CVD affect a large proportion of the world’s population, with dyslipidaemia as the major risk factor. The regular consumption of both probiotic bacteria and yeast has been associated with improvement in the serum lipid profile. Thus, the present review aims to describe and discuss the potential mechanisms responsible for the hypocholesterolaemic effect of regular consumption of probiotic bacteria and yeast. Regarding the hypocholesterolaemic effect of probiotic bacteria, the potential mechanisms responsible include: deconjugation of bile salts; modulation of lipid metabolism; and decreased absorption of intestinal cholesterol through co-precipitation of intestinal cholesterol with the deconjugated bile salts, incorporation and assimilation of cholesterol in the cell membrane of the probiotics, intestinal conversion of cholesterol in coprostanol, and inhibition of the expression of the intestinal cholesterol transporter Niemann–Pick C1 like 1 (NPC1L1) in the enterocytes. The potential mechanisms responsible for the hypocholesterolaemic effect of probiotic yeasts include: deconjugation of bile salts; co-precipitation of intestinal cholesterol with the deconjugated bile salts; incorporation and assimilation of cholesterol in the cell membrane; and inhibition of hepatic cholesterol synthesis. The regular consumption of probiotic bacteria and yeast, as a non-pharmaceutical approach to help manage cardiovascular risk, holds promise, according to the beneficial hypocholesterolaemic effects described herein. However, the hypocholesterolaemic effects vary according to the strains used, the physiological state of the host, and the type of diet to which the probiotics are added. Further studies are necessary to fill the gaps with regard to the knowledge related to this topic.

New and more effective nutritional measures are urgently needed for the prevention of obesity. The role of Ca and vitamin D in obesity has been recently implicated. Low Ca intake and low vitamin D status have been linked with an increased risk of obesity in epidemiological studies; however, clinical intervention trials designed to test this association have produced controversial results. The suggested anti-obesity mechanisms of Ca and vitamin D include the regulation of adipocyte death (apoptosis), adipogenesis and lipid metabolism. Dietary Ca has been also shown to increase faecal fat excretion. The potential role of Ca and vitamin D in shifting energy balance towards a more negative state is an area of considerable interest. Ultimately, a review of recent research findings does not allow the reaching of a definitive conclusion that increasing Ca intake and rising vitamin D status will influence fat mass and body weight or decrease the risk of obesity and overweight.

Health and wellbeing are challenged constantly by pathogens. A number of defence mechanisms exist to protect the body from pathogen colonisation and invasion, with an important role to play for the natural intestinal bacterial flora (mainly by bifidobacteria and lactobacilli). The present paper reviews the evidence on the effects of inulin and oligofructose on colonisation and translocation of pathogens and the prevention of intestinal diseases. In vitro experiments have shown that lactic acid-producing bacteria have antagonistic (antibacterial) activity against pathogens partly because of the production of organic acids which are the endproducts of inulin and oligofructose fermentation. In addition, studies with epithelial layers have shown that inulin and oligofructose inhibit pathogen colonisation and that endproducts of their fermentation have the ability to support barrier function. Furthermore, studies in various animal models have shown that inulin and oligofructose accelerate the recovery of beneficial bacteria, slow down pathogen growth, decreasing pathogen colonisation and systemic translocation. Finally, data from human intervention trials either in patients with intestinal disorders or disease, or prone to critical illness, found that inulin and oligofructose restore the balance when the gut microbial community is altered, inhibit the progression of disease or prevent it from relapsing and/or developing. To conclude, the dietary use of inulin and oligofructose offers a promising approach to restore microbial communities and to support barrier function of the epithelia by their prebiotic action. This may offer the host protection against invasion and translocation of pathogens (endogenous and/or exogenous) and in the prevention of gastrointestinal diseases.

Acute and chronic alcohol (ethanol) intake and subsequent withdrawal exert major effects on tryptophan (Trp) metabolism and disposition in human subjects and experimental animals. In rats, activity of the rate-limiting enzyme of Trp degradation, liver Trp pyrrolase (TP), is enhanced by acute, but inhibited after chronic, ethanol administration, then enhanced during withdrawal. These changes lead to alterations in brain serotonin synthesis and turnover mediated by corresponding changes in circulating Trp availability to the brain. A low brain-serotonin concentration characterizes the alcohol-preferring C57BL/6J mouse strain and many alcohol-preferring rat lines. In this mouse strain, liver TP enhancement causes the serotonin decrease. In man, acute ethanol intake inhibits brain serotonin synthesis by activating liver TP. This may explain alcohol-induced depression, aggression and loss of control in susceptible individuals. Chronic alcohol intake in dependent subjects may be associated with liver TP inhibition and a consequent enhancement of brain serotonin synthesis, whereas subsequent withdrawal may induce the opposite effects. The excitotoxic Trp metabolite quinolinate may play a role in the behavioural disturbances of the alcohol-withdrawal syndrome. Some abstinent alcoholics may have a central serotonin deficiency, which they correct by liver TP inhibition through drinking. Further studies of the Trp and serotonin metabolic status in long-term abstinence in general and in relation to personality characteristics, alcoholism typology and genetic factors in particular may yield important information which should facilitate the development of more effective screening, and preventative and therapeutic strategies in this area of mental health.

The food choice and intake of animals (including humans) has typically been studied using frameworks of learning and feeding motivation. When used in isolation such frameworks could be criticized because learning paradigms give little consideration to how new food items are included or excluded from an individual's diet, and motivational paradigms do not explain how individuals decide which food to eat when given a choice. Consequently we are posed with the question of whether individuals actively interact with the food items present in their environment to learn about their nutritional properties? The thesis of this review is that individuals are motivated to actively sample food items in order to assess whether they are nutritionally beneficial or harmful. We offer a unifying framework, centred upon the concept of exploratory motivation, which is a synthesis of learning and paradigms of feeding motivation. In this framework information gathering occurs on two levels through exploratory behaviour: (i) the discrimination of food from nonfood items, and (ii) the continued monitoring and storage of information concerning the nutritional properties of these food items. We expect that this framework will advance our understanding of the behavioural control of nutrient intake by explaining how new food items are identified in the environment, and how individuals are able to monitor changes in the nutritional content of their food resource.

Increased oxidative stress has been implicated as a potential causal factor in the development of several diseases. In the last decade, an extensive literature has been produced on vitamin D, not limited to its well-known function like a steroid hormone on skeletal tissue, but for its potential pleiotropic role in human health. Several researchers have suggested relationships between vitamin D intake and health outcomes such as cancer prevention and increased immunity, or possible role in preventing diabetes, and in inflammation. Little is known about its antioxidant effect. The aim of the present review was to explore major evidence regarding the potential scavenger capacity of vitamin D in high-evidence human studies. Studies considered by the present review suggest that the potential role of vitamin D as an antioxidant could not be confirmed. Current literature showed controversial effects about the ability of cholecalciferol to prevent or ameliorate oxidative stress biomarkers, and there is need of further and high-quality studies testing the antioxidant effect of vitamin D supplementation.

In the current post-antibiotic era, botanicals represent one of the most employed nutritional strategies to sustain antibiotic-free and no-antibiotic-ever production. Botanicals can be classified either as plant extracts, meaning the direct products derived by extraction from the raw plant materials (essential oils (EO) and oleoresins (OR)), or as nature-identical compounds (NIC), such as the chemically synthesised counterparts of the pure bioactive compounds of EO/OR. In the literature, differences between the use of EO/OR or NIC are often unclear, so it is difficult to attribute certain effects to specific bioactive compounds. The aim of the present review was to provide an overview of the effects exerted by botanicals on the health status and growth performance of poultry and pigs, focusing attention on those studies where only NIC were employed or those where the composition of the EO/OR was defined. In particular, phenolic compounds (apigenin, quercetin, curcumin and resveratrol), organosulfur compounds (allicin), terpenes (eugenol, thymol, carvacrol, capsaicin and artemisinin) and aldehydes (cinnamaldehyde and vanillin) were considered. These molecules have different properties such as antimicrobial (including antibacterial, antifungal, antiviral and antiprotozoal), anti-inflammatory, antioxidant, immunomodulatory, as well as the improvement of intestinal morphology and integrity of the intestinal mucosa. The use of NIC allows us to properly combine pure compounds, according to the target to achieve. Thus, they represent a promising non-antibiotic tool to allow better intestinal health and a general health status, thereby leading to improved growth performance.

Voluntary food intake and the selection between foods are important subjects especially in ruminants in view of the economic importance of this class of animal and the complex digestive system with its attendant metabolic peculiarities. There is evidence that intake is limited by the capacity of the rumen as well as by metabolic factors; some theories assume that intake is controlled by the first limiting factor but this is not satisfying on physiological grounds and there is evidence that signals from feedback factors are integrated in an additive manner. It is now well established from research in which animals are given the chance to learn the metabolic consequences of eating food with a particular sensory profile, including a choice of foods, that animals including ruminants can adjust their diet, both quantitatively and qualitatively, to their nutrient requirements. It is proposed that they do this in order to minimise the total of the discomfort generated by the several signals from various body systems. The learning process is aided by the considerable day-to-day variation often seen in the intake of individual animals. An optimisation model is proposed and presented in a simple form, involving the addition of discomforts (calculated as the square of the deviation of the supply of metabolisable energy, crude protein and neutral-detergent fibre) and iterative elucidation of the intake at which total discomfort is minimal. With parameters appropriate for growing lambs the model provides reasonable agreement with observations, both in terms of daily intake and selection between foods of different protein contents. Manipulation of food composition and of nutrient requirements produces predictions broadly in agreement with reality except that protein deficiency has less severe consequences for the model than for real animals; it is proposed that protein deficiency be given more weighting than protein excess, and this may be true for other resources as well. This model is proposed as a philosophy and a starting point for further development and is not purveyed as a complete, working model. It nevertheless provides support for the concept of total minimal discomfort as a suitable base from which to view the control of intake and selection in all animals.

Periods of immobilisation are often associated with pathologies and/or ageing. These periods of muscle disuse induce muscle atrophy which could worsen the pathology or elderly frailty. If muscle mass loss has positive effects in the short term, a sustained/uncontrolled muscle mass loss is deleterious for health. Muscle mass recovery following immobilisation-induced atrophy could be critical, particularly when it is uncompleted as observed during ageing. Exercise, the best way to recover muscle mass, is not always applicable. So, other approaches such as nutritional strategies are needed to limit muscle wasting and to improve muscle mass recovery in such situations. The present review discusses mechanisms involved in muscle atrophy following disuse and during recovery and emphasises the effect of age in these mechanisms. In addition, the efficiency of nutritional strategies proposed to limit muscle mass loss during disuse and to improve protein gain during recovery (leucine supplementation, whey proteins, antioxidants and anti-inflammatory compounds, energy intake) is also discussed.

The experimental and epidemiological evidence demonstrating that Ca inhibits Fe absorption was reviewed, with the objectives of estimating the potential impact of variations in Ca intake on dietary Fe bioavailability and of providing some guidelines for predicting the effects on Fe status of recent recommendations for higher dietary Ca intake. In animal models Ca salts reduced both haem- and non-haem-Fe absorption, the effect being dependent on the amount of Ca administered rather than the Ca:Fe molar ratio; dairy products had a variable effect; factors other than Ca may have been important. In single-meal human absorption studies, both haem- and non-haem-Fe absorption was inhibited by Ca supplements and by dairy products, the effect depending on the simultaneous presence of Ca and Fe in the lumen of the upper small intestine and also occurring when Ca and Fe were given in the fasting state. The quantitative effect, although dose dependent, was modified by the form in which Ca was administered and by other dietary constituents (such as phosphate, phytate and ascorbic acid) known to affect Fe bioavailability. The mechanism by which Ca influences Fe absorption has not been elucidated. The effects of factors that modulate Fe bioavailability are known to be exaggerated in single-meal studies, and measurements based on several meals are more likely to reflect the true nutritional impact. The results of most multiple-meal human studies suggest that Ca supplementation will have only a small effect on Fe absorption unless habitual Ca consumption is very low. Outcome analyses showed that Ca supplements had no effect on Fe status in infants fed Fe-fortified formula, lactating women, adolescent girls and adult men and women. However it should be noted that the subjects studied had adequate intakes of bioavailable Fe and, except in one study, had relatively high habitual Ca intakes. Although cross-sectional analyses in Europe have shown a significant inverse correlation between Ca intake (derived primarily from dairy foods) and Fe stores, the quantitative effect was relatively small. The general conclusion is that dietary Ca supplements are unlikely to have a biologically significant impact on Fe balance in Western societies unless Ca consumption is habitually very low; however, increased consumption of dairy products may have a small negative effect that could be functionally important in pregnancy if Fe supplements are not taken. It is uncertain whether the inverse relationship between consumption of dairy products and Fe status is due entirely to increased Ca intake; substitution of milk proteins for meat may also have negative effects on Fe balance.

Up to one billion people live in areas where they may be at risk from I deficiency. Many of the debilitating effects of the deficiency may be irreversible, consequently it is essential to understand the mechanisms whereby lack of I can cause disease through decreased thyroxine and 3, 3',5-triiodothyronine (T3) synthesis. Since Se has an essential role in thyroid hormone metabolism, it has the potential to play a major part in the outcome of I deficiency. These effects of Se derive from two aspects of its biological function. First, three Se-containing deiodinases regulate the synthesis and degradation of the biologically active thyroid hormone, T3. Second, selenoperoxidases and possibly thioredoxin reductase (EC 1.6.4.5) protect the thyroid gland from H2O2 produced during the synthesis of thyroid hormones. The mechanisms whereby Se deficiency exacerbates the hypothyroidism due to I deficiency have been elucidated in animals. In contrast to these adverse effects, concurrent Se deficiency may also cause changes in deiodinase activities which can protect the brain from low T3 concentrations in I deficiency. Animals with Se and I deficiency have changes in serum thyroid hormone concentrations that are similar to those observed in patients with I deficiency disease. However such animal models show no thyroid involution, a feature which is characteristic of myxoedematous cretinism in man. These observations imply that if Se deficiency is involved in the outcome of I deficiency in human populations it is likely that other interacting factors such as goitrogens are also implicated. Nevertheless the protection of the thyroid gland from H2O2 and the regulation of tissue T3 levels are the functions of Se that are most likely to underlie the interactions of Se and I.

Beneficial effects of probiotic, prebiotic and polyphenol-rich interventions on fasting lipid profiles have been reported, with changes in the gut microbiota composition believed to play an important role in lipid regulation. Primary bile acids, which are involved in the digestion of fats and cholesterol metabolism, can be converted by the gut microbiota to secondary bile acids, some species of which are less well reabsorbed and consequently may be excreted in the stool. This can lead to increased hepatic bile acid neo-synthesis, resulting in a net loss of circulating low-density lipoprotein. Bile acids may therefore provide a link between the gut microbiota and cardiovascular health. This narrative review presents an overview of bile acid metabolism and the role of probiotics, prebiotics and polyphenol-rich foods in modulating circulating cardiovascular disease (CVD) risk markers and bile acids. Although findings from human studies are inconsistent, there is growing evidence for associations between these dietary components and improved lipid CVD risk markers, attributed to modulation of the gut microbiota and bile acid metabolism. These include increased bile acid neo-synthesis, due to bile sequestering action, bile salt metabolising activity and effects of short-chain fatty acids generated through bacterial fermentation of fibres. Animal studies have demonstrated effects on the FXR/FGF-15 axis and hepatic genes involved in bile acid synthesis (CYP7A1) and cholesterol synthesis (SREBP and HMGR). Further human studies are needed to determine the relationship between diet and bile acid metabolism and whether circulating bile acids can be utilised as a potential CVD risk biomarker.

A food can be regarded as ‘functional’ if it can demonstrate a beneficial efficacy on one or more target functions in the body in a convincing way. Beyond adequate nutritional qualities, functional foods should either improve the state of health and wellbeing and/or reduce the risk of disease. Functional foods that are marketed with claims of heart disease reduction focus primarily on the major risk factors, i.e. cholesterol, diabetes and hypertension. Some of the most innovative products are designed to be enriched with ‘protective’ ingredients, believed to reduce risk. They may contain, for example, soluble fibre (from oat and psyllium), useful both for lowering cholesterol and blood pressure, or fructans, effective in diabetes. Phytosterols and stanols lower LDL-cholesterol in a dose-dependent manner. Soya protein is more hypocholesterolaemic in subjects with very high initial cholesterol and recent data indicate also favourable activities in the metabolic syndrome. n-3 Fatty acids appear to exert significant hypotriacylglycerolaemic effects, possibly partly responsible for their preventive activity. Dark chocolate is gaining much attention for its multifunctional activities, useful both for the prevention of dyslipidaemia as well as hypertension. Finally, consensus opinions about tea and coffee have not emerged yet, and the benefits of vitamin E, garlic, fenugreek and policosanols in the management of dyslipidaemia and prevention of arterial disease are still controversial.

The role of meat in the diet has come under scrutiny recently due to an increased public emphasis on providing healthy diets from sustainable food systems and due to health concerns relating to the consumption of red and processed meat. The present review aimed to summarise dietary guidelines relating to meat, actual meat intakes and the contribution of meat to energy and nutrient intakes of children, teenagers and adults in Europe. The available literature has shown that food-based dietary guidelines for most countries recommend consuming lean meat in moderation and many recommend limiting red and processed meat consumption. Mean intakes of total meat in Europe range from 40 to 160 g/d in children and teenagers and from 75 to 233 g/d in adults. Meat contributes to important nutrients such as protein, PUFA, B vitamins, vitamin D and essential minerals such as Fe and Zn; however, processed meat contributes to significant proportions of saturated fat and Na across population groups. While few data are available on diaggregated intakes of red and processed meat, where data are available, mean intakes in adults are higher than the upper limits recommended by the UK Scientific Advisory Committee on Nutrition (70 g/d) and the World Cancer Research Fund (500 g/week). While there are no recommendations for red and processed meat consumption in children and teenagers, intakes currently range from 30 to 76 g/d. The present review provides a comprehensive overview of the role of meat in the European diet which may be of use to stakeholders including researchers, policy makers and the agri-food sector.

Obesity and type 2 diabetes mellitus (T2DM) epidemics, which have already spread, imply the possibility of both conditions being closely related. Thus, the goal of the present review was to draw a parallel between obesity, adipose tissue (AT) changes, and T2DM development. To this end, a search was conducted in PubMed, MEDLINE and SciELO databases, using the following key words and their combinations: obesity; diabetes; insulin resistance; diet; weight loss; adipocin; inflammation markers; and interleukins. Based on a literature review, AT dysfunction observed in obesity is characterised by adipocyte hypertrophy, macrophage infiltration, impaired insulin signalling and insulin resistance. In addition, there is release of inflammatory adipokines and an excessive amount of NEFA promoting ectopic fat deposition and lipotoxicity in muscle, liver and pancreas. Recent evidence supports the hypothesis that the conception of AT as a passive energy storage organ should be replaced by a dynamic endocrine organ, which regulates metabolism through a complex adipocyte communication with the surrounding microenvironment. The present review demonstrates how glucose homeostasis is changed by AT dysfunction. A better understanding of this relationship enables performing nutritional intervention strategies with the goal of preventing T2DM.

Polyphenols are a group of widely distributed phytochemicals present in most foods of vegetable origin. A growing number of biological effects have been attributed to these molecules in the past few years and only recently has their interference with the transport capacity of epithelial barriers received attention. This review will present data obtained concerning the effect of polyphenols upon the transport of some compounds (organic cations, glucose and the vitamins thiamin and folic acid) at the intestinal and placental barriers. Important conclusions can be drawn: (i) different classes of polyphenols affect transport of these bioactive compounds at the intestinal epithelia and the placenta; (ii) different compounds belonging to the same phenolic family often possess opposite effects upon transport of a given molecule; (iii) the acute and chronic/short-term and long-term exposures to polyphenols do not produce parallel results and, therefore, care should be taken when extrapolating results; (iv) the effect of polyphenolics in combination may be very different from the expected ones taking into account the effect of each of these compounds alone, and so care should be taken when speculating on the effect of a drink based on the effect of one component only; (v) care should be taken in drawing conclusions for alcoholic beverages from results obtained with ethanol alone. Although most of the data reviewed in the present paper refer to in vitro experiments with cell-culture systems, these studies raise a concern about possible changes in the bioavailability of substrates upon concomitant ingestion of polyphenols.

Existing reviews suggest that milk and other dairy products do not play a role in the development of obesity in childhood, but they do make an important contribution to children’s nutrient intake. It is thus curious that public health advice on the consumption of dairy products for children is often perceived as unclear. The present review aimed to provide an overview of the totality of the evidence on the association between milk and other dairy products, and obesity and indicators of adiposity, in children. Our search identified forty-three cross-sectional studies, thirty-one longitudinal cohort studies and twenty randomised controlled trials. We found that milk and other dairy products are consistently found to be not associated, or inversely associated, with obesity and indicators of adiposity in children. Adjustment for energy intake tended to change inverse associations to neutral. Also, we found little evidence to suggest that the relationship varied by type of milk or dairy product, or age of the children, although there was a dearth of evidence for young children. Only nine of the ninety-four studies found a positive association between milk and other dairy products and body fatness. There may be some plausible mechanisms underlying the effect of milk and other dairy products on adiposity that influence energy and fat balance, possibly through fat absorption, appetite or metabolic activity of gut microbiota. In conclusion, there is little evidence to support a concern to limit the consumption of milk and other dairy products for children on the grounds that they may promote obesity.

The food consumption of oats has increased in recent years due to a perceived association with a range of health benefits. Oats are unusual in that the bran is not as physically distinct as in other cereals. This provides a possible benefit in providing a high β-glucan content of the grains. However, oats contain many other phytochemicals including a range of antioxidants that may be associated with health benefits, although the evidence for such benefits is largely indirect and often confusing and contradictory. Nevertheless, the consumption of oats as part of a balanced diet does seem a reasonable approach.