A Comparison Chocolate With and Without High Cocoa Solids in Patients With Type 2 Diabetes in a Randomised Clinical Trial

Overview

Type 2 diabetes is being acknowledged as a potential public health time bomb, whose incidence is predicted to double over the next 10 years in the UK, associated with the rise in obesity and increasing sedentary lifestyles. Increased insulin resistance has been shown to be an important feature of type 2 diabetes (especially in those presenting with obesity and in particular visceral or abdominal obesity). Insulin resistance is implicated as a risk factor of cardiovascular disease and may lead to pancreatic dysfunction through increased β-cell stress in the pancreas. A combination of insulin resistance and pancreatic beta cell failure then leads to type 2 diabetes. The main cause of morbidity and mortality in type 2 diabetes is cardiovascular disease as the condition is associated with impaired vascular functioning and increased levels of oxidation markers. Epidemiological studies suggest dietary flavonoids decrease the risk of death from coronary heart disease, cancer, and stroke. Flavonoid-rich foods include fruits and vegetables as well as tea, red wine, and chocolate. In a cohort of elderly men, cocoa intake was inversely associated with blood pressure and 15-year cardiovascular and all-cause mortality. It has been reported that in healthy humans, consumption of flavanol-rich dark chocolate decreased daytime and night time blood pressure, reduced insulin resistance, and improved nitric oxide dependent vaso-relaxation. Another trial found that cocoa powder increased postprandial insulinaemia in lean young adults. These research papers have led to the hypothesis that chocolate containing high cocoa liquor may help to reduce the risk of developing type 2 diabetes. This study is design as a double-blind, controlled, single center, randomized, parallel design clinical trial. The primary outcome measure is to compare parameters of insulin resistance and glycaemic control in volunteers with type 2 diabetes after consumption of 3 different chocolates (one dark and two milk chocolates) with a secondary outcome of endothelial function, cholesterol profile and oxidative stress. Subjects will undergo medical screening, anthropometry, physical activity and dietary assessments before randomization.