Effects of alpha-lactalbumin-enriched formula containing different concentrations of glycomacropeptide on infant nutrition

BACKGROUND: Formula-fed infants have growth and plasma amino acid patterns different from those of breastfed infants. OBJECTIVE: alpha-Lactalbumin is a major protein in human milk, and the addition of bovine alpha-lactalbumin to infant formula has been proposed to modify the plasma amino acid pattern of the recipient infant, possibly allowing a reduction in the protein content of the formula, which may affect growth. DESIGN: We compared breastfed infants and infants fed standard formula or alpha-lactalbumin-enriched formulas (25% of protein) with glycomacropeptide accounting for 15% or 10% of the protein. The protein content of each formula was 13.1 g/L. Ninety-six infants aged 6 +/- 2 wk were recruited. Anthropometric measures were recorded, and interviews were conducted at enrollment and monthly until 6 mo of age. Blood samples were collected at enrollment and at 4 and 6 mo. RESULTS: Formula intake did not differ between groups, and weight gain in the alpha-lactalbumin-enriched formula groups were similar to that of the breastfed infants. The standard formula group gained significantly more weight than did the breastfed infants. All formula-fed infants had significantly higher plasma concentrations of most essential amino acids at 4 and 6 mo than did the breastfed infants, and serum urea nitrogen was also higher in the formula-fed infants. Insulin and leptin concentrations did not differ between groups. CONCLUSIONS: Compared with standard formula-fed infants, infants fed formula with a modified protein composition had growth patterns more similar to those of breastfed infants. All formula-fed groups had plasma amino acid concentrations similar to or higher than those of breastfed infants. This indicates that the protein content of alpha-lactalbumin-enriched formula can be further reduced, which should be evaluated.     

Glycomacropeptide and alpha-lactalbumin supplementation of infant formula affects growth and nutritional status in infant rhesus monkeys

BACKGROUND: Advances in dairy technology make it possible to enrich infant formula with specific bovine milk components that may enhance nutrient status. Glycomacropeptide, a carbohydrate-rich casein peptide, may increase absorption of calcium, iron, or zinc. alpha-Lactalbumin, a major breast-milk protein, may contribute to a balanced amino acid pattern and increase calcium and zinc absorption. OBJECTIVE: We determined the effects of glycomacropeptide- and alpha-lactalbumin-supplemented infant formula on growth; trace mineral status; iron, zinc, and calcium absorption; and plasma amino acid, blood urea nitrogen, and plasma insulin concentrations. DESIGN: Infant rhesus monkeys (n = 5 infants per group) were breastfed or fed control or alpha-lactalbumin- or glycomacropeptide-supplemented formula from birth to 4 mo of age. Hematologic measures and growth were assessed monthly. Mineral absorption was measured with radioisotopes and whole body counting. RESULTS: Infants fed glycomacropeptide had higher food intake than did other formula-fed infants. Infants fed glycomacropeptide or control formula had higher hematocrit values than did infants that were breastfed or fed alpha-lactalbumin. Infants fed glycomacropeptide or control formula had higher plasma zinc and zinc absorption than did breastfed infants. Where differences were observed, breastfed infants and infants fed alpha-lactalbumin had similar plasma essential amino acid and insulin profiles, which were different from those of infants fed glycomacropeptide or control formula. CONCLUSIONS: Glycomacropeptide- or alpha-lactalbumin-supplemented formula has no adverse effects on nutritional status in infant monkeys. Glycomacropeptide supplementation increases zinc absorption, which may permit the reduction of formula zinc concentrations, and alpha-lactalbumin supplementation promotes a plasma amino acid pattern similar to that of breastfed infant monkeys.     

Growth,Tolerance and Biochemical Measures in Healthy Infants Fed a Partially Hydrolyzed Rice Protein-Based Formula: A Randomized,Blinded, Prospective Trial

Objective: To evaluate growth, tolerance and plasma biochemistries in infants fed an experimental rice protein-based infant formula.

Design: Randomized, blinded, 16 week parallel feeding trial of 65 healthy infants fed either an experimental partially hydrolyzed rice protein-based infant formula fortified with lysine and threonine (RPF, n = 32), or a standard intact cow’s milk protein-based formula (CMF, n = 33) as a control. Assessments occurred at enrollment (average 2 days), 2, 4, 8, and 16 weeks of age.

Results: Growth as indicated by weight, length, and head circumference was not different between the 2 formula groups. All plasma biochemistries for both groups were within reference normal range. However, RPF group had lower phosphorus and urea nitrogen, lower essential amino acids except threonine, which was higher, and lower ratio of essential (including semi-essential) to non-essential amino acids. Differences in the concentrations and ratios of amino acids became less as feeding progressed with age. Plasma total protein, albumin, prealbumin, calcium, magnesium, and alkaline phosphatase were not different between groups.

Conclusion: Healthy infants fed an experimental partially hydrolyzed rice protein-based formula had normal growth, tolerance, and plasma biochemistry comparable to those of infants fed a standard intact milk protein-based formula, despite some differences in amino acid profiles.     

Tryptophan intake influences infants' sleep latency.

Formula-fed infants have depressed plasma tryptophan concentration relative to human milk-fed infants. Because tryptophan alters sleep-waking patterns in adults, a study was designed to determine whether additional dietary tryptophan could elevate plasma tryptophan concentrations of formula-fed infants to concentrations characteristic of human milk feeding and whether differences in plasma tryptophan or the ratio of plama tryptophan to the sum of the other plasma large neutral amino acids (tryptophan:LNAA) were of behavioral significance. Infants were fed a formula (13 g protein/L; whey:casein, 34:66) containing either 0, 294, 588 or 882 mumol/L of added tryptophan. Infants fed human milk or commercial formula (15 g protein/L; whey:casein, 18:82) were included for comparison. In formula-fed groups, plasma tryptophan was directly related to tryptophan intake (r = 0.46, P less than 0.0005). Infants fed commercial formula or the formula without added tryptophan had lower (P less than 0.001) plasma tryptophan compared with infants fed human milk. Only the infants fed the highest tryptophan formula had significantly higher plasma tryptophan:LNAA ratios than the other experimental groups, and these ratios were similar to those of infants fed human milk. The plasma tryptophan:LNAA ratios, not plasma tryptophan concentrations, were predictive of differences in the infants' sleep latency; infants fed formula containing the highest tryptophan had sleep latencies of 18.7 min, significantly shorter (P less than 0.05) than those of infants fed formulas containing less added tryptophan (27.7 min). Feeding infants formulas differing in tryptophan concentration produced differences in sleep latency, which could influence neurobehavioral developments.(ABSTRACT TRUNCATED AT 250 WORDS)     

Methionine fortification of a soy protein formula fed to infants

Data from study of nine normal full-term infants fed a soy isolate-based formula unsupplemented with methionine were compared with similar data from study of 10 similar infants fed the same formula supplemented with L-methionine and with data from previous studies of larger groups of infants receiving various other feedings. Food intake, growth, and serum chemical values were studied from 8 through 111 days of age. In addition, nitrogen balance studies were carried out. Statistically significant differences were as follows: lesser weight gain per 100 kcal by infants fed the unsupplemented soy isolate-based formula than by infants fed milk-based or other soy isolate-based formulas; lesser serum concentrations of albumin at age 28 days by infants fed the unsupplemented soy isolate-based formula than by breast-fed infants; greater serum concentrations of urea nitrogen by infants receiving the unsupplemented soy isolate-based formula than by those receiving the same formula supplemented with L-methionine. A number of other differences was noted but were not statistically significant. The results suggest that normal infants fed a formula providing 2.25 /100 kcal of a soy protein isolate not fortified with methionine performed less well during the first 6 weeks of life than did breast-fed infants and infants fed milk-based formulas or other soy isolate-based formulas fortified with methionine. The limiting nutrient appears to have been methionine.     

Taurine and cholesterol supplementation in the term infant: responses of growth and metabolism

The effects of taurine and of cholesterol supplementation to a whey-protein-predominant formula fed ad libitum on the growth and biochemical responses of term infants were studied. The responses of these infants were compared to those of infants fed formula without a supplement and infants that were breastfed. These infants were followed for 12 weeks. No effect of cholesterol was observed on any of the measurements and no effect of taurine was observed on any of the biochemical measures with the exception that taurine concentrations in plasma and urine (reduced in infants fed formula alone) were corrected to concentrations observed in breastfed infants. Taurine supplementation had no effect on the rate of weight gain or on linear growth over the complete course of the study. Thus, taurine supplementation of formulas returns plasma and urine concentrations of this amino acid to those found in human milk-fed infants. However, these data indicate that the supplementation of formulas with taurine has no benefit with respect to growth.     

Growth, tolerance and biochemical measures in healthy infants fed a partially hydrolyzed rice protein-based formula: a randomized, blinded, prospective trial

OBJECTIVE: To evaluate growth, tolerance and plasma biochemistries in infants fed an experimental rice protein-based infant formula. DESIGN: Randomized, blinded, 16 week parallel feeding trial of 65 healthy infants fed either an experimental partially hydrolyzed rice protein-based infant formula fortified with lysine and threonine (RPF, n = 32), or a standard intact cow's milk protein-based formula (CMF, n = 33) as a control. Assessments occurred at enrollment (average 2 days), 2, 4, 8, and 16 weeks of age. RESULTS: Growth as indicated by weight, length, and head circumference was not different between the 2 formula groups. All plasma biochemistries for both groups were within reference normal range. However, RPF group had lower phosphorus and urea nitrogen, lower essential amino acids except threonine, which was higher, and lower ratio of essential (including semi-essential) to non-essential amino acids. Differences in the concentrations and ratios of amino acids became less as feeding progressed with age. Plasma total protein, albumin, prealbumin, calcium, magnesium, and alkaline phosphatase were not different between groups. CONCLUSION: Healthy infants fed an experimental partially hydrolyzed rice protein-based formula had normal growth, tolerance, and plasma biochemistry comparable to those of infants fed a standard intact milk protein-based formula, despite some differences in amino acid profiles.     

The EU Childhood Obesity Project

The European Union Childhood Obesity Project was set up in 2001 to test the hypothesis that the higher risk of obesity seen in formula‐fed infants – as compared with breastfed babies – is a result of the higher protein content in infant formulas than in breastmilk. The infants participating in the study were recruited between 2002 and 2004 and followed up for 2 years. The first results of the study were published earlier this year. After 2 years, the weight‐for‐length and body mass index of the infants fed the lower‐protein formula were significantly lower than those fed the higher‐protein formulas. Extrapolating from previous studies suggests that the children in the higher‐protein group have a 13% increased risk of being obese in adolescence compared with those in the lower‐protein group. An analysis of the timing of weaning has also been published: this showed that formula‐fed infants were given solid foods on average 2 weeks earlier than breastfed infants (19 weeks compared with 21 weeks) and were twice as likely to be introduced to solid foods before the age of 4 months as breastfed infants.     

Phenylalanine kinetics differ between formula-fed and human milk-fed preterm infants

Infants fed casein-dominant formulas have higher plasma phenylalanine and tyrosine concentrations than those fed mother's milk. Conversely, elevated plasma threonine concentrations are observed in infants fed whey-dominant formulas. We recently showed that formula-fed preterm infants have a lower capacity to degrade threonine than do preterm infants fed mother's milk. We hypothesized that these same infants (n = 18) would differ in their catabolism of phenylalanine in response to phenylalanine loads provided by formulas with increasing casein content of formulas (whey:casein 60:40, 40:60, and 20:80) compared with preterm infants fed mother's milk. Plasma phenylalanine concentrations significantly rose (49, 46, 79 micromol . L(-1) for whey:casein 60:40, 40:60, and 20:80, respectively, pooled SD 8, P < 0.05); and plasma phenylalanine concentrations in infants fed mother's milk were low (40 +/- 4 micromol . L(-1)). Using [1-(13)C]phenylalanine tracer and (13)CO(2) production in breath we found that although there was a significant positive relation between phenylalanine oxidation and phenylalanine intake in formula-fed infants (r(2) = 0.43, P = 0.03), these infants were not able to increase their oxidation of phenylalanine enough to prevent a significant rise in plasma phenylalanine when fed the 20:80 formula. Compared to infants fed mother's milk, formula-fed infants had significantly lower phenylalanine oxidation (39.1 vs. 30.7% of phenylalanine intake, respectively, P < 0.05). We conclude that one of the mechanisms for the differences in plasma amino acid concentration between formula-fed and mother's milk-fed preterm infants may be in vivo down-regulated catabolism of 2 important essential amino acids (phenylalanine in addition to threonine) in formula-fed preterm infants.     

Subject Index to Volume 9

To compare the effects of the exogenous supply of long-chain polyunsaturated fatty acids (LCP) and cholesterol on the lipid and fatty acid status in full-term, 4-month old infants.

Twenty-three infants received a standard infant formula while twenty-one were given a formula enriched with LCP and cholesterol in a prospective, randomized study. The composition of the two formulas differed only in fat quality. A group of fifteen breastfed infants fed was used as reference. No one was complemented with solid foods before blood sampling at 4 months of life.

Differences in total-cholesterol and low-density lipoprotein-cholesterol (LDL-C) levels between feeding groups were mainly gender-related. Dietary cholesterol tended to increase LDL-C plasma levels. The breastfed and the enriched formula-fed groups had higher levels of circulating LCP than the group that received the standard formula. In the erythrocytes of infants fed the standard formula, C22:6 n-3 levels were less than 50% those of the breastfed and the enriched formula-fed ones. Higher C20:4 n-6 levels were found in the erythrocytes of the enriched formula-fed group.

Formula-fed, full-term infants maintain a lipid and fatty acid status close to that of breastfed infants when supplied with dietary LCP and cholesterol.     

The Association of Formula Protein Content and Growth in Early Infancy: A Systematic Review and Meta-Analysis

This systematic review aimed to examine differences in growth outcomes between breastfed infants and infants fed with formula with different protein/energy ratios during the first six months of life. We conducted a systematic review in the PubMed, Web of Science, and Springer databases. Twenty clinical trials qualified for inclusion. We extracted data about the growth outcomes of infants who were exclusive breastfed or exclusively infant formula fed in the first six months and used a meta-analysis to pool the finding data. We categorized study formulas into four groups according to their protein content: <1.8, 1.8–2.0, 2.1–2.2, and >2.2 g/100 kcal. In the first month of life, growth was not different between formula- and breastfed infants. During 2–3 months of life, growth was faster in infants who consumed formulas with protein contents higher than 2.0 g/100 kcal. After 3 months, formula-fed infants grew faster than breastfed infants. Our meta-analysis indicated that the growth outcomes of infants fed with infant formula with a relatively low protein/energy ratios, compared with that a relatively high protein/energy ratio, were close to those of breastfed infants.     

Amino acid responses to dietary intake in the first 72 hours of life

Plasma free amino acid concentrations were measured in cord blood and at 24, 48, and 72h of age in term infants who were either breastfed or fed a whey- or casein-predominant standard term-infant formula. There was a significant initial decrease in the concentrations of almost all amino acids compared with cord blood. Statistically significant effects of the type of feeding were observed in the concentrations of methionine, cystine, tyrosine, alanine, and p-serine; similarly, significant effects of postnatal age were noted in the concentrations of all amino acids with the exception of cystine. These data suggest that the metabolic milieu changes rapidly after delivery, influenced both by postnatal age and by type of feeding. Cord blood urea and histidine concentrations were significantly higher in female infants than in male infants; the route of delivery (cesarean section v vaginal delivery) affected only cord blood concentrations of alanine (vaginal greater than C-section). These data suggest that amino acid responses to the quality of dietary protein observed in infancy (for example, high tyrosine concentrations in response to feeding a casein-predominant formula) develop in the immediate postnatal period.     

Effect of reducing the phytate content and of partially hydrolyzing the protein in soy formula on zinc and copper absorption and status in infant rhesus monkeys and rat pups

BACKGROUND: Although soy formulas have been designed to meet the nutrient requirements of human infants, they also contain phytate, which may negatively affect trace element absorption. OBJECTIVE: We evaluated the effect of removing phytate on zinc and copper absorption and status in infant rhesus monkeys and suckling rat pups and evaluated differences between intact and partially hydrolyzed soy protein. DESIGN: In monkeys, regular and low-phytate soy formulas were fed exclusively for 4 mo and whole-body absorption and retention of 65Zn, 67Cu, 59Fe, 54Mn, and 47Ca were determined at different time points with a whole-body counter. Subsequently, zinc and copper absorption from several human infant formulas and the effect of phytate concentration were evaluated in suckling rat pups by using 65Zn and 64Cu. Finally, infant rhesus monkeys were fed low-phytate formulas with intact or hydrolyzed soy protein for 4 mo and plasma zinc and copper were measured monthly. RESULTS: In the first monkey study, zinc absorption at 1 mo was higher from low-phytate soy formula (36%) than from regular soy formula (22%), whereas there was no significant difference between groups in the absorption of other minerals. Plasma copper was significantly lower in monkeys fed low-phytate soy formula from 2 to 4 mo. In rat pups, zinc absorption was significantly higher from low-phytate soy formula (78%) than from regular soy formula (51%) and hydrolysis of the protein had no significant effect. Phytate content or protein hydrolysis did not significantly affect copper absorption. In the second monkey study, plasma copper concentrations were highest in monkeys fed the low-phytate, hydrolyzed-protein soy formula. CONCLUSION: Reducing the phytate content and partially hydrolyzing the protein in soy formula had a beneficial effect on zinc and copper absorption and status in infant rhesus monkeys.     

Selenium status of term infants fed selenium-supplemented formula in a randomized dose-response trial

BACKGROUND: The optimal form and dose of selenium supplementation required to achieve indicators of selenium status equivalent to those in breastfed infants are unclear. OBJECTIVE: The objective was to evaluate the effect of fortifying infant formula (6 microg Se/L) with 2 concentrations of selenate (7 and 15 microg/L) on biochemical indicators of selenium status and growth at 16 wk in term infants. DESIGN: A randomized dose-response trial was conducted in 3 groups of term infants fed formula with different selenium concentrations [6 microg/L, F+0 (control); 13 microg/L, F+7; and 21 microg/L, F+15] and in a parallel breastfed reference group (BF; 11 +/- 2 microg Se/L). RESULTS: One hundred sixty-one (47% males) infants completed the 16-wk study. Baseline plasma selenium was 0.3 +/- 0.1 micromol/L. At 16 wk, plasma selenium had increased in all groups (P < 0.001) and was greater (P < 0.01) in the F+7 and F+15 groups and lower (P < 0.05) in the F+0 group than in the BF group. Plasma glutathione peroxidase increased in the F+15 group, decreased in the F+0 group, and, at 16 wk, was lower in the F+0 group than in the other groups (all P < 0.05). Erythrocyte selenium and glutathione peroxidase decreased in all groups (P < 0.05), but the magnitude of the change was greater in the F+0 than in the F+15 group (P < 0.05). There was no effect of selenium supplementation on growth. CONCLUSIONS: Selenate fortification of formula resulted in an increase in plasma indicators of selenium status relative to indicators observed in infants fed low-selenium-containing formula. Although the erythrocyte indicators decreased in all groups, the 21-microg/L dose (F+15 group) resulted in a smaller decrease and in higher erythrocyte selenium than did the standard formula. Supplementation of low-selenium formula to provide a net selenium concentration close to that found in the breast milk of US women (18 microg/L) may be justified.     

Infant formulas with increased concentrations of alpha-lactalbumin

Human and bovine milk differ substantially in the ratio of whey to casein protein (approximately 60:40 in human milk and approximately 20:80 in bovine milk) and in the proportions of specific proteins. Although current infant formulas closely mimic the ratio of total whey to casein inhuman milk, the concentration of a-lactalbumin (the dominant protein in human milk) is relatively low in formula, whereas beta-lactoglobulin, a protein not found in human milk, is the most dominant whey protein in formula. Because of the differences in the protein profiles of human milk and infant formula, amino acid profiles also differ. To meet all essential amino acid requirements of infants, formula concentrations of protein must be higher than those in human milk. Recently, whey sources with elevated concentrations of alpha-lactalbumin have become available, which permitted the development of formulas with increased concentrations of this protein and decreased concentrations of beta-lactoglobulin. alpha-Lactalbumin is rich in tryptophan, which is typically the limiting amino acid in formula, and as a result, formulas have been developed with lower protein but higher tryptophan concentrations. This type of formula may offer a number of advantages to the neonate, which include producing plasma tryptophan concentrations equal to those found in breastfed infants and obviating the need for the body to dispose of excess nitrogen loads.     

Changes in the fatty acid profiles of plasma lipid fractions induced by dietary nucleotides in infants born at term

This study was designed to determine the polyunsaturated fatty acid (PUFA) composition of plasma lipid fractions in newborn infants fed human milk (HM), milk formula (MF) or nucleotide-supplemented milk formula (NMF) during the first month of life. Linoleic acid was increased in infants fed formulas in all plasma lipid fractions with respect to those fed HM. Plasma phospholipids in MF-fed infants had lower percentages of PUFA of both omega 6 and omega 3 series, namely arachidonic and docosahexaenoic acids, than those fed HM or NMF; the unsaturation index was decreased in infants fed MF as compared to those fed HM or NMF. Arachidonic acid showed a similar behaviour in plasma cholesteryl esters as in phospholipids. No changes for long chain PUFA among the groups studied were observed for plasma triglycerides and free fatty acids. These results support previous findings that dietary nucleotides are involved in the regulation of desaturation and elongation of linoleic and linolenic acid to their longer superior homologous fatty acids. We suggest that dietary nucleotides may reverse the partial inhibition of delta 5-desaturase caused by an excess of linoleic acid in the diet during early postnatal life.     

Requirement for sulfur-containing amino acids in infancy

A series of studies designed to define the requirement of normal infants for sulfur-containing amino acids (methionine, cystine) was conducted with formulas providing 3.0, 2.8, 2.6, 2.2 or 1.8 g of isolated soy protein per 100 kcal. The formulas were fed with or without a methionine supplement. Adequacy of the diet was determined by measurement of growth, serum chemical indices and nitrogen balance. Nitrogen balance demonstrated a beneficial effect of methionine supplementation only at the lowest protein concentration (1.8 g/100 kcal). However, measurement of weight gain and/or serum concentrations of urea nitrogen and albumin clearly showed a beneficial effect of methionine supplementation at protein concentrations of 2.2 and 2.6 g/100 kcal. Intakes of sulfur-containing amino acids of 435 and 495 mumol/100 kcal therefore appear inadequate. At higher intakes of protein (2.8 and 3.0 g/100 kcal) there was no beneficial effect of methionine supplementation. Possible exceptions were male infants provided with 3.0 g protein per 100 kcal, in whom weight gain between 8 and 56 d of age was significantly (P less than 0.05) greater with than without a methionine supplement. Based on intakes of sulfur-containing amino acids from the formula providing 2.8 g of isolated soy protein per 100 kcal without methionine supplementation, we conclude that for male infants older than 56 d the requirement for sulfur-containing amino acids is no more than 588 mumol/100 kcal when intake of methionine is 264 mumol/100 kcal. However, it seems possible that such intake fails to meet the requirement in male infants less than 56 d of age. For female infants, regardless of age, 533 mumol/100 of sulfur-containing amino acids per 100 kcal meet the requirement when intake of methionine is 239 mumol/100 kcal.     

Plasma fatty-acid composition and antioxidant capacity in low birth-weight infants fed formula enriched with n-6 and n-3 long-chain polyunsaturated fatty acids from purified phospholipids

OBJECTIVE: To determine whether a formula containing n-6 and n-3 long-chain polyunsaturated fatty acids (LCP) from purified phospholipids increases the content of 20:4n-6 and 22:6n-3 of plasma lipids and modifies the plasma antioxidant capacity in low-birth-weight infants. STUDY DESIGN: Seventeen infants were fed a conventional formula for low birth-weight infants (F), and 17 a formula containing n-6 and n-3 LCP from purified pig-brain phospholipids (LCP-F). Fourteen infants receiving human milk from a human milk bank were used as a reference (HM). Growth index were measured and blood samples were taken at entry and after 15 days and 30 days of feeding. RESULTS: In infants fed LCP-F the levels of 22:6n-3 in total plasma lipids and in plasma phospholipids and triglycerides were higher than in infants fed F and closer to the levels of HM group throughout the study. Docosahexaenoic acid concentration in total plasma lipids was 3.46+/-0.19 mg/dl in infants fed LCP-F and 2.08+/-0.20 in infants fed F after 15 days of feeding (P<0.001), and 3.83+/-0.30 and 2.15+/-0.20 in infants fed LCP-F and F respectively, after 30 days of feeding (P<0.001). The concentration of 20:4n-6 in the LCP-F was significantly higher than in the F group at 15 and 30 days of feeding. Plasma antioxidant capacity did not differ significantly between the study groups. CONCLUSION: Feeding low birth-weight infants a formula containing LCP phospholipids results in an increase of n-3 and n-6 LCP in plasma towards that of infants fed human milk.     

Comparison of human milk with 3 different types of infant food in the nutrition of full-term neonates]

Healthy, term infants who were either breast-fed, or received conventional formula (Mildibé, EGIS; Pre-Aptamil, Milupa), or a formula containing hydrolyzed proteins (Aptamil H. A., Milupa) were investigated. Each group consisted of 10 infants who were fed ad libitum. Somatic development (gain in weight, length and head- and chest circumferences), serum Ca and P levels, alkaline phosphatase activities and basic biochemical parameters of protein metabolism (serum total protein, albumin, uric acid, creatinine and urea nitrogen levels) were determined at the ages of 2, 4 and 8 weeks. Anthropometric measurements did not reveal considerable differences between the groups investigated. At the age of four weeks, serum calcium levels were significantly higher in the breast-fed infants than in those receiving formula. Both at the ages of four and eight weeks, serum total protein levels were significantly lower in the infants receiving the formula consisting of hydrolyzed proteins than in the breast-fed controls. No difference of considerable extent was seen in the other biochemical parameters measured. The results obtained indicate that, in the lack of the possibility of breast-feeding, all the three formulae investigated can be used as substitute of breast milk.     

Extent of thermal processing of infant formula affects copper status in infant rhesus monkeys

BACKGROUND: Infant rhesus monkeys are excellent models in which to study the effect of infant formulas on trace element absorption and status. Infants fed powdered formula from birth exhibit normal growth and have blood variables similar to those of breast-fed infants. OBJECTIVES: The objectives were to evaluate the effects of feeding ready-to-feed (RTF) formulas exposed to different heat treatments to infant monkeys, and, for one of these formulas, to compare the effect of fortification with 2 iron concentrations. DESIGN: From birth to age 5 mo, infant monkeys (n = 6/group) were fed one of the following formulas exclusively: 1) 12 mg Fe/L processed in cans (RTF-12), 2) formula in glass bottles with 12 mg Fe/L and manufactured by an ultrahigh-temperature (UHT) process (UHT-12), or 3) formula manufactured by a standard thermal process (STP), containing either 8 (STP-8) or 12 (STP-12) mg Fe/L. All formulas had similar copper concentrations (0.6 mg Cu/L). Anthropometric measures and venous blood samples were taken monthly. RESULTS: Weight and length gain did not differ among groups; however, the STP-12 group weighed less than the UHT-12 group at ages 2, 4, and 5 mo. Hemoglobin values were significantly lower in the RTF-12 group than in all other groups at ages 4 and 5 mo and serum ferritin was lower in the RTF-12 group than in the STP-12 group at age 5 mo. Copper status was lower in STP-12 infants than in STP-8 infants. There was a progressive and significant decline in plasma copper, ceruloplasmin, and Cu/Zn superoxide dismutase activity in infants fed canned formula (RTF-12). Furthermore, coat color changed from normal brown to silver. These outcomes suggest that the canned formula induced copper deficiency in infant monkeys. CONCLUSIONS: Excessive heat treatment of formula can have a pronounced negative effect on copper status. High iron concentrations did not improve iron status but may adversely affect copper status.