Comparison of the portion size and frequency of consumption of 156 foods across seven European countries: insights from the Food4ME study.

There are no standardised serving/portion sizes defined for foods consumed in the European Union (EU). Typical serving sizes can deviate significantly from the 100 g/100 ml labelling specification required by the EU legislation. Where the nutritional value of a portion is specified, the portion size is determined by the manufacturers. Our objective was to investigate the potential for standardising portion sizes for specific foods, thereby ensuring complementarity across countries. We compared portion size for 156 food items measured using a food frequency questionnaire across the seven countries participating in the Food4me study. The probability of consuming a food and the frequency of consumption differed across countries for 93% and 58% of the foods, respectively. However, the individual country mean portion size differed from the average across countries in only 16% of comparisons. Thus, although dietary choices vary markedly across countries, there is much less variation in portion sizes. Our results highlight the potential for standardisation of portion sizes on nutrition labels in the EU.

Plasma sulfur amino acids and stearoyl-CoA desaturase activity in two Caucasian populations.

In rats, dietary restriction of the cysteine precursor methionine suppresses hepatic stearoyl-CoA desaturase (SCD)-1 expression and activity, whereas cysteine supplementation reverses these effects. In 2 independent cohorts: Hordaland Health Study (HUSK; N=2021, aged 71-74y), Norway, and Hoorn study (N=686, aged 50-87y), Netherlands, we examined the cross-sectional associations of plasma sulfur-containing compounds (SCC; methionine, S-adenosylmethionine, S-adenosylhomocysteine, homocysteine, cystathionine, total cysteine (tCys), glutathione and cysteinylglycine) with SCD-16 index (16:1n-7/16:0), estimated from fatty acid profiles of total plasma or serum lipids. Only tCys was consistently associated with SCD-16 index after adjustments for sex and age (HUSK: partial r=0.14; Hoorn: partial r=0.11, P<0.001 for both), and after further adjustments for other SCC, body fat, diet, exercise and plasma lipids (HUSK: partial r=0.07, P=0.004; Hoorn: partial r=0.12, P=0.013). Together with animal data showing an effect of dietary cysteine on SCD1, our results suggest a role for cysteine in SCD1 regulation in humans.

A gene variation (rs12691) in the CCAT/enhancer binding protein α modulates glucose metabolism in metabolic syndrome.

BACKGROUND AND AIMS: CCAAT/enhancer-binding protein alpha (CEBPA) is a transcription factor involved in adipogenesis and energy homeostasis. Caloric restriction reduces CEBPA protein expression in patients with metabolic syndrome (MetS). A previous report linked rs12691 SNP in CEBPA to altered concentration of fasting triglycerides. Our objective was to assess the effects of rs12691 in glucose metabolism in Metabolic Syndrome (MetS) patients. METHODS AND RESULTS: Glucose metabolism was assessed by static (glucose, insulin, adiponectin, leptin and resistin plasma concentrations) and dynamic (disposition index, insulin sensitivity index, HOMA-IR and acute insulin response to glucose) indices, performed at baseline and after 12 weeks of 4 dietary interventions (high saturated fatty acid (SFA), high monounsaturated fatty acid (MUFA), low-fat and low-fat-high-n3 polyunsaturated fatty acid (PUFA)) in 486 subjects with MetS. Carriers of the minor A allele of rs12691 had altered disposition index (p = 0.0003), lower acute insulin response (p = 0.005) and a lower insulin sensitivity index (p = 0.025) indicating a lower insulin sensitivity and a lower insulin secretion, at baseline and at the end of the diets. Furthermore, A allele carriers displayed lower HDL concentration. CONCLUSION: The presence of the A allele of rs12691 influences glucose metabolism of MetS patients.

Effects of dietary fat modification on insulin sensitivity and on other risk factors of the metabolic syndrome--LIPGENE: a European randomized dietary intervention study.

BACKGROUND: Excessive energy intake and obesity lead to the metabolic syndrome (MetS). Dietary saturated fatty acids (SFAs) may be particularly detrimental on insulin sensitivity (SI) and on other components of the MetS. OBJECTIVE: This study determined the relative efficacy of reducing dietary SFA, by isoenergetic alteration of the quality and quantity of dietary fat, on risk factors associated with MetS. DESIGN: A free-living, single-blinded dietary intervention study. SUBJECTS AND METHODS: MetS subjects (n = 417) from eight European countries completed the randomized dietary intervention study with four isoenergetic diets distinct in fat quantity and quality: high-SFA; high-monounsaturated fatty acids and two low-fat, high-complex carbohydrate (LFHCC) diets, supplemented with long chain n-3 polyunsaturated fatty acids (LC n-3 PUFAs) (1.2 g per day) or placebo for 12 weeks. SI estimated from an intravenous glucose tolerance test (IVGTT) was the primary outcome measure. Lipid and inflammatory markers associated with MetS were also determined. RESULTS: In weight-stable subjects, reducing dietary SFA intake had no effect on SI, total and low-density lipoprotein cholesterol concentration, inflammation or blood pressure in the entire cohort. The LFHCC n-3 PUFA diet reduced plasma triacylglycerol (TAG) and non-esterified fatty acid concentrations (P < 0.01), particularly in men. CONCLUSION: There was no effect of reducing SFA on SI in weight-stable obese MetS subjects. LC n-3 PUFA supplementation, in association with a low-fat diet, improved TAG-related MetS risk profiles.

Dietary supplementation of tetradecylthioacetic acid increases feed intake but reduces body weight gain and adipose depot sizes in rats fed on high-fat diets.

AIM: The pan-peroxisome proliferator-activated receptor (PPAR) ligand and fatty acid analogue tetradecylthioacetic acid (TTA) may reduce plasma lipids and enhance hepatic lipid metabolism, as well as reduce adipose tissue sizes in rats fed on high-fat diets. This study further explores the effects of TTA on weight gain, feed intake and adipose tissue functions in rats that are fed a high-fat diet for 7 weeks. METHODS: The effects on feed intake and body weight during 7 weeks' dietary supplement with TTA ( approximately 200 mg/kg bw) were studied in male Wistar rats fed on a lard-based diet containing approximately 40% energy from fat. Adipose tissue mass, body composition and expression of relevant genes in fat depots and liver were measured at the end of the feeding. RESULTS: Despite higher feed intake during the final 2 weeks of the study, rats fed on TTA gained less body weight than lard-fed rats and had markedly decreased subcutaneous, epididymal, perirenal and mesenteric adipose depots. The effects of TTA feeding with reduced body weight gain and energy efficiency (weight gain/feed intake) started between day 10 and 13. Body contents of fat, protein and water were reduced after feeding lard plus TTA, with a stronger decrease in fat relative to protein. Plasma lipids, including Non-Esterified Fatty Acids (NEFA), were significantly reduced, whereas fatty acid beta-oxidation in liver and heart was enhanced in lard plus TTA-fed rats. Hepatic UCP3 was expressed ectopically both at protein and mRNA level (>1900-fold), whereas Ucp1 mRNA was increased approximately 30-fold in epididymal and approximately 90-fold in mesenteric fat after lard plus TTA feeding. CONCLUSION: Our data support the hypothesis that TTA feeding may increase hepatic fatty acid beta-oxidation, and thereby reduce the size of adipose tissues. The functional importance of ectopic hepatic UCP3 is unknown, but might be associated with enhanced energy expenditure and thus the reduced feed efficiency.

Fat-soluble vitamins in breast-fed preterm and term infants.

OBJECTIVE: To examine the supply and status of fat-soluble vitamins in very low birth weight (VLBW) infants compared to a reference group of normal birth weight (NBW) infants. DESIGN: A longitudinal study of VLBW infants in the early neonatal period. Blood samples were drawn at 1 week of age and at discharge from hospital. Plasma was analyzed for the fat-soluble vitamins: retinol, 25-OH-vitamin D, alpha-tocopherol and phylloquinone (vitamin K(1)) using high-performance liquid chromatography. SUBJECTS: A total of 40 VLBW infants were included in the study. A reference group of 33 NBW infants was randomly selected from one of our previous studies. RESULTS: The VLBW infants received fortified human milk, and daily oral vitamin supplement (Multibionta). In VLBW infants, plasma retinol concentrations decreased and plasma 25-OH-vitamin D increased during the study period. VLBW infants had significantly lower plasma retinol (0.3 vs 0.7 mu M) and higher plasma 25-OH-vitamin D (166 vs 25 nM) at discharge compared to NBW infants. Plasma phylloquinone concentration in VLBW infants was very high (53 ng/ml) at one week of age, especially in the youngest infants (192 ng/ml), but decreased rapidly during the study period resulting in low/normal plasma concentrations (0.9 ng/ml) at discharge. CONCLUSIONS: We observed alterations in plasma concentration of retinol and 25-OH-vitamin D in VLBW infants in the early neonatal period, resulting in marked differences between VLBW at discharge and NBW. Further trials are needed to evaluate whether changes in vitamin supplementation may improve clinical outcome in VLBW infants.

Similar effects on infants of n-3 and n-6 fatty acids supplementation to pregnant and lactating women.

OBJECTIVE: There have been indications that high intake of n-3 long-chain polyunsaturated fatty acids (PUFAs) during pregnancy may increase birth weight and gestational length. In addition, n-3 long-chain PUFAs may be important for the neurobiological development of the infants. High levels of docosahexaenoic acid (DHA, 22:6 n-3) are found in the gray matter of the cerebral cortex and in the retina, and it seems as if the availability of long-chain PUFAs may be limiting cerebral development. The fetus and the newborn are dependent on a high supply from their mothers, either via the placenta or via breast milk. We supplemented pregnant and lactating women with n-3 or n-6 long-chain PUFAs to evaluate the effect on birth weight, gestational length, and infant development. DESIGN: We performed a double-blind, randomized study recruiting 590 pregnant, healthy, nulli- or primiparous women (19-35 years old) in weeks 17 to 19 of pregnancy. The women were provided 10 mL of either cod liver oil or corn oil daily until 3 months after delivery. MAIN OUTCOME MEASURES: Primary outcomes were gestational length and birth weight. Electroencephalography (EEG) was done on the second day of life and at 3 months of age. Novelty preference (Fagan test) was used as an indicator of cognitive function at 6 and 9 months of age. The fatty acid pattern in umbilical plasma phospholipids and in breast milk was measured, and dietary assessments were performed, both on the mothers during pregnancy and on the infants at 3 months of age. The growth of the infants was followed up to 1 year of age. RESULTS: Three hundred forty-one mothers took part in the study until delivery. There were no significant differences in maternal body mass index before pregnancy and at birth, or parity between the 2 groups. Smoking habits and parental education were also similar in the 2 groups. The mean age of the mothers receiving cod liver oil was, by chance, 1 year higher than the age of the mothers receiving corn oil (28.6 [3.4] vs 27.6 [3.2] years). The maternal dietary intake in the 2 groups receiving cod liver oil or corn oil was similar, except for the supplementation. There were no differences in gestational length or birth weight between the cod liver oil group and the corn oil group (279.6 [9.2] vs 279.2 [9.3] days; 3609 [493] vs 3618 [527] g, respectively). Birth length, head circumference, and placental weight were also similar in the 2 groups. The concentrations of the n-3 fatty acids eicosapentaenoic acid (20:5 n-3), docosapentaenoic acid (22:5 n-3), and DHA in umbilical plasma phospholipids were higher in the cod liver oil group compared with the corn oil group (10.8 [7.6] vs 2.5 [1.8] microg/mL, 5.0 [2.6] vs 2.9 [1.3] microg/mL, 55.8 [20.6] vs 45.3 [12.8] microg/mL, respectively). Neonates with high concentration of DHA in umbilical plasma phospholipids (upper quartile) had longer gestational length than neonates with low concentration (lower quartile; 282.5 [8.5] vs 275.4 [9.3] days). No differences in EEG scores or Fagan scores were found, but neonates with mature EEG (N = 70) had a higher concentration of DHA in umbilical plasma phospholipids than neonates with immature EEG (N = 51) on the second day of life. Dietary information from 251 infants at 3 months of age was collected and 85% of these infants were exclusively breastfed, in addition to 12% who were partly breastfed. The breast milk of mothers supplemented with cod liver oil contained more n-3 long-chain PUFAs and less n-6 long-chain PUFAs than breast milk of mothers supplemented with corn oil. There were no significant differences in infant growth during the first year of life between the 2 groups. CONCLUSIONS: This study shows neither harmful nor beneficial effects of maternal supplementation of long-chain n-3 PUFAs regarding pregnancy outcome, cognitive development, or growth, as compared with supplementation with n-6 fatty acids. However, it confirms that DHA concentration may be related to gestational length and cerebral maturation of the newborn.

High intake of energy, sucrose, and polyunsaturated fatty acids is associated with increased risk of preeclampsia.

OBJECTIVE: Preeclampsia is associated with high body mass index, insulin resistance, and hypertriglyceridemia. Our objective was to investigate prospectively whether diet in the first half of pregnancy is associated with the risk for preeclampsia. STUDY DESIGN: This prospective, population-based, cohort study of pregnant women investigated dietary intake early in the second trimester with a quantitative food frequency questionnaire. RESULTS: The questionnaire was completed by 3133 women (83%). Preeclampsia developed in 85 women. Adjusted odds ratio (95% CI) for preeclampsia was 3.7 (1.5-8.9) for energy intake of >3350 kcal/d compared with < or =2000 kcal/d. Adjusted odds ratio (95% CI) for preeclampsia was 3.6 (1.3-9.8) for sucrose intake (percent of total energy) of >25% compared with < or =8.5% and 2.6 (1.3-5.4) for polyunsaturated fatty acids intake (percent of total energy) of >7.5% compared with < or =5.2%. Other energy-providing nutrients were not associated with the risk for preeclampsia. CONCLUSION: The current study suggests that high intakes of energy, sucrose, and polyunsaturated fatty acids independently increase the risk for preeclampsia.

Reduction of leptin gene expression by dietary polyunsaturated fatty acids.

Supplementation with n-3 polyunsaturated fatty acids (PUFA) for 6 weeks did not alter plasma leptin concentrations in male smokers. Changes in dietary intake of saturated fatty acids (FA) correlated positively, whereas changes in the intake of PUFA correlated negatively to changes in plasma leptin levels. A 3-week n-3 PUFA-enriched diet, as compared with a 3-week lard-enriched diet, induced lower plasma leptin concentration and reduced leptin mRNA expression in rat epididymal adipose tissue. In the human trophoblast cell line (BeWo), n-3 PUFA had a dose- and time-dependent effect on leptin expression. One mM of eicosapentaenoic acid or docosahexaenoic acid (DHA) reduced leptin expression by 71% and 78%, respectively, as compared with control, after 72 h. There was no effect on expression of the signal transducing form of the leptin receptor. In BeWo cells transfected with the human leptin promoter, we found that n-3 PUFA reduced leptin promoter activity; in contrast saturated and monounsaturated FA had no effect on leptin promoter activity. The transcription factors peroxysomal proliferator activated receptor gamma and sterol regulatory element binding protein-1 mRNAs were reduced after incubation with n-3 PUFA, whereas the expression of CCAAT/enhancer binding protein alpha was unchanged. DHA-reduced leptin expression was abolished in BeWo cells grown in cholesterol-free medium. In conclusion, n-3 FA decreased leptin gene expression both in vivo and in vitro. The direct effects of PUFA on leptin promoter activity indicate a specific regulatory action of FA on leptin expression.

Dietary habits among patients with atopic dermatitis.

OBJECTIVE: To evaluate the dietary habits among adult patients with moderate to severe atopic dermatitis and relate intake to clinical symptoms. DESIGN: Data were obtained from a clinical trial. SETTING: Five departments of dermatology at Norwegian University hospitals. SUBJECTS: Outpatients, 46 men (median age 27 y) and 92 women (median age 28 y). METHOD: A quantitative food frequency questionnaire was filled in before attending the clinical trial. The results were compared to the diet of age- and sex-matched reference groups. RESULTS: Male patients had higher content of refined sugar in their diet than reference men (P=0.014). Among female patients, the intake of saturated fatty acids was higher (P=0.049), whereas the intake of very long-chain n-3 fatty acids was lower (eicosapentaenoic acid, P=0.032, docosahexaenoic acid, P=0.017) than in the reference group. In both genders, more patients than reference subjects had vitamin D intake below recommended level. Furthermore, the female patients had significantly lower intake of fruit compared to the reference group (P=0.002). No correlation was found between nutrient intake of the patients and their clinical scores. CONCLUSIONS: The patients's diet were fairly similar to the diet of reference groups. The intake of vitamin D and very long-chain n-3 fatty acids was low, especially among female patients. Furthermore, we could not detect any association between dietary habits and clinical status. European Journal of Clinical Nutrition (2000) 54, 93-97

Plasma homocysteine concentration related to diet, endothelial function and mononuclear cell gene expression among male hyperlipidaemic smokers.

BACKGROUND: Elevated plasma concentration of homocysteine is an independent risk factor for development of cardiovascular diseases. MATERIALS AND METHODS: We evaluated potential links between homocysteine and atherothrombogenesis by relating the plasma concentration of homocysteine to (i) dietary antioxidants and omega-3 fatty acids (and determined influence of intervention with antioxidants or omega-3 fatty acids); (ii) markers of endothelial cell function; and (iii) peripheral blood mononuclear cell mRNA levels. RESULTS: We observed an inverse relationship between the plasma homocysteine concentration and dietary intake of vegetables, vitamin C and beta-carotene and between homocysteine and the serum concentration of folate, vitamin B12 and omega-3 fatty acids. Intervention with antioxidants or omega-3 fatty acids did not affect plasma homocysteine concentration. The plasma levels of cysteinylglycine and vitamin B12 correlated positively with circulating E-selectin and VCAM-1, respectively, whereas folate in serum and blood correlated negatively with P-selectin. A negative correlation was found between the concentrations of homocysteine and von Willebrand factor. Negative and positive correlations were found between plasma homocysteine and the mononuclear cell mRNA levels of peroxisome proliferator activated receptor delta (PPAR delta) and c-myc respectively. A negative correlation was also found between plasma homocysteine and mononuclear cell mRNA levels of the proteoglycan serglycin. Homocysteine was not correlated with serum activity of glutathione peroxidase or with the mRNA level of glutathione peroxidase in mononuclear cells. CONCLUSION: The plasma homocysteine level was negatively correlated with dietary intake of vegetables, including vitamins C and E, and serum omega-3 fatty acids, whereas supplementation with antioxidants or omega-3 fatty acids did not affect plasma homocysteine concentration. Homocysteine was not associated with circulating adhesion molecules or increased procoagulant activity, but homocysteine may alter mononuclear cell gene expression. Cysteine showed no significant correlation with these parameters.

Fatty acid composition in maternal milk and plasma during supplementation with cod liver oil.

OBJECTIVE: We investigated how cod liver oil influences the amount of essential fatty acids in mothers' breast milk. DESIGN AND INTERVENTION: Lactating mothers (n =22) were randomized into four groups 3-8 weeks after parturition. They were supplemented for 14 days with 0, 2.5, 5 and 10 ml cod liver oil (7.7 g eicosapentaenoic acid (EPA, 20:5n-3), 10.2 g docosahexaenoic acid (DHA, 22:6n-3) and 22.9 g n-3 fatty acids in total per 100 ml). RESULTS: In maternal plasma phospholipids there was an increase in the content of EPA and DHA in the group supplemented with 10 ml cod liver oil daily (P < or = 0.05). DHA concentrations in breast milk pre-supplementation ranged from 0.15 to 1.56 wt% and increased in all supplemented groups (P< or =0.05). The concentration of EPA in breast milk increased in the groups supplemented with 5 or 10 ml cod liver oil (P< or =0.05), whereas the concentration of arachidonic acid (AA, 20:4n-6) did not change in any of the supplemented groups. Total intake of DHA adjusted to body mass index (BMI), correlated to DHA concentrations in plasma (r = 0.49, P = 0.02) and breast milk (r = 0.45, P = 0.04). The concentration of tocopherol did not change during the supplementation period, neither in plasma nor in breast milk. CONCLUSION: Dietary intake of DHA is reflected in the concentration of DHA in breast milk, without affecting the concentration of AA or tocopherol.

Intake of very-long-chain n-3 fatty acids related to social status and lifestyle.

OBJECTIVES: Little information is available about the intake of very-long-chain n-3 fatty acids in random samples of populations. We examined if the intake of these fatty acids was associated with gender, social status and lifestyle in a similar way as other indicators for a healthy diet in a nationwide survey. DESIGN AND SUBJECTS: Data were obtained from self-administered quantitative food frequency questionnaires filled in by a representative sample of Norwegian men and women, aged 16-79 y. 3144 (63%) of the invited subjects responded with acceptable questionnaires. RESULTS: Daily intake of very-long-chain n-3 fatty acids was on average 0.9 g/d and 0.4% of total energy was derived from these fatty acids. Energy derived from very-long-chain n-3 fatty acids was slightly higher among men than women, and two-fold higher among subjects aged 60-79 vs 16-29 y. White collar workers had higher intake of very-long-chain n-3 fatty acids than blue collar workers. Men and women in the highest quartile of intake of very-long-chain n-3 fatty acids had 2-3 E% higher fat intake (mostly mono- and polyunsaturated fatty acids), as compared to individuals in the lowest quartile. They also had 3-4 fold higher daily intake of retinol and vitamin D, as well as 20-50% higher intake of fruits and vegetables, dietary fibre and vitamin C. CONCLUSIONS: Intake of very-long-chain n-3 fatty acids was correlated to indicators for healthy dietary habits. However, contrary to many other indicators of a healthy diet, energy derived from very-long-chain n-3 fatty acids was not significantly associated with female gender or non-smoking.

Effects of omega-3 fatty acids and/or antioxidants on endothelial cell markers.

BACKGROUND: Increased expression of cell adhesion molecules and increased procoagulant activity of the vascular endothelium have been postulated to characterize dysfunctional endothelium. The cellular effects of n-3 fatty acids (n-3 FAs) and antioxidants are still not clarified. METHODS: In a randomized, factorial two-by-two design study, we have investigated 41 male smokers with hyperlipidaemia before and after 6 weeks of supplementation with either n-3 FAs (4.8 g daily) or placebo with the addition of antioxidants (150 mg of vitamin C, 75 mg of vitamin E and 15 mg of beta-carotene daily) or placebo with regard to the effects on some endothelial cell markers: thrombomodulin (sTM), von Willebrand factor (vWF), tissue plasminogen activator antigen (tPAag) and soluble forms of the cell adhesion molecules E-selectin, P-selectin and vascular cell adhesion molecule 1 (VCAM-1). RESULTS: In the n-3 FA group, significant reductions in the plasma levels of vWF (P = 0.034) and sTM (P < 0.001) were demonstrated compared with placebo, whereas increased levels were found for E-selectin (P = 0.001) and VCAM-1 (P = 0.010). In the antioxidant group, no differences in changes were noted for any of the variables. CONCLUSION: The reduction in the levels of sTM and vWF with n-3 FA supplementation could indicate an improvement with regard to the haemostatic markers of endothelial dysfunction, whereas the simultaneous increase in the soluble forms of E-selectin and VCAM-1 may suggest an adverse effect on the inflammatory system. The antioxidants seem to be neutral in their effect on these endothelial cell markers in our study population of smokers. The interpretation of the soluble forms of these molecules are, however, still debatable.

Postprandial decrease in plasma unesterified fatty acids during n-3 fatty acid feeding is not caused by accumulation of fatty acids in adipose tissue.

Dietary supplementation of very long-chain n-3 fatty acids to rats reduces postprandial plasma concentrations of triacylglycerol, unesterified fatty acids and glycerol after long-term feeding by unknown mechanisms [Rustan et al., J. Lipid Res. 34 (1993) 1299-1309]. In the present study we examine the role of adipose tissues in metabolism of fatty acids. Postprandial plasma concentrations of triacylglycerol, unesterified fatty acids and glycerol were reduced by 75%, 50% and 30%, respectively, during 49 days of feeding high-fat diets containing n-3 fatty acids (6.5% n-3 fatty acid concentrate, 13% lard) as compared to lard (19.5% lard). These differences were observed already after two days of feeding. Plasma concentration of unesterified very long-chain n-3 fatty acids increased to 50 microM in n-3 fatty acid-supplemented rats, whereas these fatty acids were undetectable in lard-fed animals. The n-3 fatty acid-enriched diet limited cell volumes of perirenal and epididymal adipocytes by 40% and 30%, respectively, after 49 days, as compared to lard feeding. This reduction in cell volume was not due to reduced synthesis of glycerolipids in epididymal adipocytes. Acute incubation of perirenal and epididymal adipocytes with oleic acid or eicosapentaenoic acid, caused similar increase in synthesis of triacylglycerol. Dietary supplementation with n-3 fatty acids decreased basal and total lipolysis (isoprenalin-stimulated) in perirenal adipocytes. Basal lipolysis in epididymal adipocytes was reduced by n-3 fatty acids only after 49 days. n-3 fatty acids increased total lipolysis in mesenteric and subcutaneous fat cells compared to adipocytes derived from lard-fed animals, whereas basal lipolysis was unchanged. These results suggest that the reduced postprandial plasma concentration of unesterified fatty acids after n-3 fatty acid-supplementation is not caused by accumulation of fatty acids in adipose tissue. The reduced trophic growth of adipocytes might be due to decreased supply of unesterified fatty acids for triacylglycerol storage. (c) 1998 Elsevier Science B.V.

Effect of a coffee lipid (cafestol) on cholesterol metabolism in human skin fibroblasts.

Consumption of boiled coffee promotes an elevation of plasma cholesterol concentration in humans. The active compounds found in the lipid fraction of the coffee have been identified as the diterpenes cafestol and kahweol. We have studied the effects of pure cafestol on cholesterol metabolism in human skin fibroblasts (HSF). The uptake of [125I]-labeled tyramine cellobiose-labeled low density lipoprotein ([125I]TC-LDL) was decreased by about 50% (P< 0.05) after 18 h preincubation time with cafestol (20 microg/ml), as compared to the control cells. The specific binding of radiolabeled LDL was reduced by 54% (P < 0.05) after preincubation for 18 h with cafestol. A reduced amount of LDL receptors was demonstrated by a protein-normalized Scatchard plot analysis (20% decrease in Bmax) as well as by immunoblotting (25%) after cafestol incubation. No significant effect was observed on the level of mRNA for the LDL receptor after 11 and 23 h incubation with cafestol. Furthermore, we transfected HSF cells with a promoter region for the LDL receptor gene linked to a reporter gene, chloramphenicol acetyl transferase (CAT). No change was seen in the CAT activity after incubation with cafestol (20 microg/ml). Moreover, cafestol caused a 2.3-fold (P < 0.05) higher incorporation of radiolabeled [14C]oleic acid into cholesteryl esters after 24 h incubation, as compared to control cells, suggesting an increased acyl-CoA:cholesterol acyl transferase (ACAT) activity. Incorporation of [14C]acetate into cholesterol was reduced by approximately 40% (P < 0.05) with cafestol (20 microg/ml), as compared to control after 24 h preincubation, indicating a decreased 3-hydroxy-3-methylglutaryl CoA (HMG-CoA) reductase activity. Our results suggest that intake of cafestol may cause increased concentration of plasma cholesterol via the down-regulation of low density lipoprotein receptors by post-transcriptional mechanisms.

Leptin levels in pregnant women and newborn infants: gender differences and reduction during the neonatal period.

OBJECTIVE: Leptin is a highly hydrophilic protein that circulates in plasma as a 16-kDa protein. It is produced in adipose tissue and also recently described to be synthesized by placental tissue. Plasma concentration of leptin is positively correlated to body fat mass, and administration of recombinant leptin to mice indicates that leptin participates in the regulation of food intake and energy expenditure. Leptin may have a role during initiation of human pubertal development. Gender differences have been reported among adults as well as among children, even after correction for body fat content. Little is known about variation in leptin levels during pregnancy or the level or function of leptin in the growing fetus and infants. The aim of the present study was to examine plasma concentration of leptin in pregnant women and their newborn infants during the first 3 months of life, and to relate plasma leptin concentration to body weight and gender during this period. MATERIALS AND METHODS: Among 609 women recruited to study the effect of very long-chain n-3 fatty acids during pregnancy, 180 women were selected to study leptin as well. The women were all healthy and nulli- or primiparas, and 16% were smokers. The study was randomized and double-blinded, and the participants received either 10 mL of cod liver oil (Peter Moller, avd.av Orkla ASA, Oslo, Norway) daily or the same amount of corn oil. Blood samples were taken from the mothers during pregnancy in weeks 18 and 35, and from the umbilical cord and from 4- and 14-week-old infants. The mothers' body mass index (BMI) at 18 and 35 weeks of pregnancy was calculated by using body weight recorded within 1 week or, if this was missing, by using means from weights at the closest time points before and after the sampling. The infants were weighed and measured at local health care centers. Plasma leptin concentration was measured by radio immunoassay (Linco Research, St Charles, MO) using recombinant 125I-leptin as tracer. RESULTS: We found no differences between the group receiving cod liver oil and the group receiving corn oil in any of the measured variables; thus, the groups are treated statistically as one. Leptin concentration in maternal plasma increased during pregnancy from 15.5 +/- 9.0 microg/L (n = 175) in week 18 to 17.7 +/- 10.7 microg/L (n = 166) in week 35. Mothers, pregnant with female fetuses (n = 77), had a significant increase in plasma leptin concentration, from 15.5 +/- 8.8 microg/L (n = 83) at 18 weeks to 18.5 +/- 10.9 microg/L (n = 80) at 35 weeks of pregnancy, whereas in mothers pregnant with male fetuses, the increase was insignificant (15.4 +/- 9.3 microg/L (n = 92) to 17.0 +/- 10.5 microg/L (n = 86). BMI increased during the same time period, from 24.2 +/- 3.3 kg/m to 27.8 +/- 3.8 kg/m (n = 174). There was a significant correlation between BMI and plasma leptin concentration at 18 weeks (r = 0.54, n = 169) and at 35 weeks (r = 0.45, n = 160), but we found no change in the relative leptin concentration (plasma leptin concentration/BMI) from week 18 to week 35. We found no significant difference between smokers and nonsmokers in plasma leptin concentration, neither at 18 nor 35 weeks of pregnancy. Gender differences in plasma leptin concentration was present already at birth in umbilical cord plasma (10.8 +/- 9.2 microg/L for girls [n = 65] vs 7.6 +/- 6.6 microg/L for boys [n = 74]). We also observed gender differences in plasma leptin concentration at 4 weeks (3.9 +/- 1.8 microg/L, n = 68 vs 3.2 +/- 1.8 microg/L, n = 71) and 14 weeks of age (4.9 +/- 2.1 microg/L, n = 61 vs 4.1 +/- 3.1 microg/L, n = 73). Plasma leptin levels at 4 and 14 weeks were lower than the level in umbilical cord plasma (n = 101). An increase in plasma leptin concentration was observed from 4 to 14 weeks of age, both for girls (n = 48) and for boys (n = 60). Leptin concentration in umbilical cord plasma correlated with birth weight (r = 0.44, n = 139), and there was significant corre

Peroxidation of LDL from combined-hyperlipidemic male smokers supplied with omega-3 fatty acids and antioxidants.

The effects of marine omega-3 polyunsaturated fatty acids (FAs) and antioxidants on the oxidative modification of LDL were studied in a randomized, double-blind, placebo-controlled trial. Male smokers (n = 41) with combined hyperlipidemia were allocated to one of four groups receiving supplementation with omega-3 FAs (5 g eicosapentaenoic acid and docosahexaenoic acid per day), antioxidants (75 mg vitamin E, 150 mg vitamin C, 15 mg beta-carotene, and 30 mg coenzyme Q10 per day), both omega-3 FAs and antioxidants, or control oils. LDL and human mononuclear cells were isolated from the patients at baseline and after 6 weeks of supplementation. LDL was subjected to cell-mediated oxidation by the patients' own mononuclear cells, as well as to Cu(2+)-catalyzed and 2,2'-azobis-(2-amidinopropane hydrochloride) (AAPH)-initiated oxidation. Extent of LDL modification was measured as lag time, the formation rate of conjugated dienes (CDs), the maximum amount of CDs formed, formation of lipid peroxides, and the relative electrophoretic mobility of LDL on agarose gels. Dietary supplementation with omega-3 FAs increased the concentration of total omega-3 FAs in LDL and reduced the concentration of vitamin E in serum. The omega-3 FA-enriched LDL particles were not more susceptible to Cu(2+)-catalyzed, AAPH-initiated, or autologous cell-mediated oxidation than control LDL. In fact, enrichment with omega-3 FAs significantly reduced the formation rate of CDs when LDL was subjected to AAPH-induced oxidation. Supplementation with moderate amounts of antioxidants significantly increased the concentration of vitamin E in serum and increased the resistance of LDL to undergo Cu(2+)-catalyzed oxidation, measured as increased lag time, reduced formation of lipid peroxides, and reduced relative electrophoretic mobility compared with control LDL. Supplementation with omega-3 FAs/antioxidants showed oxidizability of LDL similar to that of control LDL and omega-3 FA-enriched LDL. In conclusion, omega-3 FAs neither rendered the LDL particles more susceptible to undergo in vitro oxidation nor influenced mononuclear cells' ability to oxidize autologous LDL, whereas moderate amounts of antioxidants protected LDL against oxidative modification.

Omega-3 and omega-6 fatty acids in the insulin resistance syndrome. Lipid and lipoprotein metabolism and atherosclerosis.

Dietary fatty acids appear to be of significant importance for several of the most-common diseases in modern societies. To obtain more knowledge about the health consequences of dietary fatty acids, we depend upon a better understanding of the mechanisms of action of these fatty acids in vivo. With regard to the IRS, omega-3 PUFA may exert beneficial effects upon many of the associated pathophysiological metabolic changes. Omega-3 PUFA reduce fasting and postprandial TG, may improve insulin sensitivity (as shown in animal experiments), decrease platelet and leukocyte reactivity, alter immunological functions, and may slightly decrease blood pressure. Omega-3 PUFA may also beneficially influence vessel wall characteristics and blood rheology. Furthermore, both types of PUFA (omega-3 and omega-6) have been shown to inhibit cardiac arrhythmias in animals. The role of omega-3 PUFA in blood clotting and fibrinolysis still remains controversial, whereas omega-6 fatty acids may lead to increased oxidation of lipoproteins. Regardless of the effects on LDL oxidizability, both types of PUFA have shown beneficial effects on the development of atherosclerosis. As yet, little is known about the effect of specific omega-6 fatty acids with respect to the IRS. Potential adverse effects of dietary PUFA must not be neglected, but should be viewed in light of the beneficial effects of these agents.

Response rates with different distribution methods and reward, and reproducibility of a quantitative food frequency questionnaire.

OBJECTIVES: To evaluate the use of a self-administered quantitative food frequency questionnaire (QFFQ) in a national dietary survey concerning (a) response rates with different distribution methods and reward; (b) degree of underreporting of energy intake; (c) reproducibility of the QFFQ; and (d) seasonal variation on reported intake. DESIGN AND SUBJECTS: A pilot study was performed in 1992 to test response rates to the QFFQ with three different distribution methods, with and without reward, in a random sample of 1200 adults aged 16-79 y. In another study, the QFFQ was distributed to a nation-wide, representative random sample of 5008 adults aged 16-79 y during June, September, November 1993 and March 1994. Reproducibility was evaluated among 90 responders to the survey who answered another QFFQ six weeks later. RESULTS: The distribution method combining postal distribution and collecting the QFFQ by interviewer as well as an offer to participate in a lottery, gave the highest response rate (72%). The possibility to get a reward increased the response rate by 9, 14 and 57%, respectively, depending on the distribution method used. The mean daily energy intake and the percentage of subjects claiming to have unlikely low energy intake did not differ significantly between the different ways of distribution. In the main survey the mean ratio between energy intake and estimated basal metabolic rate was 1.58 among men and 1.47 among women, and 37% of men and 45% of women had a ratio below 1.35. Spearman rank correlations between the two QFFQ ranged from 0.48 (edible fats) to 0.91 (coffee) with a median coefficient of 0.70. For nutrients correlations ranged from 0.55 (carbohydrate E%) to 0.81 (alcohol), with a median coefficient of 0.72. The season of questionnaire administration was of minor importance for the reported intake of the main foods and nutrients. CONCLUSIONS: The QFFQ-method is suitable for use in a Norwegian nutritional surveillance system. SPONSORSHIP: National Nutrition Council, Ministry for Agriculture, Ministry for Health and Social Affairs and Norwegian Research Council.