Effect of a high monounsaturated fatty acid diet alone or with combined vitamin E and C,or lycopene intake on oxidative stress in patients with type 2 diabetes mellitus

Abstract

The aims of this study were to investigate the effect of a high monounsaturated fatty acid (MUFA) diet alone or with combined vitamin E and C, or lycopene intake on oxidative stress in type 2 diabetes in Saudi Arabia. Forty-eight type 2 diabetic patients consumed a high MUFA diet for 16 weeks. After four weeks of high MUFA diet alone, supplements of vitamins E (400 mg) and C (1,000 mg) were taken for four weeks, followed by a four-week washout period. In the final four weeks, subjects consumed a high MUFA diet with tomato paste (equivalent to 12 mg lycopene). Plasma samples were tested for vitamin E and C, lycopene, malondialdehyde (MDA), total antioxidant status, fasting plasma glucose and glycated haemoglobin A_1c (HbA_1c). A high-MUFA diet with vitamins E and C or lycopene caused significant elevation of plasma vitamins E, C and lycopene compared to a high-MUFA diet alone. Plasma MDA was reduced with vitamins, but not lycopene supplementation. The total antioxidant status increased significantly following a high-MUFA diet and with vitamin and lycopene supplementations. Fasting glucose was not affected whereas HbA_1c decreased significantly after vitamin supplementation compared to baseline. A high-MUFA diet supplemented with vitamin E and C, or lycopene improves antioxidant status in type 2 diabetes.