Social acceptance of drinking involves social and cultural roles and has important implications for public health. Since extensive evidence indicates that alcohol possesses immunomodulatory properties, scientists have recently debated the influence of alcohol consumption on the immune response, particularly in countries where drinking in a social setting is a part of cultural identity. Experimental and clinical data support the conclusion that alcohol is a potent immunomodulator. While high alcohol consumption suppresses a wide range of immune responses, leading to an increased incidence of a number of infectious diseases, moderate alcohol consumption may have a beneficial impact on the immune system, compared to alcohol abuse or abstinence, most likely due to the multiple components of polyphenol-rich alcoholic contributing to the protective effect seen for moderate alcohol consumption on CVD and the immune system. Despite this, the scientific literature appears to be concerned about the diseases associated with excessive drinking in some societies and cultures. Thus, the present review recognizes the importance to consider social and cultural aspects of drinking when examining the whole dimension of alcohol consumption (amount, beverage type, frequency and variability), in order to estimate global risk of consequences on host defence to better understand alcohol-related harm or benefit.

Dramatic advances have been made in the understanding of the differing molecular mechanisms used by nutrients to regulate genes that are essential for their biological roles to carry out normal metabolism. Classical studies have focused on nutrients as ligands to activate specific transcription factors. New interest has focused on histone acetylation as a process for either global or limited gene activation and is the first mechanism to be discussed. Nuclear ATP-citrate lyase generates acetyl-CoA, which has been shown to have a role in the activation of specific genes via selective histone acetylation. Transcription factor acetylation may provide a second mode of control of nutrient-responsive gene transcription. The third mechanism relates to the availability of response elements within chromatin, which as well as the location of the elements in the gene may allow or prevent transcription. A fourth mechanism involves intracellular transport of Zn ions, which can orchestrate localized enzyme inhibition–activation. This process in turn influences signalling molecules that regulate gene expression. The examples provided in the present review point to a new level of complexity in understanding nutrient–gene communication.

Clinical response to medication can differ between patients. Among the known sources of variability is an individual's nutrition status. This review defines some pharmacokinetic terms, provides relevant body size metrics and describes the physiologic influences of protein–energy malnutrition and obesity on drug disposition. Weight-based drug dosing, which presumes a healthy BMI, can be problematic in the protein–energy malnourished or obese patient. The use of total body weight, lean body weight, or an adjusted body weight depends on the drug and how it is differently handled in malnutrition or obesity. Most of the recognized influences are seen in drug distribution and drug elimination as a result of altered body composition and function. Distribution characteristics of each drug are determined by several drug-related factors (e.g. tissue affinity) in combination with body-related factors (e.g. composition). Drug elimination occurs through metabolic and excretory pathways that can also vary with body composition. The current data are limited to select drugs that have been reported in small studies or case reports. In the meantime, a rational approach to evaluate the potential influences of malnutrition and obesity can be used clinically based on available information. Antimicrobials are discussed as a useful example of this approach. Further advancement in this field would require collaboration between experts in body composition and those in drug disposition. Until more data are available, routine monitoring by the clinician of the protein–energy malnourished or obese patient receiving weight-based drug regimens is necessary.

The present report discusses targeted and non-targeted approaches to monitor single nutrients and global metabolite profiles in nutritional research. Non-targeted approaches such as metabolomics allow for the global description of metabolites in a biological sample and combine an analytical platform with multivariate data analysis to visualise patterns between sample groups. In nutritional research metabolomics has generated much interest as it has the potential to identify changes to metabolic pathways induced by diet or single nutrients, to explore relationships between diet and disease and to discover biomarkers of diet and disease. Although still in its infancy, a number of studies applying this technology have been performed; for example, the first study in 2003 investigated isoflavone metabolism in females, while the most recent study has demonstrated changes to various metabolic pathways during a glucose tolerance test. As a relatively new technology metabolomics is faced with a number of limitations and challenges including the standardisation of study design and methodology and the need for careful consideration of data analysis, interpretation and identification. Targeted approaches are used to monitor single or multiple nutrient and/or metabolite status to obtain information on concentration, absorption, distribution, metabolism and elimination. Such applications are currently widespread in nutritional research and one example, using stable isotopes to monitor nutrient status, is discussed in more detail. These applications represent innovative approaches in nutritional research to investigate the role of both single nutrients and diet in health and disease.

Celiac disease is an inflammatory disorder of the small intestine, triggered by the ingestion of gluten proteins contained in wheat, barley or rye, in genetically susceptible individuals. This disorder is considered to be mainly mediated by cellular immunity and restricted to the human leucocyte antigen-DQ presentation of gluten-derived toxic peptides to T-cells. Moreover, the involvement of innate immunity has been recently demonstrated to be necessary also for the development of intestinal tissue damage. Genetic susceptibility accounts for an uncertain proportion of the disease risk and gluten introduction works as the precipitating factor. However, currently, the research interest is also focused on environmental factors and gene–environment interactions, especially during the first months of life, which might help explain the onset of the disease. Infectious and dietary factors that could modulate the immune response orientating it either towards tolerance or intolerance/autoimmunity are the focus of primary attention. A significant number of studies have looked into the protective effect of breast-feeding against the disease. It is generally accepted that breast-feeding during the introduction of dietary gluten and increasing the duration of breast-feeding are associated with reduced risk of developing celiac disease. However, it is still not fully established whether breast-feeding truly protects with permanent tolerance acquisition or only reduces the symptoms and delays the diagnosis. Moreover, the timing and dose of gluten introduction also seem to be relevant and long-term prospective cohort studies are being carried out in order to elucidate its role in celiac disease development.

Drugs have the potential to interact with nutrients potentially leading to reduced therapeutic efficacy of the drug, nutritional risk or increased adverse effects of the drug. Despite significant interest in such interactions going back to over more than 40 years, the occurrence and clinical significance of many drug–nutrient interactions remains unclear. However, interactions involving drugs with a narrow therapeutic margin such as theophylline and digoxin and those that require careful blood monitoring such as warfarin are likely to be those of clinical significance. Drugs can affect nutrition as a result of changes in appetite and taste as well as having an influence on absorption or metabolism of nutrients. Moreover, foods and supplements can also interact with drugs, of which grapefruit juice and St John's wort are key examples. Significant numbers of people take both supplements and medication and are potentially at risk from interactions. Professionals, such as pharmacists, dietitians, nurses and doctors, responsible for the care of patients should therefore check whether supplements are being taken, while for researchers this is an area worthy of significant further study, particularly in the context of increasingly complex drug regimens and the plethora of new drugs.