The Health Professionals Follow-Up Study (HPFS) was started in 1986 by researchers from Harvard T.H. Chan School of Public Health as an all-male complement to the all-female Nurses’ Health Study. Every two years since then, participants—51,529 at the start and still nearly 15,000 actively participating—have answered questionnaires about their health and lifestyles. This trove of data, along with biological samples collected from participants, has generated nearly 1,500 scientific articles and has provided important insights into diet and health, aging, and diseases such as prostate cancer and heart disease.
HPFS will be holding an anniversary symposium on Sept. 10 to celebrate 40 years of scientific accomplishments and participant contributions. The study’s co-principal investigator Lorelei Mucci, professor of epidemiology, recently spoke about the study’s important advances toward understanding health—and its future as its youngest original participants reach their 80s and beyond.
Q: What is unique about HPFS?
Lorelei Mucci
A: We are one of the largest and longest-running cohorts focused solely on males. Along with the Nurses’ Health Study, we are one of the few cohorts with detailed data on participants collected at multiple time points over many years. That’s important because dietary patterns and things like use of supplements or medications can vary over time. We’re able to capture all of the changes that are happening and see how they influence human health.
The study’s design has also allowed us to explore emerging areas of interest and add new sets of questions for exposures such as sleep health and new dietary patterns, as well as outcomes such as healthy aging, cognitive health, and emotional health.
We have blood samples from 18,000 of the participants that we collected between 1993 and 1995. Today, we are in the middle of a new blood collection, which is an impressive commitment from the participants, who are now in their 80s, 90s, and even 100s. This is being led by Yuan Ma, assistant professor of epidemiology. We also have assembled a tumor tissue repository from 7,500 participants diagnosed with cancer in the cohort, and we have one of the largest collections of toenails in the world, which can be examined for things like exposure to heavy metals.
Q: What are some of the study’s significant areas of research?
A: We’ve been able to identify the key components of a healthy dietary pattern that enhances longevity and minimizes risk of cancer, cardiovascular disease, and cognitive decline. We also have exciting work that’s come out on physical activity and health—for example, identifying the types of physical activity that help cancer patients not only extend survival, but improve quality of life.
One of the major areas of research interest within the HPFS is prostate cancer, which is the most common male cancer in the United States. More than 9,000 of our participants have been diagnosed with prostate cancer at some point. A sub-study with these patients asks them about quality of life, treatments, and progression of their disease since their cancer diagnosis. We also have prostate tumor tissue from over 4,000 of the participants. So, we’ve really contributed in a big way to understanding, for example, biological markers that are associated with better or worse prognosis from prostate cancer. We’ve also identified important epidemiologic data on lifestyle and diet that can improve survivorship, providing an evidence basis for physicians, prostate cancer patients, and their families.
In addition, our large blood repositories have enabled us to delve into understanding the inherited genetic factors that predispose people to diseases like cancer, heart disease, and Parkinson’s disease.
A large number of our study participants are dentists, and data from our cohort helped to make a compelling case that good oral health is associated with better overall health. For example, we’ve had studies showing that individuals who have significant periodontal disease may have an excess risk of heart disease and certain types of cancers and inflammatory conditions.
Q: What is the current status of the study and how was it impacted by last year’s funding interruptions to grants at Harvard?
A: A large part of the funding for our study infrastructure and science comes from the National Institutes of Health. Unfortunately, we were part of the mass terminations of Harvard grants last year, and that had a big impact on our study team, with layoffs of study personnel and impacts on early career investigators. The funding came back for the main study, but it had a pretty big impact in the short term that we’ve been trying to bounce back from.
Although that main study grant is going to be ending in a year, we do have funding from individual research grants that support different components of the study, for example: healthy aging, prostate cancer, cardiovascular disease, and diet.
Q: The anniversary event is going to feature study participants. What have you heard from participants about what the experience has meant to them?
A: A common theme that we hear is how much they have learned about health because of the data that have come out of our cohort study, and how it’s changed how they—and members of their families—live their lives.
I have a card in my office from a participant who’s 92 years old. He’s in an assisted living facility and can’t see very well anymore, but he really wanted to wish us a happy 40th anniversary. So, he had somebody help him write a card thanking us for 40 years of feeling like he was contributing to something important, and that person helped him fill out his questionnaire because he wanted to make sure we got it back.
We also get a lot of handwritten letters from the men taking part in the prostate cancer sub-study. They want to tell us about their quality of life, the symptoms they’re having, and the side effects from treatment. It helps them, I think, go through the process of being a cancer survivor, as does feeling like they’re part of a community.
Finally, we receive many personal letters from spouses or children of HPFS participants sharing an announcement of their deaths. These letters give us a unique insight into not only how important being part of the HPFS study was for their loved ones, but the family members, as well.
Q: How long have you been involved with HPFS and what has it meant for your career?
A: I first began working with study data during my postdoctoral training at Harvard Chan School to work specifically in the area of prostate cancer. It was an incredible opportunity to explore a cancer that I didn’t know a lot about, and to learn about what having prostate cancer means to men and their families.
The cohort work really gave me opportunities for leadership experience. For example, I took on the role of overseeing our tumor tissue repository and got to collaborate with pathologists, clinicians, and molecular biologists, and learn what it was like to be part of a multidisciplinary team.
Around 2014, I joined Walter Willett as co-principal investigator of the study. The experience of learning from Walter and the study’s senior investigators about how to run a cohort and how to run a research team in a kind of different way, was so influential in my own career growth and toward my ultimately becoming a full professor at the School. And I would say, I’m one of many, many people whose careers really benefited from being actively involved in the Health Professionals Follow-Up Study.
About The Author
Amy Roeder
Senior Editor, Harvard Chan Magazine; Senior Writer in the Office of Communications
