Post-prandial Effects of Extra Virgin Olive Oil on Endothelial Function in Adults at Risk for Type 2 Diabetes: A Randomized Crossover Controlled Trial

Detailed Summary

Purpose: The number of cases of adults with Type 2 diabetes has quadrupled since 1980. This increase in the number of cases of diabetes is attributed to changes in dietary patterns, which include an increase in the consumption of obesogenic foods such as sugary foods and beverages. Patients with diabetes or at risk for diabetes are more likely to develop a cardiovascular event. Though glycemic control remains the basis of diabetes care, the co-management of atherosclerosis, hypertension and cardiovascular risk reduction, and prevention of long-term consequences are also important predictable measures to improve survival. The progression from prediabetes to Type 2 diabetes and complications of diabetes could be prevented. Lifestyle interventions (i.e., nutrition and physical activity) are the cornerstone for the primary prevention of Type 2 diabetes. Healthful eating can also improve cardio-metabolic risk factors associated with those at risk for or Type 2 diabetes. Foods that are low in fat and calories and high in fiber, with a focus on fruit, vegetables, whole grains, and the inclusion of healthful oils in their diets are typically recommended to prevent the progression from prediabetes to diabetes and complications of diabetes. Diets rich in mono- and polyunsaturated fatty acids have been shown to improve cardio-metabolic health in those at risk for or with Type 2 diabetes patients. However, the effect of olive oils on endothelial function (a surrogate marker of cardiovascular risk) in adults at risk for Type 2 diabetes is controversial. Refined olive oils lack important antioxidants and anti-inflammatory properties. Extra virgin olive oils have relatively higher levels of some minor phenolic compounds, and more naturally-occurring minerals and vitamins found in olives, that are essential to improve cardio-metabolic risk factors in those at risk for or with Type 2 diabetes. We propose a prospective, randomized, controlled crossover study to assess the post-prandial effects of extra virgin olive oil, versus post-prandial effects of a refined olive oil, on endothelial function and blood pressure in adults at risk for Type 2 diabetes. Specific Aims To assess the post-prandial effect of extra virgin olive oil on endothelial function, measured as flow mediated dilatation, in adults at risk for Type 2 diabetes. Specifically, to demonstrate at least a 3.5% improvement in endothelial function following the consumption of a meal with 50 mL of extra virgin olive oil, compared with a meal with 50 mL of refined olive oil, in individuals at risk for Type 2 diabetes. To assess the post-prandial effect of extra virgin olive oil on blood pressure in adults at risk for Type 2 diabetes. Specifically, to demonstrate at least 3 mmHg improvements in systolic and diastolic blood pressure after the consumption of a meal with 50 mL of extra virgin olive oil compared with a meal with 50 mL of refined olive oil, in individuals at risk for Type 2 diabetes. Hypotheses Consumption of a meal with extra virgin olive oil compared with a meal with refined olive oil will show superior benefits in endothelial function in adults at risk for Type 2 diabetes. Consumption of a meal with extra virgin olive oil compared with a meal with refined olive oil will show better improvement in blood pressure in adults at risk for Type 2 diabetes.

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