Andrew Joseph Clifford

Andrew Joseph Clifford was born in Ardfert, County Kerry, Ireland, on January 9, 1940. He died peacefully on March 5, 2022, at 82. Andy was highly valued as a colleague. He possessed the analytical mindset and skills that are crucial for critical thinking. His friends and colleagues will remember Andrew for his tenacious commitment to research, problem-solving, and engaging sense of humor. 

Professor Clifford attended University College in Dublin, Ireland, where he received his undergraduate and master's degrees. His initial interests were agriculture and the animal sciences. He received a scholarship to attend Oklahoma State University, where he earned a Ph.D. in 1967. He further honed his analytical and biological skills at Cornell University in Ithaca, NY, and at MIT in Cambridge, Massachusetts, in post-doctoral positions focusing on nucleotide and amino acid metabolism.

Andrew joined the faculty of the Nutrition Department at UC Davis as an Assistant Professor in 1972. He came with his wife, Dr. Carolyn Kay Harman Clifford, and young daughter, Berniece Vourneen Clifford. Carolyn and Andrew met in Stillwater, Oklahoma, married, and started a family during their stay in Ithaca, NY. Later, a son was born in Davis, CA, Amel John Clifford. Carolyn Clifford also completed a Ph.D. at Cornell University, which evolved into a distinguished career as a director in the cancer prevention research program at DHHS/NIH.

During his 41 years on the faculty at UC Davis, where he moved through the ranks from Assistant Professor to Distinguished Professor, Andrew published in areas focusing on purines and the metabolism of folic acid, carotenoids, and tocopherol in humans. Professor Clifford's work was pioneering. Through well-organized collaborations, he and his collaborators developed novel approaches to analyzing isotopically labeled compounds in human studies. The work had multiple components. He partnered with mathematical modelers and statisticians to create state-of-the-art kinetic models to improve bioavailability and metabolic research strategies. Importantly, these interactions were broad-based, resulting in highly visible publications and the organization of a conference in biostatistical methodology. Additional collaborations with chemists and plant scientists produced labeled compounds that were unavailable commercially.

Much of the analytical work was centered at Lawrence Livermore utilizing accelerator mass spectrometry. The sensitivity of accelerator mass spectrometry allowed using nanomolar doses of vitamins in human studies to follow metabolism with an actual tracer (leaving the metabolic system unperturbed). Their approaches provided 'proof of concept' that labeled nutrients at attomole levels could be measured over long periods (months) using milligram-sized samples. Moreover, throughout his career, he consistently participated in national and international meetings. For example, his group presented work annually at the American Society of Nutrition meeting. The Academie Amorim, an international group of wine researchers, writers, and producers, recognized Professor Clifford and his colleagues for research identifying the antioxidant and anticarcinogenic properties of phenolic compounds in wine. The award was given in Paris, honoring the Davis team for advancing enology knowledge. Moreover, his excellence in research won him national program funding for his entire academic career from agencies such as the National Institutes of Health and the National Science Foundation and a distinguished professor title. He was recognized as a Fellow of the American Society of Nutrition in 2006, the highest honor that the Society bestows.

Professor Clifford was also at the forefront of teaching and graduate program administration. He served as an advisor for the Nutritional Biology Graduate Group, chair for the Agricultural and Environmental Chemistry Graduate Group, and a founding member of the Biostatistics Graduate Group, where he was instrumental in achieving approval of Biostatistics as a graduate group. He also served on its first Executive Committee. Like his insight related to research endeavors, his participation always resulted in improvements, often critical to resolving conflicts. Moreover, Andrew was active in national associations, such as the American Society of Nutrition and the American Chemical Society. In addition, he served on the editorial board for Plant Food for Human Nutrition.

Andrew enjoyed traveling with his family to their family farm in Oklahoma. Like his research colleagues, family comments also emphasized his keen sense of humor and pride in his Irish heritage. In addition, his travels often took him to the NIH, Bethesda, Maryland, sustaining the long-distant successful companionship with his wife of 30 years, Carolyn Clifford, as well as short sabbaticals. Finally, a gratifying traveling endeavor was a trip to Dublin to facilitate nutrition-related components of the UC Davis-University College, Dublin partnership, i.e., his college alma mater.

Professor Andrew Clifford will be missed.

Robert Rucker 
James Fadel 
Hans-Georg Müller
Janet Novotny