About the Authors
Zaneta M. Thayer is a biological anthropologist pursuing her doctorate at Northwestern University, and she has a B.A. in anthropology and biology from Dartmouth College. Thayer is interested in how the environment affects patterns of human biological variation, particularly during early development. Her primary research has been on the epigenetic effects seen in fetal development. One of her long term goals is to unite developmental biology with the Modern Synthesis as an expansion of modern evolutionary theory.
Chris Kuzawa, a Professor at Northwestern University, is a biological anthropologist with a background in epidemiology. He received both his PhD and his MsPH (Masters of Science in Public Health) from Emory in 2001. He focuses on developmental biology and the diseases and effects that early postnatal environments have on humans. The premise of this research is that what a mother eats during pregnancy, her access to adequate prenatal care, or her stress level, may permanently alter offspring biology in a fashion that influences risk for the most common causes of adult morbidity and mortality, including hypertension, diabetes, and heart attacks. He focuses on the term "Developmental Plasticity", which is the sensitivity of a developing body to its environment.
His current projects are on developmental influences on obesity and male reproductive ecology in the Philippines and Inter-generational influences on health in the United States
Biological memories of past environments: Epigenetic Pathways to health disparities
This article was rather interesting as it similar to the discussion we had in class on Tuesday on the lead affecting children. Following are just some summed points from each section of the paper.
- The introduction spoke about current and recent research that environmental exposures can influence biology and health, which is epigenetics.
- Although that has been studied, the linkage between environmental factors and patterns of disease through epigenetics processes.
- Previous research has seen a deleterious health impacts of economic and status inequality, such as stress or discrimination. And that being of low social status increases disease risk.
- Although these linkages are understood, the biology behind them isn't totally clear.
- Studies like these are important from a public health perspective as they can help to understand where certain diseases are coming from.
- Nutritional status can influence epigenetic profiles.
- Several studies have show than nutritional exposure during critical periods can significantly affect the life course of an individual. For instance a low protein maternal diet in rats led to increased risk of type 2 diabetes.
- Nutritional epigenetic effects may extend into successive generations through germ lines. Food shortage in a generation may increase the grandchild's mortality risk from cardiovascular diseases.
- Food security and access to food supplies affects functional outcomes in offspring.
- Traditional studies of stress and health tend to involve blood pressure or hormone metabolism, but new research is trying to link psychosocial stress and epigenetically-based changes in gene regulation.
- Data has shown that stress related epigenetic changes can be passed on to offspring, as with the stressed out rats, passing on their epigenetic profiles to their children.
- Stress can also be varied in humans based on socio-economic status and other factors such as perceived discrimination. Differing levels of stress can cause certain groups to be at risk for different diseases and affects.
- It is well known that toxic chemicals and materials can affect epigenetic markers and change gene expression. Heavy metals in particular have been seen to affect methylation (an important biological process whereby a methyl group is added to another biological compound) and serotonin production.
- Exposure during pregnancy can modify genes and lead to eventual development of diseases down the road.
- Certain chemical exposure can even affect several generations, as mice treated with an endocrine disruptor were seen to affected negatively sperm for several generations. This shows the long lasting effects of certain toxicants.
- To get a better idea of what areas and groups to study we have to look at the underlying social structure.
- Studies need to be conducted on the potential to change epigenetic linked diseases, not just conducted to identify them.
- This knowledge of epigenetics needs to be brought to the public's attention and to the policy makers in an attempt to show how important environmental factors are on developing bodies.
Food for Thought
- Are there other ill health effects that could potentially be linked to early epigenetic factors besides those mentioned in the article?
- Can any other diseases previous attributed to other things, such as stress actually be epigenetic in origin?