The potential impact of nutrient profiles on dairy-related energy and nutrient intake in German children and adolescents.

BACKGROUND/OBJECTIVES: To evaluate the potential impact of nutrient profiling-based dairy product choices on energy and nutrient intake in German children and adolescents. SUBJECTS/METHODS: Consumption data were obtained from product-specific dietary records in the DONALD Study (Dortmund Nutritional and Anthropometric Longitudinally Designed Study). We compared actual intake data with intake data that were calculated based on the assumption that participants exclusively consumed products that met the criteria of selected nutrient profiling models. RESULTS: For most profiling models, the percentage of compliant products was unrelated to the percentage of the participants' dairy consumption rated eligible. The participants' intake of energy, saturated fatty acids (SAFA), sodium, calcium and vitamin D would be reduced significantly (P<0.0001) if only qualifying products were consumed. The impact on the participants' nutrient intake levels was not directly related to the impact on the product's nutrient content levels. Lower fat consumption was correlated with reduced vitamin D intake, and the models' disqualification of (semi-) hard cheeses had a negative impact on the calcium intake. CONCLUSIONS: The evaluation of product-specific intake data was critical to understand the potential impact of any profiling scheme on nutrient intake. Selecting dairy products based on nutrient profiling could help reduce the intake of less-desirable nutrients, such as SAFA and sodium. However, models that are too restrictive might negatively impact calcium and vitamin D intake. Ultimately, the effectiveness of nutrient profiling models will be determined by the fact whether or not complying foods are consumed.

Nutrient profiling and food label claims: evaluation of dairy products in three major European countries.

BACKGROUND/OBJECTIVES: This study reviews commercially available dairy products with nutrition or health-related on-pack communication against selected nutrient profiling models. It aims to provide guidance on the model characteristics required to appropriately categorise products into those that are suitable for carrying claims, versus those whose overall nutritional composition does not support such product communication. SUBJECTS/METHODS: More than 300 dairy products carrying claims were identified in Germany, France and the UK and evaluated against six existing nutrient profiling models. All models were assessed regarding their underlying principles, generated results and inter-model agreement levels. RESULTS: In most cases, products failed the criteria of a given model because of too high levels of total fat, saturated fatty acids, sugars and/ or sodium. The Swedish Keyhole and the Smart Choices Program were the most restrictive models and showed the highest level of agreement. In general, the application of nutrient profiles helped to select products with significantly lower average levels of nutrients that are linked to chronic diseases when consumed in excess. However, calcium levels were also highly impacted in some cases. CONCLUSIONS: A nutrient profiling model that targets saturated fatty acids, sugars and sodium can meaningfully and comprehensively identify dairy products with a favourable nutritional composition. However, thresholds have to be set carefully to not reduce the average calcium contribution of the category. The use of separate criteria for cheeses and other dairy products seems necessary to take into account intrinsic compositional differences.

Fine bakery wares with label claims in Europe and their categorisation by nutrient profiling models.

BACKGROUND/OBJECTIVES: This study assesses a range of commercially available fine bakery wares with nutrition or health related on-pack communication against the criteria of selected nutrient profiling models. Different purposes of the application of nutrient profiles were considered, including front-of-pack signposting and the regulation of claims or advertising. SUBJECTS/METHODS: More than 200 commercially available fine bakery wares carrying claims were identified in Germany, France, Spain, Sweden and United Kingdom and evaluated against five nutrient profiling models. All models were assessed regarding their underlying principles, generated results and inter-model agreement levels. RESULTS: Total energy, saturated fatty acids, sugars, sodium and fibre were critical parameters for the categorisation of products. The Choices Programme was the most restrictive model in this category, while the Food and Drug Administration model allowed the highest number of products to qualify. According to all models, more savoury than sweet products met the criteria. On average, qualifying products contained less than half the amounts of nutrients to limit and more than double the amount of fibre compared with all the products in the study. None of the models had a significant impact on the average energy contents. CONCLUSIONS: Nutrient profiles can be applied to identify fine bakery wares with a significantly better nutritional composition than the average range of products positioned as healthier. Important parameters to take into account include energy, saturated fatty acids, sugars, sodium and fibre. Different criteria sets for subcategories of fine bakery wares do not seem necessary.

Effects of dietary long-chain polyunsaturated fatty acids on the essential fatty acid status of premature infants.

The effect of different diets on the percentage content of long-chain polyunsaturated fatty acids (LCP; metabolites of linoleic and alpha-linolenic acids) in plasma lipids was studied in 29 premature infants on days 4 and 21 of life. Eleven infants were fed human milk which supplies LCP (1.7% of the fatty acids), 10 a commercially available milk formula without LCP, and 8 a new formula enriched with LCP of the omega-6 and the omega-3 series (0.5% LCP). LCP values in plasma lipids remained stable during the observation period in infants fed human milk. In contrast, LCP decreased markedly in plasma lipids of infants fed the conventional formula. Since the precursor fatty acids linoleic and alpha-linolenic acids were high in their diet and plasma, this finding indicates that premature infants have a limited capacity for LCP biosynthesis and may require their dietary supplementation. Infants fed the LCP enriched formula had significantly higher LCP proportions in plasma lipids than infants given the conventional formula, but less than infants fed human milk. Our results demonstrate that small concentrations of dietary LCP have marked effects on plasma lipid composition, particularly on phospholipids, suggesting that dietary LCP are preferentially channelled into structural lipids. We conclude that the essential fatty acid status of formula-fed premature infants can be improved by a supplementation of omega-6- and omega-3-LCP.

Vitamin K1 content of maternal milk: influence of the stage of lactation, lipid composition, and vitamin K1 supplements given to the mother.

Using a sensitive electrochemical assay for vitamin K1 and standardized techniques for breast-milk collection, we studied the vitamin K1 content of human milk during the first 5 wk of lactation with respect to 1) individual and interindividual differences, 2) the relationship of vitamin K1 to other lipids, and 3) the influence of oral supplements of vitamin K1 on breast milk concentrations. Comparison of fore and hind milk from the mothers revealed higher vitamin K1 concentrations in hindmilks, suggesting that the lipid content influences the vitamin K1 concentration in maternal milk. Samples of maternal milk from nine mothers collected from day 1 to day 36 of lactation showed significantly higher vitamin K1 concentrations in colostral milk than in mature milk. For colostral milk there was a significant correlation of vitamin K1 to cholesterol (r = 0.62) but not to total lipid or phospholipid suggesting a role for cholesterol in the secretion of vitamin K1 into colostral milk. For mature milk correlation coefficients of vitamin K1 with all lipids were low (r = 0.29-0.37) suggesting that at later stages of lactation dietary fluctuations of vitamin K1 may be a more important determinant of the vitamin K1 content of breast milk than the lipid composition. To test the influence of diet, mothers were given oral supplements of vitamin K1.(ABSTRACT TRUNCATED AT 250 WORDS)

Vitamin E in human milk from mothers of preterm and term infants.

The content of vitamin E (alpha- and beta + gamma-tocopherol) was analyzed in 63 human milk samples obtained from 13 mothers of preterm infants ("preterm" milk) and in 59 milk samples obtained from nine mothers of full-term infants ("term" milk). The changing pattern of the alpha- and beta + gamma-tocopherol content during the course of lactation was identical for both groups. Total vitamin E, alpha- as well as beta + gamma-tocopherol, decreased during the first 2 weeks of lactation and remained constant thereafter. The ratio of alpha- to beta + gamma-tocopherol decreased from about 10:1 to 4:1. At days 3 and 36 of lactation, vitamin E contents (median values and ranges) expressed as milligrams alpha-tocopherol equivalent per 100 ml were 1.45 (0.64-6.4) and 0.29 (0.17-0.48), respectively, for preterm and 1.14 (0.63-4.21) and 0.28 (0.19-0.86), respectively, for term human milk. The vitamin E, alpha-tocopherol and beta + gamma-tocopherol content of preterm human milk did not differ significantly (p less than or equal to 0.05) from that of term human milk at each sampling day. Based on these findings we conclude that the increased requirement of prematures for vitamin E is not reflected in the vitamin E content of milk from mothers delivering preterm infants.

Effect of proteins on availability of zinc. II. Bioavailability of zinc from casein and whey protein--retention study in young rats.

The availability of zinc from two semi-synthetic diets with isolated whey protein (Wp D) or with isolated casein (Cas D) as protein component (20% W/W) was compared in a 21-day study with growing male rats (initial weight 40 g; 14 animals/group). Zinc concentration in both diets (18 ppm) was adequate to meet the requirements of the animals fed ad libitum. For radiolabeling approximately 13 micrograms 65Zn (= 4 microCi) was given daily by intragastric intubation to each animal. The investigation was designed primarily as a retention study, but also general parameters like weight development, food and water intake, organ weights etc. were registered and the activity of alkaline phosphatase was determined in serum and femur tissue. A significantly higher percentage of 65Zn was retained in the whole body from the Wp D (36.5%) than from the Cas D (31.6%) during the experimental period. The same is valid for the percentage retention of 65Zn in the femur and for the 65Zn concentration in femur and hair as well as for the total zinc concentration (65Zn and non-labeled zinc) of the femur. The other parameters determined were not unequivocally influenced by the protein component of the diet. The study clearly demonstrated that the availability of zinc by the growing rat was better from a diet with whey protein than from one with casein as the protein component. The reason on this phenomenon has to be elucidated by further investigations.

Biochemistry of human milk in early lactation.

With the analysis of more than 550 human milk samples we showed that triglycerides (accounting for 96-99% of the total lipids) increased from 2 to 3.5 g/100 ml mainly during the first week postpartum and remained constant thereafter. In contrast, both cholesterol and vitamin E concentrations decreased from 35 to 20 mg/100 ml and from 1.7 to 0.30 mg/100 ml, respectively. The phospholipids remained constant (40 mg/100 ml). Also the fatty acid composition of total lipids changed. Mid chain fatty acids (C10, C12, C14) increased, whereas the long chain polyunsaturated fatty acids decreased. The P/S-ratio of 0.32 remained constant throughout lactation. The mean protein content of human milk decreased from approximately 2 g/100 ml at day 2 to approximately 1 g/100 ml at day 36 of lactation. The content of each individual amino acid decreased likewise. However, when we expressed the amino acid values in relation to the protein value--that is as g amino acid per g protein--some decreased, some remained constant and some increased indicating a changing protein pattern. From these data we computer-calculated a sharp decrease in IgA content, a moderate decrease for lactoferrin and constant values for casein and a-Lactalbumin. Throughout the whole period of investigation, non protein nitrogen accounted for about 20% of total nitrogen. Although the absolute values decreased according to total nitrogen, the sum of free amino acids, as well as the amount of taurine, remained constant. Lactose increased from about 4 g/100 ml to 6 g/100 ml during the first days of lactation. The calcium content increased from a mean value of 25 mg/100 ml at day 1 to 32 mg/100 ml at day 5 and remained constant at 30 mg/100 ml up to day 36. Phosphorus content increased from 10 mg/100 ml at day 1 to 17 mg/100 ml at day 8 and then continuously decreased to 13 mg/100 ml at day 36. The protein-bound part of the calcium remained constant during the period investigation, the fat-associated part increased from 11% to 26%. Protein-bound phosphorus decreased from 45% in colostral milk to 29% in transitional and 23% in mature milk.

Biochemistry of maternal milk in early lactation.

The analysis of more than 550 human milk samples showed that triglycerides (accounting for 96-99 per cent of the total lipids) increased from 2 to 3.5 g/100 ml mainly during the first week postpartum and remained constant thereafter. In contrast, both cholesterol and vitamin E concentrations decreased from 35 to 20 mg/100 ml and from 1.7 to 0.30 mg/100 ml, respectively. The phospholipids remained constant (40 mg/100 ml). The fatty acid composition of total lipids showed remarkable changes. Mid-chain fatty acids (C10, C12, C14) increased, whereas the long-chain polyunsaturated fatty acids decreased. The P/S ratio of 0.32 remained constant throughout lactation. The mean protein content of human milk decreased from approximately 2 g/100 ml at day 2 to approximately 1 g/100 ml at day 36 of lactation. The content of each individual amino acid decreased likewise. However, when we expressed the amino acid values in relation to the protein value--that is as gram of amino acid per gram of protein--some decreased, some remained constant and some increased indicating a changing protein pattern. Throughout the whole period of investigation, non-protein nitrogen accounted for about 20 per cent of total nitrogen, taurine ranging at about 6 mg/100 ml. The calcium content increased from a mean value of 25 mg/100 ml at day 1 to 32 mg/100 ml at day 5 and remained constant at 30 mg/100 ml up to day 36. The mean phosphorus content increased from 10 mg/100 ml at day 1 to 17 mg/100 ml at day 8 and then continuously decreased to 13 mg/100 ml at day 36.

Effect of proteins on availability of zinc. I. Gastrointestinal transit time of casein and whey protein and zinc absorption in weaned rats.

The availability of zinc from isolated casein (CasD) was compared with that from whey protein (WpD) in 23-25 day old rats. The study was designed to show the course of the gastrointestinal transit time of either chyme (radiolabeled by 141Ce as a non-absorbable marker) or zinc (as 65Zn) in groups of 9 to 12 animals each. Animals were killed either 1/4, 1/2, 1, 2, 6, 12 or 24 hours after intragastric intubation of the protein suspensions. Immediately afterwards, intragastric pH was measured and the determination of zinc retention in intestinal tissues and liver as well as in the carcass was performed. 30 and 60 minutes after intubation the intragastric pH of the CasD group was significantly lower than that of the WpD group. The precipitation behaviour of the two protein fractions - compact curd formation by the CasD versus flocculent structure of the WpD - was determining for the pattern of gastric emptying. With the WpD the chyme was emptied according to an exponential function; while the CasD precipitate left the stomach in three distinct phases. With either protein suspension zinc left the stomach ealier than the bulk of the chyme, indicating a partial disintegration of the zinc-protein-complexes. With the WpD, zinc was emptied exponentially, whereas with the CasD a biphasic emptying pattern was found. Ileum was found to be the main zinc absorbing segment, mainly due to the long time of contact with zinc. After 2 and 12 hours zinc retention from the CasD was significantly higher than that from the WpD, however, after 24 hours retention was significantly better from the WpD. From the present study it can be concluded that, for comparison of zinc availability from diets containing different proteins, short-term experiments are not appropriate. Furthermore, it can be supposed that preabsorptive processes in the stomach are crucial for the availability of zinc.

Human milk nonprotein nitrogen components: changing patterns of free amino acids and urea in the course of early lactation.

Free amino acids and urea were analyzed in 78 human milk samples obtained during the first 5 wk of lactation from 10 mothers delivering at term. Significant differences (p less than 0.05) in the concentrations between colostral and mature milk were found for glutamic acid, glutamine, alanine, glycine, cystine, and phosphoethanolamine which increased, and with serine, phosphoserine, aspartic acid + asparagine, arginine, lysine, isoleucine, phenylalanine, proline, methionine, tryptophan, and beta-alanine which decreased. Some of these changes occurred within the first 5 days of lactation, so that differences between transitional and mature milk became negligible (glutamic acid, alanine, and serine, aspartic acid + asparagine, lysine, isoleucine, methionine, tryptophan, respectively). No significant differences between any of the three stages of lactation were found regarding the concentrations of total free amino acids, urea, taurine, threonine, valine, leucine, histidine, and tyrosine. Possible relevances for free amino acids, including nonprotein ones, in human milk are discussed.

[Dependency of human milk lipids on length of the lactation period, time of day, nursing and maternal diet]. / Abhängigkeit der Frauenmilchlipide von der Dauer der Stillperiode, der Tageszeit, dem Stillvorgang und der mütterlichen Ernährung.

The dependency of the human milk lipids triglycerides (TG), cholesterol (Chol), phospholipids (PL), and the fatty acid composition of both TG and PL on the stage of lactation, the day time, the course of one nursing, and on the mother's diet was shown by analyzing more than 350 milk samples. In progressing lactation (day 1-36) TG increased from 1.9 to 3.9 g/100 ml. Chol decreased from 35 to 20 mg/100 ml, while PL remained with 40 mg/100 ml rather constant. The resulting decrease in the PL/TG- and Chol/TG-ratios indicates an increasing size of fat globules. During one nursing, TG and Chol increased four-fold and PL doubled. During the day lipids (TG, Chol, PL) of the milk of German mothers reached their peak values in the afternoon, whereas the ones of milks obtained from English mothers were found in the late evening. With 3 mothers (n = 3) carbohydrate-rich diets (65 cal%) led to an increase of the milk fat content. In contrast high fat diets (50 cal%) resulted in milks with low fat contents (2.6/4.1 g/100 ml). Chol (20.8/37.5 mg/100 ml) and PL (26.4/45.3 mg/100 ml) showed the same dependency. The fatty acid composition changed mainly dependent on the duration of the lactation and the mother's diet, but not during one single nursing and during the day. Long-chain polyunsaturated fatty acids were higher in early than in mature milks. The P/S-ratio of TG was found to remain constant in progressing lactation (0.32), whereas the one of PL increased from 0.6 to 0.71. Dependent on the regimen of the mother the P/S-ratios (n = 3) were found to be 0.27 (high carbohydrate diet) and 0.46 (high fat/high linoleic acid diet).

Effects of the diet on the composition of human milk.

In a crossover study with 3 nursing mothers it was shown that the concentration and composition of human milk lipids and the concentration of lactose, but not that of protein, quickly respond to changes in the mother's diet. Triglycerides were high with low-fat/high-carbohydrate diets as compared to high-fat/low-carbohydrate diets. Lactose was affected reversibly. The intake of linoleic-acid-rich fats resulted in milk lipids with a respective high linoleic acid content. Milk cholesterol and phospholipid concentrations correlated positively with the respective triglyceride concentrations.

Capillary gas chromatography of fatty acid methyl esters from human milk lipid subclasses.

The fatty acid (FA) composition of the human milk lipid subclasses sphingomyelin, phosphatidylcholine, phosphatidylethanolamine and cholesterol esters (CE) were analysed by capillary gas chromatography (GC) on wall-coated open-tubular glass columns. Compared with GC on packed columns, capillary GC was found to be ten times more sensitive (0.1 microgram of each individual FA methyl ester could be quantified), and the time needed for the analysis could be reduced by a factor of five. The reproducibility of the analysis was good relative standard deviation (4-7%) and comparable to that obtained by packed column GC.

Changing patterns of human milk lipids in the course of the lactation and during the day.

Lipids were analyzed in 308 human milk samples, obtained during the first 5 wk of lactation from 17 mothers delivering at term. The mean triglyceride content increased mainly during the 1st postpartum wk and remained constant thereafter. In contrast, the cholesterol concentration decreased, whereas the phospholipids remained rather constant, resulting in a decrease of both the phospholipid/triglyceride and the cholesterol/triglyceride ratio. Circadian variations of the parameters analyzed were not uniform and differed in milks obtained from German mothers as compared to milks obtained from English mothers. The fatty acid composition was determined in the total lipids and in the phospholipid fraction as well. Changes were found in progressing lactation, but not during the day. Some data are discussed with regard to their possible physiological or physiochemical relevance.

Variation in the composition of breast milk during the first 5 weeks of lactation: implications for the feeding of preterm infants.

Milk samples were collected from 10 mothers by a standardised technique with complete expression of both breasts at each feed for 24 hours. Samples were obtained at 8 intervals during the first 36 days of lactation. Analyses were performed for trichloroacetic acid-precipitable protein, total protein, lactose, triglycerides, phospholipids, cholesterol, energy, sodium, potassium, calcium, magnesium, zinc, copper, pH, and osmolality. The results give a comprehensive picture of the development of milk composition from transitional to mature milk. The most striking feature of the results was the high degree of variation observed both between samples from the same mother and between samples from different mothers on the same day of lactation.