Tom Brenna is Professor Emeritus since 2017.  His research couples Nutrition and Chemistry in a broadly interdisciplinary program.  He is a member of graduate fields in Cornell's four large colleges: Nutrition (CHE and CALS), Food Science and Technology (CALS), Chemistry and Chemical Biology (Arts), and Geological Sciences (Engineering and CALS), among other collaborations. His research group has been funded by institutes/centers at the NIH (NIGMS, NEI, NICHD, NCCIH) and private industry. These grants have supported fundamental work in the nutrition of polyunsaturated fatty acids and the development of advanced mass spectrometry instrumentation and techniques.

Most of the work of the Brenna Group is translational, tying basic research to biomedicine and human nutrition.  His work focuses on most aspects of fatty acid nutrition probed with mass spectrometry of various types. He is known internationally for original research and policy-related reviews on polyunsaturated and branched chain fatty acids.  These are facilitated by specialized mass spectrometry techniques developed in his lab. His extensive work on high precision isotope ratio mass spectrometry led to major contributions to endogenous performance enhancing drugs, particularly testosterone, as well as methods for detecting exogenous drugs. 

His work has influenced nutrition policy, notably the FDA's acceptance of the addition of omega-3 DHA to infant formulas (2001) and UN/Codex Alimentarius recommendations on the lipid composition of Ready-to-Use Therapeutic Foods to treat children with Severe Acute Malnutrition (2022). Professor Brenna has served on numerous national and international advisory panels on human nutrition.  He was a member of the 2015 Dietary Guidelines Advisory Committee appointed by the US Secretaries of Health and Human Services and of Agriculture and the latest WHO/FAO Expert Consultancy on Fats and Fatty Acids (2010).  He was President of ISSFAL, the International Society for the Study of Fatty Acids and Lipids. His work has been recognized with numerous professional honors: the Osborne and Mendel and the Robert Hermann Awards of the American Society for Nutrition for basic and clinical research, respectively; the Supelco Research, Ralph Holman, and Herbert J. Dutton Awards of the American Oil Chemists Society for basic research, lifetime achievement in lipid nutrition, and contributions to analytical chemistry, respectively.