انسیه فلاح نوروزی نژاد

Dietary energy-dense foods predispose to obesity and may be associated with risk of type 2 diabetes; therefore, the aim of our study was to investigate the association between dietary energy density (DED) and the risk of type 2 diabetes. In this matched nested case-control study, 178 new onset cases of diabetes were selected from among participants of the Tehran Lipid and Glucose Study, and followed for over 9 years. Each case was randomly matched with 3 controls from among participants who had not developed diabetes. Dietary intakes were determined using a valid and reliable food frequency questionnaire. DED was calculated as energy intakes (kcal) from foods and beverages divided by the weight (grams) of foods. The mean ages of participants were 43±6.5 and 44.5±12 years, in women and men respectively. Individuals with higher DED had higher calories, total fat, carbohydrate and processed meat intakes and lower fruit and vegetable intakes in men and women (P<0.05). Energy density was positively associated with incident diabetes in women, after adjustment for diabetes risk factors and total calorie intake (OR: 2.28, P trend=0.02) or total fat intake (OR: 2.15, P trend=0.03), an association which was not significant in men. In this nested case-control study, there was positive association between DED and risk of type 2 diabetes in women.

Oxidative stress plays a key role in the pathogenesis of late diabetic complications, the markers of which could be improved by the beneficial effects of legumes. In this randomized crossover trial, 24 overweight subjects, aged 50-80 years, with type 2 diabetes, were selected. We aimed to determine the effects of non-soybean legumes consumption on oxidative stress markers such as ox-LDL (oxidative LDL), MDA (Malonedialdehyde) and TAC (total antioxidant capacity) in type 2 diabetic patients. The subjects were randomly assigned into two groups, receiving two diets – the TLC (controls) or the TLC diet with legumes (receiving 2 servings of legumes instead of meat three days of the week in the TLC diet). Duration of each diet was 8 weeks with a 4 week wash-out period. At the beginning and end of each dietary period, fasting plasma glucose, ox-LDL, MDA, TAC and weight were measured. After the nutritional intervention, diabetic patients, those individuals who followed the legume-based TLC diet had significant reduction in ox- LDL (-3.1±0.5 vs. -0.7±0.4; P=0.003) and MDA (-1.1±0.2 vs. -0.3±0.1; P=0.006), but no change was observed in the TAC and BMI of the case and control groups. The legume-based TLC diet improves oxidative stress markers in diabetic patients, compared to the legume-free TLC diet.