We studied the effect of supplementation with vitamins C, E and beta-carotene (PARABION, produced by Syndipharma) on antioxidative status in kidneys of male Wistar rats with diabetes induced by intravenous application of streptozotocin (45 mg.kg-1 of body weight). The animals received subtherapeutic doses of Insulin Interdep (6 U.kg-1 of body weight). A significant decrease of malondialdehyde (MDA), reduced (GSH) and oxidized (GSSG) glutathione and reduction of the activities of Se-glutathione peroxidase (Se-GSH-PX, EC. 1.11.1.9.) and glutathione S-transferase (GST, EC. 2.5.1.18.) were observed in kidneys of diabetic rats treated with these vitamins. On the contrary, the activity of CuZn-superoxide dismutase (CuZn-SOD, EC. 1.15.1.1) and the level of vitamin C (vit. C) increased significantly. No changes were observed for vitamin E (vit. E), beta-carotene and catalase (CAT, EC. 1.11.1.6). Supplementation with vitamins C, E and beta-carotene resulted in an improvement of antioxidative status of kidneys of rats with streptozotocin-induced diabetes.

To evaluate the health and nutritional status of children with two different nutritional habits, the authors examined 26 vegetarians (lacto- and lacto-ovo; an average period of vegetarianism 2.8 years) and 32 individuals on mixed diet (omnivores) in the age range 11-14 years. Vegetarian children had significantly lower erythrocyte number as well as reduced levels of haemoglobin and iron compared to omnivores. The average level of iron did not reach the lower limit of the physiological range and hyposiderinemia was found in 58% of vegetarians vs 9% of omnivores. Reduced iron levels were observed in spite of increased intake of vegetable iron sources and vitamin C (which facilitates the conversion to ferro-form). This reduction can be attributed to the absence of animal iron sources with high utilizability and to lower iron utilization in the presence of phytic acid (higher intake of grains compared to omnivores). The incidence of hypoalbuminemia and hypoproteinemia in vegetarian children was 38 and 12%, respectively, compared to 0% in omnivores. The protein mixture from milk, eggs and vegetable sources is complete, but vegetarian children had significantly reduced intake of milk and dairy products. Favourable lipid and antioxidant parameters in vegetarian children reflect the optimal nutrition composition with respect to the prevention of free radical diseases. Such a nutrition results in significantly lower levels of cholesterol and LDL-cholesterol compared to omnivores and significantly higher and over threshold values of essential antioxidants--vitamin C, vitamin E/cholesterol (more effective protection against LDL oxidation), beta-carotene, vitamin A.

Selected vitamin (A, C, E, β-carotene) and trace element (selenium, zinc, copper) levels were estimated in the blood of 67 vegetarian nonsmokers aged 34-60 years. The average period of lacto- or lacto-ovovegetarianism was 6.2 years. The results were compared with those of 75 nonvegetarians of the same age and living in the same region. Vegetarians had significantly higher plasma levels of essential antioxidants: vitamin C, β-carotene, and vitamin A. A significantly higher molar ratio vitamin E/cholesterol indicates a more effective protection especially of low-density lipoproteins against peroxidation. Oxidation of low-density lipoproteins represents one of the key factors in the pathogenesis of atherosclerosis. The molar ratio vitamin E/total lipids was significantly higher in plasma of vegetarians, demonstrating a more effective protection of polyunsaturated fatty acids against peroxidation. Vegetarians had significantly higher plasma levels of selenium and similar levels of zinc and copper when compared to nonvegetarians. These trace elements are important for the activity of antioxidant enzymes. The results document a beneficial effect of vegetarian nutritional habits on antioxidative parameters and thus on the reduction of cardiovascular diseases and cancer risk. Reactive products of oxygen metabolism and subsequent toxic products of lipid peroxidation play an important role in the etiology of these diseases.

Parameters of lipid metabolism (triacylglycerols TG, cholesterol CH, HDL-CH, LDL-CH, atherogenic index AI, profile of fatty acids) were measured in blood samples of 81 healthy lacto and lacto-ovo vegetarians (42 males, 39 females; age range 19-39 years). The average period of being on a vegetarian diet was 6.2 years. Low levels of TG, CH, LDL-CH, AI and HDL-CH values on the borderline between standard and reduced risk (1.4 mmol.l-1) can be considered as favourable from the atherosclerosis prevention aspect. Compared with non-vegetarians (n = 62), the levels of TG, CH, LDL-CH, and AI are significantly reduced in the vegetarian group. As opposed to non-vegetarians, vegetarians showed a higher total sum of polyunsaturated fatty acids, a significantly higher content of linoleic acid (C 18:2) and linolenic acid (C 18:3), unchanged content of oleic acid (C 18:1), stearic acid (C 18:0) and other polyunsaturated fatty acids. The process of lipoperoxidation (with polyunsaturated fatty acids as substrate) is involved in the etiology of cardiovascular and oncological diseases. Favourable values of prooxidative-antioxidative parameters demonstrated a reduced risk of lipoperoxidation in vegetarians, compared to non-vegetarians (significantly reduced content of conjugated dienes of fatty acids in plasma, significantly higher plasma levels of vitamin C, beta-carotene, vitamin E/cholesterol ratio--and indicator of LDL protection, vitamin E/triacylglycerols ratio--an indicator of fatty acid protection--, selenium and glutathione-peroxidase activity).

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