Karen E. Peterson
Professor and Chair, Department of Nutritional Sciences
From Metabolomics to Epigenetics, Nutrition Is about More Than Food
Karen Peterson spends a lot of time thinking about how children grow and grow up.
As professor and chair of the Nutritional Sciences department at Michigan Public Health,
Peterson wants public health to have a greater role in preventing disease in children
and in offering effective interventions when things have gone off track.
"Most children are healthy and can adapt well to their environment as they grow,"
Peterson says. But many things can push a child off track. "Infections, hunger, an
obesogenic food supply, toxicants. And the effects can be more adverse in sensitive
periods—periods of growth characterized by dramatic changes in biology, behavior,
and social environments."
Peterson's research focuses on these sensitive periods. She studies the biological,
social, and environmental influences on growth during sensitive transitions—from womb
to early infancy, preschool to school, puberty, and late adolescence into young adulthood.
"During these periods, a child's physiologic growth and maturation is accelerated,
and the child also has to adapt rapidly to the environment. If something even small
goes wrong during one of these periods, it can set the child up for chronic disease
later in life."
Peterson wants us to understand just how important education and preparation can be.
"Public health practitioners have tremendous opportunities—via interventions during
sensitive periods when a child is developing rapidly— to help that child remain on
a normal course. Even small changes can shift the course dramatically," she says.
This intersection of behavior and biology in child development is important for understanding
the potential of nutrition to contribute to lifelong health, Peterson explains. "You
can be exposed in the womb to certain toxicants yet be less at risk of lifelong effects
if your mother had an adequate intake of vital nutrients during pregnancy."
Mexico has been a focal point for Peterson's interest in the relationship between
toxicant exposure and chronic disease. Peterson and her research team—including colleagues
from Instituto Nacional de Salud Pública de Mexico (INSP)—have spent 22 years and
counting conducting the Early Life Exposure in Mexico to ENvironmental Toxicants (ELEMENT)
study in Mexico City. The project is longitudinal, meaning the same subjects are observed
over long periods of time, and comprises three birth cohorts of women—the original
recruits from 1994 to 2004, their children now aged 12–22, and a generation of grandchildren
currently being born.
The study began two decades ago with observing the impact of endocrine-disrupting
chemicals and metals on metabolic and cognitive development in participants. "Now
the team is looking at menopause—in the grandmothers—as yet another sensitive developmental
transition," says Peterson. In recording the multigenerational effects of toxicant
exposure, the recently re-funded ELEMENT study has produced numerous papers and created
a valuable repository of data for future studies on diet and toxicant interactions,
epigenetics, and metabolic health.
Peterson does most of her work within a "partnership model," engaging community, state,
and national public health organizations that already have primary responsibility
for carrying out population-based interventions.
In Massachusetts, Peterson and colleagues designed a child-obesity intervention called
Planet Health for middle school students in the Boston area. Over a two-year period,
Planet Health schools infused basic behavior change messages into their lesson plans:
eat more fruits and vegetables, eat healthier fats, be more active, cut down on television.
The intervention was a tremendous success, cutting in half the chance that girls in
the study would be obese at the end of middle school.
With the Massachusetts Department of Public Health and Blue Cross/Blue Shield of Massachusetts,
the study was redesigned for a much larger population. More than 100 schools across
Massachusetts adopted Planet Health, and in a field of over 20,000 children, the prevalence
of overweight and obesity in boys and girls was reduced from 42.1 to 38.4 %.
Peterson attributes much of the success of these studies to good relationships. "We
had strong partners in those four school systems, and we worked closely with teachers
to integrate the study into their health curriculum," Peterson says. "Teacher input
on curriculum and their commitment to implementation was vital to the study."
The Power of Nutritional Sciences
Nutritional Sciences pay attention to the role of food in society, but nutrition is
much more than that. "Nutrition is not synonymous with food," Peterson explains when
asked about common misconceptions of her field. "Nutrition is a rich science that's
concerned with food but focuses on what happens to those nutrients when they enter
your body—how they affect your physiology, your metabolism, your health and well-being."
"We have faculty and students working on topics ranging from how livestock husbandry
might affect anemia to risk factors for eating disorders to clinical and community
interventions addressing obesity," Peterson says. "Nutrition is truly a hard science,"
she reminds us, "because it addresses physiological effects on the body with such
precision." But nutrition also looks closely at social and cultural influences as
well as behavioral outcomes, making it a dynamic interdisciplinary field that appeals
to researchers from all kinds of backgrounds.
Despite her many successes in collaborative and interdisciplinary research, Peterson
knows the field of nutritional sciences can offer even more. "We know how to produce
modest effects through nutrition interventions, but how do we shake up our frameworks
and come up with more innovative solutions, new ways of understanding childhood obesity
to make some truly big leaps?" Peterson asks.
Some of those leaps are happening right here on campus. Peterson is director of the
Momentum Center, an interdisciplinary research center she designed to conduct innovative
childhood obesity research. In one large scale multi-collaborative project, for example,
Momentum Center investigators from Kinesiology, Public Health, and Architecture and
Design are redesigning classrooms and testing the metabolic effects of different activity
breaks during the day. "How can we make the classroom more alive and mobile—and therefore
healthier?" the research team is asking.
Teaching Nutritional Sciences
Peterson strives to make her courses come alive for students. "I think a lot about
why the content matters to them, why they would care, why they would take the time
for this course." She wants them to think about how this knowledge will help them
make a difference in the world and make a difference in their own career path. "I
design my courses to foster future professional development, reminding students that
public health practitioners, researchers, and organizations will actually pay them
to know and interpret this material. I want them to become experts and professionals
in the field."
In a field that is constantly evolving and generating new knowledge, Peterson has
to ask every day where nutrition will go next. "Nutrition will continue to change,
so the knowledge is important. But my students need the ability to examine and critique
our current paradigms so that they can advance the field and be prepared for those
inevitable shifts in how we actually think about nutritional sciences."
Peterson looks to her students to identify the open questions, the modes of thinking
that have not yet entered the field, let alone garnered attention. "I want my students
to remember that scientific results are not necessarily 'truth' and might capture
only a piece of the puzzle. They are a step on the way to understanding, and the very
methods we used to arrive at these results should remain open to reflection and reinvention."