Thiamin (vitamin B1) is required in animal diets because it is the precursor of the enzyme cofactor, thiamin diphosphate. Unlike other B vitamins, the dietary thiamin requirement is proportional to non-fat energy intake but there is no obvious biochemical reason for this relationship. In the present communication we show for two enzymes that the cofactor undergoes a slow destruction during catalysis, which may explain the interdependence of thiamin and energy intakes.

Tree nuts, peanuts and seeds are nutrient dense foods whose intake has been shown to be associated with reduced risk of some chronic diseases. They are regularly consumed in European diets either as whole, in spreads or from hidden sources (e.g. commercial products). However, little is known about their intake profiles or differences in consumption between European countries or geographic regions. The objective of this study was to analyse the population mean intake and average portion sizes in subjects reporting intake of nuts and seeds consumed as whole, derived from hidden sources or from spreads. Data was obtained from standardised 24-hour dietary recalls collected from 36 994 subjects in 10 different countries that are part of the European Prospective Investigation into Cancer and Nutrition (EPIC). Overall, for nuts and seeds consumed as whole, the percentage of subjects reporting intake on the day of the recall was: tree nuts = 4·4%, peanuts = 2·3% and seeds = 1·3%. The data show a clear northern (Sweden: mean intake = 0·15 g/d, average portion size = 15·1 g/d) to southern (Spain: mean intake = 2·99 g/d, average portion size = 34·7 g/d) European gradient of whole tree nut intake. The three most popular tree nuts were walnuts, almonds and hazelnuts, respectively. In general, tree nuts were more widely consumed than peanuts or seeds. In subjects reporting intake, men consumed a significantly higher average portion size of tree nuts (28·5 v. 23·1 g/d, P<0·01) and peanuts (46·1 v. 35·1 g/d, P<0·01) per day than women. These data may be useful in devising research initiatives and health policy strategies based on the intake of this food group.

A severe reduction in insulin release in response to glucose is consistently noticed in protein-deprived rats and is attributed partly to the chronic exposure to elevated levels of NEFA. Since the pancreatic and duodenal transcription factor homeobox 1 (PDX-1) is important for the maintenance of β-cell physiology, and since PDX-1 expression is altered in the islets of rats fed a low protein (LP) diet and that rats show high NEFA levels, we assessed PDX-1 and insulin mRNA expression, as well as PDX-1 and p38/stress activated protein kinase 2 (SAPK2) protein expression, in islets from young rats fed low (6 %) or normal (17 %; control) protein diets and maintained for 48 h in culture medium containing 5·6 mmol/l glucose, with or without 0·6 mmol/l palmitic acid. We also measured glucose-induced insulin secretion and glucose metabolism. Insulin secretion by isolated islets in response to 16·7 mmol/l glucose was reduced in LP compared with control rats. In the presence of NEFA, there was an increase in insulin secretion in both groups. At 2·8 mmol/l glucose, the metabolism of this sugar was reduced in LP islets, regardless of the presence of this fatty acid. However, when challenged with 16·7 mmol/l glucose, LP and control islets showed a severe reduction in glucose oxidation in the presence of NEFA. The PDX-1 and insulin mRNA were significantly higher when NEFA was added to the culture medium in both groups of islets. The effect of palmitic acid on PDX-1 and p38/SAPK2 protein levels was similar in LP and control islets, but the increase was much more evident in LP islets. These results demonstrate the complex interrelationship between nutrients in the control of insulin release and support the view that fatty acids play an important role in glucose homeostasis by affecting molecular mechanisms and stimulus/secretion coupling pathways.

The prevalence and increasing trends of obesity in Spain are a matter of concern. In adults, the prevalence of obesity and overweight is 14·5 and 38·5 %, respectively, whereas in children and adolescents it is 13·9 and 26·3 %. This situation prompted the Spanish Ministry of Health and Consumer Affairs to draw up the Strategy for Nutrition, Physical Activity and the Prevention of Obesity (NAOS), which aims to improve the diet and encourage the regular practice of physical activity by all citizens, with special emphasis on children. Coordinated by the Spanish Food Safety Agency and the General Directorate of Public Health, a wide range of stakeholders participated in drafting the Strategy through a broad consultative process. Anchored on the core goal of adopting a lifelong perspective in the prevention and control of obesity, NAOS encompasses recommendations for action in four fields: family and community, schools, private sector, and the health system. Launched on 10 February 2005, the Strategy will undergo careful monitoring and evaluation. A newly created Obesity Observatory will carry out epidemiological surveillance, define indicators to measure impact of interventions, facilitate the exchange of experiences among different initiatives, identify research priorities, monitor adherence and application of the self-regulation agreements, and conduct rigorous evaluation of initiatives to identify those that are successful and should be prioritized. To our knowledge, NAOS is the first strategy of its kind in Europe and we recommend it as an example to be followed by countries that, like Spain, face the challenge of combating the pervasive epidemic of obesity.

The results of two acute placebo-controlled, double-blind cross-over studies assessing the effect of Panax ginseng (G115) on blood glucose levels are reported. In study 1, thirty participants received three treatments: placebo; 200 mg G115; 400 mg G115. In study 2, twenty-seven participants received four treatments: placebo (0 mg ginseng and 30 mg saccharin); ginseng (200 mg ginseng and 30 mg saccharin); placebo–glucose (0 mg ginseng and 25 g oral glucose); ginseng–glucose (200 mg ginseng and 25 g oral glucose). Blood glucose levels were measured at baseline (at 09.00 hours after an overnight fast) and then 60, 90 (study 1 only) and 120 min post-dose. Both studies demonstrated that G115 alone significantly lowers fasting blood glucose levels. Conversely, in study 2 there was a significant drink × ginseng interaction suggesting opposing glycaemic effects of ginseng under fasting and raised blood glucose conditions. These data have implications for the use of ginseng in individuals with poor gluco-regulation.

Since the founding of the Food and Agriculture Organization of the United Nations in 1946, it has reported on the serious problem of hunger in the world and has undertaken various initiatives for eradicating this problem; however, they have ended in failure. The number of people suffering from hunger has increased from 500 to 800 million in a period of six decades, despite constant growth in world food production, which has been more than sufficient to cover the needs of all of humanity since the 1970s. This paper analyses FAO initiatives in the framework of the evolution of the nutritional situation in developing countries and identifies national and regional contexts in which technical solutions may be successful, as well as those requiring the implementation of economic, political and social measures.

Laboratory studies have shown that the resistance of isolated LDL-cholesterol or linoleic acid to oxidation is increased in incubations with chilli extracts or capsaicin – the active ingredient of chilli. It is unknown if these in vitro antioxidative effects also occur in the serum of individuals eating chilli regularly. The present study investigated the effects of regular consumption of chilli on in vitro serum lipoprotein oxidation and total antioxidant status (TAS) in healthy adult men and women. In a randomised cross-over study, twenty-seven participants (thirteen men and fourteen women) ate ‘freshly chopped chilli’ blend (30g/d; 55% cayenne chilli) and no chilli (bland) diets, for 4 weeks each. Use of other spices, such as cinnamon, ginger, garlic and mustard, was restricted to minimum amounts. At the end of each dietary period serum samples were analysed for lipids, lipoproteins, TAS and Cu-induced lipoprotein oxidation. Lag time (before initiation of oxidation) and rate of oxidation (slope of propagation phase) were calculated. There was no difference in the serum lipid, lipoproteins and TAS at the end of the two dietary periods. In the whole group, the rate of oxidation was significantly lower (mean difference −0·23 absorbance ×10−3/min; P=0·04) after the chilli diet, compared with the bland diet. In women, lag time was higher (mean difference 9·61min; P<0·001) after the chilli diet, compared with the bland diet. In conclusion, regular consumption of chilli for 4 weeks increases the resistance of serum lipoproteins to oxidation.

Enhancement of the redox status of cells is a cytoprotective strategy against oxidative damage. We recently showed that DHA upregulates glutathione (GSH) content via an induction of its related enzymes γ-glutamylcysteine ligase and glutathione reductase. In the present study, we investigated the effects of eight other fatty acids on the redox status and lipid peroxidation of human fibroblasts. After 48 h, only arachidonic acid and conjugated linoleic acid (CLA) enhanced GSH content through an induction of γ-glutamylcysteine ligase. CLA was more potent than arachidonic acid in inducing GSH synthesis. For all the fatty acids tested, lipoperoxidation, estimated by cell malondialdehyde measurement, did not differ from that of controls at 48 h but dramatically increased at 7 d, except for CLA. Lipoperoxidation is associated at 7 d with a high level of reactive oxygen species and with increased haemoxygenase-1 and cyclooxygenase-2 mRNA expression. As demonstrated by a tert-butylhydroperoxide cytotoxicity test, the GSH synthesis obtained with arachidonic acid is not sufficient to protect the cells, whereas this protective effect was obvious with CLA at 48 h as well as at 7 d. The present results show that CLA is the only PUFA able to induce GSH synthesis without any change in oxidative balance, whereas an upregulation of cyclooxygenase-2 by other PUFA is concomitant with an overproduction of malondialdehyde and reactive oxygen species. The particular hairpin conformation obtained for CLA by molecular modelling could account for this specific biological effect.

Studies have demonstrated that isolated soya protein (ISP) can slow the progression of renal injury, reduce blood pressure and improve the serum lipid profile in experimental animals and human subjects. The mechanisms and components of soya responsible have not been fully established. The present study was designed to evaluate the effects of the hydrophilic supernatant fraction (SF) and the hydrophobic precipitate fraction (PF) isolated from soya protein hydrolysate on renal function, lipid metabolism and blood pressure in five-sixths nephrectomized rats. Experimental animals were subjected to a nephrectomy and allocated to four groups (180g casei/g, 180g IS/g, 100g casei/g with 80g S/g, and 100g casei/g with 80g P/g). The SF group had the most significant decreases in blood pressure and total cholesterol, as well as a significantly retarded progression of the experimentally induced renal disease, compared with the other groups. The PF group exhibited a significantly increased faecal excretion of total steroids. The serum creatinine, level of proteinuria, total cholesterol and LDL-cholesterol concentrations, and blood pressure were significantly reduced, and HDL-cholesterol was significantly increased, in the ISP and PF groups compared with the casein group, but no significant differences were observed between the ISP and PF groups. These results suggest that both soya protein hydrolysate fractions favourably affected chronic renal failure induced by a five-sixths nephrectomy, and the hydrophilic fraction of soya protein hydrolysate had the most pronounced effect on attenuating hypertension and slowing the progression of renal disease.

On the basis of the high fat content of nuts, they are traditionally considered as foods that provide a high amount of energy. However, epidemiologic and clinical observations do not indicate an association between nut intake and increased BMI. There is a notorious variability in macronutrient composition among nuts, although they have some consistent patterns. Nuts contain all major macronutrients: protein, carbohydrate, and fat. The total protein content is relatively high, which makes them a good source of plant protein (especially for vegetarians). Although nuts contain low amounts of some essential amino acids, this is not a nutritional concern due to the complement of protein. In addition, nuts have a low lysine:arginine ratio, which is inversely associated with the risk of developing hypercholesterolemia and atherosclerosis. Carbohydrates are the second highest macronutrient in nuts in terms of total calories provided. The fat fraction is characterized by a high amount of unsaturated fatty acids and a low content of saturated fatty acids. In conclusion, the high content in unsaturated fatty acids, the low lysine:arginine ratio, and the presence of other bioactive molecules (such as fibre, phytosterols, vitamin and other antioxidants, and minerals) make the addition of nuts to healthy diets a useful tool for the prevention of cardiovascular heart diseases.

To investigate whether dietary α-linolenic acid (ALA) content alters the effect of β-carotene on mammary carcinogenesis, we conducted a chemically induced mammary tumorigenesis experiment in rats randomly assigned to four nutritional groups (15 rats per group) varying in β-carotene supplementation and ALA content. Two oil formula-enriched diets (15%) were used: one with 6g ALA/kg diet in an essential fatty acids (EFA) ratio of linoleic acid:ALA of 5:1 w/w (EFA 5 diet), the other with 24g ALA/kg diet in an EFA ratio of 1:1 w/w (EFA 1 diet), both designed with a similar linoleic acid content. β-Carotene was either added (10mg/kg diet per d) or not added to these diets. β-Carotene supplementation led to decreased tumour incidence and tumour growth when added to the EFA 5 diet, whereas it had no effect when added to the EFA 1 diet. The decreased tumour growth did not result from an involvement of lipoperoxidation (tumour malondialdehyde content being similar between the groups) or from an inhibition of tumour cell proliferation (as there was an unchanged S phase fraction in the tumours). We concluded that an adequate content of ALA in the diet is required to allow a protective effect of β-carotene in mammary carcinogenesis. Whether such an interaction between ALA and β-carotene influences the risk of breast cancer in women needs to be investigated.

Although numerous environmental factors are documented to influence serum ascorbic concentrations, little is known about the genetic versus environmental contributions to variation of this trait. The aim of this study was to estimate family correlation and, additive genetic heritability and household effects in a variance component analysis for serum ascorbic acid concentrations. In a sample of ninety French families, information was obtained regarding serum ascorbic acid concentrations, usual dietary intake, lifestyle, and other related covariates. Spouse, parent–offspring and offspring–offspring significant correlation coefficients for serum ascorbic acid concentrations, adjusted for age, cigarette consumption and oral contraceptive use, were 0·432, 0·298 and 0·485, respectively, and for adjusted values for additional diet covariates (vitamin C intake and fruit and vegetable consumption), were 0·362, 0·154 and 0·348, respectively. Variance component analysis for serum ascorbic concentrations showed no significant genetic contribution to variability of this trait. Conversely, household common environment accounted for 27·7 and 42·6 % in parents and offspring, respectively, after adjustment for age, cigarette consumption and oral contraceptive use. After adjustment for the two additional diet covariates (vitamin C intake and fruit and vegetable consumption) household common variance decreased to 13·6 and 30·5 % in parents and offspring, respectively. These results show that serum ascorbic acid concentrations aggregate within healthy families partly due to diet intake but without a significant genetic component.

Recently, transgenic crops have been considered as possible donors of transgenes that could be taken up by micro-organisms under appropriate conditions. In an in vitro rumen simulation system, effects of ampicillin on microbial communities growing either on rumen contents with transgenic maize carrying a gene that confers resistance to ampicillin or its isogenic counterpart as substrates were examined continuously over 13 d. Rate of production of SCFA was measured to determine functional changes in the rumen model and single-strand conformational polymorphism was used to detect alterations in structure of the microbial community. Rumen contents treated with ampicillin displayed a marked decrease in the rate of production of SCFA and diversity of the microbial community was reduced severely. In the presence of transgenic maize, however, the patterns of change of rumen micro-organisms and their metabolic profiles were different from that of rumen fluid incorporating maize bred conventionally. Recovery of propionate production was observed both in the rumen fluid fed transgenic and conventional maize after a delay of several days but recovery occurred earlier in fermenters fed transgenic maize. Alterations in the microbial population structures resulting from the ampicillin challenge were not reversed during the experimental run although there was evidence of adaptation of the microbial communities over time in the presence of the antibiotic, showing that populations with different microbial structures could resume a pre-challenge metabolic profile following the introduction of ampicillin, irrespective of the source of the plant material in the growth medium.

Epidemiological studies show that dietary products rich in carotenoids delay the progression of age-related macular degeneration. Experimental evidence from cellular studies on the antioxidant actions of carotenoids in the retinal pigment epithelium is still, however, fragmentary. The present study examined the uptake and protective potential of dietary carotenoids from tomato on the human retinal pigment epithelial cell line ARPE-19. ARPE-19 cells were incubated in medium supplemented with tomato extract containing high levels of ß-carotene, lycopene and traces of lutein. The cellular uptake of carotenoids was analysed by reverse-phase HPLC. Oxidative stress was induced by treatment with 1 mm-H2O2. Nitrotyrosine was detected by immunocytochemistry, and oxidised proteins (protein carbonyls) were measured by a quantitative ELISA method. Lipid peroxidation was assessed by quantifying thiobarbituric acid reactive substances. ARPE-19 cells preferentially accumulated lutein and ß-carotene rather than lycopene. Nitrotyrosine formation was considerably reduced in cells incubated with tomato extract compared with controls after H2O2 treatment. Protein carbonyls were reduced by 30 % (P=0·015), and the formation of thiobarbituric acid-reactive substances was reduced by 140 % (P=0·003) in cells incubated with tomato extract. The present study provides the experimental evidence for protective effects of dietary tomatoes rich in carotenoids on oxidative stress in the retinal pigment epithelium.

It has been estimated that more than 50% of deaths before the age of 5 years have undernutrition as an underlying cause. Severe childhood malnutrition, an extreme form of undernutrition, occurs as oedematous and non-oedematous syndromes. The reasons why only some children develop oedematous severe childhood malnutrition (OSCM) have remained elusive, but the heterogeneity of clinical appearances among children from relatively homogeneous backgrounds suggests that interindividual variation in susceptibility to OSCM may exist. We investigated variants of four glutathione S-transferase (GST) genes in a retrospective study among subjects (n136) previously admitted to the Tropical Metabolism Research Unit, Jamaica, for the treatment of either OSCM (cases) or non-oedematous severe childhood malnutrition (controls). We found that GSTP1 Val105 homozygotes were significantly more common among the cases (odds ratio (OR) 3·5; 95% CI 1·1, 10·8). We also found an association of borderline significance between non-deletion GSTT1 genotypes (i.e. +/+ or +/0) and OSCM (OR 2·4; 95% CI 1·0, 5·9). There was no significant association between OSCM and any of the other GST variants. These preliminary findings suggest that genetic variation within the GST superfamily may contribute to the risk of OSCM. Additional, larger data sets and studies of variants in other candidate genes are required in order to properly assess the true contribution, if any, of genetic variation to risk of OSCM. Such studies may improve our understanding of the causes of clinical heterogeneity in malnutrition.

It is well established that, due to their high content of saturated fatty acids (SFA), the intake of meat and meat products is strongly associated with elevated blood cholesterol concentrations and an increased risk of hypertension, diabetes and cardiovascular diseases. Conversely, the intake of foods rich in unsaturated fatty acids, such as those contained in most vegetable fats and oils and oily fish, is associated with improved lipid profiles, a lower potency of intermediate biomarkers of atherosclerosis and lesser incidence of cardiovascular diseases. There are persuasive evidences that dietary substitution of monounsaturated fatty acids (MUFA) or n-6 polyunsaturated fatty acids (PUFA) for SFA lowers blood cholesterol and may have beneficial effects on inflammation, thrombosis, and vascular reactivity. MUFA may have an advantage over PUFA because enrichment of lipoprotein lipids with MUFA increases their resistance to oxidation. Marine n-3 PUFA have a number of anti-atherosclerotic effects, including anti-arrhythmic properties and, at relatively high doses, reduce serum triglycerides. These effects appear to be shared in part by vegetable n-3 PUFA. Nuts are natural foods rich in unsaturated fatty acids; most nuts contain substantial amounts of MUFA, while walnuts are especially rich in both n-6 and n-3 PUFA. Healthy fats in nuts contribute to the beneficial effects of frequent nut intake observed in epidemiological studies (prevention of coronary heart disease, diabetes, and sudden death) and in short-term feeding trials (cholesterol lowering, LDL resistance to oxidation, and improved endothelial function).

Conjugated linoleic acid (CLA) has protective properties in breast cancer. Here, we studied the mechanisms underlying the effects of CLA on MCF-7 breast cancer cell proliferation, especially in correlation with the involvement of the extracellular signal-regulated kinase 1/2 (ERK1/2) pathway and protein phosphatase 2A (PP2A). CLA inhibits MCF-7 cell growth in a concentration- and time-dependent manner, without triggering apoptosis. In assessing expression levels of proteins that play obligatory roles in the ERK cascade, we evidenced that CLA down-regulated Raf-1 and decreased levels of phospho-ERK1/2, as well as c-myc expression. Increase in PP2A expression rates were additionally observed after CLA treatment of MCF-7 cells. The above effects, as well as CLA-induced inhibition of cell growth, were reversed by okadaic acid, a specific inhibitor of PP2A. Thus, PP2A likely participates in deactivation of ERK1/2, and its up-regulation may represent a novel mechanism for CLA-induced inhibition of cell proliferation.

Different classes of fibres differ in their potential to lower lipid levels. In order to examine how chemically diverse fibres differ in their hypolipidaemic activity, mucilages of varying chemical composition isolated from three different sources were administered to experimental animals and the metabolism of lipids and lipoproteins was studied. The mucilages used were a galactomannan isolated from fenugreek (Trigonella foenum-graecum) seeds, a glucomannan from Dioscorea esculenta tubers and an arabinogalactan from Colocasia esculenta tubers. Rats were fed these mucilages at a dose of 4 mg/100 g body weight per d for 8 weeks and the changes in the levels of total cholesterol and triacylglycerols in serum, liver and aorta were analysed. All these mucilages decreased lipid levels both in serum and tissues. Among these mucilages, glucomannan showed the most hypolipidaemic effect followed by galactomannan and arabinogalactan. Further, hepatocytes were isolated from the livers of mucilage-fed rats and the synthesis and secretion of lipoproteins were studied using metabolic labelling. There was a decrease in the synthesis and secretion of apoB-containing lipoproteins, mainly VLDL, by hepatocytes isolated from mucilage-fed rats when compared to control (P < 0·05). This was further confirmed by pulse chase analysis. Among the different mucilages, mannose-rich glucomannan showed the most effect followed by galactomannan, and mannose-free arabinogalactan showed minimal effect. Comparison of relative viscosity and water-holding capacity showed that mannan-rich mucilages like galactomannan and glucomannan, which showed greater hypolipidaemic effect, had greater relative viscosity and water-holding capacity. The present results suggested that the hypolipidaemic effect of dietary fibre involves a decrease in hepatic production of VLDL and further that it varies with the nature of the fibre.

Equol, a derivative of daidzein produced by enterobacteria, has greater activity as a phyto-oestrogen compared with daidzein. Difructose anhydride III (DFAIII) is a newly manufactured non-digestible disaccharide with unique fermentation properties. The present study evaluated the prebiotic effects of DFAIII on equol production and on plasma cholesterol concentrations related to the changes in equol production. We compared plasma equol concentrations at 10.00 and 18.00 hours and faecal isoflavone excretion in three groups of seven rats (male Wistar-ST strain, 6 weeks old) fed a basal diet or a DFAIII or fructooligosaccharide (15/g diet) diet containing 1g soya isoflavone/g diet for 20d. Equol concentrations in the DFAIII group were higher than in the control and fructooligosaccharides groups, especially in the later phase of the light period (18.00 hours) throughout the experiment. Daizein and genistein concentrations did not change between the diet groups. The faecal ratios of equol:daidzein were very high in all groups, but the ratios were higher in the DFAIII group than the control and fructooligosaccharide groups on day 3, and this tendency continued throughout the experiment. On day 20, the plasma total cholesterol concentration was lowest in the DFAIII group. Additionally, the cholesterol concentrations were inversely correlated to plasma equol concentration in all the rats. In conclusion, DFAIII efficiently enhanced plasma equol concentrations, which may be associated with an increase in equol production and a decrease in equol degradation by enterobacteria. Higher plasma equol concentrations may contribute to the hypocholesterolaemic effect of DFAIII feeding.

High prevalence of malnutrition is often linked to conflict situations. Conflicts affect local livelihoods, impair productive activities and limit access to safe foods and basic services. Strategies to protect and promote nutrition of affected households and communities must be based on an understanding of this impact. While nutrition rehabilitation and food aid are clearly essential to preserve lives in the short run, they cannot provide lasting solutions. Impaired nutritional status ultimately reflects livelihood degradation but anthropometric indicators cannot be used to target timely interventions. They should be combined with simple indicators of food consumption which react more quickly to both crisis and relief/rehabilitation interventions. Local institutions should be encouraged to share information and build causality models of malnutrition for the main vulnerable livelihood groups as a basis for an integrated response. A communication component will systematically be needed to allow people to make informed decisions in a context with which they are often not familiar.