3′,5′-Cyclic AMP (cAMP) is one of the most important second messengers in mammalian cells, mediating a multitude of diverse cellular signalling responses. Its homeostasis is primarily regulated by adenylate cyclases and phosphodiesterases (PDE), the activities of which are partially dependent on the downstream events of adenosine receptor signalling. The present study was conducted to determine whether coffee constituents other than caffeine can influence the homeostasis of intracellular cAMP in vitro and in vivo by evaluating the effects of selected constituents present in coffee, coffee brews and coffee extracts on platelet PDE activity. In addition, to evaluate the potential effects of these constituents on platelet cAMP concentrations and PDE activity in humans, a 7-week pilot intervention study with eight subjects was conducted. The subjects consumed a regular commercial coffee and a low-caffeine coffee at a rate of 750 ml/d for 2 weeks each. The in vivo results revealed a highly significant inhibition of PDE activity (P< 0·001) after coffee intervention that was not directly dependent on the caffeine content of coffee. Although our in vitro and in vivo findings suggest that caffeine plays some role in the modulation of platelet cAMP status, other natural and roasting-associated compounds such as pyrazines and other currently unidentified species also appear to contribute significantly. In conclusion, moderate consumption of coffee can modulate platelet PDE activity and cAMP concentrations in humans, which may contribute to the putative beneficial health effects of coffee. Further detailed mechanistic investigations will be required to substantiate these beneficial effects and to elucidate the underlying mechanisms.

The aim of the present study was to evaluate the effect of flaxseed on choroid–sclera complex thickness and on LDL oxidation in the sclera, choroid and retina of diet-induced hypercholesterolaemic rabbits. New Zealand male albino rabbits (n 21) were divided into two groups: group 1 (G1; n 11), fed a hypercholesterolaemic diet, and group 2 (G2; n 10), fed a hypercholesterolaemic diet enriched with flaxseed flour. The serum concentrations of total cholesterol (TC), LDL-cholesterol (LDL-C), HDL-cholesterol, TAG and fasting blood glucose were determined at the start of the experiment and on the day of killing (8th week). Choroid and sclera samples were subjected to haematoxylin–eosin (HE) staining and histomorphometric and immunohistochemical analyses with the anti-oxidised LDL antibody. Sensory retina samples were subjected to an immunohistochemical analysis with the primary monoclonal nitrotyrosine antibody. At the end of the experiment, a significant increase was observed in TC and LDL-C concentrations in G1 rabbits when compared with G2 rabbits (P= 0·008 and P= 0·02, respectively). HE staining revealed a significant increase in choroid–sclera complex thickness in G1 rabbits when compared with G2 rabbits (P< 0·001). Immunohistochemical analysis of choroid and sclera samples with the anti-oxidised LDL marker revealed a significant increase in immunoreactivity in G1 rabbits when compared with G2 rabbits (P< 0·001). Immunohistochemical analysis of sensory retina samples with the anti-nitrotyrosine marker revealed a significant increase in immunoreactivity in G1 rabbits when compared with G2 rabbits (P= 0·002). Flaxseed reduced the choroid–sclera complex thickness of diet-induced hypercholesterolaemic rabbits and the expression of oxidised LDL in the choroid–sclera complex as well as the expression of nitrotyrosine in the sensory retina.

Several epidemiological studies have shown that the consumption of finger millet (FM) alleviates diabetes-related complications. In the present study, the effect of finger millet whole grain (FM-WG) and bran (FM-BR) supplementation was evaluated in high-fat diet-fed LACA mice for 12 weeks. Mice were divided into four groups: control group fed a normal diet (10 % fat as energy); a group fed a high-fat diet; a group fed the same high-fat diet supplemented with FM-BR; a group fed the same high-fat diet supplemented with FM-WG. The inclusion of FM-BR at 10 % (w/w) in a high-fat diet had more beneficial effects than that of FM-WG. FM-BR supplementation prevented body weight gain, improved lipid profile and anti-inflammatory status, alleviated oxidative stress, regulated the expression levels of several obesity-related genes, increased the abundance of beneficial gut bacteria (Lactobacillus, Bifidobacteria and Roseburia) and suppressed the abundance of Enterobacter in caecal contents (P≤ 0·05). In conclusion, FM-BR supplementation could be an effective strategy for preventing high-fat diet-induced changes and developing FM-BR-enriched functional foods.

To elucidate the effects of maternal dietary betaine supplementation on hepatic expression of cholesterol metabolic genes in newborn piglets and the involved epigenetic mechanisms, we fed gestational sows with control or betaine-supplemented diets (3 g/kg) throughout pregnancy. Neonatal piglets born to betaine-supplemented sows had higher serum methionine concentration and hepatic content of betaine, which was associated with significantly up-regulated hepatic expression of glycine N-methyltransferase. Prenatal betaine exposure increased hepatic cholesterol content and modified the hepatic expression of cholesterol metabolic genes in neonatal piglets. Sterol regulatory element-binding protein 2 was down-regulated at both mRNA and protein levels, while 3-hydroxy-3-methylglutaryl CoA reductase (HMGCR) was down-regulated at the mRNA level, but up-regulated at the protein level, in betaine-exposed piglets. The transcriptional repression of HMGCR was associated with CpG island hypermethylation and higher repressive histone mark H3K27me3 (histone H3 lysine 27 trimethylation) on the promoter, whereas increased HMGCR protein content was associated with significantly decreased expression of miR-497. Furthermore, LDL receptor was significantly down-regulated at both mRNA and protein levels in the liver of betaine-exposed piglets, which was associated with promoter CpG hypermethylation. In addition, the expression of cholesterol-27α-hydroxylase (CYP27α1) was up-regulated at both mRNA and protein levels, while the expression of cholesterol-7α-hydroxylase (CYP7α1) was increased at the mRNA level, but unchanged at the protein level associated with increased expression of miR-181. These results indicate that maternal betaine supplementation increases hepatic cholesterol content in neonatal piglets through epigenetic regulations of cholesterol metabolic genes, which involve alterations in DNA and histone methylation and in the expression of microRNA targeting these genes.

Postprandial TAG-rich lipoproteins (TRL) can be taken up by macrophages, leading to the formation of foam cells, probably via receptor-mediated pathways. The present study was conducted to investigate whether the postprandial time point at which TRL are collected modulates this process. A meal containing refined olive oil was given to nine healthy young men and TRL were isolated from their serum at 2, 4 and 6 h postprandially. The lipid class and apoB compositions of TRL were determined by HPLC and SDS–PAGE, respectively. The accumulation of lipids in macrophages was determined after the incubation of THP-1 macrophages with TRL. The gene expression of candidate receptors was measured by real-time PCR. The highest concentrations of TAG, apoB48 and apoB100 in TRL were observed at 2 h after the consumption of the test meal. However, excessive intracellular TAG accumulation in THP-1 macrophages was observed in response to incubation with TRL isolated at 4 h, when their particle size (estimated as the TAG:apoB ratio) was intermediate. The abundance of mRNA transcripts in macrophages in response to incubation with TRL was down-regulated for LDL receptor (LDLR), slightly up-regulated for VLDL receptor and remained unaltered for LDLR-related protein, but no effect of the postprandial time point was observed. In contrast, the mRNA expression of scavenger receptors SRB1, SRA2 and CD36 was higher when cells were incubated with TRL isolated at 4 h after the consumption of the test meal. In conclusion, TRL led to excessive intracellular TAG accumulation in THP-1 macrophages, which was greater when cells were incubated with intermediate-sized postprandial TRL isolated at 4 h and was associated with a significant increase in the mRNA expression of scavenger receptors.

Individual differences in sleep patterns of children may have developmental origins. In the present study, two factors known to influence behavioural development, monoamine oxidase A (MAOA) genotype and prenatal Fe-deficient (ID) diet, were examined for their influences on sleep patterns in juvenile rhesus monkeys. Sleep patterns were assessed based on a threshold for inactivity as recorded by activity monitors. Pregnant monkeys were fed diets containing either 100 parts per million (ppm) Fe (Fe sufficient, IS) or 10 ppm Fe (ID). At 3–4 months of age, male offspring were genotyped for polymorphisms of the MAOA gene that lead to high or low transcription. At 1 and 2 years of age, sleep patterns were assessed. Several parameters of sleep architecture changed with age. At 1 year of age, monkeys with the low-MAOA genotype demonstrated a trend towards more sleep episodes at night compared with those with the high-MAOA genotype. When monkeys reached 2 years of age, prenatal ID reversed this trend; ID in the low-MAOA group resulted in sleep fragmentation, more awakenings at night and more sleep episodes during the day when compared with prenatal IS in this genotype. The ability to consolidate sleep during the dark cycle was disrupted by prenatal ID, specifically in monkeys with the low-MAOA genotype.

A frequent eating pattern may alter glycaemic control and augment postprandial insulin concentrations in some individuals due to the truncation of the previous postprandial period by a subsequent meal. The present study examined glucose, insulin, C-peptide and glucose-dependent insulinotropic peptide (GIP) responses in obese individuals when meals were ingested in a high-frequency pattern (every 2 h, 6M) or in a low-frequency pattern (every 4 h, 3M) over 12 h. It also examined these postprandial responses to high-frequency, high-protein meals (6MHP). In total, thirteen obese subjects completed three 12 h study days during which they consumed 6276 kJ (1500 kcal): (1) 3M – 15 % protein and 65 % carbohydrate; (2) 6M – 15 % protein and 65 % carbohydrate; (3) 6MHP – 45 % protein and 35 % carbohydrate. Blood samples were collected every 10 min and analysed for glucose, insulin, C-peptide and GIP. Insulin total AUC (tAUC) and peak insulin concentrations (P< 0·05) were higher in the 3M condition than in the 6M condition, but there were no differences in glucose tAUC between the conditions. The 6MHP regimen (glucose: 3569 (se 83) mmol/l × min (64·3 (se 1·5) g/dl × min), insulin: 1·577 (se 0·146) pmol/l (22·7 (se 2·1) μIU/dl) for 12 h) lowered glucose and insulin excursions more so over 12 h than either the 3M regimen (glucose: 3913 (se 78) mmol/l × min (70·5 (se 1·4) g/dl × min), insulin: 2·195 (se 0·146) pmol/l × min (31·6 (se 2·1) μIU/dl × min) for 12 h) or the 6M regimen (glucose: 3902 (se 83) mmol/l × min (70·3 (se 1·5) g/dl × min), insulin: 1·861 (se 0·174) pmol/l × min (26·8 (se 2·5) μIU/dl × min) for 12 h; P< 0·01). Insulin secretion, GIP concentrations and the glucose:insulin ratio were not altered by meal frequency or composition. In obese subjects, ingestion of meals in a low-frequency pattern does not alter glucose tAUC, but increases postprandial insulin responses. The substitution of carbohydrates with protein in a frequent meal pattern results in tighter glycaemic control and reduced postprandial insulin responses.

The use of caffeine containing energy drinks has dramatically increased in the last few years, especially in the sport context because of its reported ergogenic effect. The ingestion of low to moderate doses of caffeinated energy drinks has been associated with adverse side effects such as insomnia or increased nervousness. The aim of the present study was to assess psycho-physiological changes and the prevalence of side effects resulting from the ingestion of 3 mg caffeine/kg body mass in the form of an energy drink. In a double-blind and placebo controlled experimental design, ninety experienced and low-caffeine-consuming athletes (fifty-three male and thirty-seven female) in two different sessions were provided with an energy drink that contained 3 mg/kg of caffeine or the same decaffeinated energy drink (placebo; 0 mg/kg). At 60 min after the ingestion of the energy drink, participants completed a training session. The effects of ingestion of these beverages on psycho-physiological variables during exercise and the rate of adverse side effects were measured using questionnaires. The caffeinated energy drink increased self-perceived muscle power during exercise compared with the placebo beverage (6·41 (sd 1·7) v. 5·66 (sd 1·51); P= 0·001). Moreover, the energy drink produced a higher prevalence of side effects such as insomnia (31·2 v. 10·4 %; P< 0·001), nervousness (13·2 v. 0 %; P= 0·002) and activeness (16·9 v. 3·9 %; P= 0·007) than the placebo energy drink. There were no sex differences in the incidence of side effects (P>0·05). The ingestion of an energy drink with 3 mg/kg of caffeine increased the prevalence of side effects. The presence of these side effects was similar between male and female participants.

Many Muslim women worldwide are pregnant during Ramadan and adhere to Ramadan fasting during pregnancy. In the present study, we determined whether maternal adherence to Ramadan fasting during pregnancy has an impact on the birth weight of the newborn, and whether the effects differed according to trimester in which Ramadan fasting took place. A prospective cohort study was conducted in 130 pregnant Muslim women who attended antenatal care in Amsterdam and Zaanstad, The Netherlands. Data on adherence to Ramadan fasting during pregnancy and demographics were self-reported by pregnant women, and the outcome of the newborn was retrieved from medical records after delivery. The results showed that half of all the women adhered to Ramadan fasting. With strict adherence to Ramadan fasting in pregnancy, the birth weight of newborns tended to be lower than that of newborns of non-fasting mothers, although this was not statistically significant ( − 198 g, 95 % CI − 447, 51, P= 0·12). Children of mothers who fasted in the first trimester of pregnancy were lighter at birth than those whose mothers had not fasted ( − 272 g, 95 % CI − 547, 3, P= 0·05). There were no differences in birth weight between children whose mothers had or had not fasted if Ramadan fasting had taken place later in pregnancy. Ramadan fasting during early pregnancy may lead to lower birth weight of newborns. These findings call for further confirmation in larger studies that should also investigate potential implications for perinatal and long-term morbidity and mortality.

A 12-month, dose–response, randomised, intervention trial was conducted to determine adequate Ca intake levels for Chinese adolescents by investigating the effect of Ca supplementation on bone mineral accretion. A total of 220 Han adolescents (111 girls and 109 boys) aged 12–14 years were recruited. All subjects were randomly divided into three groups. The bone mineral content (BMC) and bone mineral density (BMD) of the whole body, lumbar spine (L1–L4), left hip and femoral neck were measured by dual-energy X-ray absorptiometry. Girls in the high-Ca group (actual Ca intake: 1243 (sd 193) mg/d) exhibited greater increases in the femoral neck BMC compared with those in the low-Ca group (9·7 v. 6·4 %, P =0·04) over the 1-year intervention period. The increases in femoral neck BMC were greater in boys in the high-Ca and medium-Ca groups (actual Ca intake: 985 (sd 168) mg/d) than in those in the low-Ca group (15·7 v. 11·7 %, P =0·03; 15·8 v. 11·7 %, P =0·03). Ca supplementation had significant effects on the whole-body BMC and BMD in subjects with physical activity levels>34·86 metabolic equivalents and on the spine BMD and BMC and BMD of most sites in subjects with Tanner stage < 3. Increasing Ca intake levels with Ca supplementation enhanced femoral neck mineral acquisition in Chinese adolescents. Furthermore, high physical activity levels and low Tanner stage appeared to significantly contribute to the effect of Ca supplementation on bone mass. Whether this is a lasting beneficial effect leading to the optimisation of peak bone mass needs to be determined in other long-term prospective studies.

A number of studies have demonstrated that consuming almonds increases satiety but does not result in weight gain, despite their high energy and lipid content. To understand the mechanism of almond digestion, in the present study, we investigated the bioaccessibility of lipids from masticated almonds during in vitro simulated human digestion, and determined the associated changes in cell-wall composition and cellular microstructure. The influence of processing on lipid release was assessed by using natural raw almonds (NA) and roasted almonds (RA). Masticated samples from four healthy adults (two females, two males) were exposed to a dynamic gastric model of digestion followed by simulated duodenal digestion. Between 7·8 and 11·1 % of the total lipid was released as a result of mastication, with no significant differences between the NA and RA samples. Significant digestion occurred during the in vitro gastric phase (16·4 and 15·9 %) and the in vitro duodenal phase (32·2 and 32·7 %) for the NA and RA samples, respectively. Roasting produced a smaller average particle size distribution post-mastication; however, this was not significant in terms of lipid release. Light microscopy showed major changes that occurred in the distribution of lipid in all cells after the roasting process. Further changes were observed in the surface cells of almond fragments and in fractured cells after exposure to the duodenal environment. Almond cell walls prevented lipid release from intact cells, providing a mechanism for incomplete nutrient absorption in the gut. The composition of almond cell walls was not affected by processing or simulated digestion.

Intakes of saturated fat (SF) and dietary fibre, body mass and physical activity are all associated with the incidence of type 2 diabetes mellitus. Their relative importance for the maintenance of normal glucose metabolism is not fully known. In a population-based sample of 1114 individuals, aged 58–78 years, dietary intakes were assessed by 4 d food records and cardiorespiratory fitness as maximal oxygen uptake. Insulin secretion, insulin sensitivity, the early-phase disposition index (DI30) and the total disposition index (DI120) were assessed based on an oral glucose tolerance test. Linear associations were modelled using linear regression. Combined effects were studied by introducing SF and fibre intakes, as well as cardiorespiratory fitness and waist circumference (WC) as dichotomised variables in general linear models. Intakes of dietary fibre and whole-grain bread were positively associated with insulin sensitivity, independent of physical fitness and WC. In women, dietary fibre intake was also positively associated with DI30. The negative association of high WC with DI30 was attenuated by a combination of low SF intake and high cardiorespiratory fitness. In conclusion, dietary fibre and a combination of low SF intake and high cardiorespiratory fitness may contribute to the maintenance of normal glucose metabolism, independent of WC.

Elevated postprandial hyperglycaemia and oxidative stress increase the risks of type 2 diabetes and CVD. Green tea catechin possesses antidiabetic properties and antioxidant capacity. In the present study, we examined the acute and continuous effects of ingestion of catechin-rich green tea on postprandial hyperglycaemia and oxidative stress in healthy postmenopausal women. Participants were randomly assigned into the placebo (P, n 11) or green tea (GT, n 11) group. The GT group consumed a catechin-rich green tea (catechins 615 mg/350 ml) beverage per d for 4 weeks. The P group consumed a placebo (catechins 92 mg/350 ml) beverage per d for 4 weeks. At baseline and after 4 weeks, participants of each group consumed their designated beverages with breakfast and consumed lunch 3 h after breakfast. Venous blood samples were collected in the fasted state (0 h) and at 2, 4 and 6 h after breakfast. Postprandial glucose concentrations were 3 % lower in the GT group than in the P group (three-factor ANOVA, group × time interaction, P< 0·05). Serum concentrations of the derivatives of reactive oxygen metabolites increased after meals (P< 0·05), but no effect of catechin-rich green tea intake was observed. Conversely, serum postprandial thioredoxin concentrations were 5 % higher in the GT group than in the P group (three-factor ANOVA, group × time interaction, P< 0·05). These findings indicate that an acute ingestion of catechin-rich green tea has beneficial effects on postprandial glucose and redox homeostasis in postmenopausal women.

High blood pressure (BP) variability, which may be an important determinant of hypertensive end-organ damage, is emerging as an important predictor of cardiovascular health. Dietary antioxidants can influence BP, but their effects on variability are yet to be investigated. The aim of the present study was to assess the effects of vitamin E, vitamin C and polyphenols on the rate of daytime and night-time ambulatory BP variation. To assess these effects, two randomised, double-blind, placebo-controlled trials were performed. In the first trial (vitamin E), fifty-eight individuals with type 2 diabetes were given 500 mg/d of RRR-α-tocopherol, 500 mg/d of mixed tocopherols or placebo for 6 weeks. In the second trial (vitamin C–polyphenols), sixty-nine treated hypertensive individuals were given 500 mg/d of vitamin C, 1000 mg/d of grape-seed polyphenols, both vitamin C and polyphenols, or neither (placebo) for 6 weeks. At baseline and at the end of the 6-week intervention, 24 h ambulatory BP and rate of measurement-to-measurement BP variation were assessed. Compared with placebo, treatment with α-tocopherol, mixed tocopherols, vitamin C and polyphenols did not significantly alter the rate of daytime or night-time systolic BP, diastolic BP or pulse pressure variation (P>0·05). Treatment with the vitamin C and polyphenol combination resulted in higher BP variation: the rate of night-time systolic BP variation (P= 0·022) and pulse pressure variation (P= 0·0036) were higher and the rate of daytime systolic BP variation was higher (P= 0·056). Vitamin E, vitamin C or grape-seed polyphenols did not significantly alter the rate of BP variation. However, the increase in the rate of BP variation suggests that the combination of high doses of vitamin C and polyphenols could be detrimental to treated hypertensive individuals.

Varied diets are diverse with respect to diet quality, and existing dietary variety indices do not capture this heterogeneity. We developed and evaluated the multidimensional US Healthy Food Diversity (HFD) index, which measures dietary variety, dietary quality and proportionality according to the 2010 Dietary Guidelines for Americans (DGA). In the present study, two 24 h dietary recalls from the 2003–6 National Health and Nutrition Examination Survey (NHANES) were used to estimate the intake of twenty-six food groups and health weights for each food group were informed by the 2010 DGA. The US HFD index can range between 0 (poor) and 1 − 1/n, where n is the number of foods; the score is maximised by consuming a variety of foods in proportions recommended by the 2010 DGA. Energy-adjusted Pearson's correlations were computed between the US HFD index and each food group and the probability of adequacy for fifteen nutrients. Linear regression was run to test whether the index differentiated between subpopulations with differences in dietary quality commonly reported in the literature. The observed mean index score was 0·36, indicating that participants did not consume a variety of healthful foods. The index positively correlated with nutrient-dense foods including whole grains, fruits, orange vegetables and low-fat dairy (r 0·12 to 0·64) and negatively correlated with added sugars and lean meats (r − 0·14 to − 0·23). The index also positively correlated with the mean probability of nutrient adequacy (r 0·41; P< 0·0001) and identified non-smokers, women and older adults as subpopulations with better dietary qualities. The US HFD index may be used to inform national dietary guidance and investigate whether healthful dietary variety promotes weight control.

Vitamin E is believed to play a preventive role in diseases associated with oxidative stress. The aims of the present study were to quantify vitamin E intake levels and plasma concentrations and to assess dietary vitamin E adequacy in Irish adults. Intake data from the National Adult Nutrition Survey were used; plasma samples were obtained from a representative cohort of survey participants. Plasma α- and γ-tocopherol concentrations were measured by HPLC. The main sources of vitamin E in the diet were ‘butter, spreadable fats and oils’ and ‘vegetables and vegetable dishes’. When vitamin E intake from supplements was taken into account, supplements were found to be the main contributor, making a contribution of 29·2 % to vitamin E intake in the total population. Supplement consumers had significantly higher plasma α-tocopherol concentrations and lower plasma γ-tocopherol concentrations when compared with non-consumers. Consumers of ‘vitamin E’ supplements had significantly higher vitamin E intake levels and plasma α-tocopherol concentrations compared with consumers of other types of supplements, such as multivitamin and fish oil. Comparison with the Institute of Medicine Estimated Average Requirement of 12 mg/d indicated that when vitamin E intake from food and supplement sources was taken into account, 100 % of the study participants achieved the recommended intake levels. When vitamin E intake from food sources was taken into account, only 68·4 % of the females were found to achieve the recommended intake levels compared with 99·2 % of the males. The results of the present study show that dietary vitamin E intake has a significant effect on plasma α- and γ-tocopherol concentrations. Furthermore, they show that the consumption of supplements is a major contributor to overall intake and has a significant effect on plasma vitamin E concentrations in the Irish population.