Emerging evidence suggests that dietary-derived flavonoids have the potential to improve human memory and neuro-cognitive performance via their ability to protect vulnerable neurons, enhance existing neuronal function and stimulate neuronal regeneration. Long-term potentiation (LTP) is widely considered to be one of the major mechanisms underlying memory acquisition, consolidation and storage in the brain and is known to be controlled at the molecular level by the activation of a number of neuronal signalling pathways. These pathways include the phosphatidylinositol-3 kinase/protein kinase B/Akt (Akt), protein kinase C, protein kinase A, Ca–calmodulin kinase and mitogen-activated protein kinase pathways. Growing evidence suggests that flavonoids exert effects on LTP, and consequently memory and cognitive performance, through their interactions with these signalling pathways. Of particular interest is the ability of flavonoids to activate the extracellular signal-regulated kinase and the Akt signalling pathways leading to the activation of the cAMP-response element-binding protein, a transcription factor responsible for increasing the expression of a number of neurotrophins important in LTP and long-term memory. One such neurotrophin is brain-derived neurotrophic factor, which is known to be crucial in controlling synapse growth, in promoting an increase in dendritic spine density and in enhancing synaptic receptor density. The present review explores the potential of flavonoids and their metabolite forms to promote memory and learning through their interactions with neuronal signalling pathways pivotal in controlling LTP and memory in human subjects.

Accurate assessment of maternal micronutrient status is critical to the prevention of suboptimal micronutrient status and anaemia during pregnancy. Measurement of Fe, folate and vitamin B12 status is complicated by adaptive changes to maternal and placental physiology that markedly affect concentrations of circulating micronutrients and their functional biomarkers. Validation of new assessment methods by comparison with gold standards is often prevented by ethical considerations. Antenatal screening in the UK is predominantly concerned with the detection of anaemia, although estimation of maternal Fe stores by serum ferritin at the start of antenatal care may be a more effective preventive strategy. Functional assessment of maternal anaemia is highly problematic, so instead reference data are used for its definition. The effect of mild-to-moderate anaemia on pregnancy outcome is unclear because of the crude nature of its assessment and the influence of confounding factors. Fe-deficient erythropoiesis may be detected by assessment of erythrocyte Zn protoporphyrin and reticulocyte Hb, although such measures may be unavailable in many clinical laboratories. Serum soluble transferrin receptor is highly responsive to tissue Fe deficiency and is less affected by inflammation than most other indicators. Direct inter-assay comparison of serum and erythrocyte folate values is inadvisable since recovery rates differ greatly between methods. Serum total homocysteine is a useful functional biomarker of both folate and vitamin B12 status but during pregnancy is influenced by other factors that reduce its sensitivity. Isotope-dilution liquid chromatography–tandem MS and serum holo-transcobalamin provide new opportunities to gain detailed data of folate species and vitamin B12 fractions in large samples.

HIV/AIDS is associated with biological and social factors that affect the individual's ability to consume and utilize food and to acquire food. These biological and social factors lead to poor nutritional status and weight loss, which are an important cause of morbidity in individuals infected with HIV, resulting in a poor quality of life; weight loss is an important predictor of death from AIDS. The links between nutrition and HIV/AIDS amplify the negative effects of HIV infection on human development at individual, household, community and national levels. For many developing countries the incidence of HIV/AIDS and malnutrition is impeding progress towards achieving the UN millennium development goals. Aggressive interventions to curb the spread of HIV continue to be needed. Concurrent efforts to improve nutrition for populations living with HIV/AIDS should also be given priority.