My research revolves primarily around four major prospective studies: the Nurses’ Health Study, a cohort of 121,700 nurses followed since 1976, Nurses’ Health Study II, a cohort of 116,680 nurses followed since 1989, the Health Professionals Follow-Up Study, a cohort of 51,000 men begun in 1986, and the Physicians’ Health Study of 22,071 men followed since 1982. I serve as co-PI for the Nurses’ Health Study, and am a founding co-investigator for the other three studies. Biologic samples have been collected in each of the cohorts, sometimes repeatedly. Using a nested case-control design, the samples are analyzed for a variety of markers of cancer and heart disease risk. Endpoints of interest include cancer, cardiovascular diseases, fractures, diabetes, and other major health problems. We use food frequency questionnaires, diet records, anthropometry, and biochemical analyses of serum, plasma, DNA, RNA, red cells, adipose tissue, tumor tissue, and toenails. I served as chair of the Department of Epidemiology 2000-2007, and am co-PI of the longest-running cancer epidemiology training grant. At Channing Division of Network Medicine I served as Head of the Chronic Disease Epidemiology Unit 2006-2016. I served on the US Dietary Guidelines Advisory Committee in 2000. For three years I served on the steering committee of the NCI cancer cohort consortium. I previously served as leader for Cancer Epidemiology and as deputy director for population sciences of the Dana Farber/Harvard Cancer Center.

My primary research efforts are in the study of chronic disease prevention and improved prognosis, with a particular interest in nutrition.