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Marjorie McCullough, ScD

Senior Scientific Director
Epidemiology Research

close up portrait of Marjorie McCullough, ScD Strategic Director, Nutritional Epidemiology

What Inspires Me

Growing up with a father who had a chronic disease, I saw firsthand the critical role that diet played in managing his condition. This experience inspired me to pursue a career in nutritional epidemiology. My research at the American Cancer Society focuses on discovering ways to prevent and manage cancer through diet and lifestyle.”

At ACS since 1999

As Senior Scientific Director of Epidemiology Research, Marjorie (Marji) McCullough, ScD, RD, oversees nutrition research initiatives and diet assessment in the Population Science department at the American Cancer Society (ACS). Her research focuses on investigating the role of diet on cancer risk and prognosis, using both survey data and blood-based biological markers.

McCullough is co-principal investigator of the ACS’s Cancer Prevention Study-II cohort, a prospective cohort of 1.2 million adults in the United States. She also serves on the Guidelines on Nutrition and Physical Activity for Cancer Prevention and for Cancer Survivors committees at the ACS.

Research focus and accomplishments

McCullough investigates the interplay of dietary factors, nutrition, metabolism, and lifestyle behaviors on the risk of cancer and other chronic diseases. She’s a recognized expert in several areas and contributed to the evidence on the role of vitamin D and overall diet and lifestyle patterns on cancer risk and mortality.

Here are two examples of her publications that were widely cited and garnered significant media attention.

McCullough and colleagues found that people who most closely followed the ACS's nutrition and physical activity recommendations had a significantly lower risk of dying from cancer. This finding has since been replicated in several populations and in studies of colorectal and breast cancer survivors who follow the ACS diet recommendations.

Working with a large international consortium, McCullough and colleagues recently reported that vitamin D deficiency is associated with a higher risk of colorectal cancer.


For a full list of McCullough's publications, visit her Google Scholar page.  


Professional organizations

  • American Association for Cancer Research; MEG Steering Committee, 2012-2014, and MEG  Member
  • American Society for Nutrition
  • American Society for Preventive Oncology (ASPO); Lifestyle, Energy Balance and Chemoprevention Special Interest Group, Chair, 2019-20


  • ScD: Nutrition (minor: Epidemiology and Biostatistics), Harvard School of Public Health, 1999
  • MS: Dietetics, MGH Institute of Health Professions, 1986
  • BS: Dietetics, Michigan State University, 1983

Personal life 

I live in Atlanta with my family and dog, Kobe. I enjoy biking, music, and art.