Effects of Green-Leafy Vegetable Intake on Postprandial Glycemic and Lipidemic Responses and ^|^alpha;-Tocopherol Concentration in Normal Weight and Obese Men

Abstract

Summary Vegetable consumption has been encouraged as a component of nutritional education for obese and insulin-resistant patients. However, the benefits of vegetable intake in a therapeutic diet on postprandial glycemic and lipidemic responses have not been clarified. We studied the effects of the intake of spinach, a green-leafy vegetable rich in dietary fiber and a-tocopherol, with a fat-rich meal on postprandial glycemic and lipidemic changes. Fourteen normal weight and 10 obese men consumed three test meals of bread, as a control, bread and butter, and bread and butter with boiled spinach. Blood samples were obtained prior to and 30, 60, 120, 180 and 240 min after consuming the test meals. Compared with the bread meal, consumption of the bread and butter meal showed a reduced peak glucose response at 30 min in normal (p,0.05) but not in obese subjects. The increase in triglyceride and decrease in LDL-cholesterol were greater after the butter-containing meal than after the bread meal (p,0.05). The a-tocopherol/lipid level decreased and remained low after the bread and butter meal, but the decrease was smaller with the spinach-containing meal in obese subjects (p,0.05). These results suggest that green-leafy vegetable intake with a fat-rich meal is effective for supplying postprandial a-tocopherol in obese subjects, but consumption of a regular-sized dish cannot be expected to improve abnormal postprandial hyperglycemic or hyperlipidemic responses.

The effects of hydroalcoholic extract of spinach on prevention and treatment of some metabolic and histologic features in a rat model of nonalcoholic fatty liver disease

“…Spinach thylakoids can also increase the secretion of GLP‐1, which is an incretin hormone and induces insulin secretion . The effects of spinach and thylakoids on insulin have been very inconsistent in previous studies . There were no significant differences in serum insulin in our study but an improvement in the HOMA‐IR index indicates that spinach extract ameliorated insulin resistance.…”

The Metabolic Concept of Meal Sequence vs. Satiety: Glycemic and Oxidative Responses with Reference to Inflammation Risk, Protective Principles and Mediterranean Diet

“…A focus on the acute meal effect is important, due to the fact that in the modern world, people are increasingly found to be in a ‘postprandial’ state, resulting from increasing exposure to eating opportunities throughout the day, propagating the effects of western meals on cumulative metabolic trends [222]. Addressing these key related factors has already been shown to favourably affect postprandial outcomes [23,126,215,223,224].…”

“…Notably, some aspects of the three axes are quite consistent with one another, as demonstrated by the composite pyramid (Figure 4). For example, vegetables being first, due to their combined contribution of high satiating potential [64], antioxidative capacity [223] and reduced glycaemic impact [224]. Further food qualities, including whole food structure and selected components e.g., fibre and phytonutrients, and recommended preparation methods such as light cooking, together with a variety of plants, herbs, olive oil and spices, all positively influence the three axes.…”

Research update for articles published in EJCI in 2012

“…Indeed, a recent paper showed that hypocaloric diet and regular moderate exercise are effective in reducing oxidative stress along with weight loss in obese patients . In addition, it has been shown that consumption of green leafy vegetables, together with a fat‐rich meal, improves antioxidant defences in obese subjects : vegetable consumption has been encouraged as a component of nutritional education for obese and insulin‐resistant patients.…”