This analysis was conducted to evaluate the evidence of the efficacy of iron biofortification interventions on iron status and functional outcomes. Iron deficiency is a major public health problem worldwide, with a disproportionate impact on women and young children, particularly those living in resource-limited settings. Biofortification, or the enhancing of micronutrient content in staple crops, is a promising and sustainable agriculture-based approach to improve nutritional status. Previous randomised efficacy trials and meta-analyses have demonstrated that iron-biofortification interventions improved iron biomarkers; however, no systematic reviews to date have examined the efficacy of biofortification interventions on health outcomes. We conducted a systematic review of the efficacy of iron-biofortified staple crops on iron status and functional outcomes: cognitive function (e.g. attention, memory) and physical performance. Five studies from three randomised efficacy trials (i.e. rice, pearl millet, beans) conducted in the Philippines, India and Rwanda were identified for inclusion in this review. Iron status (Hb, serum ferritin, soluble transferrin receptor, total body iron, α-1-acid glycoprotein) was measured at baseline and endline in each trial; two studies reported cognitive outcomes, and no studies reported other functional outcomes. Meta-analyses were conducted using DerSimonian and Laird random-effects methods. Iron-biofortified crop interventions significantly improved cognitive performance in attention and memory domains, compared with conventional crops. There were no significant effects on categorical outcomes such as iron deficiency or anaemia. Further studies are needed to determine the efficacy of iron-biofortified staple crops on human health, including additional functional outcomes and other high-risk populations.

β-Carotene intake and tissue/blood concentrations have been associated with reduced incidence of several chronic diseases. Further bioactive carotenoid-metabolites can modulate the expression of specific genes mainly via the nuclear hormone receptors: retinoic acid receptor- and retinoid X receptor-mediated signalling. To better understand the metabolic conversion of β-carotene, inter-individual differences regarding β-carotene bioavailability and bioactivity are key steps that determine its further metabolism and bioactivation and mediated signalling. Major carotenoid metabolites, the retinoids, can be stored as esters or further oxidised and excreted via phase 2 metabolism pathways. In this review, we aim to highlight the major critical control points that determine the fate of β-carotene in the human body, with a special emphasis on β-carotene oxygenase 1. The hypothesis that higher dietary β-carotene intake and serum level results in higher β-carotene-mediated signalling is partly questioned. Alternative autoregulatory mechanisms in β-carotene / retinoid-mediated signalling are highlighted to better predict and optimise nutritional strategies involving β-carotene-related health beneficial mediated effects.

This review presents mechanistic studies performed in vitro and in animal models, as well as data obtained in patients that contribute to a better understanding of the impact of nutrients interacting with the gut microbiota on metabolic and behavioural alterations linked to obesity. The gut microbiota composition and function are altered in several pathological conditions including obesity and related diseases i.e. non-alcoholic fatty liver diseases (NAFLD). The gut–liver axis is clearly influenced by alterations of the gut barrier that drives inflammation. In addition, recent papers propose that specific metabolites issued from the metabolic cooperation between the gut microbes and host enzymes, modulate inflammation and gene expression in the liver. This review illustrates how dietary intervention with prebiotics or probiotics influences host energy metabolism and inflammation. Indeed, intervention studies are currently underway in obese and NAFLD patients to unravel the relevance of the changes in gut microbiota composition in the management of metabolic and behavioural disorders by nutrients interacting with the gut microbiota. In conclusion, diet is among the main triggers of NAFLD and the gut microbiota is modified accordingly, underlining the importance of the concomitant study of the nutrients and microbial impact on liver health and metabolism, in order to propose innovative, clinically relevant, therapeutic approaches.

Micronutrient deficiencies are widespread and disproportionately affect women and children in low- and middle-income countries (LMIC). Among various interventions, food fortification and supplementation with micronutrients have been proven to be cost-effective. The aim of the present paper is to review existing literature to assess risks of excessive intake in LMIC to then highlight programmatic changes required to maximise benefits of micronutrient interventions while minimising risks of adverse effects. While very few LMIC have national food consumption surveys that can inform fortification programmes, many more are implementing mandatory fortification programmes. The risks of inadequate micronutrient intakes were common, but risks of excessive intakes were also present for iodine, vitamin A, folic acid and iron. Excessive salt consumption, high concentrations of iodine in ground-water and excessive levels of iodisation were linked with excessive iodine intake. For vitamin A, overlapping interventions were the main risk for excessive intake; whereas for iron, contamination with iron from soil and screw-wares of millers and high iron concentration in drinking-water increased the risk of excessive intake, which could be further exacerbated with fortification. Before implementing micronutrient interventions, adherence to the basic principles of documenting evidence confirming that the deficiency in question exists and that fortification will correct this deficiency is needed. This can be supported with dietary intake assessments and biochemical screening that help diagnose nutrient deficiencies. Targeting micronutrient interventions, although programmatically challenging, should be considered whenever possible. Moreover, closer monitoring of appropriate fortification of foods and overlapping interventions is needed.

Periconceptional folic acid (FA) is known to have a protective effect in the prevention of neural tube defects (NTD), leading to global recommendations for FA supplementation before and in early pregnancy. Maternal folate throughout pregnancy may have other roles in offspring health, including neurodevelopment and cognitive performance in childhood. Folate is essential for C1 metabolism, a network of pathways involved in several biological processes including nucleotide synthesis, DNA repair and methylation reactions. The evidence reviewed here shows a conclusive role for offspring health of maternal folate nutrition in early pregnancy and probable benefits in later pregnancy. Folate-mediated epigenetic changes in genes related to brain development and function offer a plausible biological basis to link maternal folate with effects in offspring brain, albeit this research is in its infancy. Mandatory FA fortification of food has proven to be highly effective in decreasing NTD cases in populations where it has been implemented, but this policy is controversial owing to concerns related to potential adverse effects of over-exposure to FA. In the absence of population-wide fortification, and given the generally poor compliance with current FA recommendations, optimising folate status of mothers in very early pregnancy for protection against NTD remains challenging. Thus, current policy in the UK, Ireland and elsewhere in Europe for the prevention of NTD (based on periconceptional FA supplementation only), has proven to be largely ineffective. This review addresses the evidence and the controversies that surround this area, as well as identifying the challenges in translating policy into practice.

Ageing population suffer from increased risk of malnutrition which is a major determinant of accelerated loss of autonomy, adverse health outcomes and substantial health-care costs. Malnutrition is largely attributed to reduced nutrient intake which may be associated with several endogenous factors, such as decline of muscle mass, oral functions and coordination that can make the eating process difficult. From an exogenous viewpoint, nutritionally dense foods with limited innovations in food texture have been traditionally offered to elderly population that negatively affected pleasure of eating and ultimately, nutrient intake. Recent research has recognised that older adults within the same age group are not homogenous in terms of their preferences, nutritional needs, capabilities and impediments in skill-sets. Hence, a new term eating capability (EC) has been coined to describe various quantifiable endogenous factors in the well-coordinated eating process that may permit characterisation of the capabilities of elderly individuals in food handling and oral processing. This review covers current knowledge on EC focusing on parameters, such as hand and oro-facial muscle forces. Although limited in literature, EC score measured using a comprehensive toolkit has shown promise to predict eating difficulty perception and oral processing behaviour. Further systematic studies are required to explore relationships between individual/multiple constituents of EC and oral comfort. Such knowledge base is needed to underpin the creation of next generation personalised texture-modified foods for elderly population using sophisticated technologies, such as 3D printing to enhance eating pleasure, increase nutrient intake that will ultimately contribute to tackling malnutrition.

Nutritional science has traditionally used the reductionist approach to understand the roles of individual nutrients in growth and development. The macronutrient dense but micronutrient poor diets consumed by many in the Western world may not result in an overt deficiency; however, there may be situations where multiple mild deficiencies combine with excess energy to alter cellular metabolism. These interactions are especially important in pregnancy as changes in early development modify the risk of developing non-communicable diseases later in life. Nutrient interactions affect all stages of fetal development, influencing endocrine programming, organ development and the epigenetic programming of gene expression. The rapidly developing field of stem cell metabolism reveals new links between cellular metabolism and differentiation. This review will consider the interactions between nutrients in the maternal diet and their influence on fetal development, with particular reference to energy metabolism, amino acids and the vitamins in the B group.

Population ageing is rapidly progressing and it is estimated that by 2050 one in every five people globally will be aged 60 years or over. Research has shown that adequate nutritional status can positively impact the ageing process, resulting in improved quality of life and the prevention of chronic disease and mortality. However, due to physiological and social changes associated with ageing, older adults may be at increased risk of nutrient deficiencies. This review aims to investigate the nutrient intake and status of older adults in Europe and to explore the potential role of fortified foods and nutritional supplements in addressing some of the nutritional challenges identified in this population group. The available literature has highlighted unfavourable intakes of total and saturated fat, sugar, salt and dietary fibre together with low intakes and suboptimal status of key micronutrients such as vitamins D, B2, B12, folate and calcium. Evidence has shown that the consumption of fortified foods and use of nutritional supplements make significant contributions to intakes and status of these micronutrients in older adults. Continued monitoring of nutrient intake and status is important in light of changing fortification practices and food consumption patterns. Future strategies to address the nutritional issues identified in older adults could include the promotion of healthy food choices together with improvements of the food supply including reformulation (fat, sugar and salt), food fortification or supplementation to support successful ageing of our populations.

This review aims to explore trends of early consumption of sugar-sweetened beverages (SSB) in sub-Saharan Africa (SSA), within the context of growing child and adolescent obesity and escalating type-2 diabetes prevalence. We explore efforts to mitigate these, drawing on examples from Africa and elsewhere. SSB, including carbonated drinks and fruit juices, play a contributory role in the development of obesity and associated non-communicable diseases (NCD). SSA is an attractive market for beverage companies owing to its rapid economic growth, growing middle class and youthful populations. SSB already contribute significantly to total sugar and energy consumption in SSA where a plethora of marketing techniques targeted at younger people are utilised to ensure brand recognition and influence purchasing and brand loyalty. Coupled with a general lack of nutrition knowledge or engagement with preventative health, this can lead to frequent consumption of sugary drinks at a young age. Public health efforts in many high income and some middle-income countries address increasing prevalence of obesity and type-2 diabetes by focusing on strategies to encourage reduction in sugar consumption via health policy and public education campaigns. However, similar efforts are not as developed or forthcoming in low-income countries. Health care systems across SSA are ill-prepared to cope with epidemic proportions of NCD, particularly when contextualised with the ongoing battle with infectious diseases. We conclude that greater efforts by governments and the nutrition community to educate the public on the health effects of increased and excessive consumption of SSB are necessary to help address this issue.

Iodine is an essential trace mineral, vital for its functions in many physiological processes in the human body. Both iodine deficiency (ID) and excess are associated with adverse health effects; ID and excess iodine intake have both been identified in sub-Saharan Africa (SSA). The review aims to (1) review the iodine status among populations in SSA until October 2018, and (2) identify populations at risk of excess or inadequate iodine intakes. A systematic search of relevant articles was carried out by a seven-member research team using PubMed, Science Direct and Scopus. A total of twenty-two articles was included for data extraction. Of the articles reviewed, the majority sought to determine the prevalence of iodine status of the study populations; others measured the impact of uncontrolled and unmonitored salt iodisation on iodine excess and tested the effectiveness of water iodisation. Although iodine status varied largely in study populations, ID and excessive iodine intake often coexisted within populations. The implementation of nutrition interventions and other strategies across SSA has resulted in the reduction of goitre prevalence. Even so, goitre prevalence remains high in many populations. Improvements in access to iodised salt and awareness of its importance are needed. The emerging problem of excess iodine intakes, however, should be taken into consideration by policy makers and programme implementers. As excessive iodine intakes may have adverse health effects greater than those induced by iodine deficient diets, more population-based studies are needed to investigate iodine intakes of the different population groups.

SFA intakes have decreased in recent years, both in Ireland and across other European countries; however a large proportion of the population are still not meeting the SFA recommendation of <10% of total energy (TE). High SFA intakes have been associated with increased CVD and type-2 diabetes (T2D) risk, due to alterations in cholesterol homoeostasis and adipose tissue inflammation. PUFA, in particular EPA and DHA, have been associated with health benefits, including anti-inflammatory effects. It is well established that dietary fat composition plays an important role in biological processes. A recent review of evidence suggests that replacement of SFA with PUFA has potential to reduce risk of CVD and T2D. The public health and molecular impact of EPA and DHA have been well-characterised, while less is known of effects of α-linolenic acid (ALA). The current dietary guideline for ALA is 0·5% TE; however evidence from supplementation trials suggests that benefit is observed at levels greater than 2 g/d (0·6–1% TE). This review highlights the gap in the evidence base relating to effects of the replacement of SFA with ALA, identifying the need for randomised controlled trials to determine the optimal dose of ALA substitution to define the efficacy of dietary fat modification with ALA.

In the past, vitamins and minerals were used to cure deficiency diseases. Supplements nowadays are used with the aim of reducing the risk of chronic diseases of which the origins are complex. Dietary supplement use has increased in the UK over recent decades, contributing to the nutrient intake in the population, but not necessarily the proportion of the population that is sub-optimally nourished; therefore, not reducing the proportion below the estimated average requirement and potentially increasing the number at risk of an intake above the safety limits. The supplement nutrient intake may be objectively monitored using circulation biomarkers. The influence of the researcher in how the supplements are grouped and how the nutrient intakes are quantified may however result in different conclusions regarding their nutrient contribution, the associations with biomarkers, in general, and dose–response associations specifically. The diet might be sufficient in micronutrients, but lacking in a balanced food intake. Since public-health nutrition guidelines are expressed in terms of foods, there is potentially a discrepancy between the nutrient-orientated supplement and the quality of the dietary pattern. To promote health, current public-health messages only advocate supplements in specific circumstances, but not in optimally nourished populations.

Some food bioactives potentially exert anti-obesity effects. Anthocyanins (ACN), catechins, β-glucan (BG) and n-3 long chain PUFA (LCPUFA) are among the most promising candidates and have been considered as a strategy for the development of functional foods counteracting body weight gain. At present, clinical trials, reviews and meta-analyses addressing anti-obesity effects of various bioactives or bioactive-rich foods show contradictory results. Abdominal obesity is an important criterion for metabolic syndrome (MetS) diagnosis along with glucose intolerance, dyslipidaemia and hypertension. Food bioactives are supposed to exert beneficial effects on these parameters, therefore representing alternative therapy approaches for the treatment of MetS. This review summarises outcomes on MetS biomarkers in recent clinical trials supplementing ACN, catechins, BG and n-3 LCPUFA, focusing mainly on anti-obesity effects. Overall, it is clear that the level of evidence for the effectiveness varies not only among the different bioactives but also among the different putative health benefits suggested for the same bioactive. Limited evidence may be due to the low number of controlled intervention trials or to inconsistencies in trial design, i.e. duration, dose and/or the method of bioactive supplementation (extracts, supplements, rich or enriched food). At present, the question ‘Are bioactives effective in weight management and prevention of metabolic syndrome?’ remains inconclusive. Thus, a common effort to harmonise the study design of intervention trials focusing on the most promising bioactive molecules is urgently needed to strengthen the evidence of their potential in the treatment of obesity, MetS and related diseases.