Maternal dietary fat and fatty acid intake during lactation and the risk of asthma in the offspring

AIM

To explore the association between maternal dietary fat and fatty acid (FA) intake during lactation, and the risk of asthma in the offspring by the age of 5 years.

METHODS

The subjects comprised 1798 mother-child pairs from the Type 1 Diabetes Prediction and Prevention (DIPP) Nutrition Study. Dietary intake was assessed by a validated 181-item food frequency questionnaire, which covered the third month of lactation. The cumulative incidence of asthma was assessed at the age of 5 years with a questionnaire modified from the International Study of Asthma and Allergies in Childhood (ISAAC). Cox proportional hazards regression was used for statistical analysis.

RESULTS

The maternal use of margarines during lactation was associated with a marginally increased risk of asthma [hazard ratio (HR) for user vs. nonuser 1.96, 95% confidence interval (CI) 1.01-3.82, p = 0.047] after adjusting for putative confounders. The maternal intakes of n-3 polyunsaturated FA (PUFA) and fish during lactation were not associated with the risk of asthma.

CONCLUSION

Maternal use of margarines during lactation was weakly associated with an increased risk of asthma in the offspring at the age of 5 years. Other fats or FAs during lactation were not associated with the risk of asthma. However, the nonadherence to dietary recommendations regarding especially fats of our study population may restrict the generalizability of our results.

Poor relationship between joint swelling detected on physical examination and effusion diagnosed by ultrasonography in glenohumeral joints in patients with rheumatoid arthritis

The purpose of this study was to assess the relationship between swelling detected on physical examination and effusion diagnosed by ultrasonography (US) in glenohumeral (GH) joints in patients with rheumatoid arthritis (RA). Fifty consecutive patients with RA entered the study and 20 healthy control persons formed a control group. Altogether 100 GH joints of the RA patients and 40 of the controls were evaluated. The clinical assessments were carried out by one doctor and the US investigations by another, and they were blinded to each other's results. The clinical examination and US gave similar results in 70 GH joints, whereas they differed in the remaining 30 GH joints. The kappa coefficient between these investigations was 0.202, showing poor agreement. These results showed poor agreement between the clinical assessment of swelling and effusion detected by US in GH joints. Therefore, US may considerably improve the accuracy of diagnosis of effusion in GH joints, which usually means synovitis in patients with RA.

Plasma chain-breaking antioxidants in preterm infants with good and poor short-term outcome

Many complications of prematurity have been suggested to result from free radical generation and an inadequacy of antioxidative capacity. We measured the plasma total peroxyl radical-trapping capability (TRAP) and concentrations of the main chain-breaking antioxidants contributing to it, i.e. uric acid, ascorbic acid, alpha-tocopherol, protein sulfhydryl groups and bilirubin, in 21 preterm infants with a mean birth weight of 1440 g and gestational age of 30 wk. The infants were divided into two groups according to their short-term outcome; the good outcome group (GOG) (N = 11) with no signs of morbidity and the poor outcome group (POG) (N = 10) with intraventricular haemorrhage and/or bronchopulmonary dysplasia and/or retinopathy. Arterial blood samples were obtained 3 and 10 days postpartum. TRAP was measured with a chemiluminescent method. As a comparison, venous blood samples from 13 adults (aged from 18 to 34) were used. At day 3 the poor outcome group had significantly higher TRAP than the good outcome or control group, mainly because of elevated uric acid concentration. Also the concentration of unidentified antioxidants was significantly lower in GOG. By day 10 the TRAP decreased substantially in both groups. However, from the components of TRAP, both ascorbate and the unidentified fraction decreased more in POG (p = 0.017 and 0.021, respectively). Furthermore in POG on day 10 urate concentration did not significantly differ from day 3 values. In conclusion, in preterm infants high TRAP was associated with high plasma uric acid concentration and a poor short-term prognosis.

Birth stress increases adrenomedullin in the newborn

Adrenomedullin is a peptide that induces pulmonary vasodilation in experimental animals. Adrenomedullin was measured in blood samples from cord artery and vein from 41 term newborns. In 23 of the newborns delivered vaginally, levels of adrenomedullin in the cord artery, 71.8+/-45.8 pg ml(-1) (mean +/- SD), and vein, 75.6+/-45.2 pg ml(-1), were significantly higher than in 18 newborns delivered by elective Caesarean section (40.7+/-14.6 pg ml(-1) and 32.4+/-10.3 pg ml(-1), respectively; both p < 0.01). A significant correlation existed between the concentration of adrenomedullin and pH in the cord artery (r = -0.545, p = 0.002). The fetus responds to birth stress by secreting high concentrations of adrenomedullin. As a potent vasodilator, the peptide may play a role in postnatal cardiovascular adaptation.

Impact of solid food on plasma arachidonic and docosahexaenoic acid status of term infants at 8 months of age

We studied healthy term infants at 6 and 8 months of age to assess the effect of fat-containing solid foods (mashed veal, chicken, and pork provided in ready-to-feed cans) on plasma long-chain polyunsaturated fatty acid (LCP) status. Twenty-one infants were breast-fed and 49 were formula-fed. The fat of the formula contained 16.2% linoleic acid and 2.3% alpha-linolenic acid but no LCPs. The solid-food intake was assessed with a 7-day dietary record. Blood samples were obtained at 6 and 8 months of age, and the fatty acid composition of plasma cholesteryl esters (CE) and phospholipids (PL) were analyzed with capillary gas liquid chromatography. The solid food-derived fat intake was higher in the formula-fed than in the breast-fed group at 6 months, and it increased significantly in both groups (from 0.15 to 0.39 g/kg/day and from 0.24 to 0.43 g/kg/day in breast-fed and formula-fed groups, respectively). The relative plasma concentrations of arachidonic acid (20:4n-6) and docosahexaenoic acid (22:6n-3) were significantly lower in the formula-fed than in the breast-fed group at both 6 and 8 months. In the formula-fed group at 8 months, the proportion of solid food-derived fat correlated positively with plasma 20:4n-6, and the mean percentage of PL-20:4n-6 were 8.0% (95% confidence interval, 7.4-8.5) and 9.0% (8.3-9.7) in its lowest and highest quartiles, respectively. In the breast-fed group, solid food-derived fat intake had no effect on plasma 20:4n-6. The two groups were similar in that solid-food fat had no effect on plasma PL- or CE-22:6n-3. In conclusion, the introduction of meat containing solid foods to formula-fed infants increases their plasma 20:4n-6, but not to levels found in breast-fed infants. Further studies are needed to establish an optimal fatty acid composition of solid foods during weaning.

Fatty acid composition of serum lipid fractions in relation to gender and quality of dietary fat

The fatty acid compositions of serum lipid fractions are believed to reflect the quality of dietary fat, but only a few cross-sectional studies have examined these relationships in a representative free-living population. We related the composition of dietary fat obtained by 7-day food records from 84 free-living middle-aged married couples, on their habitual diets, to gas chromatographic analyses of the percentage compositions of fatty acids in three lipid fractions of fasting sera. Dietary polyunsaturated fat had Pearson's correlation coefficients of 0.63, 0.73 and 0.44 with n-6 polyunsaturated fatty acids in serum cholesteryl esters, triglycerides and phospholipids, respectively. Intake of fish showed correlations of 0.60, 0.36 and 0.52 with the percentage of eicosapentaenoate in the respective fractions. Dietary saturated fat had correlations of 0.57 and 0.54 with saturated fatty acids in serum cholesteryl esters and triglycerides, respectively. Dietary monounsaturated fat did not correlate positively with monounsaturated fatty acids in any serum lipid fraction. There were some small but significant gender differences in the serum fatty acid compositions.

CONCLUSIONS

of the three serum lipid fractions, triglycerides appear to be the best reflectors of dietary polyunsaturated and saturated fat, but the intake of monounsaturated fat is poorly reflected in all serum lipid fractions. Intake of fish is mirrored in all serum lipid fractions, best in cholesteryl esters and phospholipids.

The fatty acid composition of banked human milk and infant formulas: the choices of milk for feeding preterm infants

The fatty acid composition of 48 samples of banked human milk for preterm infants and four standard infants formulas available in Finland were analysed by capillary gas liquid chromatography. The banked milk was collected from mothers who had given birth 0-8 weeks previously. Saturated fatty acids accounted for approximately 50% of the fatty acids in both human milk and the formulas, while the relative content of monoenoic fatty acids tended to be higher in human milk than in the formulas. The relative content of 18:2n-6 was higher in the formulas (range 14.7%-23.2%) than in human milk (median 9.1%, range 6.3%-13.4%). Fat of banked human milk contained 0.9% and 0.7% polyunsaturated fatty acids with 20 and 22 carbon atoms (LCP), respectively, which is comparable to that of fresh mature human milk. In contrast, LCP could not be detected in any of the formulas. Conclusion. Banked human milk is a good source of LCP and offers a good alternative to LCP containing formulas.

Fatty acid composition of plasma and red blood cell phospholipids in preterm infants from 2 weeks to 6 months postpartum

The purpose of this study was to follow the long-chain polyunsaturated fatty acid (LCP) status in initially human milk-fed preterm infants from 2 weeks to 6 months postpartum. Twenty-two infants aged 27-33 weeks of gestation at birth who had a birthweight of 710-2525 g were fed human milk for > or = 4 weeks. After discharge from the hospital, they were either human milk-fed or formula-fed according to their mothers' decision: 10 were fully breast-fed for 6 months and 12 were formula-fed after discharge at 1-2 months. The formula fat contained 20% 18:2n-6 and 3% 18:3n-3 but was devoid of long-chain polyunsaturated fatty acids (LCP). Blood samples were taken at 2 weeks, 3 months, and 6 months postpartum. Percentage fatty acid compositions in red blood cell (RBC) and plasma total phospholipids were analyzed by capillary gas liquid chromatography. In formula-fed infants, the change from human milk to formula resulted in a significant rise in plasma and RBC 18:2n-6 and 18:3n-3 and a decrease in plasma 20:4n-6. Interestingly, RBC 20:4n-6 remained constant in both groups, even after 4-5 months of formula feeding. In the formula-fed group, RBC 22:5n-6 showed an increasing trend. The largest changes were seen in 22:6n-3; in the formula-fed group, it decreased in both plasma and RBC, whereas in the human milk-fed group, it showed an increasing trend.(ABSTRACT TRUNCATED AT 250 WORDS)

Changes in the fatty acid composition of preterm and term human milk from 1 week to 6 months of lactation

Using capillary gas chromatography, we analyzed the fatty acid composition of human milk from 23 women who had delivered prematurely and 16 women who had delivered at term. Milk samples were obtained at 1, 2, 4, 12, and 26 weeks after delivery. The relative amounts of saturated and monounsaturated fatty acids in preterm and term milk remained stable throughout the 6 months of lactation. The proportions of linoleate (18:2n-6) and alpha-linolenate (18:3n-3) were similar in preterm and term milk and showed an increasing trend from transitional (8.7-9.9% and 0.9-1.1% of total fatty acids, respectively) to mature milk (9.9-11.8% and 1.2-1.5%, respectively). The proportions of the major long-chain polyunsaturated fatty acids (LCP), 20:3n-6, 20:4n-6, 22:5n-3 and 22:6n-3, were highest at 1 week and decreased thereafter in both types of milk. In term milk, the proportion of LCP continued to decrease from 1 month to 6 months, whereas in preterm milk it was fairly constant. Consequently, at 6 months of lactation, the relative content of arachidonate (20:4n-6) was 1.5 times (p < 0.05) and that of docosahexaenoate (22:6n-3) was two times higher (p < 0.01) in preterm than in term milk. We conclude that in long-term lactation, preterm human milk provides a significantly higher relative supply of LCP than term human milk. This higher LCP content may be of special benefit to the development of a preterm infant.