How do environmental and psychosocial factors can change the epigenome?
One’s epigenome can be changed based on what the person eats or drinks, whether the person exercises or not, whether the person smokes or what medicine the person takes. In other words, epigenetic researchers have discovered that the environment, both the physical and the social aspect of it can cause changes in the molecular structure that expresses the gene and these can be passed down to future generations. Waterland and Jirtle (2003)‘s study showed how changes in mice mothers' diet during pregnancy could change the epigenome and phenotype of their offspring. The food ingested has the nutrition that goes directly to the child, which affects the next generation. Champagne et al. (2006) has found that the variations observed in maternal care of mice can be passed on to the next generation of mothers. The early caregiving environment has become central place in human's understanding of normal and abnormal psychological development (Bowlby, 1965). If the children receive early abuse or neglect, they will lead to different cognitive and emotional impairments, and there is considerable evidence that early maltreatment affects the same neural structures that mediate attachment. Also, animal models now suggest that the influence of early caregiving penetrates to DNA.
How are some experience and epigenetic changes of an individual passed down to more than one generation of descendants?
The effects of nature upon nurture can also be passed down to many generations, which affect the offspring of them as well. Susser, Hoek and Brown found out in their study that the effects of famine in the Netherlands during World War II on passed on generations. After the "Dutch Hunger Winter" enabled researchers to identify the long-term effects on prenatal exposure to famine. In comparison with the offspring who were not exposed to prenatal famine, the exposed cohort exemplified higher rates of a wide range of childhood and adult disorders including low birth weight, infant mortality, obesity, diabetes, heart disease and cancer. The results also showed the increase of schizophrenia and diagnoses of schizoid personality disorder in the exposed group. Kaati, Bygren, Edvinson showed that the amount of food available in a certain place may affect the mortality spanning two generations. The study of the location is cohorts born in 1890, 1905, 1920 in a small town north of Sweden. The results showed that paternal grandfathers' food supplies were linked only to the mortality rates of their grandson and the mortality rates of granddaughters are linked to the food supplies of their paternal grandmothers. Another example is that female offspring who receive high LG became high LG mothers themselves, whereas those who receive low LG