take place. The concept of genetics could be compared to screen writing, while epigenetics  would be like directing. The script may stay the same, but the director can choose to eliminate or accentuate certain scenes or dialogues, thus changing the course of the story.

Epigenetic effects may occur anytime throughout the life span, from within the womb to old age. Epigenetic influences include what you eat, how you sleep, who you interact with and whether you exercise. They also include environmental factors, such as the quality of the air you breathe and how safe you feel in your home and in your community. For instance, children whose pregnancies occurred during the Dutch famine of 1944-45 have been found to have increased rates of coronary heart disease, obesity and schizophrenia in comparison to the children of mothers who were not exposed to famine.  Other research has shown that children who had experienced stressful events during the pregnancy or during childhood were more likely to experience depression if they have mutations on a small number of genes, including those affecting neurotransmitter serotonin.

The really exciting element of the new research on epigenetics involves the  possibility that lifestyle factors can reverse or mitigate the negative elements of gene mutations. For instance, there is intense interest in the impact of diet on ADHD symptoms. At this point, the findings from the analysis of a large number of studies indicate that Omega-3 (fish oil) can have a small but measurable effect in reducing symptoms, and food additives and allergens can cause or worsen  symptoms in children who are sensitive to these triggers. Exercise has been proven to improve cognition and brain plasticity, the effects of which can be felt for a long time. We are just at the beginning of these investigations, with more exciting findings to come.

References and Resources:

Neurosci Biobehav Rev. Author manuscript; available in PMC 2018 Sep 1.

Published in final edited form as: Neurosci Biobehav Rev. 2017 Sep; 80: 443–456. Published online 2017 Jun 27. doi: 10.1016/j.neubiorev.2017.06

Weinhold, Bob. Epigenetices: The Science of Change. Environmental Perspectives 2006 Mar: 114 (3): 160-167

A Super Brief and Basic Explanation of Epigenetics for Total Beginner: Epigenetics Simplified. https://www.whatis epigenetics.com/what-is-epigenetics

Epigenetics: Fundamentals: Epigenetics Simplified. https://www.whatis epigenetics.com/what-is-epigenetics

Nigg, Joel (2017) Getting Ahead of ADHD. New York. Guilford Press