Personalized public health
By Martha McKenzie
When a research colleague asked Colleen McBride if she’d like to join him on a sailing trip along the Turkish coast, she accepted immediately. No matter that she did not know the other four people who were taking the trip. Or that she didn’t know how to sail. Or that she is prone to seasickness.
So why would she go?
"Why not?" says McBride, a behavioral epidemiologist.
McBride, whose sailing adventure turned out just fine, brings that venturesome spirit to her new post as chair of the Department of Behavioral Sciences and Health Education. She plans to build on her previous work as the founding chief and senior investigator of the Social and Behavioral Research Branch of the National Human Genome Research Institute (NHGRI). In that position, McBride was among the first to focus on using genetic information to inform public health interventions—the public health equivalent of personalized medicine.
"All the discoveries coming out of basic science, particularly genetics, are shaking up other fields, but they are not making a lot of changes in the way things are done in behavioral science," says McBride. "I would like to see us apply scientific imagination in bringing the worlds of genetics and behavioral sciences together."
Specifically, McBride would like to put that scientific imagination to work in addressing a vexing problem for behavioral scientists—relapse rates. "We can get people to lose weight, but they gain it back," she says. "We can get people to exercise, but they fall off. We can get people to stop smoking, but they start again. And we don’t pay a lot of attention to why that happens."
Genetics can provide some answers, she believes. How people react to behavior change interventions is influenced by their genetic makeup. Some people get a "runner’s high" when they exercise, for example. Others take more effort to get the same high or do not get one at all. Some people suffer mood dips when they are calorie deprived, and others don’t. If people could be grouped by different traits, perhaps interventions could be tailored to provide a better fit.
"I’m not envisioning that we could customize interventions to each individual’s genome," says McBride. "But if we could identify phenotypes—groups of people who share similar traits—we could get away from the one-size-fits-all interventions and move toward customization."
Early adopter
The daughter of an Army sergeant, McBride moved 15 times during elementary school. "I think that’s why I’m not afraid to try new things," she says. "When you are thrown into a new situation every six months, things that may seem risky to other people don’t seem that risky to you."
She was the first in her family to go to college, and once she started, she didn’t stop. She earned her MA in sociology at the University of Arizona and her PhD in behavioral epidemiology at the University of Minnesota in the department founded by Ancel Keys, who is famous for showing the health benefits of the Mediterranean Diet.
McBride was wrapping up her formal education in the very early days of genetic discovery. The Human Genome project was just beginning. Around that same time, researchers identified the BRCA1 and BRCA2 genes as indicators of increased risk of breast or ovarian cancers. The HNPCC gene was linked to colon cancer.
"There was this enthusiasm and excitement about genetics as a susceptibility indicator," says McBride. "So I started thinking about using genetic susceptibility as a tool in behavioral interventions."
She pursued this interest at Duke University Medical Center, where she became the director of the Cancer Prevention and Control Research Program and chief of the Division of Prevention Research.
In 2002, Francis Collins, then head of the Human Genome Project and now director of the National Institutes of Health, called her to talk about starting a social behavioral research unit at the NHGRI. "I was astonished," says McBride. "It was sort of like coming home to find Brad Pitt had left you a voice mail and wanted to get together."
True to form, McBride didn’t let the fact that she had no formal genetics training deter her. She had done a lot of self-study and considered herself bilingual. "I could get myself to the bathroom in genetics," she says. "And I was really intrigued by the challenge of the intramural experience, which was very much about high-risk, high-reward research that couldn’t get funded in the extramural world."
Collins gave her carte blanche to set the research agenda for her new program and figure out how behavioral sciences and genetics could be merged. At that point, the field was dominated by questions rather than answers. Do people even want to know their genetic risk for various diseases? What is the best way to communicate this information? How will this information affect people’s health behaviors and medical decisions?
McBride set out to find some answers. She and a basic science colleague devised a study to look at the effects of genetic susceptibility testing for eight common health conditions.
She enrolled 1,599 people at the Henry Ford Health System in Detroit, instructing them to go online to learn about the genetic tests offered and decide whether or not they wanted to participate. Those who opted to participate submitted a blood sample and got their test results in the mail. A follow-up caller discussed what the results meant to them and how they planned to use the information.
McBride also accessed participants’ electronic medical records to see if they used more medical services after getting the results. "This was at a time when people were saying this kind of direct-to-consumer genetics testing information would be damaging to the general public," says McBride. "They would misunderstand it. They would misuse it—‘Oh, I’m not at risk for heart disease, so I can eat whatever I want.’ And they would want it in droves—so badly that it would overwhelm the system."
McBride’s results proved such suppositions wrong. By and large, the general public didn’t want to learn their genetic risk information—only about 13% of those approached elected to take the genetic test. The ones who did take it understood the results, and their health care usage did not change after the testing.
The study also showed participants were not likely to make any behavioral changes as a result of their findings. "I’m puzzling about where I’m going with the relationship between genetics and behavioral science," says McBride. "I do think providing risk information is necessary, but I don’t think it’s powerful enough to make a lot of difference in what people do. We have so many psychological defenses to protect us from something that is scary, and those defenses diffuse the motivational impact of genetic risk information."
Intramural in extramural world
McBride, who was recently awarded the Society of Behavioral Medicine’s 2015 Distinguished Scientist Award, left her mark on the NHGRI. "Dr. McBride was a visionary leader during her 10 years here," says Eric Green, director of the NHGRI. "She fostered new and important areas of genomics research and made critical contributions to the field of genomics, especially those related to how new genomic technologies are being introduced to society and integrated into health care."
McBride now brings her musings and her intramural sensibilities to her new post at Rollins. While genetic information may not make much difference in initial adoption of a behavioral change, it might be useful in tailoring interventions so people stick with them.
"If we can figure out how to make interventions fit people better—make them more personalized based on genetic information—then I think they would be more likely to sustain the change," she says. "We might be able to make some headway into reducing our relapse rates."
McBride is ready to start testing her hypothesis even though some in the extramural world think it’s premature. "Discovery researchers are still identifying associations between different genetic variants and traits," says McBride. "The discovery culture says, ‘Wait until we get this all figured out and then we can start to do some translation research.’ I say, ‘Why wait?’ If there are some conceptually credible associations between genetics and some traits, such as exercise or smoking, what’s the harm in trying to ask these questions now?
"It’s a gamble," she continues. "I know I can’t do what I did at the Genome Institute—it wouldn’t get funded. But I want to bring that sensibility of focusing research on areas that meet a pressing need rather than on what can get funded. It’s a delicate balance, and I’m trying to find it."
Related Resources:
Emory Department of Behavioral Sciences and Health Education