Early determinants of development: a lipid perspective

The protective effect of breastfeeding on febrile seizures: a systematic review with meta-analysis

Several potential risk factors have been identified in the etiopathogenesis of febrile seizures (FS), including the type and extent of breastfeeding (BF). Given the lack of conclusive data, this study aims to systematically evaluate the evidence on the association between BF and FS. We conducted a systematic review and meta-analysis according to PRISMA guidelines. The search was conducted using descriptors for FS, BF, and formula feeding in MEDLINE, Embase, and Web of Science databases. We included observational studies that compared the incidence of FS between those who had ever breastfed and those who were formula fed. The study protocol was registered on the PROSPERO platform under the number CRD42023474906. A total of 1,893,079 participants from 8 datasets were included. Our main analysis showed no significant association of any type of BF on the incidence of FS compared with formula-fed children (OR: 0.84; CI: 0.67-1.04; I2 = 78%; Cochran's Q = 0.0001), although meta-regression showed that BF was associated with a lower incidence of FS in preterm infants. Our secondary outcome showed a significantly reduced incidence of FS in children who received BF exclusively (OR: 0.80; CI: 0.65-0.99; I2 = 70%; Cochran's Q = 0.02).    Conclusion: There was no significant reduction in the incidence of FS in those who were breastfed compared to formula feeding. However, our meta-regression analysis indicated an association between BF and a lower incidence of FS in preterm infants. Additionally, children who exclusively received BF had a significantly reduced incidence of FS. These findings should be further investigated in prospective cohorts. What is Known: • Breastfeeding can modify risk factors for febrile seizures, such as susceptibility to viral and bacterial infections, micronutrient deficiencies, and low birth weight. • However, studies have shown conflicting results regarding the impact of breastfeeding on febrile seizures. What is New: • When comparing any breastfeeding pattern with no breastfeeding, there is no significant difference in the incidence of febrile seizures. • When comparing exclusive breastfeeding with no breastfeeding, there may be a decrease in the occurrence of febrile seizures.

Overview of sialylation status in human nervous and skeletal muscle tissues during aging

Sialic acids (Sias) are a large and heterogeneous family of electronegatively charged nine-carbon monosaccharides containing a carboxylic acid and are mostly found as terminal residues in glycans of glycoproteins and glycolipids such as gangliosides. They are linked to galactose or N-acetylgalactosamine via α2,3 or α2,6 linkage, or to other Sias via α2,8 or more rarely α2,9 linkage, resulting in mono, oligo and polymeric forms. Given their characteristics, Sias play a crucial role in a multitude of human tissue biological processes in physiological and pathological conditions, ranging from development and growth to adult life until aging. Here, we review the sialylation status in human adult life focusing on the nervous and skeletal muscle tissues, which both display significant structural and functional changes during aging, strongly impacting on the whole human body and, therefore, on the quality of life. In particular, this review highlights the fundamental roles played by different types of glycoconjugates Sias in several cellular biological processes in the nervous and skeletal muscle tissues during adult life, also discussing how changes in Sia content during aging may contribute to the physiological decline of physical and nervous functions and to the development of age-related degenerative pathologies. Based on our current knowledge, further in-depth investigations could help to develop novel prophylactic strategies and therapeutic approaches that, by maintaining and/or restoring the correct sialylation status in the nervous and skeletal muscle tissues, could contribute to aging slowing and the prevention of age-related pathologies.

Long-Chain Polyunsaturated Fatty Acids, Homocysteine at Birth and Fatty Acid Desaturase Gene Cluster Polymorphisms are Associated with Children's Processing Speed up to Age 9 Years

Both pre- and early postnatal supplementation with docosahexaenoic acid (DHA), arachidonic acid (AA) and folate have been related to neural development, but their long-term effects on later neural function remain unclear. We evaluated the long-term effects of maternal prenatal supplementation with fish-oil (FO), 5-methyltetrahydrofolate (5-MTHF), placebo or FO + 5-MTHF, as well as the role of fatty acid desaturase (FADS) gene cluster polymorphisms, on their offspring's processing speed at later school age. This study was conducted in NUHEAL children at 7.5 (n = 143) and 9 years of age (n = 127). Processing speed tasks were assessed using Symbol Digit Modalities Test (SDMT), Children Color Trails Test (CCTT) and Stroop Color and Word Test (SCWT). Long-chain polyunsaturated fatty acids, folate and total homocysteine (tHcy) levels were determined at delivery from maternal and cord blood samples. FADS and methylenetetrahydrofolate reductase (MTHFR) 677 C > T genetic polymorphisms were analyzed. Mixed models (linear and logistic) were performed. There were significant differences in processing speed performance among children at different ages (p < 0.001). The type of prenatal supplementation had no effect on processing speed in children up to 9 years. Secondary exploratory analyses indicated that children born to mothers with higher AA/DHA ratio at delivery (p < 0.001) and heterozygotes for FADS1 rs174556 (p < 0.05) showed better performance in processing speed at 9 years. Negative associations between processing speed scores and maternal tHcy levels at delivery were found. Our findings suggest speed processing development in children up to 9 years could be related to maternal factors, including AA/DHA and tHcy levels, and their genetic background, mainly FADS polymorphism. These considerations support that maternal prenatal supplementation should be quantitatively adequate and individualized to obtain better brain development and mental performance in the offspring.

Decoding the Metabolome and Lipidome of Child Malnutrition by Mass Spectrometric Techniques: Present Status and Future Perspectives

Child malnutrition (CM) is a global public health problem. It contributes to poor health in one in four children under five years worldwide and causes serious health problems in children, including stunted, wasted, and overweight growth. These serious public health issues lead to a higher chance of living in poverty in adulthood. Malnutrition is related with reduced economic productivity and increases the serious national and international burden. Currently, there is no meaningful therapeutic intervention of CM, and the use of different therapeutic foods has shown poor outcomes among supplemented malnourished children. The role of metabolites and lipids has been extensively recognized as early determinants of child health, but their contribution in CM and its pathobiology are poorly understood. This perspective provides a most recent update on these aspects. After briefly introducing the disciplines of metabolomics and lipidomics, we describe a mass spectrometry-based metabolic workflow for analysis of both metabolites and lipids and summarize several recent applications of metabolomics and lipidomics in CM. Finally, we discuss the future directions of the field toward the development of meaningful interventions for CM through metabolomics and lipidomics advances.

Gender-Associated Impact of Early Leucine Supplementation on Adult Predisposition to Obesity in Rats

Early nutrition plays an important role in development and may constitute a relevant contributor to the onset of obesity in adulthood. The aim of this study was to evaluate the long-term impact of maternal leucine (Leu) supplementation during lactation on progeny in rats. A chow diet, supplemented with 2% Leu, was supplied during lactation (21 days) and, from weaning onwards, was replaced by a standard chow diet. Then, at adulthood (6 months of age), this was replaced with hypercaloric diets (either with high-fat (HF) or high-carbohydrate (HC) content), for two months, to induce obesity. Female offspring from Leu-supplemented dams showed higher increases in body weight and in body fat (62%) than their respective controls; whereas males were somehow protected (15% less fat than the corresponding controls). This profile in Leu-females was associated with altered neuronal architecture at the paraventricular nucleus (PVN), involving neuropeptide Y (NPY) fibers and impaired expression of neuropeptides and factors of the mTOR signaling pathway in the hypothalamus. Interestingly, leptin and adiponectin expression in adipose tissue at weaning and at the time before the onset of obesity could be defined as early biomarkers of metabolic disturbance, predisposing towards adult obesity under the appropriate environment.

Lipids in human milk

Fat is the main energy providing component in human milk and comprising a complex mixture of different lipid species, with quantitative dominance of triglycerides. After elucidating the fatty acid composition, more recent research has looked at influencing factors and the importance of specific lipids. Here we review quantitative aspects of maternal metabolism which contribute to the milk fatty acid composition, especially considering essential fatty acids and their long chain polyunsaturated derivatives. In this context studies with stable isotopes have indicated the importance of maternal body pools for mediating the effects of diet on milk composition. Furthermore, the importance of positioning of palmitic acid at the glycerol backbone of triglycerides is discussed, and the phospholipids of the milk fat globule membrane are described and examples for their potential importance for infant development are presented.

Benefits of Lactoferrin, Osteopontin and Milk Fat Globule Membranes for Infants

The provision of essential and non-essential amino acids for breast-fed infants is the major function of milk proteins. In addition, breast-fed infants might benefit from bioactivities of milk proteins, which are exhibited in the intestine during the digestive phase and by absorption of intact proteins or derived peptides. For lactoferrin, osteopontin and milk fat globule membrane proteins/lipids, which have not until recently been included in substantial amounts in infant formulas, in vitro experiments and animal models provide a convincing base of evidence for bioactivities, which contribute to the protection of the infant from pathogens, improve nutrient absorption, support the development of the immune system and provide components for optimal neurodevelopment. Technologies have become available to obtain these compounds from cow´s milk and the bovine compounds also exhibit bioactivities in humans. Randomized clinical trials with experimental infant formulas incorporating lactoferrin, osteopontin, or milk fat globule membranes have already provided some evidence for clinical benefits. This review aims to compare findings from laboratory and animal experiments with outcomes of clinical studies. There is good justification from basic science and there are promising results from clinical studies for beneficial effects of lactoferrin, osteopontin and the milk fat globule membrane complex of proteins and lipids. Further studies should ideally be adequately powered to investigate effects on clinically relevant endpoints in healthy term infants.

High cholesterol dietary intake during pregnancy is associated with large for gestational age in a sample of low-income women of Rio de Janeiro, Brazil

The association between the quality of maternal dietary fat intake during pregnancy and the infant's birthweight (BW) remains controversial. Our goal was to investigate the association between maternal dietary fat intake during pregnancy and the rate of large for gestational age (LGA) newborns. This study employed a cross-sectional analysis of 297 pairs of mothers/children attending a public maternity at Rio de Janeiro, Brazil. BW for gestational age according to the Intergrowth 21st was defined as follows: adequate for gestational age (AGA ≤ 90th percentile) and LGA (>90th percentile). The statistical analysis was a Poisson regression with robust estimations of the standard errors. Maternal dietary fat intake variables comprised lipids (% total energy); saturated (mg/1000 kcal), monounsaturated (mg/1000 kcal) and polyunsaturated (mg/1000 kcal) fats; and cholesterol (mg/1000 kcal), all of which were obtained with a Food Frequency Questionnaire. The mean BW was 3338 g (SD = 446.9), and the rate of LGA newborns was 13.1%. The mean maternal total energy intake was 2880 kcal (SD = 1074), cholesterol was 154.3 mg/1000 kcal (SD = 68.1) and monounsaturated fat was 6.9 mg/1000 kcal (SD = 2). Mothers of LGA newborns reported higher cholesterol dietary intake (195.8 vs. 148 mg/1000 kcal; P < 0.001), pre-pregnancy body mass index (25.1 vs. 23.5 kg/m2 ; P = 0.026) when compared with mothers of AGA newborns. Women with cholesterol intake within the fourth quartile were 2.48 (95% confidence interval: 1.31-4.66) times more likely to have an LGA infant compared with those in the 1-3 quartiles. Dietary intake of cholesterol during pregnancy influences LGA even after adjusting for other confounders.

Role of Sphingolipids in Infant Gut Health and Immunity

Sphingomyelin (SM), glycosphingolipids, and gangliosides are important polar lipids in the milk fat globule membrane but are not found in standard milk replacement formulas. Because digestion and absorption of SM and glycosphingolipids generate the bioactive metabolites ceramide, sphingosine, and sphingosine-1-phosphate (S1P), and because intact gangliosides may have beneficial effects in the gut, this may be important for gut integrity and immune maturation in the neonate. The brush border enzymes that hydrolyze milk SM, alkaline sphingomyelinase (nucleotide phosphodiesterase pyrophosphatase 7), and neutral ceramidase are expressed at birth in both term and preterm infants. Released sphingosine is absorbed, phosphorylated to S1P, and converted to palmitic acid via S1P-lyase in the gut mucosa. Hypothetically, S1P also may be released from absorptive cells and exert important paracrine actions favoring epithelial integrity and renewal, as well as immune function, including secretory IgA production and migration of T lymphocyte subpopulations. Gluco-, galacto-, and lactosylceramide are hydrolyzed to ceramide by lactase-phlorizin hydrolase, which also hydrolyzes lactose. Gangliosides may adhere to the brush border and is internalized, modified, and possibly transported into blood, and may exert protective functions by their interactions with bacteria, bacterial toxins, and the brush border.

Milk fat globule membrane coating of large lipid droplets in the diet of young mice prevents body fat accumulation in adulthood

Epidemiological studies have demonstrated protective effects of breast-feeding on childhood obesity. Differences between human milk and infant milk formula (IMF) in dietary lipid structure may contribute to this effect. In our mouse model, feeding a diet containing large lipid droplets coated with phospholipids (PL) (Nuturis^®; PL of milk fat globule membrane (MFGM) fraction origin) in early life protected against excessive body fat accumulation following a diet challenge in adult life. We now set out to determine the relevance of increased droplet size and/or MFGM lipid droplet coating to the observed anti-obesogenic effects in adult life. From day 16 to 42, male mouse pups were exposed to diets with small (S) or large (L) lipid droplets (0·3 v. 2·9 µm average mode diameter, respectively), either without MFGM or with MFGM coating around the lipid droplet, resulting in four groups: S (control diet), L, S^coating and L^coating (Nuturis^® IMF diet). Mice were subsequently challenged with a Western-style diet until dissection at postnatal day 98. A non-challenged group served as reference (REF). We repeatedly determined body composition between postnatal day 42 and 98. At day 98 plasma and gene expression measurements were performed. Only the Nuturis^® IMF diet (L^coating) in early life containing MFGM-coated large lipid droplets reduced body fat mass to a level comparable with the REF group. These data support the notion that the structural aspects of lipids in human milk, for example, both lipid droplet size as well as the MFGM coating, may contribute to its reported protective effect against obesity in later life.

Long-Term Supplementation with Beta Serum Concentrate (BSC), a Complex of Milk Lipids, during Post-Natal Brain Development Improves Memory in Rats

We have previously reported that the supplementation of ganglioside-enriched complex-milk-lipids improves cognitive function and that a phospholipid-enriched complex-milk-lipid prevents age-related cognitive decline in rats. This current study evaluated the effects of post-natal supplementation of ganglioside- and phospholipid-enriched complex-milk-lipids beta serum concentrate (BSC) on cognitive function in young rats. The diet of male rats was supplemented with either gels formulated BSC (n = 16) or blank gels (n = 16) from post-natal day 10 to day 70. Memory and anxiety-like behaviors were evaluated using the Morris water maze, dark–light boxes, and elevated plus maze tests. Neuroplasticity and white matter were measured using immunohistochemical staining. The overall performance in seven-day acquisition trials was similar between the groups. Compared with the control group, BSC supplementation reduced the latency to the platform during day one of the acquisition tests. Supplementation improved memory by showing reduced latency and improved path efficiency to the platform quadrant, and smaller initial heading error from the platform zone. Supplemented rats showed an increase in striatal dopamine terminals and hippocampal glutamate receptors. Thus BSC supplementation during post-natal brain development improved learning and memory, independent from anxiety. The moderately enhanced neuroplasticity in dopamine and glutamate may be biological changes underlying the improved cognitive function.

Ready-to-use therapeutic food with elevated n-3 polyunsaturated fatty acid content, with or without fish oil, to treat severe acute malnutrition: a randomized controlled trial

BACKGROUND

Ready-to-use therapeutic foods (RUTF) are lipid-based pastes widely used in the treatment of acute malnutrition. Current specifications for RUTF permit a high n-6 polyunsaturated fatty acid (PUFA) content and low n-3 PUFA, with no stipulated requirements for preformed long-chain n-3 PUFA. The objective of this study was to develop an RUTF with elevated short-chain n-3 PUFA and measure its impact, with and without fish oil supplementation, on children's PUFA status during treatment of severe acute malnutrition.

METHODS

This randomized controlled trial in children with severe acute malnutrition in rural Kenya included 60 children aged 6 to 50 months who were randomized to receive i) RUTF with standard composition; ii) RUTF with elevated short chain n-3 PUFA; or iii) RUTF with elevated short chain n-3 PUFA plus fish oil capsules. Participants were followed-up for 3 months. The primary outcome was erythrocyte PUFA composition.

RESULTS

Erythrocyte docosahexaenoic acid (DHA) content declined from baseline in the two arms not receiving fish oil. Erythrocyte long-chain n-3 PUFA content following treatment was significantly higher for participants in the arm receiving fish oil than for those in the arms receiving RUTF with elevated short chain n-3 PUFA or standard RUTF alone: 3 months after enrollment, DHA content was 6.3% (interquartile range 6.0-7.3), 4.5% (3.9-4.9), and 3.9% (2.4-5.7) of total erythrocyte fatty acids (P <0.001), respectively, while eicosapentaenoic acid (EPA) content was 2.0% (1.5-2.6), 0.7% (0.6-0.8), and 0.4% (0.3-0.5) (P <0.001). RUTF with elevated short chain n-3 PUFA and fish oil capsules were acceptable to participants and carers, and there were no significant differences in safety outcomes.

CONCLUSIONS

PUFA requirements of children with SAM are not met by current formulations of RUTF, or by an RUTF with elevated short-chain n-3 PUFA without additional preformed long-chain n-3 PUFA. Clinical and growth implications of revised formulations need to be addressed in large clinical trials.

TRIAL REGISTRATION

Clinicaltrials.gov NCT01593969. Registered 4 May 2012.

Breast milk from women living near Lake Malawi is high in docosahexaenoic acid and arachidonic acid

Adequate long-chain polyunsaturated fatty acid (LCPUFA) intake is critical during the fetal and infant periods. We quantified fatty acid content of breast milk (n=718) and plasma from six month old infants (n=412) in southern Malawi, and in usipa (n=3), a small dried fish from Lake Malawi. Compared to global norms, Malawian breast milk fatty acid content (% of total fatty acids) was well above average levels of arachidonic acid [ARA] (0.69% vs. 0.47%) and docosahexaenoic acid [DHA] (0.73% vs. 0.32%). Average Malawian infant plasma ARA (7.5%) and DHA (3.8%) levels were comparable to those reported in infants consuming breast milk with similar fatty acid content. The amounts (mg) of DHA, EPA and ARA provided by a 3 oz (85 g) portion of dried usipa (1439, 659 and 360, respectively) are considerably higher than those for dried salmon. Usipa may be an important source of LCPUFA for populations in this region.

Heterogeneity in cord blood DHA concentration: towards an explanation

This paper aimed to identify the dietary and non-dietary determinants of docosahexaenoic acid (DHA) levels in umbilical cord blood at delivery. DHA was measured in cord blood plasma phospholipids of 1571 participants from the DOMInO (DHA to Optimize Mother Infant Outcome) randomized controlled trial. Socioeconomic, lifestyle and clinical data relating to the mother and current pregnancy were obtained from all women and their relationships with cord blood DHA assessed. DHA concentrations in the cord plasma phospholipids at delivery covered a 3-4 fold range in both control and DHA groups. The total number of DHA-rich intervention supplement capsules consumed over the course of pregnancy and gestational age at delivery individually explained 21% and 16% respectively of the variation in DHA abundance in the cord blood plasma phospholipids at delivery, but no other clinical or life-style factors explored in this study could account for >2% of the variation. Indeed, more than 65% of the variation remained unaccounted for even when all factors were included in the analysis. These data suggest that factors other than maternal DHA intake have an important role in determining cord blood DHA concentrations at delivery, and may at least partially explain the variation in the response of infants to maternal DHA supplementation reported in published trials.

Low docosahexaenoic acid status is associated with reduced indices in cortical integrity in the anterior cingulate of healthy male children: a 1H MRS Study

Docosahexaenoic acid (DHA, 22:6n-3) is the principal omega-3 fatty acid in mammalian brain gray matter, and emerging preclinical evidence suggests that DHA has neurotrophic and neuroprotective properties. This study investigated relationships among DHA status, neurocognitive performance, and cortical metabolism measured with proton magnetic resonance spectroscopy (1H MRS) in healthy developing male children (aged 8-10 years, n = 38). Subjects were segregated into low-DHA (n = 19) and high-DHA (n = 19) status groups by a median split of erythrocyte DHA levels. Group differences in 1H MRS indices of cortical metabolism, including choline (Cho), creatine (Cr), glutamine + glutamate + γ-aminobutyric acid (Glx), myo-inositol (mI), and n-acetyl aspartate (NAA), were determined in the right and left dorsolateral prefrontal cortex (R/L-DLPFC, BA9) and bilateral anterior cingulate cortex (ACC, BA32/33). Group differences in neurocognitive performance were evaluated with the Kaufman Brief Intelligence Test and identical-pairs version of the continuous performance task (CPT-IP). Subjects in the low-DHA group consumed fish less frequently (P = 0.02), had slower reaction times on the CPT-IP (P = 0.007), and exhibited lower mI (P = 0.007), NAA (P = 0.007), Cho (P = 0.009), and Cr (P = 0.01) concentrations in the ACC compared with the high-DHA group. There were no group differences in ACC Glx or any metabolite in the L-DLPFC and R-DLPFC. These data indicate that low-DHA status is associated with reduced indices of metabolic function in the ACC and slower reaction time during sustained attention in developing male children.

Dietary arachidonic acid and docosahexaenoic acid regulate liver fatty acid desaturase (FADS) alternative transcript expression in suckling piglets

Molecular regulation of fatty acid desaturase (Fads) gene expression by dietary arachidonic acid (ARA) and docosahexaenoic acid (DHA) during early post-natal period, when the demand for long chain polyunsaturated fatty acids (LC-PUFA) is very high, has not been well defined. The objective of the current study was to determine regulation of liver Fads1, Fads2 and Fads3 classical (CS) and alternative transcripts (AT) expression by dietary ARA and DHA, within the physiological range present in human breast milk, in suckling piglets. Piglets were fed one of six milk replacer formula diets (formula-reared groups, FR) with varying ARA and DHA content from days 3-28 of age. The ARA/DHA levels of the six formula diets were as follows (% total fatty acid, FA/FA): (A1) 0.1/1.0; (A2) 0.53/1.0; (A3-D3) 0.69/1.0; (A4) 1.1/1.0; (D2) 0.67/0.62; and (D1) 0.66/0.33. The control maternal-reared (MR) group remained with the dam. Fads1 expression was not significantly different between FR and MR groups. Fads2 expression was down-regulated significantly in diets with 1:1 ratio of ARA:DHA, compared to MR. Fads2 AT1 expression was highly correlated to Fads2 expression. Fads3 AT7 was the only Fads3 transcript sensitive to dietary LC-PUFA intake and was up-regulated in the formula diets with lowest ARA and DHA contents compared to MR. Thus, the present study provides evidence that the proportion of dietary ARA:DHA is a significant determinant of Fads2 expression and LC-PUFA metabolism during the early postnatal period. Further, the data suggest that Fads3 AT7 may have functional significance when dietary supply of ARA and DHA are low during early development.

Functional glycans and glycoconjugates in human milk

Human milk contains complex carbohydrates that are important dietary factors with multiple functions during early life. Several aspects of these glycostructures are human specific; some aspects vary between lactating women, and some change during the course of lactation. This review outlines how variability of complex glycostructures present in human milk is linked to changing infants' needs.

Low fatty acid concentrations in neonatal cord serum correlate with maternal serum

OBJECTIVE

Lactating women in New Mexico have low levels of important fatty acids relative to reported international data. The objective was to correlate the proportions of long-chain polyunsaturated fatty acids (LCPUFA) in the serum phospholipids in mothers and newborns within the same population.

METHODS

The serum phospholipids of 52 maternal:neonatal pairs were analyzed. Maternal samples from consecutive admissions were collected at hospital admission, and umbilical cord blood samples were collected at delivery. Fatty acid methyl esters were prepared and then separated and quantified by gas-liquid chromatography.

RESULTS

The median maternal percentages of arachidonic acid (AA) (4.9%), eicosapentaenoic acid (EPA) (0.27%) and docosahexaenoic acid (DHA) (2.07%) were below reported international levels. The percentages of AA (9.6%) and DHA (3.2%) in cord serum phospholipids were much higher than maternal samples but remained lower than reported internationally, whereas cord EPA (1.1%) was higher than reported. The highest percentage of DHA in serum phospholipids was found in the Asian subjects (4.21 ± 0.41%), while the American Indian women had the lowest DHA percentage (1.38 ± 0.26%). The maternal DHA percentage was negatively correlated with parity (r = -0.22, p = 0.04).

CONCLUSIONS

In the setting of low maternal levels of important fatty acids, their newborns did not accrue serum levels equivalent to reported international values.

Oral nutritional supplements containing n-3 polyunsaturated fatty acids affect quality of life and functional status in lung cancer patients during multimodality treatment: an RCT

Background/Objectives:

Our objective was to investigate effects of an oral nutritional supplement containing n-3 polyunsaturated fatty acids (FAs) on quality of life, performance status, handgrip strength and physical activity in patients with non-small cell lung cancer (NSCLC) undergoing multimodality treatment.

Subjects/Methods:

In a double-blind experiment, 40 patients with stage III NSCLC were randomised to receive 2 cans/day of a protein- and energy-dense oral nutritional supplement containing n-3 polyunsaturated FAs (2.02 g eicosapentaenoic acid+0.92 g docosahexaenoic acid/day) or an isocaloric control supplement, during multimodality treatment. Quality of life, Karnofsky Performance Status, handgrip strength and physical activity (by wearing an accelerometer) were assessed. Effects of intervention were analysed by generalised estimating equations. P-values <0.05 were regarded as statistically significant.

Results:

The intervention group reported significantly higher on the quality of life parameters, physical and cognitive function (B=11.6 and B=20.7, P<0.01), global health status (B=12.2, P=0.04) and social function (B=22.1, P=0.04) than the control group after 5 weeks. The intervention group showed a higher Karnofsky Performance Status (B=5.3, P=0.04) than the control group after 3 weeks. Handgrip strength did not significantly differ between groups over time. The intervention group tended to have a higher physical activity than the control group after 3 and 5 weeks (B=6.6, P=0.04 and B=2.5, P=0.05).

Conclusion:

n-3 Polyunsaturated FAs may beneficially affect quality of life, performance status and physical activity in patients with NSCLC undergoing multimodality treatment.

Heart arachidonic acid is uniquely sensitive to dietary arachidonic acid and docosahexaenoic acid content in domestic piglets

This study determined the sensitivity of heart and brain arachidonic acid (ARA) and docosahexaenoic acid (DHA) to the dietary ARA level in a dose-response design with constant, high DHA in neonatal piglets. On day 3 of age, pigs were assigned to 1 of 6 dietary formulas varying in ARA/DHA as follows (% fatty acid, FA/FA): (A1) 0.1/1.0; (A2) 0.53/1.0; (A3-D3) 0.69/1.0; (A4) 1.1/1.0; (D2) 0.67/0.62; and (D1) 0.66/0.33. At necropsy (day 28) higher levels of dietary ARA were associated with increased heart and liver ARA, while brain ARA remained unaffected. Dietary ARA had no effect on tissue DHA accretion. Heart was particularly sensitive, with pigs in the intermediate groups having different ARA (A2, 18.6±0.7%; A3, 19.4±1.0%) and a 0.17% increase in dietary ARA resulted in a 0.84% increase in heart ARA. Further investigations are warranted to determine the clinical significance of heart ARA status in developing neonates.

Dietary counseling to improve fat quality during pregnancy alters maternal fat intake and infant essential fatty acid status

To explore the effect of maternal dietary intervention on infant essential fatty acid (FA) status, we conducted a prospective, single-blind, randomized nutrition intervention study. At the first trimester of pregnancy, 90 women from families with a history of allergy were randomized either to receive intensive dietary counseling to modify dietary intake according to current recommendations or as controls. Infants' cord and 1-mo isolated serum phospholipid FA were identified and quantified by GC. Detectable levels of eicosatrienoic acid [ETA, 20:3(n-9)] were taken as a biochemical marker for essential FA deficiency, and the DHA sufficiency index [22:6(n-3):22:5(n-6)] and the DHA deficiency index [22:5(n-6):22:4(n-6)] were taken as markers for DHA [22:6(n-3)] status. The concentration of ETA was lower in cord blood in the intervention (I) group [median 0.64 (IQR 0.40-0.78) mg/L; 2.09 (1.31-2.54) μmol/L] than in the control (C) group [0.92 (0.54-1.20) mg/L; 3.00 (1.76-3.92) μmol/L] (P = 0.048). The proportion of ETA in total FA in the I group [0.73% (0.48-0.85%)] was lower than in the C group [0.93% (0.78-1.22%)] (P = 0.003). A higher DHA sufficiency index and lower DHA deficiency index were detected in cord blood in the I group than in the C group, although the groups did not differ in the DHA concentration or proportion of the total FA. There were no differences among groups at 1 mo for any of the variables measured. Our findings suggest a better supply of essential FA, particularly important during the period of rapid development, in infants whose mothers received dietary counseling. The results thus highlight the importance of maternal diet for child health, calling for dietary counseling for pregnant women in primary health care.

Essential fatty acid supplementation of DHA and ARA and effects on neurodevelopment across animal species: a review of the literature

Docosahexanoic acid (DHA) and arachidonic acid (ARA) are long chain essential fatty acids used as supplements in commercial infant formula. DHA/ARA deficient states are associated with adverse neurological outcomes in animals and humans. Preterm infants are at risk for DHA/ARA deficiency. A few clinical reports on the effects of fatty acid supplementation have shown benefit in preterm, low birth weight, and normal infants in the first year of life, whereas others did not. Studies in animals have reported shortened gestation, fetal growth retardation, reduced infant body mass, and increased fetal mortality with consumption of fatty acids during pregnancy. To understand the data that support fatty acid supplementation in infant formula, a review of the animal model literature was undertaken, to examine the effects of DHA/ARA on neurodevelopment, including the effects on visual acuity. Several points emerged from this review. (1) Animal studies indicate that requirements for DHA/ARA vary depending on developmental age. Alterations of the ratio of DHA/ARA can impact developmental outcome. (2) The available studies suggest that while supplementation of DHA/ARA in an appropriate ratio can increase tissue levels of these fatty acids in the brain and retina, tissues sensitive to depletion of fatty acids, the benefit of routine supplementation remains unclear. Few studies measure functional outcome relative to changes in physiologic pools of DHA/ARA after supplementation. (3) Animal literature does not support a clear long-term benefit of replenishing DHA/ARA tissue levels and administration of these fatty acids at concentrations above those in human milk suggests adverse effects on growth, survival, and neurodevelopment.

Breastfeeding and risk of epilepsy in childhood: a birth cohort study

OBJECTIVE

We asked whether breastfeeding reduces the risk of epilepsy in childhood.

STUDY DESIGN

We included 69 750 singletons born between September 1997 and June 2003 in the Danish National Birth Cohort and observed them to August 2008. Information on breastfeeding was reported by mothers in two computer-assisted telephone interviews at 6 and 18 months after birth. Information on epilepsy (inpatients and outpatients) was retrieved from the Danish National Hospital Register. Cox proportional hazards regression models were used to estimate incidence rate ratios and 95% CIs.

RESULTS

Breastfeeding was associated with a decreased risk of epilepsy, with a dose-response like pattern. For example, children breastfed for 3 to 5, 6 to 8, 9 to 12, and ≥ 13 months had a 26%, 39%, 50%, and 59% lower risk of epilepsy after the first year of life, respectively, compared with children who were breastfed for <1 month. The association remained when we excluded children who had adverse neonatal conditions or children who were exposed to adverse maternal conditions during pregnancy.

CONCLUSIONS

The observed protective effect of breastfeeding may be causal. Breastfeeding may decrease epilepsy in childhood, thereby adding another reason for breastfeeding.

Dietary lipids from an evolutionary perspective: sources, structures and functions

Lipids are a complex group of biomolecules whose precise functions remain poorly understood. As a result of this poor understanding, it is difficult to make mechanistically based recommendations for appropriate dietary intakes. It is equally difficult to develop methods that are capable of diagnosing functional impairments because of insufficiencies or excesses in particular fatty acids. Lipids are abundant building blocks of cellular membranes, supply components for lipid particle assembly and substrates for metabolic fuel, and provide a precursor pool for an astonishingly diverse range of signalling molecules. In each of these broad functions, the functional consequences of different structures of fatty acids are not fully understood. According to research on membrane functions through early evolution, docosahexaenoic acid provides two biophysical properties to membranes - accelerating the lateral motion of lipids and proteins within the plane of the membrane and simultaneously slowing the rate of diffusion/leakage of charged species across the plane of the membrane. The range of fatty acid structures used as substrates for assembly of either lipoproteins or milk fat globules is broad, yet the functional consequences of differences are not known. Different lipids signal into a remarkable range of biological processes. Saturated and monounsaturated fatty acids are becoming recognized as signal molecules in their own right. The complex composition of human milk lipids implies that diets with a diversity of fatty acids in complex lipid forms and structures is more beneficial than a narrow range of any particular group of fatty acids.

Conversion of linoleic acid and alpha-linolenic acid to long-chain polyunsaturated fatty acids (LCPUFAs), with a focus on pregnancy, lactation and the first 2 years of life

Over the past two decades, there has been a marked shift in the fatty acid composition of the diets of industrialized nations towards increased intake of the n-6 fatty acid linoleic acid (LA, 18:2n-6), largely as a result of the replacement of saturated fats with plant-based polyunsaturated fatty acid (PUFA). While health agencies internationally continue to advocate for high n-6 PUFA intake combined with increased intakes of preformed n-3 long-chain PUFAs (LCPUFA) docosahexaenoic acid (DHA, 22:6n-3) and eicosapentaenoic acid (EPA, 20:5n-3) to reduce the incidence of cardiovascular disease (CVD), there are questions as to whether this is the best approach. LA competes with alpha-linolenic acid (18:3n-3) for endogenous conversion to the LC derivatives EPA and DHA, and LA also inhibits incorporation of DHA and EPA into tissues. Thus, high-LA levels in the diet generally result in low n-3 LCPUFA status. Pregnancy and infancy are developmental periods during which the fatty acid supply is particularly critical. The importance of an adequate supply of n-3 LCPUFA for ensuring optimal development of infant brain and visual systems is well established, and there is now evidence that the supply of n-3 LCPUFA also influences a range of growth, metabolic and immune outcomes in childhood. This review will re-evaluate the health benefits of modern Western diets and pose the question of whether the introduction of similar diets to nations with emerging economies is the most prudent public health strategy for improving health in these populations.

Nutritional support for extremely low-birth weight infants: abandoning catabolism in the neonatal intensive care unit

PURPOSE OF REVIEW

Obviously, the ultimate goal in neonatology is to achieve a functional outcome in premature infants that is comparable to healthy term-born infants. As nutrition is one of the key factors for normal cell growth, providing the right amount and quality of nutrients could prove pivotal for normal development. However, many premature infants are catabolic during the first week of life, which has directly been linked to growth failure, disease, and suboptimal long-term outcome. This review describes the progress in research on parenteral nutrition for premature infants with a focus on amino acids and the influence of nutrition on later outcome.

RECENT FINDINGS

Although randomized clinical trials on early nutrition for premature infants remain relatively sparse, evidence is accumulating on its beneficial effects both on the short-term and long-term. However, some research also warns for adverse effects.

SUMMARY

Despite the fact that substantially improved nutritional therapies for preterm neonates have been implemented, still, some reluctance exists when it comes to providing high amounts of nutrition to the most immature infants. Pros and cons are outlined, as well as deficits in knowledge, when it comes to providing the optimal nutrient strategy in the first postnatal phase.

The DIAMOND (DHA Intake And Measurement Of Neural Development) Study: a double-masked, randomized controlled clinical trial of the maturation of infant visual acuity as a function of the dietary level of docosahexaenoic acid

BACKGROUND

The range of human milk docosahexaenoic acid (DHA) concentrations worldwide is much broader than the range explored in randomized clinical trials to date.

OBJECTIVE

The primary objective was to determine the effect of 4 amounts of DHA supplementation on the visual acuity of formula-fed infants at 12 mo of age. Secondary objectives were to evaluate visual acuity maturation, red blood cell fatty acids, tolerance, anthropometric measures, and adverse events.

DESIGN

This double-masked, randomized trial was conducted at 2 sites (Dallas and Kansas City). Three hundred forty-three healthy, term, formula-fed infants were enrolled at 1-9 d of age and were randomly assigned to be fed 1 of the following 4 infant formulas containing equivalent nutrient amounts, except for long-chain polyunsaturated fatty acids: control (0% DHA), 0.32% DHA, 0.64% DHA, or 0.96% DHA; DHA-supplemented formulas also provided 0.64% arachidonic acid. Visual acuity was measured by visual evoked potentials in 244 infants who completed the 12-mo primary outcome examination.

RESULTS

Infants fed control formula had significantly poorer visual evoked potential visual acuity at 12 mo of age than did infants who received any of the DHA-supplemented formulas (P < 0.001). There were no significant differences in visual evoked potential visual acuity between the 3 amounts of DHA supplementation for either site at any age tested.

CONCLUSIONS

DHA supplementation of infant formula at 0.32% of total fatty acids improves visual acuity. Higher amounts of DHA supplementation were not associated with additional improvement of visual acuity. This trial was registered at clinicaltrials.gov as NCT00753818.

Toddler formula supplemented with docosahexaenoic acid (DHA) improves DHA status and respiratory health in a randomized, double-blind, controlled trial of US children less than 3 years of age

Studies of docosahexaenoic acid (DHA) intake and status in US toddlers are lacking. One national survey found low DHA intakes. The objectives of this double-blind, randomized study were to (a) determine usual DHA intakes, (b) measure the effect of consuming formulas with DHA on red blood cell (RBC) and plasma DHA and (c) record adverse events in US children between 18 and 36 months of age. Children aged 18-36 months were provided 237-ml formula with 0, 43, or 130 mg DHA per day for 60 days. Blood was obtained at 0 and 60 days and 24-hour dietary recalls at 0, 30 and 60 days. Usual median daily DHA intake was 13.3 mg. RBC DHA increased in a dose-dependent manner with increasing DHA intake (p<0.05). Toddlers consuming the formula with 130 mg DHA per day have fewer adverse events (p=0.007) and a lower incidence of respiratory illness (p=0.024), compared to the formula without DHA. US toddlers have low DHA intake and status. Modest increases in DHA intake in toddlers might improve development, including respiratory health.

Maternal arachidonic acid supplementation improves neurodevelopment of offspring from healthy and diabetic rats

Maternal diabetes may compromise infant arachidonic acid status and development. This study tested if maternal arachidonic acid supplementation improves neurodevelopment in rat offspring. Dams were randomized into 6 groups using a 3x2 design: Saline-Placebo, streptozotocin-induced diabetes with glucose controlled at <13mmol/L, or poorly controlled at 13-20mmol/L using insulin; and fed either control or an arachidonic acid (0.5% of fat) diet throughout reproduction. Offspring were tested on post-natal days 3 and 5 for righting response, days 7 and 9 for negative geotaxis, day 14 for wire hanging endurance, days 18 and 24 for rota rod endurance, and day 28 for Morris water maze performance. Only the poorly controlled group had impaired day 7 geotaxis and day 18 rota rod performance (p<0.02), but this improved with maternal arachidonic acid supplementation (p<0.0006). Arachidonic acid improved the wire hanging endurance (p=0.0003) and water maze latency (p=0.0021), suggesting enhanced neurodevelopment in all offspring.

Top-down glycolipidomics: fragmentation analysis of ganglioside oligosaccharide core and ceramide moiety by chip-nanoelectrospray collision-induced dissociation MS2-MS6

We developed a straightforward approach for high-throughput top-down glycolipidomics based on fully automated chip-nanoelectrospray (nanoESI) high-capacity ion trap (HCT) multistage mass spectrometry (MSn) by collision-induced dissociation (CID) in the negative ion mode. The method was optimized and tested on a polysialylated ganglioside fraction (GT1b), which was profiled by MS1 and sequenced in tandem MS up to MS6 in the same experiment. Screening of the fraction in the MS1 mode indicated the occurrence of six [M-2H]2- ions which, according to calculation, support 13 GT1 variants differing in their relative molecular mass due to dissimilar ceramide (Cer) constitutions. By stepwise CID MS2-MS5 on the doubly charged ion at m/z 1077.20 corresponding to a ubiquitous GT1b structure, the complete characterization of its oligosaccharide core including the identification of sialylation sites was achieved. Structure of the lipid moiety was further elucidated by CID MS6 analysis carried out using the Y0 fragment ion, detected in MS5, as a precursor. MS6 fragmentation resulted in a pattern supporting a single ceramide form having the less common (d20 : 1/18 : 0) configuration. The entire top-down experiment was performed in a high-throughput regime in less than 3 min of measurement, with an analysis sensitivity situated in the subpicomolar range.

Genetic influences on blood lipids and cardiovascular disease risk: tools for primary prevention

Genetic polymorphism in human populations is part of the evolutionary process that results from the interaction between the environment and the human genome. Recent changes in diet have upset this equilibrium, potentially influencing the risk of most common morbidities such as cardiovascular diseases, obesity, diabetes, and cancer. Reduction of these conditions is a major public health concern, and such a reduction could be achieved by improving our ability to detect disease predisposition early in life and by providing more personalized behavioral recommendations for successful primary prevention. In terms of cardiovascular diseases, polymorphisms at multiple genes have been associated with differential effects in terms of lipid metabolism; however, the connection with cardiovascular disease has been more elusive, and considerable heterogeneity exists among studies regarding the predictive value of genetic markers. This may be because of experimental limitations, the intrinsic complexity of the phenotypes, and the aforementioned interactions with environmental factors. The integration of genetic and environmental complexity into current and future research will drive the field toward the implementation of clinical tools aimed at providing dietary advice optimized for the individual's genome. This may imply that dietary changes are implemented early in life to gain maximum benefit. However, it is important to highlight that most reported studies have focused on adult populations and to extrapolate these findings to children and adolescents may not be justified until proper studies have been carried out in these populations and until the ethical and legal issues associated with this new field are adequately addressed.

Early risk determinants and later health outcomes: implications for research prioritization and the food supply. Summary of the workshop

The International Life Sciences Institute North American Branch, in conjunction with the International Life Sciences Institute Research Foundation, on 8-9 July 2008, sponsored the workshop "Early Risk Determinants and Later Health Outcomes: Implications for Research Prioritization and the Food Supply." A primary objective was to focus on the relative influence of genetics and environmental factors, particularly in relation to specific nutrients and food components, on determinants of risk within the developmental stages of pregnancy, infancy (0-12 mo), and early childhood (</=5 y of age). A panel of experts concluded the workshop by providing their reactions to the papers presented while attempting to identify the critical time windows and the research gaps and challenges for future research. This was followed by a discussion of how the food industry might assist in the acquisition and translation of the knowledge of the determinants of disease to improve human health.

Can infant feeding choices modulate later obesity risk?

Since the concept of lasting programming effects on disease risk in human adults by the action of hormones, metabolites, and neurotransmitters during sensitive periods of early development was proposed >3 decades ago, ample supporting evidence has evolved from epidemiologic and experimental studies and clinical trials. For example, numerous studies have reported programming effects of infant feeding choices on later obesity. Three meta-analyses of observational studies found that obesity risk at school age was reduced by 15-25% with early breastfeeding compared with formula feeding. We proposed that breastfeeding protects against later obesity by reducing the occurrence of high weight gain in infancy and that one causative factor is the lower protein content of human milk compared with most infant formula (the early protein hypothesis). We are testing this hypothesis in the European Childhood Obesity Project, a double-blind, randomized clinical trial that includes >1000 infants in 5 countries (Belgium, Germany, Italy, Poland, and Spain). We randomly assigned healthy infants who were born at term to receive for the first year infant formula and follow-on formula with higher or lower protein contents, respectively. The follow-up data obtained at age 2 y indicate that feeding formula with reduced protein content normalizes early growth relative to a breastfed reference group and the new World Health Organization growth standard, which may furnish a significant long-term protection against later obesity. We conclude that infant feeding practice has a high potential for long-term health effects, and the results obtained should stimulate the review of recommendations and policies for infant formula composition.

Driving research in infant and children's nutrition: a perspective on industry

As part of the workshop entitled "Early Risk Determinants and Later Health Outcomes: Implications for Research Prioritization and the Food Supply" (8-9 July 2008, Washington, DC), which was cosponsored by the International Life Sciences Institute of North America and the International Life Sciences Institute Research Foundation, representatives of the food industry discussed the practical application of nutrition science. Nutrition plays a key role in guiding health outcomes throughout the life cycle. In particular, the prenatal, postnatal, and early childhood periods are extremely sensitive to the presence of appropriate nutrition. A growing body of evidence shows that early nutrition may program the unborn and the infant's key physiologic systems, including the endocrine, cardiovascular, and central nervous systems, to influence later life outcomes. While scientists in academia continue to explore the multifactorial nature of early risk determinants and later life outcomes at a mechanistic and basic science level, it is important to understand the potential of the infant and child food industries to address questions such as what factors have been noted to drive research in these sectors of the food industry. How can scientists in these industries work alongside the scientists in academia and in government to set priorities, make decisions around these health issues, and translate academic insights into innovative nutritional solutions for the benefit of public health? Given the commitment of the infant and child food industries to deliver scientifically supported early life nutrition, it is easy to understand why this industry would work in partnership with both the scientists in academia and the government to identify a means of addressing the fundamental questions of this workshop.

Epigenetic mechanisms for nutrition determinants of later health outcomes

Epigenetic marking on genes can determine whether or not genes are expressed. Epigenetic regulation is mediated by the addition of methyl groups to DNA cytosine bases, of methyl and acetyl groups to proteins (histones) around which DNA is wrapped, and by small interfering RNA molecules. Some components of epigenetic regulation have evolved to permit control of whether maternal or paternal genes are expressed. The epigenetic imprinting of IGF2 expression is an example of maternal and paternal epigenetic marking that modulates fetal growth and fetal size. However, epigenetic regulation also permits the fetus and the infant to adapt gene expression to the environment in which it is growing; sometimes when this adjustment goes awry, the risk of chronic disease is increased. Recent progress in the understanding of nutritional influences on epigenetics suggests that nutrients that are part of methyl-group metabolism can significantly influence epigenetics. During critical periods in development, dietary methyl-group intake (choline, methionine, and folate) can alter DNA and histone methylation, which results in lifelong changes in gene expression. In rodent models, pregnant dams that were fed diets high in methionine, folic acid, and choline produced offspring with different coat colors or with kinked tails. A number of syndromes in humans can be caused by defective epigenetic regulation, including Rett syndrome. There are interesting examples of the effects of nutrition in early life that result in altered health in adults, and some of these could be the result of altered epigenetic regulation of gene expression.

Early determinants of cardiovascular disease: the role of early diet in later blood pressure control

It is now widely accepted that a gross change in the maternal diet during pregnancy results in offspring with raised blood pressure. More recently, results from human intervention studies and a range of animal experiments have questioned this concept. It thus appears that, when blood pressure is measured directly or by telemetry, the extent to which blood pressure is raised is largely dependent on the magnitude of the postnatal catch-up growth. In addition, such effects can be lost when appropriate corrections are made for current body weight. Consequently, offspring born to nutritionally manipulated mothers can actually have a lower blood pressure than control group offspring. At the same time, studies of the offspring born to contemporary women in developed countries show very little, if any, effect of changes in maternal diet on blood pressure in the offspring when assessed during childhood. In small animal studies, at least, the cardiovascular outcomes linked to small size at birth can differ between the sexes, which may be related in part to differences in kidney function between males and females. With respect to large animal studies, significant effects on blood pressure are less apparent and may relate to the much slower onset of hypertension. The challenge is to use our increased knowledge of the critical windows in early development to optimize later health. One clear priority is the prevention of excess adiposity and to determine how epigenetic mechanisms may provide novel strategies in this regard.

Early risk determinants and later health outcomes: implications for research prioritization and the food supply. Introduction to the workshop

The workshop entitled "Early Risk Determinants and Later Health Outcomes: Implications for Research Prioritization and the Food Supply," reported in this issue, was borne of a quest to consolidate current knowledge on the early determinants of maternal and child health outcomes related to obesity, cardiovascular disease risk, and neurodevelopment. The primary goal was to delineate the relative influence of genetics and environmental factors, particularly in relation to specific nutrients and food components, on determinants of risk within the developmental stages of pregnancy, infancy (0-12 mo), and early childhood up to 5 y of age. A panel of experts was charged with critiquing the evidence presented and with identifying research gaps and challenges for future research, such as when and how the food industry might translate knowledge of the determinants of disease into improvements in human health through food product development.

Childhood obesity: are genetic differences involved?

This brief review focuses on the genetic contribution to childhood obesity. Evidence for a genetic component to excess body weight during growth is presented from the perspective of genetic epidemiology studies. Parental obesity is a predictor of childhood excess weight. The familial risk ratio for childhood obesity when a parent is obese reaches >2.5. Birth weight is characterized by a genetic heritability component on the order of 30%, with significant maternal and paternal effects in addition to the newborn genes. About 5% of childhood obesity cases are caused by a defect that impairs function in a gene, and >/=5 of these genes have been uncovered. However, the common forms of childhood obesity seem to result from a predisposition that primarily favors obesogenic behaviors in an obesogenic environment. Candidate gene and genomewide association studies reveal that these obesogenic genes have small effect sizes but that the risk alleles for obesity are quite common in populations. The latter may translate into a highly significant population-attributable risk of obesity. Gene-environment interaction studies suggest that the effects of predisposing genes can be enhanced or diminished by exposure to relevant behaviors. It is possible that the prevalence of childhood obesity is increasing across generations as a result of positive assortative mating with obese husbands and wives contributing more obese offspring than normal-weight parents.