I finished my dissertation on how the war in Laos was correlated to the physical growth of Hmong refugees in 2004. The general idea was that early stressors, particularly prenatally and in infancy, can have long-term impacts on growth and health. The model I was working with came largely from David Barker’s (and others’) ‘fetal origins hypothesis,’ based on evidence that low birth-weight infants tended to grow up to have higher rates of things like type 2 diabates, coronary heart disease, hypertension, etc. A classmate in graduate school, Stephanie Rutledge, introduced me to Barker’s work and told me that I’d find it really enlightening. I did. Sadly, Barker passed away earlier this year, but his work helped spawn a new direction in research.
I wrote this piece on BeingHuman.org about how war (and the world in general) gets under our skin. It looks at the Hmong example, as well as examples from a few other wars around the world (the Dutch Hunger Winter, the Biafran famine, and the Khmer Rouge period), and how these experiences get into our bodies.
Unbending rigor is the mate of death,
And wielding softness the company of life:
Unbending soldiers get no victories;
The stiffest tree is readiest for the axe. Tao Te Ching: 76
Early in life, our bodies are like unmolded clay, ready to be shaped by our experiences. For some of us, that matching process can create problems. If circumstances change, we could end up poorly adapted to our adult environment. A child born into harsh conditions, though, may have to take that risk in order to make it to adulthood at all.
An October poll of 1,000 likely voters found that Americans are increasingly concerned about income inequality. When asked: “How Big a Problem is Income Inequality in the US?,” the majority (74%) replied that it was either a big problem or somewhat of a problem. Predictably, there were differences in opinion by political ideology, but a majority of liberals (94%), moderates (81%), and conservatives (55%) answered that inequality was at least somewhat problematic. However, as is true of many polls, it was not specified exactly what people found unsettling about it. I suppose there are many reasons that people might find increasing inequality (and climbing rates of poverty) to be troubling, but I wanted to focus here on inequality and health, particularly on obesity.
First, what do we mean by poverty? I remember watching aninterview on PBS with the economist Jeffrey Sachs years ago (transcript here– thank you, Google), where he distinguished between two types of poverty. The first was an extreme form, which he called the type of “poverty that kills.” The other type was more of a poverty of inconvenience or jealousy. I don’t want to over-interpret Sachs’ meaning. It was a passing phrase in an interview from ten years ago, and his primary focus was on alleviating the extreme poverty faced by more than a billion people in the world living on $1 per day (see Sachs 2005). Elsewhere, Sachs has lamented that the media have ignored poverty in the United States at a time when “the U.S. has the greatest income inequality, highest per capita prison population and worst health conditions of all high-income countries.” His credentials in fighting poverty are unassailable. But I cite the old interview here because I think his descriptions (‘poverty that kills’ vs. ‘poverty of jealousy’) might resonate with many people today, and not necessarily in a good way.
Extreme poverty: scavenging at a garbage dump in Phnom Penh (abcnews)
On the surface, it may not be so clear where war, health, and evolution intersect. From the perspective of biological anthropology, many have called for a holistic, transdisciplinary approach to human biology and health which considers the environment as the totality of its evolutionary, ecological, and social components, including social inequality (Little and Haas 1989; Thomas et al. 1989; Wiley 2004).
Girl in Darfur refugee camp (source: Colin Finlay)
More than a decade ago, Leatherman and Goodman (1998) suggested that biological anthropologists put more effort toward better understanding what they termed the ‘biology of poverty.’ In this sense, poverty is an ‘environment’ that may induce consistent, but obviously varying, biological responses depending upon local circumstances. Similarly, war can be conceived as a biological environment. At least in the short term from an evolutionary point of view, wartime conditions may be as biologically challenging as some of the classic ecologically extreme environments faced by humans (circumpolar, tropical, high-altitude, desert, etc.) (Clarkin 2010).
A recent study on child obesity by researchers at Harvard has received a good deal of media attention lately. In the NY Times, a synopsis of the study was one of the most emailed articles in the country (“Baby Fat May Not Be So Cute After All,” March 22). The key sentence from that article:
“More and more evidence points to pivotal events very early in life — during the toddler years, infancy and even before birth, in the womb — that can set young children on an obesity trajectory that is hard to alter by the time they’re in kindergarten.”
Harvard researchers are reporting in the journal Obstetrics & Gynecology that the average birth weight in the U.S. has actually dropped over the past 15 years. The study looked at more than 36 million full-term births between 1990 and 2005. After controlling for confounding variables, it was found that birth weight had decreased by 52 grams. This trend ran counter to that found previously, which was that birth weights had been steadily increasing over the last century. A secondary analysis suggested that the drop was not due to a change in maternal demographics, as the trend was also found in a subset of white, well-educated non-smoking women as well.