DNA is often talked about as if it’s an unchanging code carved into us and all living things. However, the more scientists are learning about genetics, the more they’re learning this is not strictly the case.
Research by scientists from Northwestern University in the US has gotten closer to understanding how your childhood experiences – whether it's the absence of a parent or how much animal poop you were exposed to – can lead to genetic changes that are a risk factor for illnesses like dementia and cancers in later life.
This field is known as epigenetics, the study of changes in gene expression that does not involve changes to the underlying DNA sequence. The word "epigenetics" literally means "on top of" genetics. This research is one of the most complete looks at the mechanisms behind epigenetic changes and how they can regulate levels of inflammation.
“Taking this a step further, the findings encourage us to reconsider the common view that genes are a 'blueprint' for the human body – that they are static and fixed at conception," study author Thomas McDade, a professor of anthropology, said in a statement.
Their study, published earlier this summer in the journal Proceedings of the National Academy of Sciences, analyzed huge amounts of data about the lives of almost 500 children from the Philippines. They found that certain experiences, socioeconomic backgrounds, and environmental changes as a child can later spark different expressions of genes associated with inflammation – a huge risk factor for multiple diseases.
They found how different nutritional, microbial, and psychosocial exposures as a kid can be used to predict DNA methylation, an epigenetic process, in nine genes associated with the regulation of inflammation.
These different childhood exposures that affected their epigenome included things such as how long they were breastfed, their exposure to animal poop, the season of birth, socioeconomic status of their family growing up, and parental absence. In turn, the inflammation caused indirectly by these experiences is associated with conditions like cardiovascular diseases.
"If we conceptualize the human genome as a dynamic substrate that embodies information from the environment to alter its structure and function, we can move beyond simplistic 'nature vs. nurture' and 'DNA as destiny' metaphors that don't do justice to the complexity of human development," said McDade, also a faculty fellow with Northwestern's Institute for Policy Research.