Tell us about your early career and about the evolution of your interest in global health, specifically your interest and experience in Samoa and American Samoa.
My training is in biological anthropology, so my first masters and my PhD are in that field. During that time, I became less interested in understanding human biology, and more interested in studying the environmental, evolutionary, and genetic forces that underlie health and wellbeing. So I began to read about public health and epidemiology, and became interested in a newly developing field called international health. It was concerned with the sociocultural and biological basis of health in developing countries. During the fourth year of my PhD program, I went to Hawaii to study Samoan migrant populations living on the island of Oahu. While there, I analyzed what happens to the biology and overall health of this population when they change their way of life very rapidly. After I finished my PhD, I completed my MPH in Epidemiology, and have been studying people in independent Samoa and in the US territory of American Samoa continuously since that time.
What do you think has been your most impactful or significant finding?
Throughout my career, I’ve been trying to measure and document what we have come to call the “Nutrition Transition” in the Samoan and American Samoan populations. The “Nutrition Transition,” also known as the modernization or westernization of the diet, means that people are eating more processed foods with more sugar, sodium, and fats in them, and as a result are consuming fewer of the healthy micronutrients that our bodies need. This has been a theme throughout my career, but we recently published a major paper in Nature and Genetics on a novel genetic variant in Samoans that we found that had never been reported before and had never been found to be related to obesity before. This gene variant is positively associated with obesity, but negatively associated with diabetes. This is very interesting because we usually find that obesity and type two diabetes are positively correlated with one another. We think this gene confers some relative protection against type two diabetes, and contributes, along with other things like diet, to increased levels of body mass index or obesity. This is interesting partially because of its novelty, for this gene is not found in any other populations. As a result, we have several new NIH grants that are going to help us unpack how this gene interacts with different biological pathways and diet and physical activity.
Our current grant focuses extensively on the physiological and biological mechanisms that underlie the relationship between obesity and diabetes of this new gene we found. We are out in Samoa right now collecting intensive phenotyping data on body composition, specifically looking at glucose and insulin responses under changes. We are also measuring eating habits and levels of physical activity to try to understand the potential metabolic pathways associated with this gene. In order to design potential interventions, or even discover a helpful drug that targets these pathways, we have to know the gene’s mechanisms. This pathway could be shared by many other humans, so by learning more about it, we could have the potential to impact health all over the globe.
Tell us about your teaching experience here at the School of Public Health.
Before there was the School of Public Health, and before there was a program in public health, I taught a course called the Burden of Disease in Developing Countries, and I’m still teaching it now. It involves a variety of guest lecturers who come in and present on their specialties, whether it’s schistosomiasis, HIV, or humanitarian emergencies, such as refugee health. Students from all different disciplines, programs, and departments take it. It’s a course that gets good evaluations and students learn a lot, and we definitely make them work hard.