Thomas McDade, Northwestern professor and biological anthropologist, is revolutionizing the way population-based biological data is collected and studied.
Using biomarkers from finger-stick blood spot samples, McDade studies how social and physical environments affect immune function and inflammation, which contribute to the risk for disease. He is also the director of Northwestern’s Laboratory for Human Biology Research where such minimally invasive methods are being further developed.
His research, in places like Samoa, Bolivia, the Philippines and the U.S., is motivated in part by trying to understand how the circumstances in which people live their everyday lives affects their behavior and physiology.
In this edited interview, McDade talks about his research abroad, and how it will have an impact in the U.S.
Where are you currently working, and what is the focus of your work?
Now, my work is focused largely in the Philippines on a study that has been ongoing for almost 30 years. It began with the recruitment of pregnant women. They were interviewed, and their households and communities were surveyed. After they gave birth, both the mothers and babies were followed-up with on a regular basis for over 25 years.
We have a lifetime of information on the social and physical environments that these kids have grown up in, and lots of information about their health and their lifestyles. Now they’re having kids of their own, because they’re in their mid-twenties, and we’re following that next generation. So, we now have three generations in the study.
It’s a really unprecedented resource for understanding how prenatal and early postnatal environments affect the human life course, and human health and physiology, such as the regulation of inflammation in adulthood.
That’s also of particular interest in the U.S. because we’re coming to understand that inflammation may be an important contributor to cardiovascular disease, diabetes and the diseases of aging that we are concerned about.
If we can understand how environments early in life shape the regulation of inflammation in adulthood, we’ll have a better understanding of how inflammation functions, and how we can manipulate it in ways that help us prevent diseases from happening.
You work with biomarker data collection. How is this done, and why is it important?
Biomarkers work is the development and application of minimally invasive methods for measuring human physiology in non-clinical settings.
Right now our understanding of human biology and human physiology is based largely on research that takes place in clinical settings in places like the U.S. and Europe. It doesn’t typically happen in more remote community-based settings because the methods are not amenable to that kind of research setting.
By using saliva sampling or finger-stick blood spot sampling, we can collect biological specimens from large numbers of people at very low cost in remote places around the world.
Why are you using similar research methods in the U.S.?
Instead of relying on a subset of individuals to come to your lab or clinic, you can go to their neighborhood or home to collect blood samples.
So the exact same methods, saliva sampling and finger-stick blood spot sampling, which were developed for places like the Amazon basin, are being used here in neighborhood or community-based settings to understand how stress and diet, or other aspects of an individual’s neighborhood, matter to their health.
What are the main benefits of such data collection techniques?
They really reduce the cost associated with collecting the samples, but they also allow you to get information from a more representative sample of people.
If you want to do a study of how poverty affects health, it’s going to be harder to convince poor people in a really underserved neighborhood to come into Northwestern Memorial Hospital, for example, and give you blood.
But if you can go into their home or community center and just ask for a drop of blood from a finger stick, they’re more likely to give that to you. So you can get information from people who you otherwise wouldn’t be able to access.
Do you have any other projects in the works?
The study that I’m focused on in the U.S. right now is called the National Longitudinal Study of Adolescent Health. It includes over 15,000 young adults in the U.S. with about 15 years of information on their school environments, neighborhoods, individual levels of stress and depression, and the quality of their social relationships.
We have finger-stick blood spot samples from all 15,000 of those people. So it’s the largest ever research application of these methods, and really an unprecedented opportunity to gather rich information on the social and physical environments in which a group of people are living in the U.S. It provides an opportunity to link that information with objective physiological information.
Something else I’m studying, and will write some papers on this year, is why inflammation is so much lower in the Philippines even though they have higher levels of infectious disease.
I think it traces back to their early environments, and ways that the immune system develops in a certain microbial environment that allows it to regulate itself more effectively, and keep levels of inflammation lower in adulthood.
I think the work in the Philippines is a nice demonstration of the value of international comparative research, and how a human physiological system in a different environment gives us some insight into how that system develops and functions in the U.S.
Learn more about McDade’s work, and read recent publications, here.