Childhood trauma may permanently alter human DNA in some

The field of epigenetics continues to make interesting discoveries about environmental effects on genetic material. A team led by Thomas McDade found that children's experiences affected their DNA, which in turn affected suscepitability to certain diseases. Via Smithsonian:

Their investigation followed more than 500 children in the Philippines and found that certain childhood situations can create modifications in genes associated with inflammation, which affects how prone we are to suffer from certain illnesses. Specifically, these factors included socioeconomic status, the prolonged absence of a parent, the duration of breastfeeding, birth during the dry season, and exposure to microbes in infancy.

This cohort comprised over 3,000 pregnant women recruited in the Philippines in 1983. These women came from all different walks of life: They differed in access to clean water or a roof over their heads, whether they lived in an urban or a rural area, and whether they came into frequent contact with animals. From the data, they looked at over 500 of those women in order to figure out if their child’s environment growing up led to epigenetic modifications to their DNA—and later to a change in inflammatory proteins in their blood in adulthood.

Once their children were born, the investigators kept track of them and of the environments they were exposed to throughout their lives. Once they turned 21, the investigators took a blood sample that they used to measure the DNA methylation throughout their genome, as well as inflammation-related proteins that have been previously associated with cardiovascular diseases and other aging-related diseases.

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Epigenetics continues to be just freaking nuts

We know that stressful experiences can have negative biological repercussions — not just for the people who experience the stress, but also for their children. Now, there's some evidence that this transfer of stress effects might not just be due to a simple case of PTSD changing the way you raise/treat your kids. In a study that's inspired both deep skepticism and jaw-dropping awe (both with good reason) scientists were able to train male mice to fear a specific smell — and then observe that same fear/stress response to the smell in the mice's children and grandchildren. This, despite the fact that the younger generations never had contact with their trained fathers. These results are crazy enough that you shouldn't take them as gospel. But they are hella interesting and will definitely lead to a lot more research as other scientists attempt to replicate them. Read the rest

Read this before you read another story on epigenetics

At Download the Universe, i09 editor Annalee Newitz critiques a new e-book about epigenetics — the science of how environmental factors can influence genetic expression — and violence. The book makes some pretty terrible (and non-scientific) insinuations about the idea of an inherent propensity towards violence and Newitz does a good job of both taking down the specific book and explaining the nuance behind a complicated topic. Read the rest