Katarina Babinska

Homocysteine Levels in Vegetarians versus Omnivores

Vitamin B12, folate, and vitamin B6 are the main determinants of homocysteinemia. The vegan diet provides no vitamin B12, but also less strict forms of alternative nutrition may suffer from a deficit of this vitamin. The plasma homocysteine level was measured in alternative nutrition groups of adults (lacto- and lactoovovegetarians, n = 62; vegans, n = 32) and compared with the levels in a group consuming traditional diet (n = 59), omnivores). In the group of vegetarians the average homocysteine level is 13.18 vs. 10.19 μmol/l in omnivores; the frequency of hyperhomocysteinemia is 29 vs. 5% in omnivores. In the group of vegans the average homocysteine value is 15.79 μmol/l (53% of the individual values exceeded 15 μmol/l). Omnivores consume the recommended amount of methionine; however, in individuals consuming an alternative diet, the intake of methionine is deficient (assessed by food frequency questionnaire; lower content of methionine in plant proteins). Under conditions of lower methionine availability the remethylation pathway prevails; therefore, vitamin B12 and folate were evaluated in relation to the homocysteine level. The serum vitamin B12 levels are significantly lower in the alternative nutrition groups (214.8 pmol/l in vegetarians, 140.1 pmol/l in vegans vs. 344.7 pmol/l in omnivores); a deficit (<179.0 pmol/l) was found in 26% of the vegetarians and in 78% of the vegans vs. 0% in omnivores. The serum folate levels were within the range of reference values in all groups; however, they were significantly lower in omnivores. The results show that the mild hyperhomocysteinemia in alternative nutrition is a consequence of vitamin B12 deficiency.

Selected Vitamins and Trace Elements in Blood of Vegetarians

Selected vitamin (A, C, E, beta-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, beta-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.

Ubiquinol Improves Symptoms in Children with Autism

Background. Autism is a spectrum of neurodevelopmental disorders with manifestation within 3 years after birth. Manifestations of autism include behavior problems (hyperactivity, toys destruction, self-harm, and agression) and sleep and eating disorders. Etiology of autism is poorly understood. Oxidative stress and antioxidants can participate in pathobiochemical mechanisms of autism. Methods. Twenty-four children, aged 3–6 years, with autism according to the DSM IV criteria and using CARS were included in the study. Concentrations of CoQ10−TOTAL, γ- and α-tocopherol, β-carotene, and lipid peroxidation were determined in plasma before and after three months of supportive therapy with ubiquinol at a daily dose 2 × 50 mg. Data on behavior of the children were collected from parents at the same time. Results. Ubiquinol supportive therapy improved symptoms in children with autism, as communication with parents (in 12%), verbal communication (in 21%), playing games of children (in 42%), sleeping (in 34%), and food rejection (in 17%), with CoQ10−TOTAL plasma level above 2.5 μmol/L. Conclusions. Beneficial effect of ubiquinol in children with autism has been demonstrated for the first time. We assume that plasma concentration of CoQ10−TOTAL and lipid peroxidation could be used as relevant biomarkers of ubiquinol supportive therapy.

Traditional and alternative nutrition - levels of homocysteine and lipid parameters in adults.

Values of homocysteine and lipid parameters were measured in groups of adults consuming alternative nutrition (vegetarians/lactoovo/, vegans) and compared with a group consuming traditional diet (omnivores, general population). Frequency of hyperhomocysteinemia was 53% in the vegans group, 28% in vegetarians vs. 5% in omnivores. In conditions of lower methionine intake (reduced content in plant proteins), the remethylation pathway of homocysteine metabolism prevails and it is vitamin B12 and folate-dependent. The intake of vitamin B12 is equal to zero in vegans; vegetarians consume 124% of the RDA vs. 383% in omnivores. Serum vitamin levels are significantly lower in subjects consuming alternative nutrition with deficiency observed in 24% of vegetarians, 78% of vegans vs. 0% in omnivores. Serum folate levels are within the reference range in all groups. Mild hyperhomocysteinemia in the groups consuming alternative diet is a consequence of vitamin B12 deficiency. Vegetarians and vegans meet the RDA for energy and fat, and have a favourable proportion of saturated, mono- and polyunsaturated fatty acids on total energy intake; the ratio of linoleic/alpha-linolenic acid in their diet corresponds with the recommendations. They have low cholesterol consumption and higher vitamin E and C intake. Optimal fat intake of correct composition is reflected in lower values of atherosclerosis risk factors (cholesterol, LDL-cholesterol, atherogenic index, saturated fatty acids, triacylglycerols), and significantly higher levels of protective substances (linoleic acid, alpha-linolenic acid, HDL-cholesterol, vitamin E, vitamin E/cholesterol, vitamin C). Low lipid risk factors but higher findings of mild hyperhomocysteinemia in vegetarians mean a diminished protective effect of alternative nutrition in cardiovascular disease prevention.

Serum Selenium Levels in Slovak Population

Blood serum selenium levels were measured in 576 healthy middle aged adults (40–60 yr, 255 men and 321 women) residing in both urban and rural areas in four districts of Slovakia. Serum selenium was determined by electrothermal AAS. The mean (±SD) serum selenium concentration was 0.852±0.335 μmol/L, ranging from 0.219–2.30 μmol/L. A large proportion of the individuals (19.62%) exhibited serum selenium levels under 0.57 μmol/L (45 μmol/L). There was no significant correlation between serum, selenium concentration and age, sex, and smoking status. There were significant differences between districts. The lowest mean (±SD) serum selenium was 0.664±0.269 μmol/L, the highest mean serum selenium (±SD) was 0.975±0.361 μmol/L. This differences could probably be attributed to the selenium, content in the soil of the different areas, which would contribute to the average daily selenium intake. In comparison with serum selenium levels in other European countries, the concentrations of selenium in the Slovak population are relatively low.

ZINC AND COPPER IN BREAST CANCER

Present incidence of breast cancer as well as its ratio to all cancer ranks Slovakia to European countries with high and still increasing incidence of breast cancer. Mortality rates became stabilised in the recent time but evidently increasing incidence of breast cancer is observed especially in lower age groups. Zinc and copper are essential trace elements that play important roles in different biochemical reactions. Relevance of zinc to cellular growth is well known. In recent years, their disbalances were linked to chronic disease etiology due to antioxidant properties. Moreover, zinc affects immunological properties and acts together with copper as cofactor of Cu, Zn-superoxide dismutase (SOD). This enzyme protects cells and their important components against free radical damage.

Serum PCB concentrations in relation to locally produced food items in eastern Slovakia

Ingestion has been a primary route of PCB exposure for people, especially those not working directly in industrial settings. During 2002–2004, women were recruited at delivery from two districts in eastern Slovakia: Michalovce with high PCB contamination from a chemical manufacturing plant, and Svidnik located 70 km to the northwest, having lower environmental levels of PCBs. Concentrations of 15 PCB congeners were measured in maternal serum using high-resolution gas chromatography with electron capture detection. A food frequency questionnaire was developed and validated at the Research Institute of Nutrition and School of Medicine in Bratislava, Slovakia. The questionnaire was comprised of 88 food items representative of the national dietary habits and designed to ascertain (1) the source of food items as reported by the women (locally produced or purchased from a retail outlet) and (2) quantities consumed of high-fat food categories representative of the national dietary habits. Our primary goal was to identify specific food sources, either locally produced or purchased from retail stores, that might predict serum concentrations of PCBs. We used multiple linear regression to examine the relationship of dietary fats to lipid-adjusted serum PCB levels in 948 adult women (Michalovce N=662, Svidnik N=284) who had recently given birth. We adjusted for residential district, age, body mass index, education and duration of previous lactation. Consumption of fat from locally produced foods was significantly associated with higher levels of lipid-adjusted serum PCB (β=0.06, P=0.007). Fat from foods purchased in retail outlets showed no significant association (β=−0.02, P=0.36). There was no interaction between district and diet in predicting serum PCB levels. Comparing women in Michalovce consuming 20 g of fat per day from local sources with those consuming 1 g of fat per day from local sources, lipid-adjusted serum concentrations were predicted to be higher by 81 ng/g lipid or 14.8% 630 ng/g lipid versus 549 ng/g lipid.

Levels of lipid peroxidation and antioxidants in vegetarians

Age dependence of lipid peroxidation levels estimated as conjugated dienes (CD) of plasma fatty acids was investigated in vegetarian and non-vegetarian males and females aged 11–14, 15–18, 19–39 and 40–60 years. The increase of CD levels with age was found in probands on both types of nutrition up to the age of 40 years. In the first three age groups, lipid peroxidation was insignificantly lower in vegetarians when compared to nonvegetar-ians. The increase of conjugated dienes was on the level of significance (p<0.05) in the oldest vegetarians vs nonvegetarians. Therefore, content of defense parameters — antioxidative vitamin and enzyme — was estimated in blood of vegetarians aged 40–60 years. Significantly higher levels of vitamin C and catalase activity were found in vegetarians (C — 63.6 and 86.5 µmol/1; CAT — 1497 and 1313 U/ml for males and females, respectively) when compared to nonvegetarians (C — 41.3 and 54.4 µmol/1; CAT — 1192 and 1086 U/ml). A significant negative linear correlation (p<0.001) for CD-C and CD-CAT was found in both sexes of vegetarians and in nonvegetarian females (p<0.05 for nonvegetarian males). Important finding is a more pronounced in vegetarians (2.5–3.4 times higher slope of regression lines) indicating positive effect of vegetarian nutrition on efficiency of protection system.

SERUM SELENIUM LEVELS IN HEALTHY SLOVAK CHILDREN AND ADOLESCENTS

Blood serum selenium levels were measured in 891 healthy children and adolescents (aged 11–18 yr, 450 girls and 441 boys) residing in both rural and urban areas from eight regions of Slovakia. Subjects were divided into four age groups (11–12 y, 13–14 y, 15–16 y, and 17–18 y). Serum selenium concentration was determined by the electrothermal atomic absorption spectrometric method. The mean (±SD) serum selenium concentrations were 0.750 ±0.255 µmol/L in girls and 0.773 ±0.235 µmol/L in boys. A large proportion of the individuals (25.7% in girls, 18.1% in boys) exhibited serum selenium levels under 0.57 µmol/L (45 µg/L). An increasing trend of the serum selenium values with age has been observed in both boys (p < 0.01) and girls (p < 0.05). Boys had higher serum selenium levels in the all age groups but the differences were not statistically significant.

Demographic, Reproductive, and Dietary Determinants of Perfluorooctane Sulfonic (PFOS) and Perfluorooctanoic Acid (PFOA) Concentrations in Human Colostrum.

To determine demographic, reproductive, and maternal dietary factors that predict perfluoroalkyl substance (PFAS) concentrations in breast milk, we measured perfluorooctane sulfonic (PFOS) and perfluorooctanoic acid (PFOA) concentrations, using liquid chromatography-mass spectrometry, in 184 colostrum samples collected from women participating in a cohort study in Eastern Slovakia between 2002 and 2004. During their hospital delivery stay, mothers completed a food frequency questionnaire, and demographic and reproductive data were also collected. PFOS and PFOA predictors were identified by optimizing multiple linear regression models using Akaikes information criterion (AIC). The geometric mean concentration in colostrum was 35.3 pg/mL for PFOS and 32.8 pg/mL for PFOA. In multivariable models, parous women had 40% lower PFOS (95% CI: -56 to -17%) and 40% lower PFOA (95% CI: -54 to -23%) concentrations compared with nulliparous women. Moreover, fresh/frozen fish consumption, longer birth intervals, and Slovak ethnicity were associated with higher PFOS and PFOA concentrations in colostrum. These results will help guide the design of future epidemiologic studies examining milk PFAS concentrations in relation to health end points in children.