Nuts are a well-defined cause of food allergy, which affect approximately 1 % of the general population in the UK and the USA. There do appear to be differences in the frequency of nut allergy between different countries because of different dietary habits and cooking procedures. For example, in the USA and France, peanuts are one of the most frequent causes of food allergy, but in other countries, it seems to be less common. Genetic factors, in particular, appear to play a role in the development of peanut allergy. While the majority of nut allergens are seed storage proteins, other nut allergens are profilins and pathogenesis-related protein homologues, considered as panallergens because of their widespread distribution in plants. The presence of specific IgE antibodies to several nuts is a common clinical finding, but the clinical relevance of this cross-reactivity is usually limited. Allergic reactions to nuts appear to be particularly severe, sometimes even life-threatening, and fatal reactions following their ingestion have been documented. Food allergy is diagnosed by identifying an underlying immunological mechanism (i.e. allergic testing), and establishing a causal relationship between food ingestion and symptoms (i.e. oral challenges). In natural history investigations carried out in peanut-allergic children, approximately 20 % of the cases outgrew their allergy or developed oral tolerance. The treatment of nut allergies should include patient and family education about avoiding all presentations of the food and the potential for a severe reaction caused by accidental ingestion. Patients and families should be instructed how to recognise early symptoms of an allergic reaction and how to treat severe anaphylaxis promptly.

During Ramadan, Muslims the world over abstain from food and water from dawn to sunset for a month. We hypothesised that this unique model of prolonged intermittent fasting would result in specific intestinal and liver metabolic adaptations and hence alter metabolic activities. The effect of Ramadan-type fasting was studied on enzymes of carbohydrate metabolism and the brush border membrane of intestine and liver from rat used as a model. Rats were fasted (12 h) and then refed (12 h) daily for 30 d, as practised by Muslims during Ramadan. Ramadan-type fasting caused a significant decline in serum glucose, cholesterol and lactate dehydrogenase activity, whereas inorganic phosphate increased but blood urea N was not changed. Fasting resulted in increased activities of intestinal lactate (+34 %), isocitrate (+63 %), succinate (+83 %) and malate (+106 %) dehydrogenases, fructose 1,6-bisphosphatase (+17 %) and glucose-6-phosphatase (+22 %). Liver lactate dehydrogenase, malate dehydrogenase, glucose-6-phosphatase and fructose 1,6-bisphosphatase activities were also enhanced. However, the activities of glucose-6-phosphate dehydrogenase and malic enzyme fell significantly in the intestine but increased in liver. Although the activities of alkaline phosphatase, γ-glutamyl transpeptidase and sucrase decreased in mucosal homogenates and brush border membrane, those of liver alkaline phosphatase, γ-glutamyl transpeptidase and leucine aminopeptidase significantly increased. These changes were due to a respective decrease and increase of the maximal velocities of the enzyme reactions. Ramadan-type fasting caused similar effects whether the rats fasted with a daytime or night-time feeding schedule. The present results show a tremendous adaptation capacity of both liver and intestinal metabolic activities with Ramadan-type fasting in rats used as a model for Ramadan fasting in people.

It has been shown previously that malnourished rats are resistant to acute gastric lesions but not to subchronic gastric ulceration. It also has been demonstrated that the essential oil obtained from the bark of Croton cajucara (Sacaca) has antiulcer properties. In the present study, the ability of this essential oil to prevent the formation of gastric ulcers in rats fed a diet with 17% protein (normoproteic rats) or 6% protein (malnourished rats) was investigated. At a dose of 100mg/kg body weight, orally, the essential oil significantly reduced the gastric injury caused by indomethacin (25% after 2h and 70% after 4h) only in normoproteic rats. In the pylorus ligature model, the essential oil increased the pH and gastric volume, but decreased the total acid concentration in both groups when compared to the respective control group. The essential oil significantly increased prostaglandin E2 production in glandular cells by 50% compared to the controls in both groups of rats. In addition, the amount of gastric mucus was two-fold higher in malnourished rats than in normoproteic rats. The present results show that the enhanced protective effect of essential oil in malnourished rats involved an increase in prostaglandin E2 production and mucus secretion, which are both factors that protect the gastric mucosa against damage. In agreement with this, malnourished rats always had a lower number of acute gastric ulcers.

The objective of the present study was to compare anthropometry with bioelectrical impedance (BIA) in relation to densitometry (dual-energy X-ray absorptiometry; DEXA) as methods of nutritional assessment and body composition in out-patients with chronic pulmonary obstructive disease (COPD). We conducted a cross-sectional clinical study with sixty-one patients with COPD (forty-two men and nineteen women), mean age of 66·5 (sd 7·9) years and forced expiratory volume in 1s of 1·3 (sd 0·6) litres (52·2 (sd 19·8) % predicted), referred to the Pulmonary Rehabilitation Center. The patients were evaluated regarding nutrition status and body composition as determined by anthropometry, BIA and DEXA. In the results, 34·4% showed mild obstruction, 31·2%, moderate and 34·4%, severe obstruction. According to the BMI (mean 24·5 (sd 4·5) kg/m2), 45·9% of the patients exhibited normal weight, while 27·9% were underweight and 26·2% were obese. Related to fat-free mass (FFM), anthropometry and BIA compared with DEXA presented high correlations (r 0·96 and 0·95 respectively; p<0·001) and high reliability between the methods (α 0·98; p<0·001). Agreement analysis between the methods shows that anthropometry overestimates (0·62 (sd of the difference 2·89) kg) while BIA underestimates FFM (0·61 (sd of the difference 2·82) kg) compared with DEXA. We concluded that according to the nutritional diagnosis, half of our population of patients with COPD showed normal weight, while the other half comprised equal parts obese and underweight patients. Body composition estimated by BIA and anthropometry presented good reliability and correlation with DEXA; the three methods presented satisfactory clinical accuracy despite the great disparity of the limits of agreement.

Young women of reproductive age appear to have a greater capacity than men to convert the essential fatty acid α-linolenic acid to DHA. The purpose of this study was to test the hypothesis that gender-related differences in n-3 PUFA metabolism are reflected in the concentrations of n-3 PUFA in plasma lipids. The subjects were healthy men (n 13) and women (n 23) aged 18–35 years consuming their habitual diet. Dietary habits were assessed by food-frequency questionnaire. Venous blood samples were collected following an overnight fast. For the women, blood collection took place on the tenth day of their menstrual cycle. The fatty acid concentrations of plasma phosphatidylcholine, triacylglycerol, NEFA and cholesteryl esters were determined by gas chromatography. There were no significant differences between men and women in their consumption of protein, carbohydrate, total fat, alcohol, individual fatty acids and selected micronutrients. DHA concentration alone was significantly higher in plasma phosphatidylcholine (31%, p=0·02), triacylglycerol (71%, p=0·02) and NEFA (33%, p=0·01), but not cholesteryl esters, in women compared with men. There were no significant differences between men and women in the concentrations of any other fatty acids measured. Overall, the present data support the suggestion that greater DHA synthesis in women than men results in a higher DHA concentration in plasma lipids.

High plasma concentrations of ascorbic acid, a marker of fruit and vegetable intake, are associated with low risk of coronary artery disease. Whether this relationship is explained by a reduction in systemic inflammation is unclear. We investigated the relationship between ascorbic acid plasma concentration and coronary artery disease risk, and in addition whether this relationship depended on classical risk factors and C-reactive protein (CRP) concentration. We used a prospective nested case–control design. The study consisted of 979 cases and 1794 controls (1767 men and 1006 women). Increasing ascorbic acid quartiles were associated with lower age, BMI, systolic and diastolic blood pressure, and CRP concentration, but with higher HDL-cholesterol concentration. No associations existed between ascorbic acid concentration and total cholesterol concentration or LDL-cholesterol concentration. When data from men and women were pooled, the risk estimates decreased with increasing ascorbic acid quartiles such that people in the highest ascorbic acid quartile had an odds ratio for future coronary artery disease of 0·67 (95% CI 0·52, 0·87) compared with those in the lowest quartile (P for linearity=0·001). This relationship was independent of sex, age, diabetes, smoking, BMI, LDL-cholesterol, HDL-cholesterol, systolic blood pressure and CRP level. These data suggest that the risk reduction associated with higher ascorbic acid plasma concentrations, a marker of fruit and vegetable intake, is independent of classical risk factors and also independent of CRP concentration.

An in situ study was conducted on four rumen-cannulated wethers to determine (using 15N infusion techniques) the microbial contamination (mg bacterial DM or crude protein (CP)/100mg DM or CP) and the associated error on the effective degradability of fourteen feeds: barley and maize grains, soyabean and sunflower meals, full-fat soyabean, maize gluten feed, soyabean hulls, brewers dried grains, sugarbeet pulp, wheat bran, lucerne and vetch-oat hays, and barley and lentil straws. The DM or CP contamination in residues (M) fitted to single exponential or sigmoid curves. A general model (M=m (1−e−ft)j) was proposed to match this fit. Asymptotic values (m) varied from 2·84% to 13·3% and from 2·85% to 80·9% for DM and CP, respectively. Uncorrected results underestimated the effective degradability of both DM (P<0·05) and CP (P<0·01). For CP, this underestimation varied from 0·59% to 13·1%, with a higher but unascertainable error for barley straw. Excluding maize grain, the microbial contamination of both DM and CP, and the associated underestimation of the effective degradability of CP, were positively related to the cellulose content of the feed. The error in the effective degradability of CP was also negatively related to the CP content and its apparent effective degradability (R2 0·867). This equation allows easier and more accurate estimates of effective degradability, needed to improve protein-rationing systems.

The aim of this study was to assess the impact of dietary counselling combined with the provision of food products on food and nutrient intake in pregnant women. We carried out a prospective cohort study of healthy and atopic pregnant women (n 209), who were randomized into dietary intervention and control groups. The intervention group received dietary counselling and food products to modify the fat composition of their diet to meet current recommendations. Three-day food records were collected during each trimester of pregnancy. Women in the intervention group consumed more vegetables, fruits, soft margarines and vegetable oils and less butter than those in the control group during the course of pregnancy (P < 0·05). The main distinction between the groups in nutrient intake over the pregnancy was attributable to a higher energy intake (% energy) of PUFA by 0·5 %energy (95 % CI 0·1, 0·8) and to a lower intake of SFA by 0·8 % energy (95 % CI − 1·4, − 0·4) in the intervention group. Dietary intake of vitamin E was 1·4 mg (95 % CI 0·6, 2·2), folate 20·9 μg (95 % CI 0·8, 41·0) and ascorbic acid 19·8 mg (95 % CI 3·5, 36·0) higher in the intervention group compared to the controls, while no differences in other nutrients were detected. Dietary counselling combined with the provision of food products during pregnancy is of importance in modifying food and nutrient intake, with potential health benefits.

Food intake varies across the menstrual cycle in mammals, energy intake usually being greater in the premenstrual phase compared with the postmenstrual phase. Premenstrual increments in energy intake and a preferential selection of carbohydrate have been suggested to be greater in women with premenstrual syndrome (PMS), who may be more sensitive to cyclical hormonal or neurotransmitter fluctuations. This has direct implications for research within populations of women, especially where the primary outcome is diet or a change in energy balance. We aimed to determine whether: the premenstrual intake of energy and macronutrients differed from the postmenstrual intake; the change in intake across the menstrual cycle differed in women with PMS compared with controls; and the change in intake was related to the severity of premenstrual symptoms. We collected 3 d dietary intake data during the postmenstrual and premenstrual phases of the menstrual cycle in thirty-one women with PMS and twenty-seven control women. The consumption of energy and macronutrient intake were similar between the phases of the cycle in women with PMS. Conversely, intakes were usually greater premenstrually in control women, although not all differences were statistically significant. Exceptions were with non-milk extrinsic sugars and alcohol, which were both consumed in greater amounts in the premenstrual phase in women with PMS. Significant correlations were observed between the severity of symptoms and the change in the consumption of these nutrients. These data suggest that a consideration of the menstrual cycle phase and PMS in diet may not be warranted, especially in cross-sectional analysis, although it may need to be taken into account when examining change in intake during dietary interventions.

The nutritional intakes of the Spanish child and adolescent population are presented, as well as the population at risk of inadequate nutrient status. A random sample of 3534 people aged 2–24 years were interviewed between 1998 and 2000. Interviews included two 24 h recalls and a general questionnaire and anthropometric evaluations for the entire sample. After excluding under-reporters (18·7 %), the final sample was 2855 individuals (1348 males and 1507 females). The average intake of energy was 9543 kJ in males and 7804 kJ in females, with important variations seen by age group. Energy intake increased with age in both sexes until 14–17 years, which also applied to almost all of the nutrients studied, with the exception of vitamin C. A decreasing trend in the percentage of energy from carbohydrates was seen in both sexes. At the low socioeconomic level, it was observed that all nutrient intakes were less favourable when compared with higher socioeconomic levels. Nutrients with associated intakes below one-third of the Spanish recommended nutrient intake (RNI) included vitamin D (42 % of the sample) and folate (10 % of females), and the percentages falling below two-thirds of the RNI corresponded to: vitamin D (97 %), vitamin A (60 %), vitamin E (54 %), folate (58 % of females), Fe (23 % of females), vitamin C (8 %), Mg (4·5 %), Ca (5 % of females) and vitamin B6 (5 % of females). Adolescents aged between 14 and 17 years was the group with the highest nutritional risk, especially among girls. Nutritional adequacy in Spanish children was, in general, adequate, although it is necessary to analyse the implications of high inadequate intakes of vitamins D, E and A, which means that the current recommended intakes should be reconsidered. It should be noted that folate levels should be doubled in the near future.

The modification of folate status was analysed in a group of sixty-seven overweight/obese women of childbearing age (20–35 years). Subjects were randomly assigned to one of two slightly hypocaloric diets: diet V (increased consumption of vegetables) or diet C (increased consumption of breakfast cereals). Dietetic, anthropometric and biochemical data were collected at the start of the study and again at 2 and 6 weeks. At 6 weeks a weight loss of 2·0 (sd 1·3) kg was achieved in V subjects and of 2·8 (sd 1·4) kg in C subjects (P<0·05). At the start of the study, 64·2 % of all subjects had a folate intake of <67 % of the recommended intake; this fell to just 3 % (7·14 % of V subjects and 0 % of C subjects) by week 6. Significant increases were only seen in C subjects in serum folate concentrations (both at 2 and 6 weeks), accompanied by a significant reduction in serum homocysteine (at week 6). Some 62·1 % of all subjects had serum folate concentrations of ≥13·6 nmol/l (associated with a very low risk of neural tube defects) at the start of the study, while 87·0 % (85·2 % of V subjects and 88·9 % of C subjects) had concentrations of ≥13·6 nmol/l at 6 weeks (P<0·01). Increasing the relative consumption of vegetables/cereals in the context of a slightly hypocaloric diet may therefore be a good way to lose body weight. Breakfast cereals may be of special help with respect to folate status and serum homocysteine levels in overweight/obese young women following energy restriction diets.

Common sage (Salvia officinalis L.) is among the plants that are claimed to be beneficial to diabetic patients, and previous studies have suggested that some of its extracts have hypoglycaemic effects in normal and diabetic animals. In the present study, we aimed to verify the antidiabetic effects of an infusion (tea) of common sage, which is the most common form of this plant consumed. Replacing water with sage tea for 14d lowered the fasting plasma glucose level in normal mice but had no effect on glucose clearance in response to an intraperitoneal glucose tolerance test. This indicated effects on gluconeogenesis at the level of the liver. Primary cultures of hepatocytes from healthy, sage-tea-drinking rats showed, after stimulation, a high glucose uptake capacity and decreased gluconeogenesis in response to glucagon. Essential oil from sage further increased hepatocyte sensitivity to insulin and inhibited gluconeogenesis. Overall, these effects resemble those of the pharmaceutical drug metformin, a known inhibitor of gluconeogenesis used in the treatment and prevention of type 2 diabetes mellitus. In primary cultures of rat hepatocytes isolated from streptozotocin (STZ)-induced diabetic rats, none of these activities was observed. The present results seem to indicate that sage tea does not possess antidiabetic effects at this level. However, its effects on fasting glucose levels in normal animals and its metformin-like effects on rat hepatocytes suggest that sage may be useful as a food supplement in the prevention of type 2 diabetes mellitus by lowering the plasma glucose of individuals at risk.

Cross-sectional population studies provide valuable information for nutrition surveillance and planning intervention strategies. The enKid Study is the largest nutrition survey on the child and adolescent Spanish population to date. In the present paper, nutrition risks in children and young people of the Basque country based on the enKid Study subsample for the Basque region are presented. Dietary assessment was completed by means of a 24 h recall and a food frequency questionnaire completed in an interview with the mother or caregiver for children under 13 years. A second 24 h recall was completed on 25 % of the sample. Body weight, height and circumference were measured on each individual. Overweight and obesity were defined using Cole et al. cut-offs. Fat intake supplied 40 % of energy intake and saturated fats 13·8 %. Overall, 80 % of the sample had intakes of fat above 35 %. Main food sources of fats were added fats (32 %), meat (20 %) and milk products (20 %). Buns, cakes and pastry supplied 11 % of total fat intake. The nutrients showing the highest proportion of people who did not reach one third (33 %) of the Spanish dietary reference intake levels were vitamin D, vitamin E, vitamin A and folate. Prevailing food pattern showed a high consumption of meat and meat products, milk, dairy products and cereals. Conversely, consumption of fruit, vegetables and fish was low; in fact, 89 % of the sample had a normal consumption of fruit and vegetables below five portions a day. Prevalence of obesity was estimated at 3·94 %, and 17·85 % of the sample was classified as overweight.

Protein–energy malnutrition and nosocomial infection (NI) are frequent in elderly patients, and a causal link between the two has often been suggested. The aim of the present study was to identify the nutritional parameters predictive of NI in elderly patients. We assessed on admission 101 patients (sixty-six women, thirty-five men, aged over 65 years) admitted to an acute care of the elderly department. Sarcopenia was detected by dual-energy X-ray absorptiometry, with appendicular skeletal muscle mass expressed with respect to body area. Weight, BMI, albuminaemia, serum transthyretin and C-reactive protein values were also determined on admission, and known risk factors, such as functional dependence and invasive biomedical material, were also evaluated. After up to 3 weeks of hospitalisation, patients were classified according to whether they had developed an NI. After 3 weeks of hospitalisation, we found that twenty-nine patients had suffered an NI, occurring after a mean of 16·1 d. Patients who were sarcopenic on admission had a significantly higher risk of contracting an NI (relative risk 2·1, 95 % CI 1·1, 3·8). None of the other morphometric or biological parameters differed significantly between the two groups of patients on admission. Patients who experienced an NI were also more likely, on admission, to have a medical device (P=0·02 to P=0·001 depending on the device), to have swallowing problems (P=0·002) or to have restricted autonomy (P<0·01). Sarcopenia on admission to an acute care of the elderly unit, as measured by X-ray absorptiometry, was therefore associated with a doubled risk of NI during the first 3 weeks of hospitalisation.

Using data from 7 d weighed dietary records, dietary intake and sources of phylloquinone (vitamin K1) were examined by socio-demographic and lifestyle factors in 1916 participants aged 16–64 years from the 1986–7 Dietary and Nutritional Survey of British Adults, and 1423 participants aged 19–64 years from the 2000–1 National Diet and Nutrition Survey. Using UK-specific food content data, geometric mean phylloquinone intakes were estimated as 72 (95 % CI 70, 74) and 67 (95 % CI 65, 69) μg/d in 1986–7 and 2000–1 respectively (P < 0·001). In 1986–7, 47 % of participants had phylloquinone intakes below the UK guideline for adequacy ( ≥ 1 μg/kg body weight per d), compared with 59 % in 2000–1 (P < 0·001). In both surveys, daily phylloquinone intake was higher among men than women and increased significantly with age. Participants of manual occupational social class, or who were smokers, had lower phylloquinone intake than their counterparts. Participants living in Scotland and northern England had lower phylloquinone intake than those living elsewhere in mainland Britain, particularly in 1986–7 when the contribution from vegetables was also lower than elsewhere. However, by 2000–1 this regional difference was no longer significant. Overall, vegetables contributed 63 % of phylloquinone intake in 1986–7 and 60 % in 2000–1, with cooked leafy green vegetables (LGV) providing 23 and 19 % respectively. In both surveys, the contribution of vegetables (cooked LGV in particular) was directly associated with age. These data show a decrease in phylloquinone intake from 1986–7 to 2000–1, mainly owing to lower consumption of cooked LGV.

Relationships between Se and Hg in erythrocytes, and between these indices and intakes of fish and other foods, were studied as an adjunct to the British National Diet and Nutrition Survey (NDNS) of young people aged 4–18 years. Hg was measured in 965 packed erythrocyte samples by inductively coupled plasma mass spectrometry. Fe measurements permitted the calculation of whole-blood Hg. Erythrocyte and plasma Se, and 7d weighed dietary intake estimates, were available. Erythrocyte Hg was positively skewed, normalised by log-transformation. It was 20% higher in girls than boys (3·17 v. 2·65nmo/, P=0·004), and increased with age in boys but not girls. It was directly and strongly correlated with erythrocyte or plasma Se. Hg and Se concentrations were directly correlated with fish intake. Certain other food groups were also directly correlated with Se and Hg concentrations, but less strongly than for fish. The strength and consistency of the relationship between erythrocyte Hg and Se suggests an important chemical link. Previous studies suggest that Se protects against the toxicity of Hg, and that fish is an important source of both. No toxic levels of Hg were found, which is reassuring because of the known health benefits of fish consumption, especially oily fish. Hg intakes need to be monitored, especially in women of child-bearing age, to ensure that Food Standards Agency guidelines are met.

The effect of long-chain n-3 PUFA on the metabolism of apoB100-containing lipoprotein in diabetic subjects is not fully understood. The objective of the present study was to determine the effect of a daily intake of 1080mg EPA and 720mg DHA for diabetic subjects on the kinetics of apoB100-containing lipoprotein in the fasting state. A kinetic study was undertaken to determine the mechanisms involved in the effects of n-3 fatty acids in terms of a decrease in triacylglycerol level in type 2 diabetic patients. We have studied the effect of fish oils on the metabolism of apoB100 endogenously labelled by [5,5,5–2H3]-leucine in type 2 diabetic patients in the fasting state. The kinetic parameters of apoB100 in VLDL, intermediate-density lipoprotein and LDL were determined by compartmental modelling in five diabetic subjects before and 8 weeks aftern-3 fatty acid treatment. Treatment did not change the plasma cholesterol level (0·801 (sd 0·120)v. 0·793 (sd 0·163) mmol/l) but lowered the plasma triacylglycerol level (1·776 (sd 0·280) v.1·356 (sd 0·595) mmol/l; p<0·05). Treated patients showed a decrease in VLDL apoB100 concentration (0·366 (sd 0·030) v.0·174 (sd 0·036) g/l; v<0·05) related to a decrease in VLDL 1 production (1·49 (sd 0·23) v.0·44 (sd 0·19) mg/kg per h; p<0·05) and an increase in the VLDL conversion rate (0·031 (sd 0·024)v.0·052 (sd 0·040) per h; p<0·05), with no change in fractional catabolic rates. Treatment led to a higher direct production of intermediate-density lipoprotein (0·02 (sd 0·01) v 0·24 (sd 0·12) mg/kg per h; p<0·05). In conclusion, the present study, conducted in the fasting state, showed that supplementation with n-3 fatty acids in type 2 diabetic patients induced beneficial changes in the metabolism of apoB100-containing lipoprotein.

Elevated total serum homocysteine (tHcy) may be a possible risk factor for CVD. A 5 μmol/l increase in tHcy is associated with an approximately 70 % increase in relative risk of CVD in adults. Data for children and adolescents are, however, limited. The purpose of the present study was to provide a reference range for tHcy and investigate any relationship between tHcy and nutritional indexes in a Greek paediatric population. tHcy, folate, vitamin B12 levels and dietary indexes were measured in 520 healthy schoolchildren (274 boys, 246 girls) aged 6–15 years. As in adults, the tHcy distribution skewed to the right, with a geometric mean for both genders of 7·4 (range 3·4–29 μmol/l). Concentrations were lower in young children and increased with age. No statistically significant difference in tHcy level was observed between gender. The 95th percentiles for the three age groups were as follows: 6–9 years, 9·98 μmol/l; 10–12 years, 10·62 μmol/l; 13–15 years, 14·4 μmol/l. Using Pearson's coefficient analysis, tHcy level was correlated with age, serum folate, BMI and systolic blood pressure. Dietary analysis showed that folate, vitamin B12 and fibre intake were inversely related with tHcy; conversely, sugar and fat were positively associated with tHcy. However, in multiple linear regression analysis, only age (odds ratio 0·246, P<0·05) and folate (odds ratio −0·346, P<0·05) were significantly and independently associated with tHcy. This study provides age-specific reference data regarding tHcy concentration in a Greek paediatric population. tHcy levels increased as a function of age. Serum folate levels were significantly and independently associated with tHcy levels.

It is essential to have a thorough knowledge of the bioavailability and metabolism of dietary flavonols to understand their role in disease prevention. Lightly fried onions containing 275μmol flavonols, principally quercetin-4′-glucoside and quercetin-3,4′-diglucoside, were fed to healthy human volunteers and plasma and urine were collected over a 24h period. Samples were analysed by HPLC with diode array and tandem mass spectrometric detection. Five flavonol metabolites, quercetin-3′-sulphate, quercetin-3-glucuronide, isorhamnetin-3-glucuronide, a quercetin diglucuronide and a quercetin glucuronide sulphate, were detected in plasma in quantifiable amounts with trace quantities of six additional quercetin metabolites. Sub-micromolar peak plasma concentrations (cmax) of quercetin-3′-sulphate, quercetin-3-glucuronide, isorhamnetin-3-glucuronide and quercetin diglucuronide were observed 0.6–0.8h after ingestion. In contrast, the cmax of quercetin glucuronide sulphate was 2.5h. The elimination half-lives (t1/2) of quercetin-3′-sulphate, quercetin-3-glucuronide and quercetin diglucuronide were 1.71, 2.33 and 1.76h respectively, while the t1/2 of isorhamnetin-3-glucuronide was 5.34h and that of quercetin glucuronide sulphate was 4.54h. The profile of metabolites excreted in urine was markedly different to that of plasma with many of the major urinary components, including quercetin-3′-glucuronide, two quercetin glucoside sulphates and a methylquercetin diglucuronide, absent or present in only trace amounts in the bloodstream indicative of substantial phase II metabolism. Total urinary excretion of quercetin metabolites was 12·9μmol, corresponding to 4·7% of intake. If these samples had been subjected to hydrolysis, as in many previous studies, only quercetin and isorhamnetin would have been detected and quantified. The bioactivity of these metabolites should be considered.

It has been shown that l-carnitine supplementation of sows increases their milk production and the postnatal growth of the suckling piglets. To test the hypothesis that this effect is due to an improved suckling behaviour of the piglets, two experiments with sows were performed. Two groups of thirteen or ten sows each (in experiments 1 and 2, respectively) were fed diets with or without supplemental l-carnitine during pregnancy (125mg/d) and lactation (250mg/d). After birth, the litters of all sows were standardised to equal sizes of eleven and nine piglets per litter in experiments 1 and 2, respectively. In experiment 1, the piglets of l-carnitine-supplemented sows had a higher total suckling time per day on days 3, 6 and 9, and greater weight gains during the suckling period, than the piglets of control sows (P<0·05). In experiment 2, all litters were taken away from their mothers and switched to other sows. Half of the control sows and half of the l-carnitine-supplemented sows were given litters born to control sows, the other half of each group being given litters born to l-carnitine-supplemented sows. Piglets born to l-carnitine-supplemented sows had a higher total suckling time per day on day 3 and greater body weight gains during the first 14d compared with piglets born to control sows (P<0·05). This study shows that piglets born to sows supplemented with l-carnitine are able to suckle for longer, which enables them to obtain more milk and grow faster than piglets born to control sows.