The protective effect of the Mediterranean diet on endothelial resistance to GLP-1 in type 2 diabetes: a preliminary report

Abstract

BackgroundIn type 2 diabetes, acute hyperglycemia worsens endothelial function and inflammation,while resistance to GLP-1 action occurs. All these phenomena seem to be related to the generation of oxidative stress. A Mediterranean diet, supplemented with olive oil, increases plasma antioxidant capacity, suggesting that its implementation can have a favorable effect on the aforementioned phenomena. In the present study, we test the hypothesis that a Mediterranean diet using olive oil can counteract the effects of acute hyperglycemia and can improve the resistance of the endothelium to GLP-1 action.MethodsTwo groups of type 2 diabetic patients, each consisting of twelve subjects, participated in a randomized trial for three months, following a Mediterranean diet using olive oil or a control low-fat diet. Plasma antioxidant capacity, endothelial function, nitrotyrosine, 8-iso-PGF2a, IL-6 and ICAM-1 levels were evaluated at baseline and at the end of the study. The effect of GLP-1 during a hyperglycemic clamp, was also studied at baseline and at the end of the study.ResultsCompared to the control diet, the Mediterranean diet increased plasma antioxidant capacity and improved basal endothelial function, nitrotyrosine, 8-iso-PGF2a, IL-6 and ICAM-1 levels. The Mediterranean diet also reduced the negative effects of acute hyperglycemia, induced by a hyperglycemic clamp, on endothelial function, nitrotyrosine, 8-iso-PGF2a, IL-6 and ICAM-1 levels. Furthermore, the Mediterranean diet improved the protective action of GLP-1 on endothelial function, nitrotyrosine, 8-iso-PGF2a, IL-6 and ICAM-1 levels, also increasing GLP-1-induced insulin secretion.ConclusionsThese data suggest that the Mediterranean diet, using olive oil, prevents the acute hyperglycemia effect on endothelial function, inflammation and oxidative stress, and improves the action of GLP-1, which may have a favorable effect on the management of type 2 diabetes, particularly for the prevention of cardiovascular disease.

Weight loss is associated with improvements in cognitive function among overweight and obese people: A systematic review and meta-analysis

“…Weight loss is associated with improvements in multiple metabolic factors (i.e. glucose tolerance, insulin sensitivity, blood pressure, oxidative stress, and inflammation), which have been implicated in the pathogenesis of cognitive impairment and dementia ( Ceriello et al, 2014;Bennett et al, 2009;Schmidt et al, 2002).…”

Improving the scientific rigour of nutritional recommendations for adults with type 2 diabetes: A comprehensive review of the American Diabetes Association guideline‐recommended eating patterns

“…Both studies found longer times to medication requirement in the Mediterranean diet arm versus the low‐fat diet arm, as well as increased partial remission and improved FBG and CVD risk markers. One of two smaller 12‐week RCTs found a statistically significant HbA1c reduction favouring a Mediterranean diet over a typical diet; the other did not find a difference between the Mediterranean diet and a low‐fat diet . Neither of these trials resulted in between‐group statistical significance for CVD risk factor markers including body mass index, blood pressure and lipids, but one found improvement in inflammation markers and flow‐mediated dilation in the Mediterranean diet arm only .…”

Mediterranean Diet and Its Effects on Preventing and Managing Type Two Diabetes: A Literature Review

“…It was acknowledged that the study sample was not a representative study of the general population of patients with T2DM. This limited the external validity of the study [7].…”

“…The diet pattern is characterized by a large consumption of legumes, fruit, vegetables, cereals, fish, olive oil, low intake of saturated fats, low to moderate consumption of dairy products, low meat consumption, and regular to moderate consumption of alcohol, preferably wine [7]. HbA1c levels were available for 262 of the 383 participants.…”