European Journal of Nutrition (v.53, #7)
Three-month B vitamin supplementation in pre-school children affects folate status and homocysteine, but not cognitive performance by Astrid Rauh-Pfeiffer; Uschi Handel; Hans Demmelmair; Wolfgang Peissner; Mareile Niesser; Diego Moretti; Vanessa Martens; Sheila Wiseman; Judith Weichert; Moritz Heene; Markus Bühner; Berthold Koletzko (1445-1456).
Suboptimal vitamin B status might affect cognitive performance in early childhood. We tested the hypothesis that short-term supplementation with folic acid and selected B vitamins improves cognitive function in healthy children in a population with relatively low folate status.We screened 1,002 kindergarten children for suboptimal folate status by assessing the total urinary para-aminobenzoylglutamate excretion. Two hundred and fifty low ranking subjects were recruited into a double blind, randomized, controlled trial to receive daily a sachet containing 220 μg folic acid, 1.1 mg vitamin B2, 0.73 mg B6, 1.2 μg B12 and 130 mg calcium, or calcium only for 3 months. Primary outcomes were changes in verbal IQ, short-term memory and processing speed between baseline and study end. Secondary outcomes were urinary markers of folate and vitamin B12 status, acetyl-para-aminobenzoylglutamate and methylmalonic acid, respectively, and, in a subgroup of 120 participants, blood folate and plasma homocysteine.Pre- and post-intervention cognitive measurements were completed by 115 children in the intervention and 122 in the control group. Compared to control, median blood folate increased by about 50 % (P for difference, P < 0.0001). Homocysteine decreased by 1.1 μmol/L compared to baseline, no change was seen in the control group (P for difference P < 0.0001) and acetyl-para-aminobenzoylglutamate was 4 nmol/mmol higher compared to control at the end of the intervention (P < 0.0001). We found no relevant differences between the groups for the cognitive measures.Short-term improvement of folate and homocysteine status in healthy children does not appear to affect cognitive performance.
Keywords: B vitamin supplementation; Cognition; Pre-school children
Freeze-dried powdered yacon: effects of FOS on serum glucose, lipids and intestinal transit in the elderly by M. M. A. Scheid; P. S. Genaro; Y. M. F. Moreno; G. M. Pastore (1457-1464).
Freeze-dried powdered yacon (FDY) can be considered a prebiotic product due to its fructooligosaccharides (FOS) content. The effect of 9 weeks of daily intake of FDY containing 7.4 g of FOS on glucose, lipid metabolism and intestinal transit in a group of elderly people was investigated.Seventy-two elderly (mean age 67.11 ± 6.11) men and women were studied for 9 weeks in a double-blind, placebo-controlled experiment. They were randomly assigned to the supplement group (which received 7.4 g of FOS as FDY) or the control group. At the beginning and end of the study, anthropometric measurements, blood sampling, clinical analyses and dietary intake were assessed.A daily intake of FDY containing 7.4 g of FOS for 9 weeks was associated with a mean decrease in serum glucose (p = 0.013), but supplementation did not reduce serum lipids in the study group. The administered dose did not adversely affect intestinal transit. It did not cause bloating, flatulence or intestinal discomfort.Freeze-dried powdered yacon is a good source of FOS, and daily consumption can have a favourable effect on serum glucose in the elderly. It is also practical, easy and safe to use and store.
Keywords: Freeze-dried powdered yacon; Elderly; Serum glucose; Serum lipids; Intestinal transit; Fructooligosaccharides
Lactobacillus strains isolated from infant faeces possess potent inhibitory activity against intestinal alpha- and beta-glucosidases suggesting anti-diabetic potential by Harsh Panwar; Danielle Calderwood; Irene R. Grant; Sunita Grover; Brian D. Green (1465-1474).
Inhibitors of intestinal alpha-glucosidases are used therapeutically to treat type 2 diabetes mellitus. Bacteria such as Actinoplanes sp. naturally produce potent alpha-glucosidase inhibitor compounds, including the most widely available drug acarbose. It is not known whether lactic acid bacteria (LAB) colonising the human gut possess inhibitory potential against glucosidases. Hence, the study was undertaken to screen LABs having inherent alpha- and beta-glucosidase inhibitory potential.This study isolated, screened, identified and extracted Lactobacillus strains (Lb1–15) from human infant faecal samples determining their inhibitory activity against intestinal maltase, sucrase, lactase and amylase. Lactobacillus reference strains (Ref1–7), a Gram positive control (Ctrl1) and two Gram negative controls (Ctrl2–3), were also analysed to compare activity.Faecal isolates were identified by DNA sequencing, with the majority identified as unique strains of Lactobacillus plantarum. Some strains (L. plantarum, L. fermentum, L. casei and L. rhamnosus) had potent and broad spectrum inhibitory activities (up to 89 %; p < 0.001; 500 mg/ml wet weight) comparable to acarbose (up to 88 %; p < 0.001; 30 mg/ml). Inhibitory activity was concentration-dependent and was freely available in the supernatant, and was not present in other bacterial genera (Bifidobacterium bifidum and Escherichia coli or Salmonella typhimurium). Interestingly, the potency and spectrum of inhibitory activity across strains of a single species (L. plantarum) differed substantially. Some Lactobacillus extracts had broader spectrum activities than acarbose, effectively inhibiting beta-glucosidase activity (lactase) as well as alpha-glucosidase activities (maltase, sucrase and amylase). Anti-diabetic potential was indicated by the fact that oral gavage with a L. rhamnosus extract (1 g/kg) was able to reduce glucose excursions (Area under curve; 22 %; p < 0.05) in rats during a carbohydrate challenge (starch; 2 g/kg).These results definitively demonstrate that Lactobacillus strains present in the human gut have alpha- and beta-glucosidase inhibitory activities and can reduce blood glucose responses in vivo. Although the potential use of LAB such as Lactobacillus as a dietary supplement, medicinal food or biotherapeutic for diabetes is uncertain, such an approach might offer advantages over drug therapies in terms of broader spectrum activities and fewer unpleasant side effects. Further characterisation of this bioactivity is warranted, and chronic studies should be undertaken in appropriate animal models or diabetic subjects.
Keywords: Lactobacillus ; Alpha-glucosidase; Beta-glucosidase
Ramadan fasting ameliorates oxidative stress and improves glycemic control and lipid profile in diabetic patients by Ahmad I. Al-Shafei (1475-1481).
The effects of Ramadan fasting on public health are important. The present study characterized the metabolic effects of Ramadan fasting and evaluated its influence on oxidative stress in diabetic patients.The current study was carried out in the city of Benha, Egypt, during the period from July 12, 2012 to October 4, 2012. This corresponds to 22 Shaban 1433 to 18 Dhul Al-Qi’dah 1433 in the Islamic Calendar. Two equal, sex- and age-matched groups (n = 40 each; age 55 ± 5 years) of non-diabetic subjects (ND group) and diabetic patients (D group) were recruited for this study. Parameters of glycemic control, lipid profile, and oxidative stress were measured pre-, during and post-fasting.Ramadan fasting reduced fasting blood glucose (FBG) insignificantly by 5.8 % and significantly by 23.0 % in the (ND) and (D) groups, respectively. Serum triglycerides (TG) and malondialdehyde (MDA) were lowered significantly by: TG (22.8, 22.1 %), MDA (54.3, 46.6 %), and total cholesterol (TC) and low-density lipoproteins (LDL) insignificantly by: TC: (4.7, 6.1 %), LDL: (4.0, 5.1 %), whereas high-density lipoproteins (HDL) were raised significantly by 6.7 % and insignificantly by 2.2 %, and blood glutathione (GSH) significantly by 52.6 and 59.4 %, in the (ND) and (D) groups, respectively. At 6 weeks post-fasting FBG, TG, TC, HDL, and LDL returned to levels indistinguishable from their baseline values in both groups, while MDA was maintained significantly lower by (25.7, 22.7 %), and GSH significantly higher by (26.3, 31.3 %), in the (ND) and (D) groups, respectively.Ramadan fasting improves glycemic control and lipids profile and alleviates oxidative stress in diabetics.
Keywords: Diabetes mellitus; Ramadan fasting; Glycosylated hemoglobin; High-density lipoproteins; Low-density lipoproteins; Glutathione; Malondialdehyde
Nutritional intake and status in persons with alcohol dependency: data from an outpatient treatment programme by Anne Wilkens Knudsen; Jens-Erik Beck Jensen; Inge Nordgaard-Lassen; Thomas Almdal; Jens Kondrup; Ulrik Becker (1483-1492).
Malnutrition increases the risk of developing alcohol-related complications. The aim of this study was to describe nutrient intake, nutritional status and nutrition-related complications in a Danish population of outpatients with alcohol dependency.This was a cross-sectional study with a 6-month follow-up enrolling persons with alcohol dependency (n = 80) admitted to a hospital-based outpatient clinic. Body mass index, the waist-to-hip ratio and handgrip strength (HGS) were measured, a 7-day food diary was collected, and biochemical testing was conducted. Dual-energy X-ray absorptiometry was performed to determine body composition and bone mineral density (BMD). In total, 64 % of the patients with alcohol dependency had vitamin D insufficiency (25-OH-vit D <50 nmol/l). Compared with surveys of the general population, the patients with alcohol dependency had lower energy intake (p = 0.008), s-zinc levels (p < 0.001), s-magnesium levels (p = 0.02), Z-scores for BMD (lumbar spine, p = 0.03; total hip, p = 0.009) and HGS (p < 0.001). Osteopenia was observed in 52 % of individuals, and overt osteoporosis was noted in 7 %. Comparing baseline data with data from the follow-up (n = 30), we found a decrease in s-CRP (p = 0.002) and s-alanine amino transferase (p = 0.01) levels and an increase in s-parathyroid hormone levels (p = 0.02). Patients with alcohol dependency have an altered nutritional status and risk of complications, as evidenced by osteopenia/osteoporosis and reduced muscle strength. Treatment at an outpatient clinic improved the variables related to liver function, but no change was observed in nutritional status over time. These findings suggest that specific screening and targeted treatment regimens for nutritional deficits could be beneficial.
Keywords: Nutrition; Alcohol; Addiction; Complications
Extract of Aronia melanocarpa-modified hemostasis: in vitro studies by Joanna Sikora; Magdalena Markowicz-Piasecka; Marlena Broncel; Elżbieta Mikiciuk-Olasik (1493-1502).
Aronia melanocarpa has an extremely high content of procyanidins and anthocyanins. The multidirectional benefits of consumption of these berries are widely reported. Although numerous studies confirmed the influence of polyphenols on various stages of hemostasis, the exact mechanism of this phenomenon is not understood. The aim of our study was to evaluate the in vitro effect of A. melanocarpa extract on various parameters of hemostasis. Adenosine 5′-diphosphate (ADP)-induced aggregation was measured with turbidimetric method. Spontaneous and ADP-activated platelet adhesion were investigated using a colorimetric method. The global assay of coagulation and fibrinolysis was performed with the use of optical clotting and lysis (CL) test. Thrombin (0.5 IU/mL) and tissue plasminogen activator (60 ng/mL) were used to obtain a CL curve. The activity of thrombin and plasmin was determined by means of chromogenic substrate (S-2238, S-2251)The aronia extract contributed to the reduction in spontaneous and ADP-activated platelet adhesion. A significant increase in overall potential of CL as well as significant changes in key parameters of these processes (T t—thrombin time, F vo—initial plasma clotting velocity, and L max—maximum lysis) was reported. Chokeberry extract significantly inhibited the amidolytic activity of thrombin and plasmin.Our in vitro findings indicate a complex mechanism of influence of chokeberry polyphenols on platelet activity and the overall potential of CL. We confirmed that chokeberry inhibits the amidolytic activity of thrombin. It was demonstrated for the first time that chokeberry polyphenols inhibit the amidolytic activity of another serine protease, i.e., plasmin, which is the main fibrinolytic enzyme. Furthermore, our research points out a significant contribution of other plasma components and fibrinogen in the modulation of hemostasis by polyphenols.
Keywords: Adhesion; Aggregation; Fibrinolysis; Thrombin activity; Plasmin activity; Aronia melanocarpa ; Chokeberry
Resveratrol increases brown adipose tissue thermogenesis markers by increasing SIRT1 and energy expenditure and decreasing fat accumulation in adipose tissue of mice fed a standard diet by João Marcus Oliveira Andrade; Alessandra Caroline Montes Frade; Juliana Bohnen Guimarães; Kátia Michelle Freitas; Miriam Teresa Paz Lopes; André Luiz Sena Guimarães; Alfredo Maurício Batista de Paula; Cândido Celso Coimbra; Sérgio Henrique Sousa Santos (1503-1510).
Adipose tissue is central to the regulation of energy balance. Two functionally different fat pads are present in mammals: white adipose tissue, the primary site of triglyceride storage, and brown adipose tissue (BAT), which is specialized in heat production. In this context, new strategies capable of modulating the development and function of white and BAT become relevant. In the present study, we analyzed the influence of resveratrol (sirtuin activator) on energy balance and the expression of thermogenesis markers.Mice were divided into two groups: standard diet (ST) and standard diet plus resveratrol (ST + RSV).After 2 months of treatment, ST + RSV mice presented significantly decreased fat accumulation in adipose tissue, with diminished total cholesterol and glucose plasma levels. Additionally, increased oxygen consumption was observed in ST + RSV group. Analyses of mRNA of thermogenesis-related genes showed significant increase in UCP1, SIRT1, PTEN and BMP-7 expression in BAT.Our data suggest that improved metabolism produced by oral administration of resveratrol is, at least in part, associated with increased thermogenesis followed by high expression of UCP1 and SIRT1, which can mediate higher energy expenditure and decreased fat accumulation in adipose tissue.
Keywords: Thermogenesis; PTEN; Adipose tissue; SIRT1; UCP1
Intake of vegetables and fruit and risk of esophageal adenocarcinoma: a meta-analysis of observational studies by Bailing Li; Gengxi Jiang; Guanxin Zhang; Qing Xue; Hao Zhang; Chong Wang; Tiejun Zhao (1511-1521).
To study the association between the intake of fruit and vegetables and risk of esophageal adenocarcinoma (EAC), we summarized the evidence from observational studies in categorical and linear dose–response meta-analyses.Eligible studies published up to June 2013 were retrieved via computerized searches of MEDLINE and EMBASE. Random-effects models were used to calculate summary relative risks (SRRs) and the corresponding 95 % confidence intervals (CIs). Between-study heterogeneity was assessed using the Cochran’s Q and I 2 statistics.A total of 12 studies involving 1,572 cases of EAC were included in this meta-analysis. Based on the highest versus lowest analysis, inverse associations were observed between intakes of vegetable (SRRs = 0.76, 95 % CIs 0.59–0.96; P heterogeneity = 0.098, I 2 40.4 %; n = 9 studies), intakes of fruit (SRRs = 0.73, 95 % CIs, 0.55–0.98; P heterogeneity = 0.03, I 2 = 52.9 %; n = 9 studies), and intakes of total vegetables and fruit combined (SRRs = 0.68, 95 % CI 0.49–0.93; P heterogeneity = 0.162, I 2 = 38.9 %; n = 5 studies). Similar results were also observed in a linear dose–response analysis.These data support the hypothesis that intakes of vegetables and fruit may significantly reduce the risk of EAC. Further investigation with prospective designs, validated questionnaires, and good control of important confounders is warranted.
Keywords: Esophageal adenocarcinoma; Meta-analysis; Fruit; Vegetable
Effect of maternal protein restriction during pregnancy and postweaning high-fat feeding on diet-induced thermogenesis in adult mouse offspring by Dyan Sellayah; Lea Dib; Frederick W. Anthony; Adam J. Watkins; Tom P. Fleming; Mark A. Hanson; Felino R. Cagampang (1523-1531).
Prenatal undernutrition followed by postweaning feeding of a high-fat diet results in obesity in the adult offspring. In this study, we investigated whether diet-induced thermogenesis is altered as a result of such nutritional mismatch.Female MF-1 mice were fed a normal protein (NP, 18 % casein) or a protein-restricted (PR, 9 % casein) diet throughout pregnancy and lactation. After weaning, male offspring of both groups were fed either a high-fat diet (HF; 45 % kcal fat) or standard chow (C, 7 % kcal fat) to generate the NP/C, NP/HF, PR/C and PR/HF adult offspring groups (n = 7–11 per group).PR/C and NP/C offspring have similar body weights at 30 weeks of age. Postweaning HF feeding resulted in significantly heavier NP/HF offspring (P < 0.01), but not in PR/HF offspring, compared with their chow-fed counterparts. However, the PR/HF offspring exhibited greater adiposity (P < 0.01) v the NP/HF group. The NP/HF offspring had increased energy expenditure and increased mRNA expression of uncoupling protein-1 and β-3 adrenergic receptor in the interscapular brown adipose tissue (iBAT) compared with the NP/C mice (both at P < 0.01). No such differences in energy expenditure and iBAT gene expression were observed between the PR/HF and PR/C offspring.These data suggest that a mismatch between maternal diet during pregnancy and lactation, and the postweaning diet of the offspring, can attenuate diet-induced thermogenesis in the iBAT, resulting in the development of obesity in adulthood.
Keywords: High-fat diet; Low-protein diet; Obesity; Thermogenesis
Plasma phospholipids indicate impaired fatty acid homeostasis in preterm infants by Wolfgang Bernhard; Marco Raith; Vera Koch; Rebecca Kunze; Christoph Maas; Harald Abele; Christian F. Poets; Axel R. Franz (1533-1547).
During fetal development, docosahexaenoic (DHA) and arachidonic acid (ARA) are particularly enriched in brain phospholipids. After preterm delivery, fetal enrichment of DHA and ARA via placental transfer is replaced by enteral and parenteral nutrition, which is rich in linoleic acid (LA) instead. Specific DHA and ARA enrichment of lipoproteins is reflected by plasma phosphatidylcholine (PC) species, whereas plasma phosphatidylethanolamine (PE) composition reflects hepatic stores. We profiled PC and PE species in preterm infant plasma, compared with cord and maternal blood, to assess whether current feeding practice meets fetal conditions in these patients.Preterm infant plasma (N = 171, 23–35 w postmenstrual age (PMA), postnatal day 1–103), cord plasma (N = 194) and maternal serum (N = 121) (both 24–41 w PMA) were collected. After lipid extraction, PC and PE molecular species were analyzed using tandem mass spectrometry.Phospholipid concentrations were higher in preterm infant than in cord plasma after correction for PMA. This was mainly due to postnatal increases in LA-containing PC and PE, resulting in decreased fractions of their DHA- and ARA-containing counterparts. These changes in preterm infant plasma phospholipids occurred during the time of transition to full enteral feeds (day 0–10 after delivery). Thereafter, the fraction of ARA-containing phospholipids further decreased, whereas that of DHA slowly reincreased but remained at a level 50 % of that of PMA-matched cord blood.The postnatal increase in LA–PC in preterm infant plasma results in decreased fractions of DHA–PC and ARA–PC. These changes are also reflected by PE molecular composition as an indicator of altered hepatic fatty acid homeostasis. They are presumably caused by inadequately high LA, and low ARA and DHA supply, at a stage of development when ARA–PC and DHA–PC should be high, probably reducing the availability of DHA and ARA to the developing brain and contributing to impaired neurodevelopment of preterm infants.
Keywords: Arachidonic acid; Docosahexaenoic acid; Linoleic acid; Plasma phosphatidylcholine; Tandem mass spectrometry; Preterm infants
MTHFR C677T genotype and cardiovascular risk in a general population without mandatory folic acid fortification by Lise Lotte N. Husemoen; Tea Skaaby; Torben Jørgensen; Betina H. Thuesen; Mogens Fenger; Niels Grarup; Camilla H. Sandholt; Torben Hansen; Oluf Pedersen; Allan Linneberg (1549-1559).
Meta-analyses have suggested an effect of MTHFR C677T genotype (rs1801133), a proxy for blood total homocysteine, on cardiovascular disease (CVD) in populations with low population dietary folate. The aim was to examine the association and effect modification by serum folate and vitamin B12 levels between MTHFR and CVD-related outcomes in a general population with no mandatory folic acid fortification policy.The study population included 13,748 adults retrieved from pooling of four population-based studies conducted in Denmark. MTHFR genotype, serum folate (measured in approximately 9,356 individuals), and serum vitamin B12 (9,215 individuals), hypertension, and dyslipidemia were measured at baseline, and participants were followed for a mean of 10.5–11.7 years in central registries for diagnoses of stroke (623 incidents), ischaemic heart disease (IHD) (835 incidents), and all-cause mortality (1,272 incidents).The MTHFR genotype (TT vs. CC/CT) was not associated with hypertension [OR (95 % CI) 1.09 (0.95–1.25)], dyslipidemia [OR (95 % CI) 0.97 (0.84–1.11)], stroke [HR (95 % CI) 0.92 (0.69–1.23)], and all-cause mortality [HR (95 % CI) 0.94 (0.77–1.14)], either overall, or in participants with low serum folate or B12 status (P values for interactions 0.15–0.94). Individuals with the MTHFR TT genotype had a higher risk of IHD (HR (95 % CI) 1.38 (1.11–1.71)), but this association was not modified by folate status (P value for interaction 0.45).Our results do not support a causal relationship between homocysteine and CVD. However, we cannot exclude a direct causal effect of MTHFR C677T genotype on IHD.
Keywords: Homocysteine; Folate; B12; Cardiovascular disease; MTHFR; rs1801133
Cardio- and cerebrovascular responses to the energy drink Red Bull in young adults: a randomized cross-over study by Erik K. Grasser; Gayathri Yepuri; Abdul G. Dulloo; Jean-Pierre Montani (1561-1571).
Energy drinks are beverages containing vasoactive metabolites, usually a combination of caffeine, taurine, glucuronolactone and sugars. There are concerns about the safety of energy drinks with some countries banning their sales. We determined the acute effects of a popular energy drink, Red Bull, on cardiovascular and hemodynamic variables, cerebrovascular parameters and microvascular endothelial function.Twenty-five young non-obese and healthy subjects attended two experimental sessions on separate days according to a randomized crossover study design. During each session, primary measurements included beat-to-beat blood pressure measurements, impedance cardiography and transcranial Doppler measurements for at least 20 min baseline and for 2 h following the ingestion of either 355 mL of the energy drink or 355 mL of tap water; the endothelial function test was performed before and two hours after either drink.Unlike the water control load, Red Bull consumption led to increases in both systolic and diastolic blood pressure (p < 0.005), associated with increased heart rate and cardiac output (p < 0.05), with no significant changes in total peripheral resistance and without diminished endothelial response to acetylcholine; consequently, double product (reflecting myocardial load) was increased (p < 0.005). Red Bull consumption also led to increases in cerebrovascular resistance and breathing frequency (p < 0.005), as well as to decreases in cerebral blood flow velocity (p < 0.005) and end-tidal carbon dioxide (p < 0.005).Our results show an overall negative hemodynamic profile in response to ingestion of the energy drink Red Bull, in particular an elevated blood pressure and double product and a lower cerebral blood flow velocity.
Keywords: Energy drink; Blood pressure; Cerebral blood flow velocity; Microvascular endothelial dysfunction; Hemodynamics; Risk factor
Coffee and caffeine intake and risk of endometriosis: a meta-analysis by Francesca Chiaffarino; Francesca Bravi; Sonia Cipriani; Fabio Parazzini; Elena Ricci; Paola Viganò; Carlo La Vecchia (1573-1579).
The potential association between endometriosis and coffee/caffeine consumption has been analysed in several epidemiological studies. In order to establish whether caffeine influences the risk of endometriosis, we provide to summarize the evidence from published studies on this issue.We performed a meta-analysis of epidemiological studies published up to January 2013. We computed summary relative risks (RR) of endometriosis for any, high and low versus no coffee/caffeine consumption.We identified a total eight studies, six case–control and two cohort studies, including a total of 1,407 women with endometriosis. The summary RR for any versus non-consumption were 1.26 [95 % confidence interval (CI) 0.95–1.66] for caffeine and 1.13 (95 % CI 0.46–2.76) for coffee consumption; the overall estimate was 1.18 (95 % CI 0.92–1.49). The summary RR were 1.09 (95 % CI 0.84–1.42) and 1.09 (95 % CI 0.89–1.33) for high and low caffeine consumption as compared to no consumption, respectively.The present meta-analysis provided no evidence for an association between coffee/caffeine consumption and the risk of endometriosis. Coffee/caffeine consumption, as currently used in diet, does not carry a health risk.
Keywords: Epidemiology; Coffee/caffeine intake; Meta-analysis; Clinical epidemiology; Gender medicine; Women’s health
Egg consumption and risk of GI neoplasms: dose–response meta-analysis and systematic review by Genevieve Tse; Guy D. Eslick (1581-1590).
Previous epidemiological studies on egg consumption and the risk of gastrointestinal (GI) neoplasms suggest a positive association; however, data are limited and the evidence remains controversial. This study aims to investigate and quantify the potential dose–response relationship with an evaluation of cancer site-specific differences. Relevant studies were identified after the literature search via electronic databases until January 2014. Subgroup analysis for serving portions was performed using two standardized classification methods: (1) less than 3, or 3 or more eggs per week; (2) less than 3, 3–5, or more than 5 eggs per week. Method two excludes studies that only reported consumption frequency. Pooled adjusted odds ratios (ORs) comparing highest and lowest categories of dietary pattern scores were calculated using a random-effects model.Thirty-seven case–control and seven cohort studies were included for meta-analysis, which contained a total of 424,867 participants and 18,852 GI neoplasm cases. The combined odds ratio (OR) was calculated to 1.15 (95 % CI 1.09–1.22; p value heterogeneity <0.001), showing only a slight increase in risk. The correlation was stronger for colon cancers 1.29 (95 % CI 1.14–1.46; p value heterogeneity <0.22). Dose–response analysis revealed similar results with stratification methods, and the ORs for an intake of <3 and ≥3 eggs per week were 1.14 (95 % CI 1.07–1.22; p value heterogeneity = 0.38) and 1.25 (95 % CI 1.14–1.38; p value heterogeneity = 0.25), respectively. With method 2, the ORs for an intake of <3, 3–5, and >5 eggs per week were 1.13 (95 % CI 1.06–1.21; p value heterogeneity = 0.25), 1.14 (95 % CI 1.01–1.29; p value heterogeneity = 0.06), and 1.19 (95 % CI 1.01–1.39; p value heterogeneity <0.001), respectively.This study provides evidence that egg consumption is associated with a positive dose–response association with the development of GI neoplasms.
Keywords: Egg; Gastrointestinal neoplasms; Colon cancer; Meta-analysis