Dr. Clifford's research concerns the dynamic and kinetic behavior of nutrient metabolism as it occurs in vivo in humans. Nutrients of special interest include folate, vitamin E, β-carotene, lutein, and food (fruits/vegetables) components (flavonoids, isothiocyanates, catechins, sulfaraphanes, resveratrol). Foods rich in the above components protect against and hold promise for improved management of developmental, chronic, and degenerative diseases.
The research approach is to incorporate a 14C-label during the synthesis of the nutrient/component (commonly referred to as the tracer) and then to follow the fate of a minute oral dose (nmole amount) of the tracer over time since dosing using accelerator mass spectrometry that can measure attomole to zeptomole of 14C. The final step is to construct a kinetic and dynamic model that quantifies the behavior of the nutrient (folate or RRR-a-tocopherol) or compound using the tracer and the tracee datasets, the tracee is the endogenous nutrient or compound that is not labeled with 14C.
If the requirements of the nutrient/compound for specific metabolic functions can be stipulated, the minimum intake of nutrient or compound to sustain these critical functions can be determined. This could be particularly significant where nutrient or compound deficiency or marginal nutrition status is widespread. Simulation of the sudden cessation of dietary intake in a nutrient- or compound-replete person can identify and quantify some interesting features of the nutrient or compound system that are testable.
