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Biomedical subjects

B Sandström

Publications and source records attributed to B Sandström.

At least 73 records · Page 4Linked to original sources

Changes in blood manganese levels during pregnancy in iron supplemented and non supplemented women.

Blood manganese levels and iron status indices were determined each trimester in 66 healthy pregnant women. Twenty-five were randomly assigned to iron supplementation, 19 to placebo and 22 received dietary advise aimed at increasing their dietary intake of fibre. Iron supplemented women had significantly higher levels of blood haemoglobin compared to the levels of the two other groups, and higher serum ferritin levels compared to the placebo group. No significant difference in blood manganese levels was observed among the three groups of women. There was a significant increase in blood manganese levels from one trimester to the next, which was slightly more pronounced in non supplemented women. The median values in the three trimesters were 154 (range 79-360) nmol/L, 190 (range 98-408) nmol/L, and 230 (range 133-481) nmol/L, respectively. Pregnancy seems to change manganese status or otherwise influence manganese metabolism irrespective of iron status and iron supplementation.

Adult↗

A Nordic project--risk evaluation of essential trace elements: essential versus toxic levels of intake.

A risk evaluation of essential and toxic intake of trace elements has been performed by a group within the Nordic Collaboration on food questions. Six elements have been evaluated: selenium, iron, iodine, chromium, copper and magnesium and small safety margins between potentially deleterious and beneficial intakes were revealed. The risk evaluation, which will be published in early 1995, will be used as a background document in the revision of the Nordic Nutrition Recommendations.

Humans↗

Consideration in estimates of requirements and critical intake of zinc. Adaption, availability and interactions.

In order to establish an adequate and safe dietary intake of zinc, several specific features of zinc metabolism have to be considered. Lacking sensitive indices of zinc status, estimates of zinc requirement have to be based on the factorial method, i.e., measurements of the daily losses of zinc via skin, intestine and kidney. The body maintains zinc homeostasis at different levels of zinc intake by changes in zinc absorption and excretion. After longer periods of a low zinc intake, daily inevitable zinc losses can be estimated to be approximately 1 mg, while at higher intakes losses are substantially higher. To translate physiological requirements to dietary requirement the availability of zinc has to be considered. From diets with a high content of phytate, less than 15% is typically absorbed while in refined animal protein based diets up to 40% is adsorbed. This means that that dietary requirement can very from < 5- > 15 mg d-1. Zinc shows a low toxicity, but high doses of zinc interact with other trace elements, especially copper. (These interactions have already been observed at an intake of 50 mg.) Thus, the range between essential and potential deleterious intake of zinc is rather narrow.

Adaptation, Physiological↗

The influence of trans fatty acids on health: a report from the Danish Nutrition Council.

Trans fatty acids constitute 0-30% of the fat in Danish margarines, most in industry and bakery margarines and usually less in table margarine. The trans fatty acids make margarines more solid at room temperature and therefore provide an economical storage advantage. In British and U.S. reports from 1984-1989, the trans fatty acids were more or less acquitted of unhealthy effects. During the last 5-6 years, however, a series of new studies has been published regarding both the connection between the consumption of trans fatty acids and the occurrence of coronary heart disease and the impact on the lipoprotein level in plasma. Studies suggest that the consumption of trans fatty acids from margarine is equally, or perhaps more, responsible for the development of arteriosclerosis than saturated fatty acids. In addition, it is now clear that both the fetus and the breast-fed baby are exposed to trans fatty acids in relation to the mother's consumption. A couple of recent studies suggest a possible restrictive influence of the trans fatty acids on the weight of the fetus. The average consumption of trans fatty acids from margarine in Denmark in 1991 was approximately 2.5 g/day per person. For about 150,000 adult Danes, the consumption is assumed to be more than 5 g/day per person. On this basis, the Danish Nutrition Council recommend that the consumption of trans fatty acids is reduced as much as possible. This can be done by reducing the fat content in food and by reducing the trans fatty acid content in all Danish margarine products to 5% or less. Thereafter, the group of adult Danes, including pregnant and breast-feeding women, with a large consumption of margarine and margarine-containing products, will on average only consume 2 g of vegetable trans fatty acids/day. This corresponds to the consumption in the low-risk groups in the above-mentioned epidemiological studies. In addition, the Danish Nutrition Council encourage the producers of margarines to make products that can be marketed as 'free of trans fatty acids'.

Adult↗

Erythrocyte levels compared with reported dietary intake of marine n-3 fatty acids in pregnant women.

It is well established that marine n-3 fatty acids measured in erythrocyte phospholipids of non-pregnant subjects reflect the subjects' intake of these fatty acids. In 135 pregnant women in the 30th week of gestation we compared intake of marine n-3 fatty acids and energy, estimated by a combined dietary self-administered questionnaire and interview, with fatty acids measured in erythrocyte phospholipids. Daily intake (g/d) and nutrient density of marine n-3 fatty acids (mg/MJ) correlated with the n-3 fatty acid: arachidonic acid ratio (FA-ratio) with correlation coefficients of 0.48 and 0.54 respectively. In a linear regression model with three frequency questions about marine sandwiches, marine cooked meals and fish oil as explanatory variables, and the FA-ratio as dependent variable, the multiple correlation coefficient was 0.46. Conclusions from the study were (1) levels of erythrocyte fatty acids in pregnant women may be employed as a qualitative method to rank subjects according to intake of marine n-3 fatty acids; (2) with respect to the power to explain FA-ratio variability, three simple marine food frequency questions were comparable with intake of marine n-3 fatty acids assessed by an elaborate semiquantitative dietary method involving an interview.

Adult↗

Gestation length and birth weight in relation to intake of marine n-3 fatty acids.

It has been hypothesized that marine n-3 fatty acids ingested during pregnancy prolong duration of pregnancy and increase fetal growth rate in humans. By a combined self-administered questionnaire and interview applied in the 30th week of gestation we assessed dietary intake of marine n-3 fatty acids and energy in a population-based sample of 965 pregnant Danish women; in a random 14% subsample we also measured marine n-3 fatty acids relative to arachidonic acid (FA-ratio) in erythrocytes. Mean intake of marine n-3 fatty acids was 0.25 (95% range 0-0.75) g/d. We could detect no association between n-3 fatty acid intake and FA-ratio on the one hand, and gestation length, birth weight and birth length on the other. The analyses were adjusted for maternal height, prepregnant weight, parity and smoking. The conclusion from the study was that within the intake range of this population, marine n-3 fatty acids ingested in the weeks prior to the 30th week of pregnancy seem not to be a predictor of gestation length or fetal growth rate.

Adult↗

Zinc absorption in adult humans: the effect of iron fortification.

The effect of Fe fortification on the absorption of Zn was studied by radioisotopic labelling of single meals, followed by measurements of whole-body retention of 65Zn at 14 d after intake. Healthy adult volunteers participated in the study. Weaning cereal, wheat bread and infant formula, foods that are all frequently Fe-fortified, were evaluated in the study. The amounts of Fe added as FeSO4 were similar to the levels in commercial products in Europe and the USA, and were 200 or 500 mg Fe/kg (weaning cereal), 65 mg Fe/kg (white wheat flour) and 12 mg Fe/l (infant formula). For comparison, Zn absorption was measured in the same subjects, from identical test meals containing no added Fe. No statistically significant differences were found when Zn absorption from the Fe-fortified test meals was compared with that from non-Fe-fortified test meals. Fractional Zn-absorption values from Fe-fortified v. non-fortified meals were 31.1 (SD 11.9) v. 30.7 (SD 7.0)% (weaning cereal; 200 mg Fe/kg), 37.7 (SD 16.6) v. 30.2 (SD 9.9)% (weaning cereal; 500 mg Fe/kg), 36.5 (SD 14.4) v. 38.2 (SD 18.1)% (bread; 65 mg Fe/kg flour) and 41.6 (SD 8.1) v. 38.9 (SD 14.5)% (infant formula; 12 mg Fe/l). The addition of Fe to foods at the currently used fortification levels was thus not associated with impaired absorption of Zn and the consumption of these Fe-fortified foods would not be expected to have a negative effect on Zn nutrition.

Adult↗

Biomarkers of habitual fish intake in adipose tissue.

The association between habitual fish and marine n-3 polyunsaturated fatty acid (PUFA) intake, and the fatty acid composition of subcutaneous fat was studied in 24 healthy young volunteers. Habitual dietary intakes were estimated from three 7-d weighted food records made at months 0, 5, and 8 of the 8-mo study period. The adipose tissue fatty acid composition of each individual was determined by gas chromatography as the mean of two gluteal biopsies, obtained in the first and the last month of the study. The daily consumption of fish and of marine n-3 PUFAs in absolute terms (g/d) was significantly associated with adipose tissue docosahexaenoic acid content (DHA; r = 0.55 and 0.58, respectively, P < 0.001), but not with eicosapentaenoic and docosapentaenoic acid contents. Our study indicates that the adipose tissue DHA content is the biomarker of choice for the assessment of long-term habitual dietary intakes of fish and marine n-3 PUFAs.

Adipose Tissue↗

Zinc absorption estimated by fecal monitoring of zinc stable isotopes validated by comparison with whole-body retention of zinc radioisotopes in humans.

Knowledge about zinc availability from human diets is limited due to methodological difficulties. Recently developed stable isotope techniques for estimating dietary zinc absorption were compared with radioisotope techniques in five men and three women. Stable and radioactive zinc isotopes were simultaneously administered. Fecal excretion of the isotopes as well as whole-body retention of the radioactive zinc isotope was monitored. Concentration of stable zinc isotope label in fecal samples was determined by inductively coupled plasma mass spectrometry by fully quantitative measurements and from inductively coupled plasma mass spectrometry isotope ratios combined with analysis of total zinc content using atomic absorption spectrometry. Zinc absorption estimated from whole-body retention was 27 +/- 6% (mean +/- SD), estimated zinc absorption obtained by fecal monitoring of radioisotope was 26 +/- 9%, and the two stable zinc measurements resulted in values of 29 +/- 12 and 33 +/- 12%, respectively. There was no significant difference in zinc absorption estimated from whole-body retention and with the fecal monitoring methods. Recovered stable zinc isotope label was significantly lower than recovered radioisotope. For individual fecal samples, systematic differences of 16% and 12%, respectively (P < 0.05), between the radioisotope recovery and the recovery of stable isotopes with the two methods for measurement was observed. The stable zinc isotope technique for measurement of zinc absorption resulted in mean results similar to those of the radioisotope technique, but with a larger variation in the measurements.

Adult↗

Effect of fats high in individual saturated fatty acids on plasma lipoprotein[a] levels in young healthy men.

Plasma lipoprotein[a] (Lp[a]) is associated with atherogenesis and thrombogenesis. We examined how plasma Lp[a] in healthy young men was affected by fats high in stearic (C18), palmitic (C16), and lauric+myristic (C12+ C14) acid (experiment I, 15 subjects), and by fats high in myristic (C14) and palmitic (C16) acid (experiment II, 12 subjects). Strictly controlled isocaloric diets with 36% of energy from test fats were served in random order for 3 weeks separated by wash-out period(s). Diets high in C18 gave significantly higher levels of Lp[a] (51(12-560) mg/L) than diets high in C16 (38(12-533 mg/L) (P = 0.020) and C12 + C14 (34(12-534) mg/L) (P = 0.002). These differences were observed in several of the subjects in experiment I. In experiment II we saw no difference in plasma Lp[a] after diets high in C16 and C14. Our observations suggest that a fat high in stearic acid might affect Lp[a] in a different way than fats high in palmitic and myristic+lauric acid. Lp[a] concentrations were not associate with changes in tissue-plasminogen activator (t-PA) activity, factor VII coagualant activity, or plasma LDL cholesterol.

Adult↗

Dietary changes in fasting levels of factor VII coagulant activity (FVII:C) are accompanied by changes in factor VII protein and other vitamin K-dependent proteins.

The mechanisms behind dietary effects on fasting coagulant activity of factor VII (FVII:C) are not clarified. In the present study of 15 young volunteers, two experimental diets differing in composition of saturated fatty acids (C18:0 [diet S] or C12:0 + C14:0 [diet ML]) were served for 3 weeks each. Fasting blood samples were collected before and after the dietary regimen and analysed for triglycerides, FVII:C, and protein concentrations of FVII, FII, FX, protein C, CRP, albumin, fibrinogen, and F1 + 2. FVII:C was significantly reduced on diet S compared with diet ML. This was accompanied by a decrease in FVII protein, F1 + 2 and the vitamin K-dependent proteins FII, FX, and protein C. In contrast, no changes were observed in triglycerides, FVII:C/FVII:Ag, albumin and CRP. Fibrinogen was increased on diet S compared with diet ML. Our findings suggest that the change in fasting FVII:C was part of a general change in concentrations of vitamin K-dependent proteins.

Adult↗

Spontaneous weight loss during 11 weeks' ad libitum intake of a low fat/high fiber diet in young, normal weight subjects.

OBJECTIVE: During the first 11 weeks of 8 months' ad libitum intake of a low fat/high fiber diet (25.5 energy-% fat, 58.5 energy-% carbohydrate, 3.9 g dietary fiber/MJ) primarily aimed at investigating the effect on blood lipids, spontaneous, unintended body weight changes occurred. The objective of the present paper was to elaborate the analyses on changes in body weight and composition during the 11 weeks' intervention period. MEASUREMENTS: Dietary intake, body weight and composition. SUBJECTS: Subjects in the intervention (I) (n = 24) and control group (C) (n = 24) were normal weight, young, healthy students. RESULTS: In the intervention group an overall decrease in body weight (-1.3 +/- 0.4 kg) (mean +/- s.e.m.) (P < 0.01) and fat mass (-1.6 +/- 0.2 kg, P < 0.001) occurred. Fat free mass remained unchanged (0.1 +/- 0.3 kg, n.s.). Subjects with the initially lowest level of body fat (n = 10) gained fat-free mass (0.6 +/- 0.2 kg) (n.s.) and lost fat mass (-0.9 +/- 0.2) (P < 0.01). In the intervention group initial body weight and fat mass correlated significantly to change in body weight (r = -0.59, P = 0.003 and r = -0.53, P = 0.008) and fat mass (r = -0.52, P = 0.01, and r = -0.50, P = 0.01). No changes were observed in the control group. CONCLUSION: The ad libitum intake of a low fat/high fiber diet lead to a spontaneous loss of body weight and fat mass in young, normal weight subjects.

Adult↗

[The effect on health of dietary antioxidants and antioxidant supplements].

Reactive free oxygen radicals are formed in the reactions involved in normal cell metabolism. This formation is closely regulated e.g. by dietary antioxidants. Present knowledge suggests that an imbalance, with surplus of free radicals, can play a role in the pathogenesis of certain types of cancer, atherosclerosis, and cataract. A number of epidemiological studies have demonstrated a reduced risk of developing these diseases in persons who consume a diet with a high content of vegetables and fruit, which contains large quantities of the antioxidants: beta-carotene, vitamins C and E. Intervention studies, using supplements of these antioxidants, have so far not been able to show a beneficial effect. The apparently protective effect of fruit and vegetables may be due to other active ingredients. In Denmark the average intake of vegetables and fruit is low, and it is estimated that an increased consumption of these foods could reduce the occurrence of certain cancer types and atherosclerosis. In contrast, there is no evidence that antioxidant supplements would provide protection against disease, and their safety remains to be established.

Antioxidants↗

[Significance of trans-fatty acids for health].

Trans fatty acids make up 0-30% of the fatty acids in Danish margarines. The intake of trans fatty acids from margarine in Denmark was in 1991 on average about 2.5 gram/person/day, and for about 150,000 Danes more than 5 gram/person/day. Several recent case-control studies and a large cohort study as well as clinical ward studies suggest that the intake of trans fatty acids enhances atherogenesis to the same extent or possibly even more than saturated fatty acids. In addition a few studies suggest that the intake of trans fatty acids by the pregnant mother impairs growth of the human foetus. On this background it seems reasonable to reduce the intake of trans fatty acids as much as possible. This could be implemented by a reduction in the fat content of the diet together with a reduction of trans fatty acid content to less than 5% in all margarines. This would ensure that Danes--including pregnant and nursing women--with a high intake of margarine on average consume less than 2 gram of trans fatty acids of vegetables origin per day. This amount corresponds to intake in low risk groups in several studies.

Denmark↗

Acrodermatitis enteropathica, zinc metabolism, copper status, and immune function.

OBJECTIVE: To study zinc metabolism, copper status, and immune function in a patient with acrodermatitis enteropathica. RESEARCH DESIGN: Case report. PATIENT: A 16-year-old boy with acrodermatitis enteropathica. INTERVENTION: Change of zinc supplementation dosage from 1000 to 525 mumol/d. MEASUREMENTS AND RESULTS: Zinc metabolism was studied with an oral dose of zinc chloride Zn 65 and whole-body counting at both zinc dosages. Zinc, copper status, and immune indexes were also measured at both dosages. The higher dosage of zinc supplementation was found to induce a state of low copper status and immune dysfunction. Lowering the dosage normalized these indexes. Zinc absorption in this patient was found to be within the reference range for healthy subjects. At the lower dosage, zinc retention and the rate of whole-body turnover also normalized. These results suggest that the primary lesion in acrodermatitis enteropathica is a cellular defect in zinc metabolism rather than an impairment of zinc absorption. CONCLUSION: Zinc and copper status and immune function should be monitored regularly in patients with acrodermatitis enteropathica to provide a proper dosage of zinc during different physiologic stages.

Acrodermatitis↗

Exogenous catalase introduced in CHO cells by electroporation does not protect against chromosome damage induced by ionizing radiation.

The relative importance of hydrogen peroxide generated as a consequence of irradiation with X-rays for the production of chromosomal aberrations has been studied in cultured CHO cells. Catalase introduced into cells by electroporation protected DNA from strand breakage induced by hydrogen peroxide given 4h later, and the yield of chromosome aberrations was also reduced. Nevertheless, when the cells were irradiated after treatment with catalase following a similar protocol and the yield of chromosomal aberrations analyzed at metaphase, no protective effect was observed as compared with cells treated with X-rays alone. These observations seem to support the hypothesis that hydroxyl radicals generated from hydrogen peroxide are not a major factor responsible for chromosome damage induced by ionizing radiation.

Animals↗