Somdat Mahabir, Ph.D., M.P.H.

Program Director
Environmental Epidemiology Branch, Epidemiology and Genomics Research Program

Telephone: (240) 276-6941
Fax: (240) 276-7920

  • Ph.D. - Nutrition, New York University
  • M.P.H. - Epidemiology, New York Medical College
  • M.S. - Clinical Nutrition, New York Institute of Technology
Contact for questions about:
  • Early-life factors
  • Environmental exposures
  • Lifestyle factors


Dr. Somdat Mahabir is a Program Director in the Environmental Epidemiology Branch (EEB) of the Epidemiology and Genomics Research Program (EGRP) in NCI's Division of Cancer Control and Population Sciences (DCCPS). His responsibilities include the management of a research portfolio that focuses on cancer epidemiology of modifiable risk factors such as environmental exposures and lifestyle factors. Dr. Mahabir has expertise in the management of several NCI-funded large-scale research projects. These include the Multi-Ethnic Cohort (MEC) Studies and the California Teachers Study (CTS). He was also involved with the development of the NIH Environmental Influences on Child Health Outcomes (ECHO) Program and afterwards continued to serve as Project Scientist. Dr. Mahabir also served as Co-Chair for Research on the 2019-2023 Trans-NIH Strategic Plan for Women’s Health Research. He is a member of the Core Planning Group of the Trans-NIH Developmental Origins of Health and Disease (DOHaD) working group and other scientific groups.

Dr. Mahabir led collaborative efforts between NCI and the National Institute of Environmental Health Science (NIEHS) to develop New Cohorts for Environmental Exposures and Cancer Risk (CEECR) and currently serves as the scientific contact for NCI’s Funding Opportunity Announcements on these initiatives (RFA-CA-20-049 and RFA-CA-20-050). He also is EGRP's scientific point of contact for the International Childhood Cancer Cohort Consortium (I4C) and Childhood Leukemia International Consortium (CLIC).

He has organized workshops at NCI to advance different areas of cancer research. They include the Expert Panel Workshop on Early-Life Events and Cancer in May 2011, the Birth Defects and Cancer: The Intersection of Genes and Prenatal Factors workshop in September 2012, Research Strategies for Nutritional and Physical Activity Epidemiology and Cancer Prevention workshop in June 2016, and Next Steps in Studying the Human Microbiome and Health in Prospective Studies workshop in May 2017.

Prior to joining EGRP in 2009, Dr. Mahabir was an Assistant Professor of Epidemiology in the Department of Epidemiology, Division of Cancer Prevention and Population Sciences, at The University of Texas M.D. Anderson Cancer Center. He was a member of the Psychosocial, Behavioral, and Health Services Research Committee Institutional Review Board (IRB) section at M.D. Anderson Cancer Center.

Dr. Mahabir is the recipient of an NCI Cancer Prevention Research Training Merit Award, NCI Director's Award, CDC/Agency for Toxic Substances and Disease Registry (ATSDR) Honor Award, NIH Director’s Award and academic awards from New York Medical College and New York Institute of Technology.

Select Publications

Tylavsky FA, Ferrara A, Catellier DJ, Oken E, Li X, Law A, Dabelea D, Rundle A, Gilbert-Diamond D, Hivert MF, Breton CV, Cassidy-Bushrow AE, Mueller NT, Hunt KJ, Arteaga SS, Lombo T, Mahabir S, Ruden D, Sauder K, Hedderson MM, Zhu Y, Polk S, Mihalopoulos NL, Vos M, Pyles L, Roary M, Aschner J, Karagas MR, Trasande L. Understanding childhood obesity in the US: the NIH environmental influences on child health outcomes (ECHO) program. Int J Obes (Lond). 2019 Oct 24. [Epub ahead of print]

Sinha R, Ahsan H, Blaser M, Caporaso JG, Carmical JR, Chan AT, Fodor A, Gail MH, Harris CC, Helzlsouer K, Huttenhower C, Knight R, Kong HH, Lai GY, Hutchinson DLS, Le Marchand L, Li H, Orlich MJ, Shi J, Truelove A, Verma M, Vogtmann E, White O, Willett W, Zheng W, Mahabir S, Abnet C. Next steps in studying the human microbiome and health in prospective studies, Bethesda, MD, May 16-17, 2017. Microbiome. 2018 Nov 26;6(1):210.

Mahabir S, Willett WC, Friedenreich CM, Lai GY, Boushey CJ, Matthews CE, Sinha R, Colditz GA, Rothwell JA, Reedy J, Patel AV, Leitzmann MF, Fraser GE, Ross S, Hursting SD, Abnet CC, Kushi LH, Taylor PR, Prentice RL. Research Strategies for Nutritional and Physical Activity Epidemiology and Cancer Prevention. Cancer Epidemiol Biomarkers Prev. 2018 Mar;27(3):233-244.

Mahabir S, Pfeiffer R, Xu X, Baer DJ, Taylor PR. Effects of low-to-moderate alcohol supplementation on urinary estrogen metabolites in postmenopausal women in a controlled feeding study. Cancer Med. 2017 Oct;6(10):2419-2423.

Mahabir S. Is nonalcoholic fatty liver disease driving the increased incidence of liver cancer? Cancer. 2016 Jul 15;122(14):2277-8.

Vedham V, Verma M, Mahabir S. Early-life exposures to infectious agents and later cancer development. Cancer Med. 2015 Dec;4(12):1908-22.

Mahabir S, Baer DJ, Pfeiffer RM, Li Y, Watkins BA, Taylor PR. Low to moderate alcohol consumption on serum vitamin D and other indicators of bone health in postmenopausal women in a controlled feeding study. Eur J Clin Nutr. 2014 Nov;68(11):1267-70.

Mahabir S. Association between diet during preadolescence and adolescence and risk for breast cancer during adulthood. J Adolesc Health. 2013 May;52(5Suppl):S30-S5.

Mahabir S, Aagaard K, Anderson LM, Herceg Z, Hiatt RA, Hoover RN, Linet MS, Medina D, Potischman N, Tretli S, Trichopoulos D, Troisi R. Challenges and opportunities in research on early-life events/exposures and cancer development later in life. Cancer Causes Control. 2012 Jun;23(6):983-90.

Hartman TJ, Mahabir S, Baer DJ, Stevens RG, Albert PS, Dorgan JF, Kesner JS, Meadows JW, Shields R, Taylor PR. Moderate alcohol consumption and 24-hour urinary levels of melatonin in postmenopausal women. J Clin Endocrinol Metab. 2012 Jan;97(1):E65-8.

Su LJ, Mahabir S, Ellison GL, McGuinn LA, Reid BC. Epigenetic contributions to the relationship between cancer and dietary intake of nutrients, bioactive food components, and environmental toxicants. Front Genet. 2012Jan;2:91.

Swartz MD, Forman MR, Mahabir S, Etzel CJ. Pooling dietary data using questionnaires with open-ended and predefined responses: implications for comparing mean intake or estimating odds rations. Am J Epidemiol. 2010 Mar15;171(6):682-90.

Mahabir S, Ettinger S, Johnson L, Baer D, Clevidence BA, Hartman TJ, Taylor PR. Measures of adiposity and body fat distribution in relation to serum folate levels in postmenopausal women in a feeding study. European Journal of Clinical Nutrition, 2008; 62:644-650.

Mahabir S, Baer DJ, Johnson LL, Hartman TJ, Dorgan JF, Campbell WS, Clevidence BA, Taylor PR. Usefulness of body mass index (BMI) as a sufficient adiposity measurement for sex hormone concentration associations in postmenopausal women. Cancer Epidemiology, Biomarkers and Prevention, 2006;15(12):2502-2507.