IPR - Institute for Policy Research - Northwestern University

IPR
at 40
Christopher Kuzawa outlines
an intergenerational model
of biology and health.
influence of fetal/
infant nutrition and
growth on adult
health and function
in the Philippines.
Three extensions
of the study are
underway. The first
uses 22 years of
longitudinal data to
investigate predictors
of metabolic disease
risk factors in
the mothers and
their young adult
offspring. The second
combines these data with saliva and plasma samples
to examine if early life nutrition affects adult male
reproductive functioning, A third follows up with the
original offspring, now adults with children of their
own, and looks at the intergenerational influences on
offspring nutrition and growth. The National Science
Foundation supports the latter two projects.
Using plasma samples from 1,875 Filipino women participating
in the Cebu study, McDade and Kuzawa, with
IPR postdoctoral fellow Julienne Rutherford and Linda
Adair of the University of North Carolina at Chapel
Hill, examined how obesity and infectious agents
affected the women’s levels of C-reactive protein (CRP).
Elevated levels of CRP can indicate the presence of cardiovascular
disease (CVD), hypertension, and diabetes.
Their data indicate that being overweight or obese and
exposed to infectious diseases are associated with elevated
CRP levels, and these associations are not linked
to socioeconomic status or other health behaviors. Their
findings also indicate that other cultures transitioning
to high-calorie, Western-style diets with lower levels
of physical activity are also experiencing comparable
levels of elevated inflammation, probably contributing
to the worldwide epidemic of CVD and metabolic
diseases. The findings were presented at the Population
Association of America meetings in April 2008 and
appeared in three new articles published in the Journal
of Nutrition and American Journal of Clinical Nutrition.
< Childhood Growth and Adult Outcomes
The Tsimane’ study links the effects of globalization
to health and early developmental conditions to later
outcomes. In a study led by McDade, the researchers
identify significant costs associated with activation
of immune defenses to growth among children in a
remote area of Amazonian Bolivia. They find that young
Tsimane’ children (aged 2 to 4) with low body fat stores
might lose 10 to 15 percent of their expected annual
height gain. Such stunted growth is associated with
reduced work capacity and poorer reproductive outcomes
in adulthood, as well as increased mortality risk.
In another study, Kuzawa, McDade, and their coauthors
are the first to find evidence for changes in
the relationship between leptin, a hormone that seems
to signal energy intake and expenditure, and body fat
during childhood growth and development. In males,
there was a small relationship between body fat and the
hormone, while in females the correlation between the
two increased markedly as they approach puberty. The
correlation suggests a more important role for leptin as
a signal of energy status in females, perhaps indicating a
larger effect on female development and reproduction.
< Intergenerational Model of Health Disparities
Kuzawa is exploring the application of an intergenerational
model of biology and health to the problem
of U.S. health disparities. He and graduate student
Elizabeth Sweet published a model of the environmental
origins of health disparities in cardiovascular disease
(CVD) between U.S. whites and blacks. They review
evidence linking stressors within the African American
community, such as discrimination, with maternal stress
during pregnancy—leading to poorer birth outcomes,
such as lower birth weights, and a higher risk of CVD
among adult offspring. They argue that the embodiment
of negative socio-environmental factors in the
prenatal environment provides a better explanation
than genetics for the biological persistence of disease
disparities. While they recognize that legislation cannot
directly address certain contributors, they point to
social policies, such as better access to prenatal care and
promoting breast feeding, that could mitigate patterns
of U.S. health disparities in future generations.
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