Biomedical subjects

T Magálová

Publications and source records attributed to T Magálová.

16 recordsLinked to original sources

PubMed2000

[Comparison of nutrient intake and corresponding biochemical parameters in adolescent vegetarians and non-vegetarians].

BACKGROUND: In comparison to food habits of non-vegetarians alternative nutrition bears several risks, but it also has beneficial effects. Considering risks represent a significant age aspect. Nutritional risk and protective factors were evaluated in a adolescent group. METHODS AND RESULTS: Food habits of 53 lactoovovegetarians (mean duration of vegetarianism 3.2 y) assessed by analysis of dietary questionnaires were compared to those of 55 nonvegetarians and evaluated with respect to basic biochemical indicators (iron, hemoglobin, calcium, total protein, cholesterol, fatty acids, vitamin A, beta-carotene, vitamin C, vitamin 3). Vegetarians consume less fat, and they have higher intake of plant fat, which is reflected din more favourable lipid levels, i.e. lower risk parameters of atherosclerosis (cholesterol, LDL-cholesterol, atherogenic index, saturated fatty acids) and higher values of factors with antisclerotic effect (32.9% ratio of HDL-cholesterol vs. 30.6% in non-vegetarians, polyunsaturated fatty acids, vitamin E/cholesterol ratio, vitamin C). Total plasma protein levels are balanced in both groups (intake of full value mixture of amino acids from grains, legumes (soya), and mild in vegetarians, similar intake of total proteins with a small difference in plant protein consumption). Iron and calcium absorption is inhibited in vegetarians as a consequence of presence of plant food--physic acid, oxaloacetic acid (20.7% hyposiderinemia vs. 0% in non-vegetarians, high iron intake in both groups, iron from plant sources represented 82% in vegetarian boys and 95% in vegetarian girls, hypocalcemia in 28% of vegetarians vs. 7.3% of non-vegetarians). Vegetarians have significantly higher levels of all antioxidant vitamins. This is result of higher consumption of vegetables, fruit, plant fat and sprouts. Higher intake and higher levels of antioxidants are reflected in significantly lower lipoperoxidation values. CONCLUSIONS: Lactoovovegetarian nutrition represents risk for adolescents if the values of iron and calcium are considered, however it has positive aspects on lipid parameters, protein values, and antioxidant parameters.

Adolescent↗

PubMed2000

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.

Adult↗

PubMed2000

Blood levels of natural antioxidants in gastric and colorectal precancerous lesions and cancers in Slovakia.

A long-term sufficient intake of fruits and vegetables reduces significantly the risk of gastric and colorectal carcinoma. It is anticipated that natural antioxidants are involved in this effect in addition to other substances. The aim of this study was to determine levels of vitamins A, C and E, as well as beta-carotene, selenium, zinc and copper in blood of 249 patients with precancerous lesions (atrophic gastritis, gastric hyperplastic polyp, gastric, colonic and rectal adenoma, chronic ulcerative colitis) and in 96 individuals with gastric, colonic or rectal carcinoma and to compare these levels with the values of a control group of 130 healthy individuals. We have found that the frequency of average values of analyzed micronutrients in precancerous groups was decreasing in the order vit C > vit E/vit A > Se > beta-car. The average levels of vitamins and beta-carotene were significantly reduced in all carcinoma groups, while selenium level showed a decrease only in the gastric carcinoma group. Copper level was elevated in the ulcerative colitis group and in all groups with carcinoma. The results indicate a frequent insufficient saturation of organism by natural antioxidants in groups with precancerous lesions and carcinomas of stomach and colorectum. Therefore, it is necessary to increase the general consumption of fruits and vegetables in Slovakia as a part of primary prevention of malignant diseases in these organs. Chemoprevention may be recommended in individuals with precancerous lesions.

Adult↗

PubMed1999

[Alternative nutrition and glutathione levels].

BACKGROUND: Low protein quality and quantity is reported to be a possible risk of alternative nutrition. Pulses contain 18-41% of methionine in relation to reference protein, moreover, its content in cereals is by one half lower. Therefore vegetarians and vegans may have an insufficient intake of sulphur-containing amino acids that may subsequently affect glutathione values (precursors of its synthesis). METHODS AND RESULTS: In groups of adults on an alternative diet--lactoovovegetarians (n = 47) and vegans (n = 44) aged 19-62 years with average duration on a vegetarian or vegan diet of 7.6 and 4.9 years, respectively, glutathione levels (GSH) were measured in erythrocytes (spectrophotometrically), as well as the activity of GSH-dependent enzymes. As nutritional control (n = 42) served an average sample of omnivores selected from a group of 489 examined, apparently healthy subjects of the same age range living in the same region. One to low protein intake (56% of RDA) exclusively of plant origin significantly lower levels of total proteins were observed in vegans with a 16% frequency of hypoproteinaemia (vs 0% in omnivores). In comparison to omnivores a significantly lower glutathione level was found (4.28 +/- 0.12 vs 4.84 +/- 0.14 mumol/g Hb, P < 0.01). Lactoovovegetarians because of their protein intake in adequate amounts with a 27% proportion of animal proteins (dairy products, eggs) consume a balanced mixture of amino acids, which is reflected in total protein levels similar to omnivores and significantly higher values of glutathione -5.26 +/- 0.12 mumol/g Hb, P < 0.05 (intake of glutathione in diet, higher consumption of fruit and vegetable in comparison to omnivores). A sufficient supply of glutathione as the substrate for enzymatic reactions of hydrogen peroxide or lipid hydroperoxide catabolism, as well as for detoxication of xenobiotics, was reflected in lactoovovegetarians in a significantly higher activity of glutathione-peroxidase and glutathione-S-transferase in erythrocytes. CONCLUSIONS: Low protein intake exclusively of plant origin, significantly lower protein levels with 16% frequency of hypoproteinaemia, significantly lower glutathione values in blood in comparison to omnivores and lactoovovegetarians confirm the risk of a vegan diet also in adult age.

Adult↗

PubMed1999

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 micromol/L in girls and 0.773+/-0.235 micromol/L in boys. A large proportion of the individuals (25.7% in girls, 18.1% in boys) exhibited serum selenium levels under 0.57 micromol/L (45 microg/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.

Adolescent↗

PubMed1999

Copper, zinc and superoxide dismutase in precancerous, benign diseases and gastric, colorectal and breast cancer.

The aim of the present study was to assess serum levels of copper and zinc levels and erythrocytes Cu,Zn-SOD activity and to determine probable changes in gastric and colorectal precancerous diseases, benign breast diseases, gastric, colorectal and breast cancer. The study included 165 subjects with cancer, 348 subjects with precancerous (atrophic gastritis, gastric adenoma, colon adenoma, rectal adenoma) and/or benign diseases (weak dysplasia, severe dysplasia, fibroadenoma, cystic disease) and 161 randomly selected healthy controls. Our results suggest that while in gastric and colorectal cancer there were mostly increased copper levels, in breast cancer they were not changed. Zinc levels were weakly decreased in atrophic gastritis, gastric adenoma and breast cancer. There was a strong positive correlation between zinc levels and SOD activity in fibroadenoma and a weak positive correlation in colorectal adenoma and colorectal cancer without any correlation between SOD activity and copper in these groups. In gastric precancerous disease there was a positive correlation between SOD and copper. The results of this study suggest that serum trace element levels and activity of related enzymes might be different in various neoplastic processes. This variation in neoplastic processes might be influenced by other factors that have to be considered in complex relationships between the whole body and neoplastic cells.

Adult↗

PubMed1998

LDL oxidizability and antioxidative status of plasma in vegetarians.

Vegetarian food with a higher content of natural antioxidants may decrease the risk of developing cardiovascular diseases. The oxidative modification of low-density lipoprotein (LDL) has been implicated in the pathogenesis of atherosclerosis. The objectives of this study were to investigate in vitro resistance of LDL against oxidation and antioxidative status of plasma in 19 lactoovovegetarians and nonvegetarians (n = 19). The kinetics of conjugated diene formation (lag time and maximal rate of oxidation, Vmax) and thiobarbituric acid reacting substances (TBARS) were determined as indices of LDL oxidation. No significant differences in lag time and Vmax were observed between vegetarians and nonvegetarians, while TBARS in native and oxidatively modified LDL were significantly lower in vegetarians. Plasma vitamin (C, E, beta-carotene) levels were increased in vegetarians, but only the vitamin C increase was statistically significant. Vegetarians also had a significantly increased plasma total antioxidant status (TAS) and molar ratio vitamin E/cholesterol which indicates a more effective protection of lipoproteins against oxidation. A significant positive correlation was observed between lag time and plasma TAS in both vegetarians and nonvegetarians. We conclude that although the resistance of LDL to in vitro oxidation, as measured by the kinetics of conjugated diene formation was not altered in vegetarians, the effect of vegetarian nutritional habits favorably affected TBARS levels in LDL and total plasma antioxidant capacity.

Adult↗

PubMed1997

Influence of vegetarian and mixed nutrition on selected haematological and biochemical parameters in children.

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.

Adolescent↗

PubMed1997

[Levels of Cu, Zn, Se and their relation to levels of ceruloplasmin and the activity of antioxidative enzymes].

BACKGROUND: Essential trace elements copper, zinc and selenium are important parts of antioxidant enzymes as superoxide dismutase, glutathione peroxidase as well as of transport protein with antioxidant properties-ceruloplasmin. Mentioned trace elements may affect antioxidant defence system. AIM OF STUDY: The aim of our study was to estimate serum levels of copper, zinc, and selenium in a group of healthy subjects and to correlate them with erythrocyte activity of Cu,Zn-SOD, GSH-Px and serum levels of ceruloplasmin. METHODS: We examined a group of 128 healthy volunteers (57 men and 71 women) aged 20 to 74 years. The analyses of trace elements we performed by atomic absorption spectrophotometry, Cu,Zn-SOD were detected by Randox test, GSH-Px by kinetic method and ceruloplasmin was measured immunoelectrophoretically. RESULTS: We have not found any correlations between investigated trace elements, age and sex. Average serum levels were as follows: copper (17.26 +/- 2.71 mumol/L), zinc (15.30 +/- 1.92 mumol/L), and selenium (0.79 +/- 0.19 mumol/L). There was a weak linear correlation between serum levels of copper and ceruloplasmin. CONCLUSION: There was no relationship between serum copper and zinc levels and Cu,Zn-SOD activity, and serum concentration of selenium and GSH-Px activity in the group of healthy subjects. A moderate linear correlation was estimated between serum values of copper and ceruloplasmin. (Tab. 2, Fig. 4, Ref. 29.)

Adult↗

PubMed1997

[Precancerous conditions and carcinomas of the stomach and colorectum--blood levels of selected micronutrients].

BACKGROUND: Optimal saturation of organism by micronutrients--vitamins and trace elements--has a significant inhibitory effect on the origin and development of malign diseases. OBJECTIVES: The aim of the study was to investigate the blood levels of A, C and E vitamins, Beta-carotene, zinc, and selenium in 249 patients with precanceroses (atrophic gastritis, hyperplastic polyp of the stomach, adenomas of the stomach and colorectum, ulcerative colitis), 96 patients with carcinoma of the stomach or colorectum, and to compare them with a control group of 130 people. RESULTS: We have discovered the frequency of decreased average levels of micronutrients in patients with precanceroses as follows: vitamin C > vitamins E and A > selenium > beta carotene. In all groups of patients with carcinoma the average levels of vitamins and Beta-carotene were significantly decreased, the level of selenium has decreased only in the group of gastric carcinoma. The copper level was increased in the group of ulcerative colitis and in all groups with carcinoma. CONCLUSION: The results indicate that in the primary prevention of these malign diseases it is necessary to improve the levels of the presented micronutrients in the population of the Slovak Republic by increasing the intake of fruit, vegetables and other sources of nutrition, the secondary prevention in persons with precanceroses requires an appropriate intermittent supplementation of micronutrients (chemoprevention). (Tab. 3, Ref. 24.)

Adult↗

PubMed1995

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.

Adult↗

PubMed1995

[Serum selenium levels in children and adolescents in selected regions in Slovakia].

BACKGROUND: There is a limited number of data concerning blood serum selenium levels in children and adolescents in the Slovak Republic. OBJECTIVES: The aim of this study was to access blood serum selenium levels in 102 healthy children (11-14 y) and 122 adolescents (15-18 y) from two regions: The district of Cadca and Modra--Pezinok area. METHODS: Serum selenium was determined by electrothermal atomic absorption spectrophotometric method using Pd as a matrix modifier. RESULTS: The mean (+/- SD) serum selenium concentration was 0.644 +/- 0.154 mumol/l in children and 0.730 +/- 0.175 mumol/l in adolescents. A large proportion of the individuals (28.43% in the children group, vs 14.05% in adolescent group) exhibited serum selenium levels below 0.57 mumol/l (45 micrograms/l). A significant correlation between serum selenium concentration and age (p < 0.001) was found. The correlation between serum selenium concentration and sex was not significant. CONCLUSIONS: In comparison with serum selenium levels in children and adolescents from other countries, the concentration of serum selenium in Slovak children and adolescents is relatively low. This differences could probably be attributed to the selenium content in the soil and to the lower average daily selenium intake via food. (Tab. 5, Fig. 2, Ref. 32).

Adolescent↗

PubMed1995

[Serum levels of vitamins A, C and E in the population of Slovakia].

BACKGROUND: Significant forms of vitamin deficiencies are rare in Slovak Republic, however mild hypovitaminoses are still relatively frequent and they have negative consequences on the functional status. Vitamins A, C and E represent an important part of the antioxidant defense system acting against free-radical damage. Imbalance between oxidative stress and antioxidant capacity which leads to free radical damage is considered to be an aetiological factor of ischaemic heart disease and cancer. OBJECTIVES: The study was focused on assessment of serum levels of vitamins A, C and E in the Slovak population older than 35 y and frequency of decreased levels. Relationship between high prevalence of chronic non-communicable diseases and high frequency of suboptimal levels of antioxidant vitamins is discussed. METHODS: Serum levels of vitamin A and E were assessed by the HPLC method, the levels of vitamin C by the colorimetric method. RESULTS: Mean levels of vitamin A were 1.85 mumol/l in both sexes (95% c.i. 1.75-1.89 in males, 1.77-1.92 in females). Mean level of vitamin C was 31.36 mumol/l in males (95% c.i. 30.06-32.72), the value observed in females was significantly higher (43.05 mumol/l, 95% c.i. 41.75-44.40). Mean level of vitamin E observed in males (29.2 mumol/l, 95% c.i. 27.62-30.87) was only slightly, not significantly higher than in females (28.11 mumol/l, 95% c.i. 26.45-29.87). Decreased levels of vitamin E were observed only in a small proportion of the sample, however almost one third of males had decreased level of vitamin C and more than 20% had low level of vitamin A. We observed high prevalence of serum levels of vitamins A, C and E suboptimal from the aspect of risk of coronary heart disease and cancer (vitamin A: males 78%, females 75.5%, vitamin E: 41.9 and 49.6%, respectively, vitamin C: 61.8% and 41.1%). CONCLUSION: Results indicate that sizeable proportion of population has decreased serum levels of vitamins, males especially of vitamin C and females of vitamin A. According to serum levels of vitamin A, C and E high percentage of population can be ranked into the group with increased risk of CHD and cancer. (Tab. 6, Ref. 29.)

Adult↗

PubMed1994

Comparison of selected nutritional indicators in children in Slovakia in 1988 and 1992.

Selected indicators of nutritional status in children and adolescents assessed in 1988 and 1992 were compared in relation to changed food consumption trends caused by liberalization of food prices. In 1992, 1507 individuals aged 11-18 years were examined and the results were compared with those of children and adolescents of the same age group examined in 1988. Negative changes in food habits are probably the cause of persisting high levels of serum lipids and increasing frequency of hypoascorbinaemia.

Adolescent↗

PubMed1994

[The antioxidant defense system and trace elements].

The survey presents current knowledge on antioxidant defence systems and on the role and meaning of trace elements in these systems. From this point of view the most important elements include transient metal iron and copper, and there after selenium, zinc and manganese. They represent essential components of antioxidant enzymes or transport proteins which participate in intermediation of antioxidant reactions of ceruloplasmin, SOD, GSPx, and catalase. Both deficiency, and in some cases also excess of mentioned trace elements may contribute to oxidative stress. (Tab. 3, Fig. 3, Ref. 27.)

Animals↗

PubMedDate not supplied

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 mumol/L, ranging from 0.219-2.30 mumol/L. A large proportion of the individuals (19.62%) exhibited serum selenium levels under 0.57 mumol/L (45 mumol/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 mumol/L, the highest mean serum selenium (+/- SD) was 0.975 +/- 0.361 mumol/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.

Adult↗