Diabetes and Thiamine: A Novel Treatment Opportunity
Underlying all diabetic conditions is poor sugar control or hyperglycemia. Hyperglycemia can be due to a lack of insulin as in Type 1 diabetes or insulin resistance as in Type 2 diabetes. In either case, the corresponding diabetic complications that evolve over time in many diabetics, the cardiovascular disease, retinopathy, peripheral nerve and vascular damage, represent the effects of sustained hyperglycemia. Until recently, the mechanisms by which diabetic vascular damage developed eluded researchers. Although multiple, seemingly discrete biomarkers had been identified, no single, unifying mechanism was understood. It turns out that diabetics, both Type 1 and Type 2, are severely deficient in thiamine or vitamin B1 and that thiamine is required for glucose control at the cell level. Why is thiamine deficient in diabetics and how does thiamine manage glucose control? The answers to those questions highlight the importance of micronutrients in basic cellular functioning, particularly mitochondrial functioning, and the role of excessive sugar in disease. ...Under normal conditions, with appropriate dietary nutrients and physiological concentrations glucose, dietary sugars are converted to ATP in the mitochondria. The byproduct of that reaction is the production of free radicals also known as oxidative stress or reactive oxygen species (ROS). ROS are neither good nor bad, but too much or too little ROS wreaks havoc on cellular functioning. The cells can clear the ROS and manage oxidative stress via activating antioxidizing pathways and shuttling the excess glucose to secondary, even tertiary processing paths. However, under conditions of chronic hyperglycemia, mediated by diet or diabetes, the conversion of glucose to ATP becomes dysregulated, the production of ROS become insurmountable and a cascade of ill-effects are set in motion.
Too much ROS causes the mitochondria to produce high concentrations of an enzyme called superoxide dismutase (SOD) in the endothelial cells of both the small and large blood vessels. SOD is a powerful antioxidant, however, like everything else, too much for too long causes problems. Superoxide then upregulates the five known chemical pathways that alone and together perturb vascular homeostasis and cause the diabetic injuries that have become commonplace. Technically speaking, hyperglycemia causes:
- Increased activation of the polyol pathway
- Increased intracellular formation of advanced glycation end products (AGEs)
- Increased AGE receptor expression and ligands<
- Upregulated protein kinase C (PKC)
- Enhanced hexosamine pathway activity
In non-technical terms, elevated concentrations of circulating glucose increase the production of ROS and superoxide, but also, and as a compensatory survival reaction to maintain cellular health, secondary and tertiary glucose processing pathways come online. These backup pathways are not nearly as efficient and so produce additional, negative metabolic byproducts which can damage blood vessels if not cleared. The body is capable of clearing these byproducts, but only when the reactions are short term and the nutrient substrates feeding those reactions are present. If, however, the nutrients are deficient and/or the hyperglycemia is chronic, or both, those clearance mechanisms are insufficient to remove the toxins. The toxic byproducts build up and diabetic vascular diseases ensue.
High Dose Thiamine Therapy and Diabetes
Over the last decade or so, researchers have found that thiamine normalizes each of these five aberrant processes activated by sustained hyperglycemia and implicated in diabetic vascular complications. High dose thiamine (300mg/day) reduces the biochemical stress of hyperglycemia human subjects. Additionally, thiamine can prevent and/or offset incipient vascular damage in diabetic patients. Finally, in rodent models of Type 1 diabetes, thiamine transporters have been identified and emerging research shows that thiamine moderates pancreatic insulin secretion significantly. In rats fed a thiamine deficient diet, glycolosis (sugar processing and conversion to ATP by mitochondria) was inhibited by 41%, utilization of fatty acids (secondary energy processing pathway) declined by 61% in just 30 days and insulin production diminished by 14%. The connection between pancreatic downregulation of fatty acid utilization and thiamine is particularly interesting considering the recent discovery of a thiamine dependent enzyme in fatty acid regulation, the HACL1.