Journal of Nutrition current issue

Dietary Saturated Fat Modulates the Association between STAT3 Polymorphisms and Abdominal Obesity in Adults [Biochemical, Molecular, and Genetic Mechanisms]

Tue, 20 Oct 2009 10:01:50 PDT

Signal transducer and activator of transcription 3 (STAT3) plays a key role in body weight regulation and glucose homeostasis, 2 important determinants of metabolic syndrome (MetS). Dietary fat is a key environmental factor that may interact with genotype to affect MetS risk. In this study, we investigated the relationship between STAT3 polymorphisms and MetS phenotypes and determined potential interactions with dietary fatty acids. STAT3 polymorphisms (rs8069645, rs744166, rs2306580, rs2293152, and rs10530050), biochemical measurements, and dietary fat composition were determined in the LIPGENE-SU.VI.MAX study of MetS cases and matched controls (n = 1754). STAT3 polymorphisms were not associated with MetS risk. However, minor G allele carriers for rs8069645, rs744166, and rs1053005 and major GG homozygotes for rs2293152 had increased risk of abdominal obesity compared with noncarriers [odds ratio (OR) = 2.22, P = 0.0005; OR = 2.08, P = 0.0017; OR = 2.00, P = 0.0033; and OR = 1.95, P = 0.028, respectively]. The number of risk alleles additively increased obesity risk (P = 0.0003). Dietary SFA intake exacerbated these effects; among all participants with the highest SFA intake (≥15.5% of energy), individuals carrying >2 risk alleles had further increased risk of obesity (OR = 3.30; 95% CI = 1.50–7.28; P = 0.0079) compared with those carrying ≤1 risk allele. Interaction analysis confirmed this gene-nutrient interaction whereby increasing SFA intake was predictive of increased waist circumference (P = 0.038). In conclusion, STAT3 gene polymorphisms influenced the risk of abdominal obesity, which is modulated by dietary SFA intake, suggesting novel gene-nutrient interactions.

Supplemental Dietary Inulin Influences Expression of Iron and Inflammation Related Genes in Young Pigs [Biochemical, Molecular, and Genetic Mechanisms]

Tue, 20 Oct 2009 10:01:50 PDT

We have previously shown improved hemoglobin (Hb) repletion efficiency by supplementing a 50:50 mixture of short (P95) and long-chain (HP) inulin (Synergy 1, BENEO-Orafti) into a corn-soybean meal-basal diet (BD) for young pigs. In this study, weanling pigs (5 or 6 wk old) were fed the BD or the BD + 4% of P95, HP, or Synergy 1 (50:50 mixtures of HP and P95) for 5–7 wk. Blood Hb concentrations of pigs were measured weekly and digesta samples were collected at the end of the trial. In a replicate experiment, total RNA was isolated from the liver and mucosa of duodenum, ileum, cecum, and colon of all pigs at the end of the trial. Relative mRNA expression of 27 genes, including iron and inflammation-related genes, was quantified using real-time quantitative-PCR. Although all 3 types of inulin resulted in similar improvements (P < 0.05) in blood Hb concentration and liver ferritin protein amount, neither type of inulin was detectable in the digesta of cecum or colon. Supplemental inulin enhanced the expression of iron-storing protein genes but decreased that of inflammation-related genes. Such effects were more pronounced (P < 0.05) in the mucosa of the lower than the upper gut and were seen on 7 genes in liver. In conclusion, all 3 types of inulin shared similar efficacy and possibly similar modes of action in improving dietary iron utilization by young pigs. Suppressing inflammation-induced genes that can negatively influence iron metabolism might help explain the benefit of inulin.

Diets Enriched in Oat Bran or Wheat Bran Temporally and Differentially Alter the Composition of the Fecal Community of Rats [Genomics, Proteomics, and Metabolomics]

Tue, 20 Oct 2009 10:01:50 PDT

A clear understanding of how diet alters gastrointestinal communities is important given the suggested link between gut community composition and a wide variety of disease pathologies. To characterize this link for commonly consumed dietary fiber sources, we investigated the change in the fecal community of rats fed diets containing 5% nonnutritive fiber (control), 3% (wt:wt) oat bran plus 2% nonnutritive fiber (OB), or 5% (w/w) wheat bran (WB) over a 28-d feeding trial using both molecular- and cultivation-based methodologies. Pooled fecal samples from 8 rats fed the same diet were analyzed at 4 time points. On d 28, bran-fed rats had approximately twice the total cultivable bacteria than rats fed the control diet. Over the course of feeding, the cultivable community was initially dominated by bacteroides, then by bifidobacteria, lactobacilli, enterococci, and various enterics. In contrast, molecular analysis revealed the appearance of new operational taxonomic units (phylotypes) that were both temporally and inequitably distributed throughout the fecal community. The majority of change occurred in 2 major lineages within the Firmicutes: the Clostridium coccoides group and the Clostridium leptum subgroup. The time course of change depended on the source of bran, with the majority of new phylotypes appearing by d 14 (OB) or d 28 (WB), although adaptation of the fecal community was slow and continued over the entire feeding trial. Bacterial community richness was higher in bran-fed rats than in those fed the control diet. Change within the C. coccoides and C. leptum lineages likely reflect their high abundance within the gut bacterial community and the role of clostridia in fiber digestion. The results illustrate the limitations of relying solely on cultivation to assess bacterial changes and illustrate that community changes are complex in an ecosystem containing high numbers of interdependent and competing species of bacteria.

Feeding Acutely Stimulates Fibrinogen Synthesis in Healthy Young and Elderly Adults [Nutrient Physiology, Metabolism, and Nutrient-Nutrient Interactions]

Caso, G., Mileva, I., Kelly, P., Ahn, H., Gelato, M. C., McNurlan, M. A. — Tue, 20 Oct 2009 10:01:50 PDT

Fibrinogen is a positive acute-phase protein and its hepatic synthesis is enhanced following inflammation and injury. However, it is not clear whether fibrinogen synthesis is also responsive to oral nutrients and whether the response to a meal may be affected by age. Our aim in this study was to investigate the acute effect of oral feeding on fibrinogen synthesis in both young and elderly men and women. Fibrinogen synthesis was determined in 3 separate occasions from the incorporation of l[²H₅]phenylalanine (43 mg/kg body weight) in 8 young (21–35 y) and 8 elderly (>60 y) participants following the ingestion of water (control), a complete liquid meal (15% protein, 30% fat, and 55% carbohydrate), or only the protein component of the meal. The ingestion of the complete meal enhanced fibrinogen fractional synthesis rates (FSR) by 17 ± 6% in the young and by 38 ± 10% in the elderly participants compared with the water meal (P < 0.02). A comparable stimulation of FSR occurred with only the protein component of the meal in both young (29 ± 7%) and elderly participants (41 ± 9%) compared with the water meal (P < 0.005). Similar results were obtained when fibrinogen synthesis was expressed as absolute synthesis rates (i.e. mg·kg^–1·d^–1). The results demonstrate that fibrinogen synthesis is acutely stimulated after ingestion of a meal and that this effect can be reproduced by the protein component of the meal alone, both in young and elderly adults.

The Pharmacokinetics of S-(-)Equol Administered as SE5-OH Tablets to Healthy Postmenopausal Women [Nutrient Physiology, Metabolism, and Nutrient-Nutrient Interactions]

Setchell, K. D. R., Zhao, X., Shoaf, S. E., Ragland, K. — Tue, 20 Oct 2009 10:01:50 PDT

The soy isoflavone metabolite, S-(-)equol, has selective affinity for estrogen receptor (ER)β and also antagonizes in vivo the action of dihydrotestosterone. It is therefore of interest as a potential new therapeutic agent in hormone-dependent conditions and is under development as a nutraceutical. Our objective in this study was to define the pharmacokinetics of natural S-(-)equol after administration of SE5-OH, a newly developed S-(-)equol supplement made by incubation of the equol-producing bacterium Lactococcus garvieae with soy germ isoflavones. In a single-center, open-label, randomized, 2-period crossover design study, the pharmacokinetics of S-(-)equol administered as single-bolus oral doses of 10 and 30 mg in the form of SE5-OH tablets was determined in 12 healthy postmenopausal women. S-(-)equol was measured in plasma and urine collected at timed intervals over a 48-h period postdosing using tandem MS. Equol-producer status was also determined after a soymilk challenge conducted after the pharmacokinetic sampling was complete. S-(-)equol was rapidly absorbed after oral administration and attained high plasma concentrations, with a plasma elimination half-life of 8 h. The maximum plasma concentration/dose, area under the plasma concentration-time curve from time 0 to infinity/dose, and the fraction of dose excreted in urine (%f_e,u) were similar for the 2 doses, indicating a dose-proportional response in total S-(-)equol pharmacokinetics. The systemic bioavailability of S-(-)equol was very high, as the %f_e,u was 82% for both doses, which is greater than published data for the soy isoflavones daidzein and genistein. Three participants were determined to be equol-producers, representing a 25% frequency, and equol-producer status had no effect on natural S-(-)equol pharmacokinetics.

Products of the Colonic Microbiota Mediate the Effects of Diet on Colon Cancer Risk [Nutrition and Disease]

Tue, 20 Oct 2009 10:01:50 PDT

It is estimated that most colon cancers can be attributed to dietary causes. We have hypothesized that diet influences the health of the colonic mucosa through interaction with the microbiota and that it is the milieu interior that regulates mucosal proliferation and therefore cancer risk. To validate this further, we compared colonic contents from healthy 50- to 65-y-old people from populations with high and low risk, specifically low risk Native Africans (cancer incidence <1:100,000; n = 17), high risk African Americans (risk 65:100,000; n = 17), and Caucasian Americans (risk 50:100,000; n = 18). Americans typically consume a high-animal protein and -fat diet, whereas Africans consume a staple diet of maize meal, rich in resistant starch and low in animal products. Following overnight fasting, rapid colonic evacuation was performed with 2 L polyethylene glycol. Total colonic evacuants were analyzed for SCFA, vitamins, nitrogen, and minerals. Total SCFA and butyrate were significantly higher in Native Africans than in both American groups. Colonic folate and biotin content, measured by Lactobacillus rhamnoses and Lactobacillus plantarum ATCC 8014 bioassay, respectively, exceeded normal daily dietary intakes. Compared with Africans, calcium and iron contents were significantly higher in Caucasian Americans and zinc content was significantly higher in African Americans, but nitrogen content did not differ among the 3 groups. In conclusion, the results support our hypothesis that the microbiota mediates the effect diet has on colon cancer risk by their generation of butyrate, folate, and biotin, molecules known to play a key role in the regulation of epithelial proliferation.

Trans-11 Vaccenic Acid Reduces Hepatic Lipogenesis and Chylomicron Secretion in JCR:LA-cp Rats [Nutrition and Disease]

Tue, 20 Oct 2009 10:01:51 PDT

Trans-11 vaccenic acid (VA) is the predominant trans isomer in ruminant fat and a major precursor to the endogenous synthesis of cis9,trans11-conjugated linoleic acid in humans and animals. We have previously shown that 3-wk VA supplementation has a triglyceride (TG)-lowering effect in a rat model of dyslipidemia, obesity, and metabolic syndrome (JCR:LA-cp rats). The objective of this study was to assess the chronic effect (16 wk) of VA on lipid homeostasis in both the liver and intestine in obese JCR:LA-cp rats. Plasma TG (P < 0.001), total cholesterol (P < 0.001), LDL cholesterol (P < 0.01), and nonesterified fatty acid concentrations, as well as the serum haptoglobin concentration, were all lower in obese rats fed the VA diet compared with obese controls (P < 0.05). In addition, there was a decrease in the postprandial plasma apolipoprotein (apo)B48 area under the curve (P < 0.05) for VA-treated obese rats compared with obese controls. The hepatic TG concentration and the relative abundance of fatty acid synthase and acetyl-CoA carboxylase proteins were all lower (P < 0.05) in the VA-treated group compared with obese controls. Following acute gastrointestinal infusion of a VA-triolein emulsion in obese rats that had been fed the control diet for 3 wk, the TG concentration was reduced by 40% (P < 0.05) and the number of chylomicron (CM) particles (apoB48) in nascent mesenteric lymph was reduced by 30% (P < 0.01) relative to rats infused with a triolein emulsion alone. In conclusion, chronic VA supplementation significantly improved dyslipidemia in both the food-deprived and postprandial state in JCR:LA-cp rats. The appreciable hypolipidemic benefits of VA may be attributed to a reduction in both intestinal CM and hepatic de novo lipogenesis pathways.

1,2-Vinyldithiin from Garlic Inhibits Differentiation and Inflammation of Human Preadipocytes [Nutrition and Disease]

Keophiphath, M., Priem, F., Jacquemond-Collet, I., Clement, K., Lacasa, D. — Tue, 20 Oct 2009 10:01:51 PDT

Obesity is a state of chronic low-grade inflammation. Limiting white adipose tissue (WAT) expansion and therefore reducing inflammation could be effective in preventing the progression of obesity and the development of associated complications. We investigated the effects of 1,2-vinyldithiin (1,2-DT), a garlic-derived organosulfur, on the differentiation and inflammatory state of human preadipocytes. Preadipocytes were prepared from subcutaneous adipose tissue of nonobese young women and differentiated in the presence of 1,2-DT. Inflammatory preadipocytes were obtained following treatment with human macrophage-secreted factors. 1,2-DT (100 µmol/L) significantly reduced gene expression of PPAR2 (–40%), CCAAT/enhancer binding protein- (–25%), lipoprotein lipase (–22%), leptin (–30%), and adiponectin (–15%). Lipid accumulation was also significantly diminished in preadipocytes differentiated in the presence of 100 µmol/L 1,2-DT (–37%) compared with controls. Furthermore, 100 µmol/L 1,2-DT treatment for 10 d significantly reduced PPAR activity (–27%). The protein expression of perilipin and the secretion levels for 2 adipokines, leptin and adiponectin, were significantly diminished in 1,2-DT-cultured preadipocytes (–37, –51, and –43%, respectively). Moreover, the secretion of inflammatory molecules (interleukin-6 and monocyte chemoattractant protein-1) induced by macrophage-secreted factors was partially abolished in 100 µmol/L 1,2-DT–treated preadipocytes (–28 and –25%, respectively). In conclusion, we demonstrated that 1,2-DT, a garlic-derived organosulfur, has antiadipogenic and antiinflammatory actions on human preadipocytes and may be a novel, antiobesity nutraceutical.

Flaxseed and Pure Secoisolariciresinol Diglucoside, but Not Flaxseed Hull, Reduce Human Breast Tumor Growth (MCF-7) in Athymic Mice [Nutrition and Disease]

Chen, J., Saggar, J. K., Corey, P., Thompson, L. U. — Tue, 20 Oct 2009 10:01:51 PDT

Previous studies have shown that dietary flaxseed (FS) can reduce the growth of established human breast tumors in athymic mice with low circulating estrogen concentrations. In this study, we determined the effect of FS compared with pure lignan at the level it is present in FS [secoisolariciresinol diglucoside (SDG)] and to the lignan-rich fraction [FS hull (FH)] on human breast tumor growth and their potential mechanisms of action. Ovariectomized, athymic mice, each with an implanted 17 β-estradiol (E2) pellet (0.36 mg), were injected with human estrogen receptor (ER) positive breast cancer cells (MCF-7). When tumors were established, the E2 pellet was removed. Mice were fed either the control basal diet (BD), FS (100 g/kg diet), SDG (1 g/kg diet), or FH (18 g/kg diet) for 8 wk. Compared with the BD, FS and SDG significantly decreased the palpable tumor size, but effects of FS, SDG, and FH did not differ from one another. All treatments significantly inhibited cell proliferation, but only FS and SDG induced significantly higher apoptosis. Both FS and SDG significantly decreased mRNA expressions of Bcl2, cyclin D1, pS2, ER, and ERβ, epidermal growth factor receptor, and insulin-like growth factor receptor. FS also reduced human epidermal growth factor receptor 2 mRNA and SDG decreased phospho-specific mitogen-activated protein kinase expression. FH did not significantly reduce these biomarkers. In conclusion, pure SDG has a similar effect as FS in reducing tumor growth and in mechanisms of action, including downregulating ER- and growth factor-mediated cell signaling. The lesser effects of FH indicate a need for a higher dose to be more effective.

Rats Fed Fructose-Enriched Diets Have Characteristics of Nonalcoholic Hepatic Steatosis [Nutrition and Disease]

Tue, 20 Oct 2009 10:01:51 PDT

Nonalcoholic steatohepatitis (NASH) and nonalcoholic fatty liver disease are increasing in adults and are likely to be increasing in children. Both conditions are hepatic manifestations of metabolic syndrome. Experimental animals fed fructose-enriched diets are widely recognized as good models for metabolic syndrome. However, few reports have described the hepatic pathology of these experimental animals. In this study, 5-wk-old Wistar specific pathogen-free rats, which are a normal strain, were fed experimental diets for 5 wk. We then evaluated the degree of steatohepatitis. The 5 diet groups were as follows: cornstarch (70% wt:wt) [control (C)], high-fructose (70%) (HFr), high-sucrose (70%) (HS), high-fat (15%) (HF), and high-fat (15%) high-fructose (50%) (HFHFr) diets. The macrovesicular steatosis grade, liver:body weight ratio, and hepatic triglyceride concentration were significantly higher in the HFr group than in the other 4 groups. However, the HFr group had a significantly lower ratio of epididymal white fat:body weight than the other 4 groups and had a lower final body weight than the HF and HFHFr groups. The HF group had a greater final body weight than the C, HFr, and HS groups, but no macrovesicular steatosis was observed. The HFr group had a significantly higher grade of lobular inflammation than the other 4 groups. The distribution of lobular inflammation was predominant over portal inflammation, which is consistent with human NASH. In conclusion, rats fed fructose-enriched diets are a better model for NASH than rats fed fat-enriched diets.

Western-Style Diets Induce Oxidative Stress and Dysregulate Immune Responses in the Colon in a Mouse Model of Sporadic Colon Cancer [Nutrition and Disease]

Tue, 20 Oct 2009 10:01:51 PDT

A Western-style diet (WD), defined by high-fat, low-calcium, and vitamin D content, is associated with increased risk of human colorectal cancer. Understanding molecular mechanisms altered by the WD is crucial to develop preventive and therapeutic strategies. Effects of a WD on the colonic transcriptome of C57Bl/6J mice, a model for sporadic colon cancer, were studied at endpoints before tumors occur. To assess whether a WD induces inflammatory changes, expression profiles of a broad spectrum of inflammatory proteins were performed and numbers of lamina propria macrophages were determined with semiquantitative morphometry. Transcriptome changes were translated into molecular interaction network maps and pathways. Pathways related to oxidative stress response; lipid, glutathione, and xenobiotic metabolism; and the immune response were perturbed by the WD. Several nuclear factor-erythroid 2-related factor 2- and aryl hydrocarbon receptor-dependent genes, including those coding for enzymes involved in phase 1 and 2 drug metabolism and oxidative stress responses, were induced. Oxidative stress was demonstrated by measurements of endogenous colonic redox-sensitive compound concentrations. Perturbations in immune response-related pathways, expression of inflammatory proteins, and increased numbers of lamina propria macrophages showed that the WD significantly alters the local colonic immune response. Collectively, these data suggest that consumption of a WD interferes with networks of related biological response pathways involving colonic lipid metabolism, oxidative stress, and the immune response. These new findings impact our understanding of links between consumption of WD and colon carcinogenesis, providing additional information for developing preventive means for decreasing colorectal cancer risk.

Olive Leaf Extract and Its Main Component Oleuropein Prevent Chronic Ultraviolet B Radiation-Induced Skin Damage and Carcinogenesis in Hairless Mice [Nutrition and Disease]

Kimura, Y., Sumiyoshi, M. — Tue, 20 Oct 2009 10:01:51 PDT

Chronic exposure to solar UV radiation damages skin, increasing its thickness and reducing its elasticity, and causes skin cancer. Our aim in this study was to examine the effects of an olive leaf extract and its component oleuropein on skin damage and the incidence of skin tumors caused by long-term UVB irradiation in hairless mice. Male hairless mice (5 wk old) were divided into 6 groups, including a non-UVB group, a vehicle-treated UVB group (control), 2 olive leaf extract-treated UVB groups, and 2 oleuropein-treated UVB groups. Five groups were UVB irradiated (36–180 mJ/cm²) 3 times each week for 30 wk and skin thickness and elasticity after UVB irradiation were measured every week. Olive leaf extract (300 and 1000 mg/kg) and oleuropein (10 and 25 mg/kg) were administered orally twice daily every day for 30 wk. The extract and oleuropein significantly inhibited increases in skin thickness and reductions in skin elasticity, and skin carcinogenesis and tumor growth. Furthermore, they prevented increases in the expression of matrix metalloproteinase (MMP)-2, MMP-9, and MMP-13 as well as in levels of vascular endothelial growth factor (VEGF) and cyclooxygenase-2 (COX-2) in the skin. Based on histological evaluation, they prevented increases in the expression of Ki-67 and CD31-positive cells induced by the irradiation. These results suggest that the preventative effects of the olive leaf extract and oleuropein on chronic UVB-induced skin damage and carcinogenesis and tumor growth may be due to inhibition of the expression of VEGF, MMP-2, MMP-9, and MMP-13 through a reduction in COX-2 levels.

Iron-Deficiency Sensitizes Mice to Acute Pain Stimuli and Formalin-Induced Nociception [Ingestive Behavior and Neurosciences]

Dowling, P., Klinker, F., Amaya, F., Paulus, W., Liebetanz, D. — Tue, 20 Oct 2009 10:01:51 PDT

Iron deficiency has been described as a risk factor in secondary restless legs syndrome (RLS), although it has not been investigated whether iron deficiency induces sensory symptoms in RLS patients. In this study, we established a mouse model of iron deficiency by administering a purified iron-deficient (ID) diet (<8 mg/kg iron) or nonpurified standard diet [normal diet (ND)] (<179 mg/kg iron) to male C57Bl/6 mice from postnatal d 28 for 1, 4, or 15 wk. The level of iron deficiency was assessed by the plasma iron concentration. After varying durations of iron deficiency, both acute and chronic sensory components of pain were measured using hot-plate and formalin tests, which preferentially assess A- and C-fibers, respectively. Based on hot-plate reaction time, ID mice had a lower acute pain threshold than the ND mice after 4 and 15 wk but not after 1 wk. In addition, ID mice had an increased chronic pain response compared with the ND mice only in the late phase of the formalin-test after 1, 4, and 15 wk of iron deficiency. This increased pain response was accompanied by an elevated expression of c-Fos immunoreactive cells at the ipsilateral dorsal horn, suggesting that iron deficiency indirectly increases cell activity at the spinal cord level. These results demonstrate that iron deficiency increases acute and chronic pain responses in mice and may cause similar alterations to the acute pain threshold and sensitivity to C-fiber–mediated chronic pain in ID RLS patients.

Satiation Due to Equally Palatable Sweet and Savory Meals Does Not Differ in Normal Weight Young Adults [Ingestive Behavior and Neurosciences]

Griffioen-Roose, S., Mars, M., Finlayson, G., Blundell, J. E., de Graaf, C. — Tue, 20 Oct 2009 10:01:51 PDT

Sensory properties are greatly involved in the process of satiation. Regarding the nature of sensory signals, an important distinction can be made between sweet and savory taste. It is unclear, however, whether sweet and savory differ in their influence on satiation. Our objective was to investigate the difference between a sweet and savory taste on satiation, independent of palatability, texture, energy density, and macronutrient composition. A crossover design was used, consisting of 3 test conditions in which 2 tastes (sweet and savory) were compared. Sixty-four healthy, nonsmoking, unrestrained participants (18 males and 46 females), with a mean age of 22.3 ± 2.4 y and a mean BMI of 21.6 ± 1.7 kg/m², enrolled. Rice was used as a test meal served in either a sweet or savory version. The meals were similar in palatability, texture, energy density, and macronutrient composition. Ad libitum intake, eating rate, and changes in pleasantness and appetite during the meals were measured. Ad libitum intake did not differ between the 2 meals; participants ate a mean of 314 ± 144 g of the sweet meal and 333 ± 159 g of the savory meal. Eating rate (sweet, 38 ± 14 g/min; savory, 37 ± 14 g/min) and changes in pleasantness and appetite during the meals were similar. Homogeneous meals with a sweet or savory taste, similar in palatability, texture, energy density, and macronutrient composition, do not differ in their influence on satiation in normal weight young adults.

A High Mixed Protein Diet Reduces Body Fat without Altering the Mechanical Properties of Bone in Female Rats [Nutrient Requirements and Optimal Nutrition]

Tue, 20 Oct 2009 10:01:51 PDT

Long-term consumption of high-protein (HP) diets at 35% of energy is postulated to negatively influence bone health. Previous studies have not comprehensively examined the biochemical, physical, and biomechanical properties of bone required to arrive at this conclusion. Our objective in this study was to examine the long-term effect of a HP diet on bone metabolism, mass, and strength in rats. Adult female Sprague-Dawley rats (n = 80) were randomized to receive for 4, 8, 12, or 17 mo a normal-protein (NP) control diet (15% of energy) or a HP diet (35% of energy). Diets were balanced for calcium because the protein sources were rich in calcium. At each time point, measurements included weight, body composition, and bone mass using dual-energy X-ray absorptiometry, mechanical strength at the mid-diaphysis of femur and tibia, microarchitecture of femurs using microcomputerized tomography and serum osteocalcin, carboxy-terminal crosslinks of type I collagen (CTX), insulin-like growth factor-1 (IGF-1), leptin, and adiponectin. Effects of diet, time, and their interaction were tested using factorial ANOVA. The HP diet resulted in lower body weight, total body, and abdominal fat and higher lean mass. Serum leptin and adiponectin were greater in HP-fed than in NP-fed rats, but IGF-1 did not differ between the groups. Whereas the HP diet resulted in higher relative bone mineral content (g/kg) in the femur, tibia, and vertebrae, serum osteocalcin and CTX and bone internal architecture and biomechanical strength were unaffected. In conclusion, HP diets at 35% of energy lower body fat content without hindering the mechanical and weight-bearing properties of bone.

Linear and Ponderal Growth Trajectories in Well-Nourished, Iron-Sufficient Infants Are Unimpaired by Iron Supplementation [Nutrient Requirements and Optimal Nutrition]

Gahagan, S., Yu, S., Kaciroti, N., Castillo, M., Lozoff, B. — Tue, 20 Oct 2009 10:01:51 PDT

Iron deficiency remains the most common nutritional deficiency worldwide and supplementation is recommended during periods of high risk, including infancy. However, questions have been raised about possible adverse effects of iron on growth in iron-sufficient (IS) infants and the advisability of across-the-board iron supplementation. This study examined whether short- or long-term growth was impaired in IS infants who received iron supplementation. From a longitudinal study of healthy, breast-fed, low- to middle-income Chilean infants randomly assigned to iron supplementation or usual nutrition at 6 or 12 mo, we retrospectively identified infants meeting criteria for iron sufficiency at the time of random assignment (n = 273). Using multilevel analysis, ponderal and linear growth were modeled before, during, and after iron supplementation up to 10 y in 3 comparisons: 1) iron supplementation compared with usual nutrition from 6 to 12 mo; 2) iron supplementation compared with usual nutrition from 12 to 18 mo; and 3) 15 mg/d of iron as drops compared with iron-fortified formula (12 mg/L). Growth trajectories did not differ during or after supplementation indicating no adverse effect of iron in any comparison. These results suggest that, at least in some environments, iron does not impair growth in IS infants.

Regular Consumption from Fast Food Establishments Relative to Other Restaurants Is Differentially Associated with Metabolic Outcomes in Young Adults [Nutritional Epidemiology]

Duffey, K. J., Gordon-Larsen, P., Steffen, L. M., Jacobs, D. R., Popkin, B. M. — Tue, 20 Oct 2009 10:01:51 PDT

Although away-from-home eating is adversely associated with weight, other comorbidities have not been examined; therefore, we sought to determine the associations of fast food (e.g. Wendy's, McDonalds) and restaurant (sit-down style) consumption (times per week) with weight and multiple metabolic outcomes, including homeostatic model assessment insulin resistance (HOMA-IR), waist circumference, and plasma triglycerides (TG), LDL cholesterol, and HDL cholesterol (HDL-C). We used 3 waves of data (exam y 7, 10, and 20) from the Coronary Artery Risk Development in Young Adults Study, a prospective cohort study of black and white young adults [aged 25–42 y in 1992–93, n = 3643 (men, 1659; women, 1984)]. Individuals in the highest (vs. lowest) quartile of baseline (defined as the mean of y 7 and 10) fast food consumption had higher y 20 weight [adjusted mean (95% CI): 5.6 kg (CI, 2.1, 9.2); P = 0.002], HOMA-IR [0.9 (CI, 0.4, 1.3); P < 0.001], waist circumference [5.3 cm (CI, 2.8, 7.9); P < 0.000], TG concentrations [0.25 mmol/L (CI, 0.10, 0.40), 22.7 mg/dL (CI, 9.1, 36.3); P = 0.001], and lower HDL-C concentrations [–0.014 mmol/L (CI, –0.215, –0.067), 5.4 mg/dL (CI, –8.3, –2.6); P < 0.000]. Baseline restaurant consumption was unrelated to y 20 outcomes. Adjusted change in weekly restaurant (P < 0.05) and fast food intake (P < 0.001) was associated with 13-y changes in body weight [0.09 kg (CI, 0.02, 0.17) and 0.15 kg (CI, 0.06, 0.24), respectively] and waist circumference [0.08 cm (CI, 0.02, 0.14) and 0.12 cm (CI, 0.04, 0.20), respectively]. Fast food consumption may be an important target for the prevention of adverse metabolic health outcomes.

Increases in Plasma Holotranscobalamin Can Be Used to Assess Vitamin B-12 Absorption in Individuals with Low Plasma Vitamin B-12 [Nutritional Epidemiology]

Tue, 20 Oct 2009 10:01:51 PDT

Low plasma concentrations of vitamin B-12 are common in Indians, possibly due to low dietary intakes of animal-source foods. Whether malabsorption of the vitamin contributes to this has not been investigated. A rise in the plasma holotranscobalamin (holo-TC) concentration after a standard dose of oral vitamin B-12 has been proposed as a measure of gastrointestinal absorption in people with normal plasma vitamin B-12 concentrations. We studied 313 individuals (children and parents, 109 families) in the Pune Maternal Nutrition Study. They received 3 doses of 10 µg (n = 191) or 2 µg (n = 122) of cyanocobalamin at 6-h intervals. A rise in plasma holo-TC of ≥15% and >15 pmol/L above baseline was considered normal vitamin B-12 absorption. The baseline plasma vitamin B-12 concentration was <150 pmol/L in 48% of participants; holo-TC was <35 pmol/L in 98% and total homocysteine was high in 50% of participants (>10 µmol/L in children and >15 µmol/L in adults). In the 10 µg group, the plasma holo-TC concentration increased by 4.8-fold from (mean ± SD) 9.3 ± 7.0 pmol/L to 53.8 ± 25.9 pmol/L and in the 2 µg group by 2.2-fold from 11.1 ± 8.5 pmol/L to 35.7 ± 19.3 pmol/L. Only 10% of the participants, mostly fathers, had an increase less than the suggested cut-points. Our results suggest that an increase in plasma holo-TC may be used to assess vitamin B-12 absorption in individuals with low vitamin B-12 status. Because malabsorption is unlikely to be a major reason for the low plasma vitamin B-12 concentrations in this population, increasing dietary vitamin B-12 should improve their status.

Adjusting for the Acute Phase Response Is Essential to Interpret Iron Status Indicators among Young Zanzibari Children Prone to Chronic Malaria and Helminth Infections [Community and International Nutrition]

Tue, 20 Oct 2009 10:01:51 PDT

The extent to which the acute phase response (APR) influences iron status indicators in chronic infections is not well documented. We investigated this relationship using reported recent fever and 2 acute phase proteins (APP), C-reactive protein (CRP), and -1-acid glycoprotein (AGP). In a sample of 690 children matched on age and helminth infection status at baseline, we measured plasma for AGP, CRP, ferritin, transferrin receptor (TfR), and erythropoietin (EPO) and whole blood for hemoglobin (Hb) concentration, zinc protoporphyrin (ZPP), and malaria parasite density, and we obtained maternal reports of recent fever. We then examined the influence of the APR on each iron status indicator using regression analysis with Hb as the outcome variable. Ferritin was inversely related to Hb in the APR-unadjusted model. Adjusting for the APR using reported recent fever alone was not sufficient to reverse the inverse Hb-ferritin relationship. However, using CRP and/or AGP resulted in the expected positive relationship. The best fit model included reported recent fever, AGP and CRP (R² = 0.241; P < 0.001). The best fit Hb-ZPP, Hb-TfR, and Hb-EPO models included reported recent fever and AGP but not CRP (R² = 0.253, 0.310, and 0.292, respectively; P < 0.001). ZPP, TfR, and EPO were minimally influenced by the APR, whereas ferritin was immensely affected. Reported recent fever alone cannot be used as a marker for the APR. Either AGP or CRP is useful for adjusting if only 1 APP can be measured. However, AGP best predicted the APR in this population.

Household Food Insecurity Is Associated with Childhood Malaria in Rural Haiti [Community and International Nutrition]

Tue, 20 Oct 2009 10:01:51 PDT

Haiti is the poorest country in the Western Hemisphere and is heavily affected by food insecurity and malaria. To find out if these 2 conditions are associated with each other, we studied a convenience sample of 153 women with children 1–5 y old in Camp Perrin, South Haiti. Household food insecurity was assessed with the 16-item Escala Latinoamericana y Caribeña de Seguridad Alimentaria (ELCSA) scale previously validated in the target communities. ELCSA's reference time period was the 3 mo preceding the survey and it was answered by the mother. Households were categorized as either food secure (2%; ELCSA score = 0), food insecure/very food insecure (42.7%; ELCSA score range: 1–10), or severely food insecure (57.3%; ELCSA score range: 11–16). A total of 34.0% of women reported that their children had malaria during the 2 mo preceding the survey. Multivariate analyses showed that severe food insecure was a risk factor for perceived clinical malaria (odds ratio: 5.97; 95% CI: 2.06–17.28). Additional risk factors for perceived clinical malaria were as follows: not receiving colostrum, poor child health (via maternal self-report), a child BMI <17 kg/m², and child vitamin A supplementation more than once since birth. Findings suggest that policies and programs that address food insecurity are also likely to reduce the risk of malaria in Haiti.

Nationally Representative Surveys Show Recent Increases in the Prevalence of Overweight and Obesity among Women of Reproductive Age in Bangladesh, Nepal, and India [Community and International Nutrition]

Balarajan, Y., Villamor, E. — Tue, 20 Oct 2009 10:01:51 PDT

Our aims in this study were to examine trends in the prevalence of overweight-obesity and underweight among women of reproductive age in 3 South Asian countries between 1996 and 2006 and to identify sociodemographic correlates of overweight in the most recent survey. Using nationally representative data from 8 Demographic and Health Surveys conducted in Bangladesh (n = 19,211), Nepal (n = 19,354), and India (n = 161,755), we examined the change in the prevalence rates of overweight-obesity (BMI ≥ 25 kg/m²) and underweight (BMI < 18.5 kg/m²) over a recent 7- to 10-y period among women aged 15–49 y. The prevalence of overweight-obesity increased substantially in all countries. Comparing the first to the latest survey in Bangladesh, the prevalence of overweight-obesity increased from 2.7 to 8.9% [age and parity-adjusted prevalence ratio (PR): 2.42; 95% CI: 1.88, 3.13]; in Nepal, from 1.6 to 10.1% [adjusted PR: 4.18; 95% CI: 3.00, 5.83]; and in India, from 10.6 to 14.8% [adjusted PR: 1.28; 95% CI: 1.20, 1.36]. These increases were observed in both rural and urban areas and were greater in rural areas. During the study period, the prevalence of underweight decreased substantially in Bangladesh and only modestly in Nepal and India. Overweight-obesity was positively related to age, higher socioeconomic status, and urban residence in all countries. In conclusion, while the prevalence of underweight has remained high in Bangladesh, Nepal, and India, the prevalence of overweight-obesity in women of reproductive age has risen between 1996 and 2006.

Maternal Milk, but Not Formula, Regulates the Immune Response to {beta}-Lactoglobulin in Allergy-Prone Rat Pups [Nutritional Immunology]

Tue, 20 Oct 2009 10:01:51 PDT

Controversy exists regarding the timing of the introduction of allergic foods into the diet. We investigated the immune response of rat pups exposed to β-lactoglobulin (BLG), one of the main allergenic proteins in cow milk. Brown Norway allergy-prone rats were allocated into groups: dam-reared and unchallenged (DR), DR challenged with BLG via gavage (11 mg/d), or rats fed via gastric cannula a formula containing BLG (11 mg/d). BLG was given from d 4 of life. Rats were killed at d 10, 14, or 21. Sera were assayed for total IgE, BLG-specific IgG1, and rat mucosal mast cell protease II (RMCPII; indicator of mucosal mast cell degranulation). Ileum was assessed for cytokine mRNA. Mesenteric lymph nodes (MLN) were assessed for forkhead boxP3 (Foxp3) and chemokine (C-C motif) receptor 7 (CCR7) expression by real-time PCR and immunostained for Foxp3⁺ CD4⁺ regulatory cells. Formula feeding compared with dam-rearing with or without oral BLG challenge resulted in significantly greater serum IgE, BLG-specific IgG1, RMCPII, and intestinal mast cells but reduced MLN Foxp3⁺ cells, Foxp3, and CCR7 expression and ileal cytokines, interleukin (IL)-4, IL-10, and interferon- (P < 0.05). Importantly, giving BLG in the presence of maternal milk resulted in an immune response profile similar to that of unchallenged DR rats but with greater Foxp3 and CCR7 mRNA expression and CD4⁺ Foxp3⁺ cells (P < 0.05). We conclude that introducing an allergenic food with breast milk reduces immunological indicators of an allergic response, whereas introduction during formula feeding generates an allergic response.

Announcements [Announcements]

Tue, 20 Oct 2009 10:01:51 PDT

Landscape Analysis of Interactions between Nutrition and Vaccine Responses in Children [Supplement: Landscape Analysis of Interactions between Nutrition and Vaccine Responses in Children]

Tue, 20 Oct 2009 10:01:51 PDT

The world's poorest children are likely to be malnourished when receiving their childhood vaccines. It is uncertain whether this affects vaccine efficacy and whether the coadministration of nutrient supplements with vaccines has beneficial or detrimental effects. More recently, a detrimental interaction between vitamin A (VA) supplementation (VAS) and the killed diphtheria-tetanus-pertussis vaccine given in early childhood has been suggested. This report provides a critical review of the published interactions between nutritional status and/or supplementation and vaccine responses in children. Due to an absence of evidence for most nutrients, this analysis focused on protein-energy, vitamins A and D, and iron and zinc. All vaccines were considered. Both observational studies and clinical trials that led to peer-reviewed publications in English or French were included. These criteria led to a pool of 58 studies for protein-energy malnutrition, 43 for VA, 4 for vitamin D, 10 for iron, and 22 for zinc. Our analysis indicates that malnutrition has surprisingly little or no effect on vaccine responses. Evidence for definitive adjunctive effects of micronutrient supplementation at the time of vaccination is also weak. Overall, the paucity, poor quality, and heterogeneity of data make it difficult to draw firm conclusions. The use of simple endpoints that may not correlate strongly with disease protection adds uncertainty. A detailed examination of the immunological mechanisms involved in potential interactions, employing modern methodologies, is therefore required. This would also help us understand the proposed, but still unproven, negative interactions between VAS and vaccine safety, a resolution of which is urgently required.

Applying the FDA Definition of Whole Grains to the Evidence for Cardiovascular Disease Health Claims [Supplement: Applying the FDA Definition of Whole Grains to the Evidence for Cardiovascular Disease Health Claims]

De Moura, F. F., Lewis, K. D., Falk, M. C. — Tue, 20 Oct 2009 10:01:51 PDT

The U.S. FDA defines whole grains as consisting of the intact, ground, cracked, or flaked fruit of the grains whose principal components, the starchy endosperm, germ, and bran, are present in the same relative proportions as they exist in the intact grain. We evaluated the effect of applying the FDA definition of whole grains to the strength of scientific evidence in support of claims for risk reduction of cardiovascular disease (CVD). We concluded that using the FDA definition for whole grains as a selection criterion is limiting, because the majority of existing studies often use a broader meaning to define whole grains. When considering only whole grain studies that met the FDA definition, we found insufficient scientific evidence to support a claim that whole grain intake reduces the risk of CVD. However, a whole grain and reduced risk of CVD health claim is supported when using a broader concept of whole grain to include studies that considered intake of fiber-rich bran and germ as well as whole grain. This type of analysis is complicated by diversity in nutrients and bioactive components among different types of whole grains.