Effect of short-term ketogenic diet on redox status of human blood.

The present study investigated the effect of a ketogenic diet on the blood redox status of healthy female subjects. Twenty healthy females with mean body mass index of 21.45 +/- 2.05 kg/m(2) were provided a low-carbohydrate (55 +/- 6 g; 13% total energy), high-fat (138 +/- 16 g; 74% total energy), calorie-restricted (-465 +/- 115 kcal/d) diet. The followings were tested prior to and after 14 days consumption of the diet: Whole body, body weight and total body fat; blood, complete blood count, red blood cells, white blood cells, hemoglobin, and hematocrit; plasma, 3-beta-hydroxybutyrate, total antioxidative status, and uric acid; red blood cells, total sulfhydryl content, malondialdehyde, superoxide dismutase activity, and catalase activity. After 14 days, weight loss was significant whereas no changes were detected in body fat. No alterations were observed in blood count or morphology. 3-beta-hydroxybutyrate, total antioxidative status, uric acid, and sulfhydryl content were significantly increased. There were no alterations in malondialdehyde, or superoxide dismutase or catalase activity. The present study demonstrates that 14 days of a ketogenic diet elevates blood antioxidative capacity and does not induce oxidative stress in healthy subjects.