Our Team

Walter C. Willett, MD, DrPH is professor of epidemiology and nutrition at Harvard T.H. Chan School of Public Health. Dr. Willett studied food science at Michigan State University, and graduated from the University of Michigan Medical School before obtaining a masters and doctorate in Public Health from Harvard T.H. Chan School of Public Health. Dr. Willett has focused much of his work over the last 40 years on the development and evaluation of methods, using both questionnaire and biochemical approaches, to study the effects of diet on the occurrence of major diseases. He has applied these methods starting in 1980 in the Nurses’ Health Studies I and II and the Health Professionals Follow-up Study. Together, these cohorts include nearly 300,000 men and women taking repeated dietary assessments. They are providing detailed information on the long-term health consequences of food choices.

Dr. Willett has published over 2,000 original research papers and reviews, primarily on lifestyle risk factors for heart disease, cancer, and other conditions and has written the textbook Nutritional Epidemiology, published by Oxford University Press, now in its third edition. He also has written four books for the general public. Dr. Willett is the most cited nutritionist internationally. He is a member of the National Academy of Medicine of the National Academy of Sciences and the recipient of many national and international awards for his research.

Dr. Mucci has been a co-investigator in HPFS since 2003, and has overseen the HPFS Tumor Repository. She is a cancer epidemiologist whose research focuses on utilizing integrative molecular epidemiology approaches, including circulating biomarkers, inherited genetic alleles, and tumor biomarkers to study cancer risk and mortality. Her research is primarily focused on prostate cancer, which is the most commonly diagnosed cancer among men in HPFS. She has led several studies that investigate the association between lifestyle and dietary factors and risk of advanced or fatal prostate cancer.

Alberto Ascherio, MD, DrPH, is a professor of epidemiology and nutrition at the Harvard T. H. Chan School of Public Health and a professor of medicine at the Harvard Medical School. Dr. Ascherio received a doctorate in medicine and surgery from the University of Milan and worked for several years in medicine and public health in Latin America and Africa before obtaining a master and doctorate in public health from Harvard. Dr. Ascherio has focused much of his work over the past 25 years on discovering the causes of neurodegenerative diseases, including multiple sclerosis (MS), Parkinson disease, amyotrophic lateral sclerosis, and cognitive decline. He has conducted longitudinal studies in many populations, including, among others, the Nurses’ Health Studies I and II, the Health Professionals Follow-up Study, the Cancer Prevention Study-II, the U.S Army, Navy and Air Force, the Danish MS Registry, and the Finnish Maternal Cohort. These studies have contributed to identifying several biomarkers and modifiable risk factors for MS (e.g. cigarette smoking, vitamin D insufficiency, and childhood obesity), Parkinson’s (pesticide exposure, low caffeine intake, low physical activity), and ALS (cigarette smoking, military service, low body mass index), and have in some cases provided the rationale for randomized trials (e.g. on physical activity in Parkinson’s disease).

My research is focused on using causal inference methods and large health databases to improve health decision-making, with a focus on cancer control. I am co-director of the VA-CAUSAL Methods Core, an initiative of the U.S. Veterans Health Administration to integrate high-quality data and explicitly causal methodologies in a nationwide learning health system. I currently teach causal inference methodology at the Harvard T.H. Chan School of Public Health, where I am assistant professor of global cancer prevention in the Department of Epidemiology.

David Christiani, MD, MPH, MS, is the Elkan Blout Professor of Environmental Genetics with the Harvard T.H. Chan School of Public Health and professor of ,edicine at Harvard Medical School. He earned his MD in 1976 from Tufts University, and an MS and MPH from the Harvard School of Public Health. He did his post-graduate medical training at Boston City Hospital and the Massachusetts General Hospital in Boston.

Professor Christiani’s major research interest lies in the interaction between human genes and the environment. In the emerging field of molecular epidemiology, he studies the impact of humans’ exposure to pollutants on health, as well as the how genetic and acquired susceptibility to these diseases along with environmental exposures can lead to acute and chronic pulmonary and cardiovascular disease. He is also developing new methods for assessing health effects after exposure to pollutants and is very active in environmental and occupational health studies internationally.

My primary research efforts focus on how nutritional, hormonal, and genetic factors are related to various malignancies, especially those of the prostate and large bowel. Much of this work is based on the Nurses’ Health Study, the Health Professionals Follow-Up Study and the Physicians’ Health Study cohorts. For prostate cancer, my work has centered on the role of specific antioxidants, particularly lycopene, and on the potentially deleterious effects of diets high in calcium and dietary fat. In addition to establishing risk factors, we have been interested in understanding etiologic mechanisms that will help provide a solid scientific rationale for preventive strategies. Specifically, I have studied how nutritional factors influence prostate cancer through modulating levels of insulin-like growth factors (IGFs) and binding proteins, insulin, vitamin D metabolites, and steroid hormones. More recently, our work has examined the role of obesity and energy balance in the progression of prostate cancer.

Dr. Frank Hu is chair of Department of Nutrition, Fredrick J. Stare Professor of Nutrition and Epidemiology at Harvard T.H. Chan School of Public Health and professor of medicine, Harvard Medical School and Brigham and Women’s Hospital. Dr. Hu received his MD from Tongji Medical College in China and MPH and PhD in Epidemiology from University of Illinois at Chicago. He completed a postdoctoral fellowship in nutritional epidemiology at Harvard T.H. Chan School of Public Health.

Dr. Hu’s major research interests include epidemiology and prevention of cardiometabolic diseases through diet and lifestyle; gene-environment interactions; nutritional metabolomics; and nutrition transitions in low- and middle-income countries. Currently, he is director of the Boston Nutrition and Obesity Research Center’s Epidemiology and Genetics Core and the director of the Dietary Biomarker Development Center at Harvard University.

He has published a textbook on Obesity Epidemiology (Oxford University Press) and more than 400 peer-reviewed papers with an H-index of 290. He served on the Institute of Medicine (IOM) Committee on Preventing the Global Epidemic of Cardiovascular Disease, the Obesity Guideline Expert Panel, American Heart Association Nutrition Committee, and the 2015 Dietary Guidelines Advisory Committee, USDA/HHS. He has served on the editorial boards of Lancet Diabetes & Endocrinology, Diabetes Care, and Clinical Chemistry. Dr. Hu was elected to the National Ac…

I am a molecular and clinical epidemiologist with a focus on cancer epidemiology and a background as a board-certified internal medicine physician. My main research interest is how potentially modifiable exposures cause solid tumors through genomic heterogeneity and influence cancer progression. I am passionate about combining well-defined observational studies and state-of-the-art genomics in order to guide cancer prevention and treatment. My methodologic and teaching interests include application and further development of epidemiologic methods for high-dimensional biomarker studies and clinical studies.

Dr. Stampfer’s research program is broadly concerned with the etiology of chronic diseases, with particular focus on nutrition and cancer.

With colleagues in the Departments of Epidemiology and Nutrition at Harvard School of Public Health, and at the Channing Division of Network Medicine and the Division of Preventive Medicine at Brigham and Women’s Hospital, Dr. Stampfer is closely involved in four large prospective cohort studies:

Nurses’ Health Study I (N = 121,700) – Co-Principal Investigator
Health Professionals Follow-Up Study (N = 51,259) – Founding co-Investigator
Physicians’ Health Studies I and II (N = 22,071) – Founding co-Investigator
Nurses’ Health Study II (N = 116,678) – Founding co-Investigator

In each of these studies, participants are surveyed every two years to gather information on diet, smoking, physical activity, medications, health screening behavior, and other variables. We also ascertain the new occurrence of cancer, cardiovascular disease, and other serious illnesses, including diabetes, fractures, kidney stones, and pre-cancerous lesions.

In addition, Dr. Stampfer leads several other NIH-funded projects, and is co-principal investigator of a T32 NIH training programs that support predoctoral students and postdoctoral fellows.

All of these large-scale studies are continuing. Over the past 20 years, Dr. Stampfer has continuously been identified as among the five most highly cited scientists in clinical medi…

My research focuses on clinical and translational epidemiology of cancer. One aspect of my work is to integrate large-scale observational studies with biomarker-based randomized clinical trials to identify novel nutritional and gut microbiota-targeted strategies for cancer prevention and treatment. Another part of my work involves integration of electronic health record (EHR) data with molecular profiling for developing cost-effective risk assessment tools for precision cancer screening and surveillance. I was awarded the NextGen Star by the American Association for Cancer Research. My current research is supported by the National Cancer Institute and American Cancer Society. The ultimate goal of my research is to translate epidemiologic advances into the clinic for improved cancer prevention and treatment.

Over the past few years, I have studied the role of diet and lifestyle factors, in conjunction with host immune factors and the gut microbiota, in colorectal cancer development and survivorship. Much of my work has been based on three large prospective cohort studies, the Nurses’ Health Study I and II, and the Health Professionals Follow-up Study, in which diet, lifestyle and colorectal cancer diagnosis and mortality have been assessed over decades with blood, stool, and tumor tissue specimens collected in a subset of participants.

As a faculty member with joint appointments in both Epidemiology and Biostatistics, Dr. Wang’s current methodological researches focus on statistical challenges encountered in epidemiological studies, including assessment of timing of effect in survival analysis, causal inferences for clustered data, evaluation of etiological disease heterogeneity, methods for pooling biomarker data, and measurement error and missing data problems. She has also developed semi-parametric methods for reducing the impact of nuisance parameters.

She has been the lead statistician for the Nurses’ Health Study II and the Health Professionals Follow-up Study, and the lead statistician for several projects based on the Harvard cohorts. She is also the lead statistician for the Pooling Project on Diet and Cancer in Women and Men, the Circulating Biomarkers and Breast and Colorectal Cancer Consortium, the Pooling Project on Gestational Weight Gain in Low- and Middle-income Countries and several HIV studies conducted in Uganda, Tanzania and India. She has been actively working on analyses, providing input into the development of analytic procedures and their interpretation, and overseeing software development for the routine implementation of advanced and novel statistical methods.

Before October 2010, she had worked on statistical collaborations in various oncology projects with Harvard-Dana Farber Cancer Institute biomedical investigators and the Eastern Cooperative Oncology Group (ECOG), with …

My research concentrates on the design and analysis of genetic association studies, with particular emphasis on studies linking variation in germline DNA to cancer risk.

I have played a key role in multiple international consortia studying genetics and other exposures in relation to cancer risk over the last ten years: I have been a member of the statistical working group of the Breast and Prostate Cancer Cohort Consortium since its inception, and currently chair the BPC3 steering committee; I played a leading role in the design and analysis of GWAS of breast, prostate and pancreatic cancers as part of the NCI’s Cancer Genetic Markers of Susceptibility and PanScan projects; and I chair the Analytic Working Group for the NCI’s “post-GWAS” GAME-ON consortium, which aims to better understand the biological mechanisms underlying GWAS-identified cancer risk markers at five cancer sites (including breast and lung) and their public health implications.

I am also the contact PI for the epidemiology project of the breast cancer arm of GAME-ON, which focuses on gene-environment interactions and risk prediction. I have been the primary statistical geneticist for the Nurses’ Health Study (NHS) and Health Professionals Follow-up Study (HPFS) for over ten years, and oversee the genotype databases for both studies, including genome-wide association data on over 20,000 subjects. I have collaborated on numerous analyses in the NHS and HPFS.

Dr. Qi Sun’s research is focused on identifying novel biomarkers of diet and environmental exposures and risk of excess weight gain, type 2 diabetes, and cardiovascular disease by integrating the state-of-the-art of omics technologies and nutritional epidemiological approaches. His research has led to the discovery of endogenous metabolites (e.g., very-long chain saturated fatty acids), endocrine disruptors (e.g., bisphenol A and per- or polyfluoroalkyl substances), circulating proteins (e.g., fatty acid binding protein 4 and soluble leptin receptor), and gut microbiome as predictors or modulators of human metabolic diseases. He is also an established nutritional epidemiologist and has led numerous projects to elucidate associations between various dietary factors and cardiometabolic conditions in populations with and without diabetes. His study findings have enhanced the understanding of the biological mechanisms underlying nutrition and metabolic health and contributed to the US dietary guidelines for chronic disease prevention.

My research has primarily focused on nutrition and cancer epidemiology. Main themes of my research have been determination of the role of plant-based diets, particularly fruit and vegetable intake, alcohol consumption, and more recently, vitamin D in the development of both common and less common cancers.

Much of my research has been conducted in two international consortia that I have been leading/co-leading for over 16 years: the Pooling Project of Prospective Studies of Diet and Cancer (DCPP) and the Circulating Biomarkers and Breast and Colorectal Cancer Consortium (BBC3). Additionally, I have participated in several analyses of dietary factors including dietary patterns, anthropometric factors, and biomarkers within the Nurses’ Health Study, Nurses’ Health Study II, and Health Professionals Follow-Up Study, three large prospective cohort studies.

As an epidemiologist trained in preventive medicine, cardiovascular epidemiology, and aging epidemiology, Dr. Ma studies the epidemiology and prevention of aging-related diseases, with a focus on cardiovascular disease and vascular contributions to brain aging and dementia.

Dr. Ma’s research work has investigated modifiable vascular risk factors and the development of effective intervention strategies for the prevention of hypertension and cardiovascular disease in prospective cohort studies, randomized trials, and health policy modeling studies.

Dr. Ma’s current research aims to improve our understanding of how vascular factors contribute to brain aging and dementia using multidisciplinary approaches that integrate advanced epidemiological methods with cutting-edge neuroimaging techniques, neuropathology data, and multi-omics methods in epidemiological studies.

Dr. Ma is a recipient of the American Heart Association Postdoctoral Fellowship Award, the National Academy of Medicine Healthy Longevity Catalyst Award, and the NIH K99 Pathway to Independence Award.