Dr. Howard D. Sesso is an Associate Epidemiologist at the Division of Preventive Medicine at Brigham and Women's Hospital, Associate Professor of Medicine at Harvard Medical School, and Associate Professor of Epidemiology at the Harvard T.H. Chan School of Public Health. He leads the design and conduct of randomized clinical trials and epidemiologic studies, focusing on dietary supplements and lifestyle factors in the prevention of cardiovascular disease (CVD), hypertension, cancer, and other aging-related outcomes. Dr. Sesso is also the Associate Director of the Division of Preventive Medicine. Dr. Sesso has led the Physicians' Health Study, consisting of trials testing aspirin, beta-carotene, vitamin E, vitamin C, and a multivitamin on aging-related outcomes in 29,071 men with long-term follow-up. Dr. Sesso is also examining vitamin D and fish oil supplements on 24-hour ambulatory blood pressure and hypertension in an ancillary study of the VITamin D and OmegA-3 TriaL (VITAL) trial. Finally, Dr. Sesso is Co-Principal Investigator of the COcoa Supplement and Multivitamin Outcomes Study (COSMOS), a recently completed randomized trial testing cocoa flavanol and multivitamin supplements in the prevention of CVD and cancer in 21,442 older women and men. He has published more than 300 papers, teaches courses on clinical trials and epidemiology, and enjoys mentoring students and junior faculty.