Scholarship and Biography
Our long-term research objective is to determine the impact of diet macronutrients (carbohydrates, fat, protein, phytochemicals, and fiber) on disorders of lipid and glucose metabolism with a primary focus on insulin, blood glucose, and lipoproteins and their association with chronic diseases, particularly diabetes complications, obesity, gallstones, and atherosclerosis.
For the last 2 decades we have focused on diabetes, initially using fat-fed mouse models to induce obesity, while studying the role of major macronutrients (CHO, fat, PROT) on development of insulin resistance and type 2 diabetes (T2DM). Interestingly, obesity and insulin resistance are prevented by increasing the dietary PROT:FAT ratio in the C57/BL6-DIO mouse model of chronic diabesity, carbohydrate having almost no influence in the equation as long as the PROT:fat ratio is adjusted during any given carb intake. This is unlike humans, where CHO and the diet glycemic load are most important in terms of T2DM pathogenesis.
More recently we have established a breeding colony of Nile grass rats (actually most likely in the gerbil family) that develop spontaneous T2DM when kept in captivity and maintained on standard rodent lab chow. And unlike common mouse and rat models, Nile rat diabetes is induced readily by hiCHO diets, and largely prevented by certain soluble fibers or phytochemical supplements. The Nile rat is also noteworthy because like humans, it divides into subpopulations of ‘resistant’ or ‘susceptible’ individuals in their propensity to diabetes similar to the so-called "thrift gene" that has been proposed for certain indigenous human populations that readily develop diabetes when exposed to Western diets and life style. The objective continues to be to define macronutrient interactions that prevent T2DM while assessing genetic aspects of their unusual diabetic proneness, ie. to discover different diet interventions that will deter or prevent the onset and expression of the diabetes in our Nile rats with the idea that a successful intervention will be applicable to the human experience, as well.