Nutritional Epigenetics and Prenatal Diets

Nutritional Epigenetics and Prenatal Diets: “I’ve been eating this way for years”

by Natali Valdez

Between 2012 and 2014 I completed participant observations and interviews at two clinical
trials, one in the United States and one in the United Kingdom. These trials tested nutritional
interventions on ethnically diverse pregnant women who were deemed obese. The recent trend to
test nutritional interventions on pregnant populations is related to the emergence of postgenomic
science. Scientists believe that a woman’s weight and diet during pregnancy can influence the
health risks of her developing fetus, and of future generations. Moreover, theories in nutritional
epigenetics claim that food can act as an environmental factor, which can modify genetic regulation
and expression. Therefore, the nutritional interventions targeting obese pregnant women are
intended to provide a healthy nutritional environment for the developing fetus.

In my ethnographic work at the clinical trials I found that food or nutrition came to mean
many different things to the scientists designing the intervention and the participants receiving the
intervention. For instance, based on the design manuals I read and interviews I had with the
principal investigators and collaborators at the StandUP trial, nutrition was framed through the notion of glycemic control. Glycemic control aims at minimizing foods that are high on the glycemic index. The glycemic index is a tool that categorizes foods based on how they will affect blood sugar levels. Therefore, the intervention focused on controlling or limiting foods that are high in sugar, saturated fats, and carbohydrates. At the trial the women in the experimental group would receive the nutritional intervention, which consisted of meeting with a health trainer at least eight times to learn how to change their diet through glycemic control.

The justification of the nutritional intervention based on glycemic control was explained to me in the following way: if a pregnant woman eats a donut, she will experience a spike in her blood
sugar levels, which will cause a cascade of reactions related to glucose metabolism. Eating a donut
will also expose the fetus to metabolic and hormonal reactions. In this case, the donut is an
environmental factor that stimulates metabolic and hormonal reactions that affect the fetus. In the
trials that I examined, pregnant women are not explicitly told that their diet is an environmental
factor. However, the scientists at the StandUP trial drew from nutritional epigenetics to justify the
significance of nutritional interventions during pregnancy precisely because food can act as an environmental factor. From my observations, the explicit framing of food as environment remained
in the realm of the scientists and not necessarily in common conversations among pregnant
participants in the trial.

From the perspective of pregnant participants enrolled in the experimental group, nutritional
epigenetics disappeared from view and what came into focus were the women’s cultural and
emotional entanglements with food. On a sunny afternoon in April Mary came in for her last
intervention visit with Diana, the health trainer for the StandUP trial. Mary was the first generation
born in England whose parents and family were all from Senegal. She self identified as African and
was studying for her masters in computer engineering in the UK. Diana identified as Afro-Caribbean since her parents migrated to England from Jamaica. Diana was one of the few women of color working on the StandUP trial.

During the session, Diana asked Mary, “what are the main staple foods in Senegal?” Mary
replied, rice, okra, and palm oil. Diana then reminded her that some of those foods were high on the
glycemic index. She then proposed that when Mary goes back to Senegal to visit her family, she
will need to focus on portion control. Mary responds, “portion, portion, portion, I do not want to
share a house with you [Diana], too much portion, I just put a plate of food down and as long as you
want to eat you just mix, eat, tummy is full.” Mary states this with a huge smile and both women
started laughing. The session continues and Diana walks Mary through a few different
questionnaires. Diana then asked Mary, “what’s been your biggest achievement and challenge?”

Mary responds by stating that her biggest achievement was how the intervention had “changed the
way I eat, the way I think about food – I behave myself more,” she says this again with a big cheeky
smile. To address the second part of the question, Mary goes on to say that one of her biggest challenges was having to always be “aware of everything, like portions and liquid beverages, I’m
not used to it, it will be hard because I’ve been eating this way for years.”

Although Diana and Mary have a warm jovial dynamic during the intervention delivery,
Mary was sincere in expressing how the intervention affected her. Take the example of portion
control. Controlling one’s portion was at first a foreign concept to Mary. The idea that one would
measure a “serving” of food calculated by grams of sugar, carbohydrates, and fat is a different
epistemological approach to food, eating, and sharing. As Mary mentioned here and in other conversations she usually just put a big plate of different kinds of food in the middle of the table and
everyone would take what they wanted. In this way encouraging the idea of portion control
intervenes not strictly in the nutritional aspect, but it also intervenes in a cultural and social way of
relating and sharing foods with others. Mary also recognizes that the intervention has “made her
behave more,” which indexes how the nutritional intervention intended to change her existing
eating habits. In addition, the idea that the intervention makes her “behave more” reflects the
underlying notion that prior to the intervention she was not “behaving” when it came to her food
and diet choices.

This snap shot of a nutritional intervention during pregnancy illustrates how different
approaches to food and nutrition are conceptualized at different levels and spaces within the same
clinical trial. On the one hand the scientific discourse and approach to the intervention focused on
nutrition as an environmental factor affecting fetal development, and glycemic control – a method
to intervene spikes in blood sugar levels. On the other hand nutrition or diet from the intervention
delivery was seen as a fundamental change in Mary’s life. A change in how she eats, shares, and
thinks about food. The juxtaposition of both these narratives exposes how a scientific tool like a
nutritional intervention is not a neutral object, but one that is rendered meaningful in different ways
based on how people engage with it.

Since returning from the field, it is clearer to me why a critical feminist perspective within
science studies and reproductive anthropology is fundamental in the examination of epigenetics.
Reproduction and pregnancy are at the center of epigenetic knowledge production, and as Rayna
Rapp reminds us, reproduction is also at the center of social theory. I appreciated the opportunity to
write this short reflection for CAR newsletter because it pushed me to think through material I have
not examined since completing the dissertation.


Natali Valdez completed her PhD in June 2016 in the Department of Anthropology at the University
of California, Irvine. She is currently a Postdoctoral Fellow in the Center for the Study of Women,
Gender, and Sexuality at Rice University. At Rice she will be working on her book manuscript titled
“Weighing the Future: An Ethnographic Examination of Epigenetics and Prenatal Interventions.”