The appetite-modulating peptide ghrelin is predominantly produced and secreted by the stomach and shows a strong growth hormone-releasing activity, which is mediated by the activation of the so-called growth hormone secretagogue type 1a receptor. Ghrelin is involved in the regulation of energy balance by increasing food intake and reducing fat utilization. Additionally, it stimulates lactotroph and corticotroph function, influences the pituitary gonadal axis, inhibits pro-inflammatory cytokine expression, controls gastric motility and acid secretion and influences pancreatic exocrine and endocrine function, as well as impacting on glucose metabolism. This review summarizes the known functions of ghrelin and its role in the regulation of the gut–brain axis.

Definitions of functional food vary but are essentially based on foods' ability to enhance the quality of life, or physical and mental performance, of regular consumers. The worldwide use of coffee for social engagement, leisure, enhancement of work performance and well-being is widely recognised. Depending on the quantities consumed, it can affect the intake of some minerals (K, Mg, Mn, Cr), niacin and antioxidant substances. Epidemiological and experimental studies have shown positive effects of regular coffee-drinking on various aspects of health, such as psychoactive responses (alertness, mood change), neurological (infant hyperactivity, Alzheimer's and Parkinson's diseases) and metabolic disorders (diabetes, gallstones, liver cirrhosis), and gonad and liver function. Despite this, most reviews do not mention coffee as fulfilling the criteria for a functional food. Unlike other functional foods that act on a defined population with a special effect, the wide use of coffee-drinking impacts a broad demographic (from children to the elderly), with a wide spectrum of health benefits. The present paper discusses coffee-drinking and health benefits that support the concept of coffee as a functional food.

Probiotics are live micro-organisms that when administered in adequate amounts confer a health benefit on the host. Consumption of yoghurt has been shown to induce measurable health benefits linked to the presence of live bacteria. A number of human studies have clearly demonstrated that yoghurt containing viable bacteria (Streptococcus thermophilus and Lactobacillus delbrueckii sp. bulgaricus) improves lactose digestion and eliminates symptoms of lactose intolerance. Thus, these cultures clearly fulfil the current concept of probiotics.

n-3 Fatty acids may protect against heart disease mortality by preventing fatal arrhythmias. Underlying effects on cardiac electrophysiology may be demonstrable in the standard electrocardiogram (ECG) and provide insight into the mechanism. Therefore, we investigated the effect of dietary n-3 fatty acids on heart-rate-corrected QT interval, T-loop width, spatial QRS-T angle and spatial U-wave amplitude in patients with frequent premature ventricular complexes. Seventy-four patients received either capsules providing 1·5 g n-3 fatty acids daily or placebo for approximately 14 weeks. ECG were recorded before and after intervention. None of the ECG characteristics was significantly affected by treatment. The present results do not provide additional support for the hypothesis that n-3 fatty acids prevent cardiac arrhythmia through generic electrophysiologic effects on heart cell membranes. However, we cannot exclude effects of n-3 fatty acids on clinical relevant endpoints that are not easily detected by prior changes in the ECG.

European sea bass larvae were fed different dietary vitamin A levels. Growth, skeletal development and the expression of genes involved in larval morphogenesis were evaluated. From 7 to 42 d post-hatching, larvae were fed five isoproteic and isolipidic compound diets with graded levels of retinyl acetate (RA; RA0, RA10, RA50, RA250 and RA1000, containing 0, 10, 50, 250 and 1000 mg RA/kg DM, respectively), resulting in an incorporation of 12, 13, 31, 62 and 196 mg all-trans retinol/kg DM. Larvae fed extreme levels of RA had weights 19 % and 27 % lower than those of the RA50 group. The RA1000 diet induced a fall in growth with an increase of circulating and storage retinol forms in larvae, revealing hypervitaminosis. High levels of RA affected maturation of the pancreas and intestine. These data indicated that the optimal RA level was close to 31 mg/kg DM. Inappropriate levels of dietary RA resulted in an alteration of head organisation characterised by the abnormal development of the splanchnocranium and neurocranium, and scoliotic fish. Of the larvae fed RA1000, 78·8 % exhibited skeletal abnormalities, whereas the RA50 group presented with 25 % malformations. A linear correlation between vitamin A level and malformation percentage was observed and mainly associated with an upregulation of retinoic acid receptor-γ expression in the RA1000 group during the 2 first weeks after hatching. The expression of retinoid X receptor-α decreased during normal larval development when that of the retinoic acid receptors increased. This work highlights the involvement of retinoid pathways in the appearance of dietary-induced skeletal malformations during post-hatching development in sea bass.

Predicting aspects of pork quality becomes increasingly important from both a nutritional and a technological point of view. Little information is, however, available concerning the quantitative relation between nutrient intake and fatty acid (FA) deposition at the whole-animal level. In this study, eight blocks of five littermate barrows were used in a comparative slaughter trial. At 24 kg body weight (BW), one pig from each litter was slaughtered to determine the initial FA composition. The other littermates were assigned to one of four feeding levels (ranging from 70 % to 100 % of intake ad libitum) and were given a diet containing 0·36 g/kg lipid and 0·22 g/kg FA. The temperature for each block was maintained at either 23 or 30°C. At 65 kg, the pigs were slaughtered and the body lipid and FA composition was determined. Seventy per cent of the digested n-6 FA and 50 % of the n-3 FA were deposited. The average composition of de novo synthesised FA corresponded to 1·7, 30·3, 2·4, 19·7 and 45·9 % for 14: , 16: , 16: 1, 18: and 18: 1 FA, respectively. At 23°C and for feeding ad libitum, 33 % of 16: FA was deposited, 1·7 % shortened to 14: , 63 % elongated to 18: and 2·8 % unsaturated to 16: 1. Twenty-eight per cent of 18: FA was deposited and 72 % unsaturated to 18: 1. At 30°C, 18: FA desaturation was reduced by 3·5 %. Feed intake and temperature independently affected the elongation of 16: FA. A reduction in feed intake increased the elongation rate, whereas the increase in temperature reduced the elongation rate.

Studies with teleost larvae have reported poor performance associated with quantitative lipid imbalances in the diet. The present study examined the effect of dietary protein:neutral lipid ratio on fatty acid (FA) absorption efficiency and metabolism in larval Senegalese sole. In addition, the effect of lipid class (triolein (TRI) and l-3-phosphatidylcholine-1,2-di-oleoyl (PC)), carbon number and degree of saturation of the labelled NEFA, stearic acid (SA), oleic acid (OA) and DHA) was tested. FA absorption was determined by tube feeding [1-14C]-labelled lipids and NEFA after a single meal of either non-enriched Artemia (NEA) or Artemia enriched on a soyabean oil emulsion (EA), or after feeding these diets over an extended period of time (18 d). The tested dietary protein:lipid ratios had no short-term influence but long-term feeding of a diet higher in neutral lipid (EA) increased lipid accumulation within the gut epithelium and resulted in lower FA absorption (higher label evacuation and lower retention of dietary FA), which may partially explain the trend for lower growth observed with this diet. The lipids and NEFA, showed different digestive and metabolic properties, independent of feeding regime. FA absorption increased with unsaturation, being lowest for SA, followed by OA, and highest for DHA. In addition, sole larvae had a lower capacity to digest and absorb FA esterified to TRI, compared with PC, with the order of decreasing absorption being NEFA>PC≫TRI. Moreover, larvae appeared to discriminate between the source of OA, as this FA in the free form or esterified to PC was catabolised less than TRI.

Four experiments were performed to study the kinetics of purine metabolism and urinary excretion in Zebu crossbred cattle. Fasting excretion was established in Expt 1, using eighteen male Bos indicus×Bos taurus crossbred cattle (261 (se 9·1) kg body weight), six of each of the following genotypes: 5/8 Bos indicus, 1/2 Bos indicus and 3/8 Bos indicus. No significant differences were observed among genotypes in fasting purine derivative excretion (277·3 (se 35·43) μmol/metabolic body weight). In a second experiment we measured the xanthine oxidase activity, which was higher in liver than in duodenal mucosa (0·64 and 0·06 (se 0·12) units/g wet tissue per min respectively; P>0·05) being in plasma 0·60 (se 0·36) units/l per min. The kinetics of uric acid were measured by intravenous pulse dose of [1,3-15N]uric acid (Expt 3). The cumulative recovery of the isotope in urine was 82 (se 6·69) %, and uric acid plasma removal, pool size and mean retention time were 0·284 (se 0·051) per h, 5·45 (se 0·823) mmol and 3·52 (se 0·521) h, respectively. Allantoin was removed from plasma at an estimated fractional rate of 0·273 (se 0·081) per h and mean retention was 3·66 (se 1·08) h. In Expt 4, the relationship between urinary purine derivative excretion (Y; mmol/d) and digestible organic matter intake (X, kg/d) was defined by the equation: Y=7·69 (se 4·2)+5·69 (se 1·68) X; n 16, Se 1·31, r 0·67.

Energy restriction (ER) and dietary fish oil (FO) are known to reduce the severity of glomerulonephritis and increase the lifespan of lupus-prone (NZB×NZW) F1 (B/W) mice. In the present study, mice were fed either ad libitum or energy-restricted (a 40 % lower energy intake than the diet ad libitum), semi-purified diets containing 5 % maize oil or 5 % fish oil supplementation. To estimate the renal damage associated with oxidative stress, the total amounts of reactive oxygen species (ROS), cyclooxygenase-derived ROS and levels of guanidino compounds were measured. Additionally, we assessed the putative action of ER and FO on several key antioxidant enzymes measured in the kidney post-mitochondrial fraction. Results showed that the age-related increase in creatinine level was significantly reduced by ER and FO in old mice. In contrast, arginine and guanidino acetic acid levels showed a decrease with age but were increased by ER and FO. The GSH:GSSG ratio showed a significant decrease with age, whereas ER and FO feeding prevented the decrease. The age-related decrease in antioxidant scavenging superoxide dismutase, catalase and glutathione peroxidase activities were all reversed by ER and FO. The moderately decreased glutathione reductase and glutathione-S-transferase activities with age were significantly increased by ER and FO. Furthermore, the increased total ROS and cyclooxygenase-derived ROS levels were effectively reduced by ER and FO. In conclusion, our data strongly indicate that ER and FO maintain antioxidant status and GSH:GSSG ratio, thereby protecting against renal deterioration from oxidative insults during ageing.

The present study was conducted to assess whether glucagon-like peptide-1 (GLP-1) release and appetite after a breakfast with or without an additional galactose/guar gum stimulation is different in normal-weight compared with overweight/obese subjects. Twenty-eight overweight/obese (BMI 30·3 (sd 2·7) kg/m2; age 44·3 (sd 9·7) years) and thirty normal-weight subjects (BMI 22·8 (sd 1·4), age 31·5 (sd12·8) years) participated in a crossover study. Fasting and postprandial plasma GLP-1, insulin, glucose and free fatty acid concentrations were measured in response to either a galactose (50 g)/guar gum (2·5 g) load (836 kJ) and a standard breakfast (1·9 MJ; GG), or water (250 ml) and the standard breakfast (W) every 30 min relative to the ingestion for 120 min. Appetite was assessed using 100 mm visual analogue scales. GLP-1 concentrations were significantly increased after GG at 30 and 60 min compared with W in both groups. Plasma GLP-1 concentrations in the W condition were higher in normal-weight than overweight/obese subjects (P=0·03). No difference was observed in the GG condition between groups. Satiety was increased in normal-weight compared with overweight/obese subjects in the GG condition at 30 (P=0·02) and 60 (P=0·04) min. We conclude that after a standard breakfast with water, GLP-1 release was lower in the overweight/obese than the normal-weight subjects. However, postprandial GLP-1 release in overweight/obese subjects was no different from that of normal-weight subjects when galactose/guar gum was added to the breakfast. The latter was not mirrored by subjective feelings of satiety. Disturbed perception of the physiological feedback of a satiety hormone rather than disturbed feedback itself might contribute to obesity.

Changes in the growth hormone (GH)–insulin-like growth factor-I (IGF-I) axis, especially acquired GH resistance, develop in many severe illnesses, including cachexia. To study changes in the GH–IGF-I axis in patients with cancer cachexia, biochemical markers and body composition parameters were measured in eighty-eight gastric cancer patients, thirty colorectal cancer patients (subclassified according to the presence or absence of cachexia) and twenty-four healthy control subjects. Fifty-nine patients were defined as cachectic, based on the percentage of weight loss compared with their previous normal weight. The remaining fifty-nine patients were defined as non-cachectic. Measurements were repeated in twenty-seven patients (sixteen with gastric cancer and eleven with colorectal cancer) 3 months after radical operation. Compared with the controls, the cachectic gastric cancer patients had high GH levels (1·36 v. 0·32 ng/ml; P=0·001), a trend towards high IGF-I levels (223·74 v. 195·15 ng/ml; P=0·128 compared with non-cachectic patients) and a low log IGF-I/GH ratio (2·55 and 2·66 v. 3·00; P=0·002), along with a decreased BMI; the cachectic colorectal cancer patients showed the biochemical characteristics of acquired GH resistance: high GH (0·71 v. 0·32 ng/ml; P=0·016), a trend towards decreased IGF-I levels (164·18 v. 183·24 ng/ml; P=0·127) and a low log IGF-I/GH ratio (2·54 v. 2·99; P=0·005), with increased IGF-I levels following radical surgery (200·49 v. 141·91 ng/ml; P=0·046). These findings suggest that normal GH reaction and sensitivity occur in gastric cancer patients, controlled by nutritional status, whereas acquired GH resistance develops in cachectic colorectal cancer patients, which may be caused by tumour itself.

We analysed the effect of (−)-epicatechin and cocoa extract on the activation of a lymphoid cell line. Particularly the expression of IL-2 receptor α (IL-2Rα or CD25) and, the secretion of IL-2 and IL-4 were established after flavonoid treatment. Two media culture conditions (1 and 10 % of fetal calf serum supplementation) and the different moments of flavonoid addition (simultaneously or 2 h before cell-activation) were compared. IL-2Rα (CD25) expression on activated cells was significantly reduced by epicatechin and cocoa extract in a dose-dependent manner, achieving the highest inhibition of about 50 % when flavonoids were added 2 h before stimulation. IL-2 secretion was also inhibited by the presence of both epicatechin and cocoa extract, displaying 60 and 75 % of inhibition, respectively. Cocoa flavonoids were also able to enhance 3–4·5-fold IL-4 release. In summary, cocoa extract down-modulated T lymphocyte activation and therefore the acquired immune response. This fact could be important in some states of the immune system hyperactivity such as autoimmune or chronic inflammatory diseases.

We investigated the effects of consuming an isoflavone aglycone-enriched soya milk containing viable bifidobacteria on urinary isoflavone excretion and percentage recovery. Sixteen postmenopausal women were randomly divided into two groups to consume either fermented or non-fermented soya milk. Each group participated in a double-blind, crossover study with three 14 d supplementation periods, separated by a 14 d washout. Subjects ingested three daily dosages of isoflavone via the soya milk and collected four 24 h pooled urine specimens per supplementation period. Soya milks were prepared with soya protein isolate and soya germ, followed by fermentation with bifidobacteria. Isoflavone levels were quantified using HPLC. Non-fermented soya milks at 20, 40 and 80 mg isoflavone/200 ml contained 10 %, 9 % and 7 % aglycone, respectively, with their fermented counterparts containing 69 %, 57 % and 36 % aglycone (P<0·001). A trend to a greater percentage urinary recovery of daidzein and glycitein was observed among women consuming fermented soya milk at a dosage of 40 mg isoflavone (P=0·13). A distinct linear dose response for the fermented soya milk group (R2=0·9993) compared with the non-fermented group (R2=0·8865) suggested less interindividual variation in isoflavone absorption. However, total urinary isoflavone excretion was similar for both groups (P>0·05), with urinary isoflavone recovery at approximately 31 %. Increasing the isoflavone dosage correlated positively with its urinary excretion, but urinary percentage recovery of isoflavone was inversely related to dosage level. Hence, a modest dosage ranging from 20 to 30 mg/d may provide the most bioavailable source of isoflavone, regardless of whether it is via an aglycone-rich fermented soya milk or a glucoside-rich soya milk.

Undernutrition contributes to poor clinical outcomes in hospitalised elderly patients but the potential impact of oral nutritional supplements may be reduced by suppressing subsequent food intake. We investigated this possibility in elderly female patients recovering mainly from hip fracture by studying the effect of oral supplements on subsequent food intake during an ad libitum buffet luncheon meal. We tested the effect in seven women by giving the supplement 90 min before the meal and compared energy and macronutrient intake with a control water pre-load condition. A similar study was carried out in another seven women with the supplement or water drink given 30 min beforehand. Both self-rated appetite and energy intake were low in these women. The nutritional supplement did not alter ratings of hunger, fullness or prospective consumption or subsequent energy and macronutrient consumption whether given 90 or 30 min before the meal. There were significant independent correlations between the lack of adequate compensation of energy intake at meals and chronic undernutrition (as assessed by skinfold thickness) and energy intake during the control meal. We conclude that elderly women during the recovery phase after major fractures have low appetites and energy intakes and markedly impaired adjustment of energy intake following liquid oral nutritional supplements. The reasons for this are unknown but are related to anorexia and undernutrition. The consumption of liquid oral supplements given up to 30 min before a meal does not suppress subsequent energy intake from meals.

The present study investigated the effects of mixed high-carbohydrate (CHO) meals (breakfast and lunch) with different glycaemic indices (GI) on substrate metabolism during rest throughout the postprandial periods and during subsequent exercise. Nine recreationally active males completed two trials, high glycaemic index (HGI) and low glycaemic index (LGI), separated by 7 d in a randomised crossover design. In each trial, participants consumed breakfast and lunch, both of which were followed by a 3 h resting postprandial period. Following this, participants completed a 60 min run at 70 % of V˙O2max. The plasma glucose and serum insulin concentrations following both meals were significantly higher in the HGI trial than in the LGI trial (P<0·05). Serum insulin concentrations remained higher throughout the postprandial period following lunch in the HGI trial compared with the LGI trial (P<0·05). The total amount of fat oxidised was higher during the 3 h rest following lunch in the LGI trial than in the HGI trial (P<0·01) and subsequently CHO oxidation was lower (P<0·005). No significant differences in substrate utilisation were observed throughout the subsequent run. At 45 and 60 min, plasma glucose concentrations were higher in the LGI trial v. the HGI trial (P<0·05). The results of the present study provide further support that the GI concept can be successfully applied to mixed meals. The results also suggest that meals composed of LGI CHO may be more beneficial for maintaining a favourable metabolic milieu during the postprandial periods. Furthermore, during subsequent exercise, plasma glucose concentrations were better maintained following the LGI CHO meals.

The aim of the present study was to determine the effect of purified high-dose anthocyanoside oligomer administration on nocturnal visual function and clinical symptoms in low-to-moderate myopia subjects. The study was a randomized, double-blind, placebo-controlled trial and involved sixty subjects with asthenopia and refractive errors between −1·00 and −8·00 diopters in both eyes. Thirty subjects were administered a purified high-dose anthocyanoside oligomer (100 mg tablet comprising 85 % anthocyanoside oligomer), and thirty were given a placebo in tablet form twice daily for 4 weeks. Prior to the treatment, the placebo and anthocyanoside groups were similar in terms of age and contrast sensitivity. Before and after treatment, subjects completed a questionnaire to determine their clinical symptoms and were also assessed for nocturnal visual function using contrast sensitivity testing. Questionnaire data analysis showed that, following treatment, twenty-two (73·3 %) anthocyanoside subjects showed improved symptoms, whereas only one placebo subject showed an improvement (Fisher's exact test, P<0·0001). Contrast sensitivity levels according to each cycle per degree significantly improved in the anthocyanoside group and remained stable in the placebo group. The mean contrast sensitivity change in the anthocyanoside group was 2·41 (SD) 1·91, compared with −0·66 (SD) 2·66 dB for the placebo group (unpaired Student's t test, P<0·0001). At all cycle per degree levels, contrast sensitivity changes in the anthocyanoside group were better than in the placebo group (unpaired Student's t test, P<0·05). The present data show that the administration of anthocyanoside oligomer appears to improve subjective symptoms and objective contrast sensitivity in myopia subjects with asthenopia.

Mitochondria are the major intracellular organelles producing ATP molecules via the electron transport chain. Cancer cells have a deviant energy metabolism, and a high rate of glycolysis is related to a high degree of dedifferentiation and proliferation. The overall net ATP production is diminished with cancer, which ultimately leads to cancer cachexia. The present study was designed to investigate the altered energy metabolism in cancer cells and to enhance ATP production in the normal host cell metabolism by enhancing the activities of mitochondrial enzymes, using energy-modulating vitamins, and thus prevent cancer cachexia. Female Sprague–Dawley rats were selected for the experimental study. Mammary carcinoma was induced by the oral administration of 7,12-dimethylbenz[a]anthracene (25 mg/kg body weight), and treatment was started by the oral administration of the energy-modulating vitamins riboflavin (45 mg/kg body weight per d), niacin (100 mg/kg body weight per d) and coenzyme Q10 (40 mg/kg body weight per d) for 28 d. Mitochondria were isolated from the mammary gland and liver of all four groups, and the Krebs cycle and oxidative phosphorylation enzymes were assayed. In mammary carcinoma-bearing animals, the activities of the Krebs cycle and oxidative phosphorylation enzymes were significantly decreased. These activities were restored to a greater extent in animals treated with energy-modulating vitamins. From these experimental results, one may hypothesize that the combination therapy of energy-modulating vitamins could be of major therapeutic value in breast cancer.

The study assessed the independent and combined effect of two speciality carbohydrates (polydextrose and xylitol) on appetite. Eight female and seven male lean volunteers were recruited from the University of Leeds campus. Using a repeated measures design, volunteers completed four conditions in a counterbalanced order. Each condition varied according to the yoghurt formulation administered: a control yoghurt (C, yoghurt+25 g sucrose) and three experimental yoghurts (X, yoghurt+25 g xylitol; P, yoghurt+25 g polydextrose; and XP, yoghurt+12·5 g xylitol and 12·5 g polydextrose). Each condition lasted for 10 d during which volunteers consumed 200 g yoghurt on each day. On days 1 and 10, the short- and medium-term effects of yoghurt consumption were assessed by measuring ad libitum lunch intake and subjective motivation to eat. The three experimental yoghurts (X, P and XP) induced a slight suppression of energy intake compared with the control (C) yoghurt, but the differences were not statistically significant. However, when the energy content of the yoghurt pre-loads were accounted for, there was a significant suppression of energy intake for P compared with C (P=0·002). The XP yoghurt induced a significantly stronger satiating effect (increase in subjective fullness) compared with C, both with (P=0·003) and without (P<0·001) the differential in energy content of the yoghurt pre-loads accounted for. The study demonstrated that pre-loads of xylitol and polydextrose caused a mild increase in satiety and suppression of energy intake, and that the effects persist after repeated daily administration. The effects exerted by the formulations containing xylitol and polydextrose did not arise from the differences in energy content of the yoghurt per se. Therefore, the usefulness of xylitol and polydextrose as ingredients in functional foods for appetite control are as a result of their lower energy content and suppression of appetite.