Assessment of body fat (BF) in pregnant women is important when investigating the relationship between maternal nutrition and offspring health. Convenient and accurate body composition methods applicable during pregnancy are therefore needed. Air displacement plethysmography, as applied in Bod Pod, represents such a method since it can assess body volume (BV) which, in combination with body weight, can be used to calculate body density and body composition. However, BV must be corrected for the thoracic gas volume (TGV) of the subject. In non-pregnant women, TGV may be predicted using equations, based on height and age. It is unknown, however, whether these equations are valid during pregnancy. Thus, we measured the TGV of women in gestational week 32 (n 27) by means of plethysmography and predicted their TGV using equations established for non-pregnant women. Body weight and BV of the women was measured using Bod Pod. Predicted TGV was significantly (P = 0·033) higher than measured TGV by 6 % on average. Calculations in hypothetical women showed that this overestimation tended to be more pronounced in women with small TGV than in women with large TGV. The overestimation of TGV resulted in a small but significant (P = 0·043) overestimation of BF, equivalent to only 0·5 % BF, on average. A Bland–Altman analysis showed that the limits of agreement were narrow (from − 1·9 to 2·9 % BF). Thus, although predicted TGV was biased and too high, the effect on BF was marginal and probably unimportant in many situations.

Resistance training is recognised as a good strategy for retarding age-related declines in muscle mass and strength. Recent studies have also highlighted the potential value of protein intakes in excess of present recommendations. The roles that leisure-time physical activity and protein quality play in the preservation of skeletal muscle during ageing, and how such influences interact in free-living people are unclear. We sought to clarify these issues using data collected on 2425 participants aged ≥ 50 years in the US National Health and Nutrition Examination Survey (2003–2006). We estimated subjects’ usual intakes of total protein and beef from two 24 h diet recalls and computed the appendicular skeletal muscle mass index from anthropometric measures. Participants self-reported their physical activity levels. Analyses accounted for demographic factors and smoking. The association between muscle-strengthening activity and the appendicular skeletal muscle mass index varied with protein intake. Furthermore, among obese subjects with protein intakes < 70 g/d, those who performed such activities had a lower appendicular skeletal muscle mass index than those who were physically inactive. Protein intakes above the present recommendations were associated with benefits to obese subjects only. The appendicular skeletal muscle mass index of non-obese subjects who performed vigorous aerobic activities was consistently high; in obese subjects, it varied with protein intake. High-protein intake was associated with a modest increase in the appendicular skeletal muscle mass index in non-obese, physically inactive subjects. The present findings reinforce the idea that muscle-strengthening exercise preserves muscle when combined with adequate dietary protein. Vigorous aerobic activity may also help.

Oral intake of Lactobacillus pentosus strain b240 (b240) has been shown to enhance the secretion of salivary secretory IgA in elderly adults. However, its clinical benefits remain to be determined. We tested the hypothesis that b240 exerts a protective effect against the common cold in elderly adults. The design of the present study was a randomised, double-blind, placebo-controlled trial (RCT) with parallel three-group comparison. For this purpose, 300 eligible elderly adults were randomly allocated to one of three groups, namely a placebo, low-dose or high-dose b240 group. Participants in the low-dose and high-dose b240 groups were given tablets containing 2 × 109 or 2 × 1010 cells, respectively, of heat-killed b240, while those in the placebo group were given tablets without b240. Each group consumed their respective tablets once daily for 20 weeks. The common cold was assessed on the basis of a diary. Change in quality of life was evaluated using the SF-36®. Of the total participants, 280 completed the 20-week RCT. The accumulated incidence rate of the common cold was 47·3, 34·8 and 29·0 % for the placebo, low-dose b240 and high-dose b240 groups, respectively (P for trend = 0·012). Lower incidence rates were consistently observed throughout the experimental period in the b240 groups (log-rank test, P= 0·034). General health perception, as determined by the SF-36®, dose-dependently increased in the b240 groups (P for trend = 0·016). In conclusion, oral intake of b240 significantly reduced the incidence rate of the common cold in elderly adults, indicating that b240 might be useful in improving resistance against infection through mucosal immunity.

The present randomised, double-blind, placebo-controlled study was conducted to determine whether consumption of probiotic Lactobacillus rhamnosus GG (GG) would lead to the recovery of GG in tonsil tissue. After 3 weeks' daily consumption of GG as a single strain (n 20), GG as a part of a multispecies combination (n 17) or placebo (n 20), tonsil tissue samples were collected from fifty-seven young adults during tonsillectomy due to chronic or recurrent tonsillitis. Strain-specific real-time PCR was used to detect GG in the tonsil tissue. GG was recovered in the tonsil sample of 40 % of the subjects in the GG group, 41 % in the multispecies group and 30 % in the placebo group (P value between groups 0·79). In all subjects with positive recovery of GG in the tonsil tissue, GG was also recovered in the faecal sample taken at the start of the intervention and at the time of the tissue sample collection, which indicates more persistent adherence of the probiotic. To conclude, GG can be recovered from tonsil tissue after oral administration as a single-strain probiotic or as a part of a multispecies probiotic combination. The present results suggest that individual variation exists in the ability of GG to adhere to tonsil tissue. Persistence of GG appears to be high in tonsil tissue as well, in addition to persistence in faecal samples, which has been demonstrated previously. Further clinical trials are warranted to evaluate whether probiotic adherence in the tonsil tissue could have a role in respiratory symptom prevalence.

Intake of marine-based n-3 fatty acids (EPA, docosapentaenoic acid and DHA) is recommended to prevent CHD. Stearidonic acid (SDA), a plant-based n-3 fatty acid, is a precursor of EPA and may be more readily converted to EPA than α-linolenic acid (ALA). While transgenic soyabeans might supply SDA at low cost, it is unclear whether SDA is associated with CHD risk. Furthermore, associations of other n-3 fatty acids with CHD risk remain inconsistent. The present ancillary study examined the association of erythrocyte SDA as well as other n-3 fatty acids with the risk of CHD. In a prospective nested case–control study of the Physicians' Health Study, we randomly selected 1000 pairs of incident CHD with matching controls. Erythrocyte fatty acids were measured using GC. We used conditional logistic regression to estimate relative risks. Mean age was 68·7 (sd 8·7) years. In a multivariable model controlling for matching factors and established CHD risk factors, OR for CHD for each standard deviation increase of log-SDA was 1·03 (95 % CI 0·90, 1·18). Corresponding values for log-ALA and log-marine n-3 fatty acids were 1·04 (95 % CI 0·94, 1·16) and 0·97 (95 % CI 0·88, 1·07), respectively. In conclusion, the present data did not show an association among erythrocyte SDA, ALA or marine n-3 fatty acids and the risk of CHD in male physicians.

Thyroid cancer is the most common cancer among Korean women. However, there are few data on dietary factors related to thyroid cancer risk. The objective of the present study was to evaluate the association between raw vegetables and fruits intake and thyroid cancer in a case–control study. We included 111 histologically confirmed malignant thyroid cancer cases and 115 benign cases. Controls who did not have nodules in thyroid ultrasonography were matched to cases by age ( ± 2 years). Food and nutrient intakes were estimated using a quantitative FFQ with 121 items. Conditional logistic regression analysis was used to obtain OR and corresponding 95 % CI. The intake of total vegetables was not associated with malignant thyroid cancer, but inversely associated with benign cases. High raw vegetable intake was inversely associated with thyroid cancer risk both in malignant and benign cases (P for trend = 0·01 in both malignant and benign cases). Among fruits, persimmon intake had an inverse association with thyroid cancer risk in both malignant and benign cases (P for trend = 0·06 in malignant cases; P for trend = 0·01 in benign cases) and tangerine intake had an inverse association in malignant cases (P for trend = 0·03). The frequency of consumption of raw vegetables and persimmon also had a consistent inverse association in both malignant and benign cases. These results suggest that high consumption of raw vegetables, persimmons and tangerines may decrease thyroid cancer risk and help prevent early-stage thyroid cancer.

Previous studies have indicated that supplementation with probiotic bacteria may improve lipid metabolism. The present study was aimed at investigating the effects of a mixture of three strains of Lactobacillus plantarum (CECT 7527, CECT 7528 and CECT 7529) on cholesterol-lowering efficacy in hypercholesterolaemic patients. A total of sixty volunteers (thirty participants in the placebo group and thirty counterparts in the L. plantarum group), aged 18–65 years old, participated in a controlled, randomised, double-blind trial. The study group received one capsule daily containing 1·2 × 109 colony-forming units of Lactobacillus strains in a unique dose; the placebo group consumed the same product without bacteria for 12 weeks. A significant reduction of 13·6 % in plasma total cholesterol (TC) levels was observed after 12 weeks of consumption in the L. plantarum group when compared with the placebo group. The lipidic outcomes were also analysed based on TC values at baseline: low initial values (LIV, 2000–2500 mg/l) v. high initial values (HIV, 2510–3000 mg/l). In the HIV group, the L. plantarum treatment showed a reduction after 12 weeks of consumption compared with the placebo group in TC, LDL-cholesterol (LDL-C) and oxidised LDL-C (17·4, 17·6 and 15·6 %, respectively). In the LIV, the L. plantarum treatment only showed a reduction after 12 weeks of consumption when compared with the placebo group in TC (9·4 %). The present results showed that the biofunctionality of L. plantarum (CECT 7527, CECT 7528 and CECT 7529) is proportional to the cardiovascular risk of the patient, having a better effect in patients with higher levels of cholesterol.

Cancer patients receiving chemotherapy have a high risk of malnutrition secondary to the disease and treatment, and 40–80 % of cancer patients suffer from different degrees of malnutrition, depending on tumour subtype, location, staging and treatment strategy. Malnutrition in cancer patients affects the patient's overall condition, and it increases the number of complications, the adverse effects of chemotherapy and reduces the quality of life. The aim of the present study was to evaluate weight-loss prevalence depending on the tumour site and the gastrointestinal (GI) symptoms of oncology patients receiving chemotherapy. We included 191 cancer patients receiving chemotherapy. Files of all patients were reviewed to identify symptoms that might potentially influence weight loss. The nutritional status of all patients was also determined. The cancer sites in the patients were as follows: breast (31·9 %); non-colorectal GI (18·3 %); colorectal (10·4 %); lung (5·8 %); haematological (13·1 %); others (20·5 %). Of these patients, 58 % experienced some degree of weight loss, and its prevalence was higher among the non-colorectal GI and lung cancer patients. Common symptoms included nausea (59·6 %), anorexia (46 %) and constipation (31·9 %). A higher proportion of patients with ≥ 5 % weight loss experienced anorexia, nausea and vomiting (OR 9·5, 2·15 and 6·1, respectively). In conclusion, these results indicate that GI symptoms can influence weight loss in cancer patients, and they should be included in early nutritional evaluations.

Previous studies on individual foods and nutrients and Parkinson's disease (PD) risk have been inconsistent. Furthermore, only one study has examined the association between the quality of diet and PD. We investigated the prediction of food groups and diet quality on PD in the Finnish Mobile Clinic Survey (1966–72). The population comprised 4524 individuals, aged 40–79 years and free from PD at baseline. Data collection included health examinations, a questionnaire and a 1-year dietary history interview. A modified Alternate Healthy Eating Index was formed to assess diet quality. Statistical analyses were based on Cox's model. During a 41-year follow-up, eighty-five incident cases of PD occurred. No statistically significant associations were found between PD incidence and most of the food groups examined. A few exceptions were fruits and berries in men and milk in women, which showed positive associations. An inverse association between the intake of meat products and PD was found in women. The diet quality index did not predict PD, the adjusted relative risk between the highest and lowest quartiles being 1·83 (95 % CI 0·65, 5·18) in men and 0·97 (95 % CI 0·38, 2·48) in women. The present study suggests that since most of the single food groups or the quality of diet did not predict PD occurrence, the role of diet is apparently rather modest.

Non-alcoholic fatty liver disease is associated with insulin resistance and dyslipidaemia and can progress to steatohepatitis and cirrhosis. We sought to determine whether dietary fat and saturated fat content alter liver fat in the absence of weight change in an older population. Liver fat was quantified by magnetic resonance spectroscopy before and after 4 weeks on an isoenergetic low-fat/low-saturated fat/low-glycaemic index (LGI) (LSAT: 23 % fat/7 % saturated fat/GI < 55) or a high-fat/high-saturated fat/high-GI (HSAT: 43 % fat/24 % saturated fat/GI>70) diet in older subjects. In the present study, twenty subjects (seven males/thirteen females; age 69·3 (sem 1·6) years, BMI 26·9 (sem 0·8) kg/m2) were randomised to the LSAT diet and fifteen subjects (six males/nine females; age 68·6 (sem 1·8) years, BMI 28·1 (sem 0·9) kg/m2) to the HSAT diet. Weight remained stable. Liver fat decreased significantly on the LSAT diet (median 2·2 (interquartile range (IQR) 3·1) to 1·7 (IQR 1·8) %, P= 0·002) but did not change on the HSAT diet (median 1·2 (IQR 4·1) to 1·6 (IQR 3·9) %). The LSAT diet lowered fasting glucose and total cholesterol, HDL-cholesterol and LDL-cholesterol and raised TAG (P< 0·05), while the HSAT diet had no effect on glucose or HDL-cholesterol but increased total cholesterol and LDL-cholesterol (P< 0·05). Fasting insulin and homeostasis model of insulin resistance did not change significantly on either diet, but the Matsuda index of insulin sensitivity improved on the LSAT diet (P< 0·05). Assignment to the LSAT v. HSAT diet was a predictor of changes in lipid parameters but not liver fat. We conclude that diet composition may be an important factor in the accumulation of liver fat, with a low-fat/low-saturated fat/LGI diet being beneficial.

Type 2 diabetes (T2D) is a highly prevalent but preventable disorder. We assessed the association between an a priori Mediterranean diet (MeDiet) score and fasting glucose and insulin at baseline and incident T2D after a 6-year follow-up in the Multi-Ethnic Study of Atherosclerosis. Dietary intake was measured at baseline using a 127-item FFQ in 5390 men and women aged 45–84 years free of prevalent diabetes and clinical CVD. A MeDiet score was created based on the intake of ten food components: vegetables; whole grains; nuts; legumes; fruits; ratio of monounsaturated:saturated fat; red and processed meat; dairy products; fish; alcohol. Multivariable linear and proportional hazards models were used to estimate the association of the MeDiet, categorised in quintiles, with baseline insulin and glucose, and incident diabetes, respectively. The models were adjusted for demographic, physiological and behavioural characteristics. After multivariable adjustment, individuals with a higher MeDiet score had lower baseline mean insulin levels (Q1: 5·8 (95 % CI 5·6, 6·0) μmol/l; Q5: 4·8 (95 % CI 4·6, 5·0) μmol/l; P for trend < 0·0001). A higher MeDiet score was also associated with significantly lower glucose levels after basic adjustment, but was attenuated after adjustment for waist circumference. During the follow-up, 412 incident diabetes events accrued. The MeDiet was not significantly related to the risk of incident diabetes (P for trend = 0·64). In summary, greater consistency with a Mediterranean-style diet, reflected by a higher a priori MeDiet score, was cross-sectionally associated with lower insulin levels among non-diabetics, and with lower blood glucose before adjustment for obesity, but not with a lower incidence of diabetes.

Intake of specially processed cereal (SPC) stimulates endogenous antisecretory factor (AF) activity, and SPC intake has proven to be beneficial for a number of clinical conditions. The aim of the present study was to investigate the dosage relationship between SPC intake and plasma AF activity and to further correlate achieved AF levels to a biological effect. SPC was fed to rats in concentrations of 5, 10 or 15 % for 2 weeks. A further group was fed 5 % SPC for 4 weeks. AF activity and the complement factors C3c and factor H were analysed in plasma after the feeding period. Groups of rats fed the various SPC concentrations were subjected to a standardised freezing brain injury, known to induce increases in intracranial pressure (ICP). The AF activity in plasma increased after intake of SPC, in a dosage- and time-dependent manner. The complement factors C3c and factor H increased in a time-dependent manner. Measurements of ICP in animals fed with SPC prior to the brain injury showed that the ICP was significantly lower, compared with that of injured rats fed with a standard feed, and that the change was dose and time dependent. AF activity increases, in a dosage- and time-dependent manner, after intake of SPC. The inverse relationship between ICP after a head injury and the percentage of SPC in the feed indicate that the protective effect is, to a large extent, due to AF.

The aim of the present study was to describe the present knowledge of healthcare professionals and the practices surrounding enteral feeding in the UK and Irish paediatric intensive care unit (PICU) and propose recommendations for practice and research. A cross-sectional (thirty-four item) survey was sent to all PICU listed in the Paediatric Intensive Care Audit Network (PICANET) database (http://www.picanet.org.uk) in November 2010. The overall PICU response rate was 90 % (27/30 PICU; 108 individual responses in total). The overall breakdown of the professional groups was 59 % nursing staff (most were children's nurses), 27 % medical staff, 13 % dietitians and 1 % physician assistants. Most units (96 %) had some written guidance (although brief and generic) on enteral nutrition (EN); 85 % of staff, across all professional groups (P= 0·672), thought that guidelines helped to improve energy delivery in the PICU. Factors contributing to reduced energy delivery included: fluid-restrictive policies (60 %), the child just being ‘too ill’ to feed (17 %), surgical post-operative orders (16 %), nursing staff being too slow in starting feeds (7 %), frequent procedures requiring fasting (7 %) and haemodynamic instability (7 %). What constituted an ‘acceptable’ level of gastric residual volume (GRV) varied markedly across respondents, but GRV featured prominently in the decision to both stop EN and to determine feed tolerance and was similar for all professional groups. There was considerable variation across respondents about which procedures required fasting and the duration of this fasting. The present survey has highlighted the variability of the present enteral feeding practices across the UK and Ireland, particularly with regard to the use of GRV and fasting for procedures. The present study highlights a number of recommendations for both practice and research.

We sought to determine whether consumption of blueberries could reduce postprandial oxidation when consumed with a typical high-carbohydrate, low-fat breakfast. Participants (n 14) received each of the three treatments over 3 weeks in a cross-over design. Treatments consisted of a high blueberry dose (75 g), a low blueberry dose (35 g) and a control (ascorbic acid and sugar content matching that of the high blueberry dose). Serum oxygen radical absorbance capacity (ORAC), serum lipoprotein oxidation (LO) and serum ascorbate, urate and glucose were measured at fasting, and at 1, 2 and 3 h after sample consumption. The mean serum ORAC was significantly higher in the 75 g group than in the control group during the first 2 h postprandially, while serum LO lag time showed a significant trend over the 3 h for both blueberry doses. Changes in serum ascorbate, urate and glucose were not significantly different among the groups. To our knowledge, this is the first report that has demonstrated that increased serum antioxidant capacity is not attributable to the fructose or ascorbate content of blueberries. In summary, a practically consumable quantity of blueberries (75 g) can provide statistically significant oxidative protection in vivo after a high-carbohydrate, low-fat breakfast. Though not tested directly, it is likely that the effects are due to phenolic compounds, either directly or indirectly, as they are a major family of compounds in blueberries with potential bioactive activity.

Vegetable and fruit intake has been associated with a reduced risk of cancer and CVD, but its relationship to the risk of type 2 diabetes remains unclear. We prospectively examined the association between vegetable and fruit intake and the incidence of type 2 diabetes. Subjects were 21 269 men and 27 168 women aged 45–75 years who participated in the second survey of the Japan Public Health Center-based Prospective Study and had no history of type 2 diabetes or other serious diseases. Intake of vegetables and fruit was estimated using a validated 147-item FFQ. The OR of self-reported, physician-diagnosed type 2 diabetes over 5 years was estimated using multiple logistic regression. A total of 896 newly diagnosed cases of type 2 diabetes were self-reported. Intake of vegetables and fruit combined or fruit only was not associated with a lower risk of type 2 diabetes. However, there was an approximately 20 %, albeit not statistically significant, risk reduction associated with vegetables (men only), green leafy vegetables (men and women) and cruciferous vegetables (men only). Such risk reduction was somewhat greater among obese or smoking men than non-obese or non-smoking men. In conclusion, although a small beneficial effect of vegetables, especially green leafy and cruciferous vegetables, cannot be excluded, vegetable and fruit intake may not be appreciably associated with the risk of type 2 diabetes for Japanese adults.

Choline and betaine are nutrients involved in one-carbon metabolism. Choline is essential for neurodevelopment and brain function. We studied the associations between cognitive function and plasma concentrations of free choline and betaine. In a cross-sectional study, 2195 subjects (55 % women), aged 70–74 years, underwent extensive cognitive testing including the Kendrick Object Learning Test (KOLT), Trail Making Test (part A, TMT-A), modified versions of the Digit Symbol Test (m-DST), Block Design (m-BD), Mini-Mental State Examination (m-MMSE) and Controlled Oral Word Association Test (COWAT). Compared with low concentrations, high choline (>8·4 μmol/l) was associated with better test scores in the TMT-A (56·0 v. 61·5, P= 0·004), m-DST (10·5 v. 9·8, P= 0·005) and m-MMSE (11·5 v. 11·4, P= 0·01). A generalised additive regression model showed a positive dose–response relationship between the m-MMSE and choline (P= 0·012 from a corresponding linear regression model). Betaine was associated with the KOLT, TMT-A and COWAT, but after adjustments for potential confounders, the associations lost significance. Risk ratios (RR) for poor test performance roughly tripled when low choline was combined with either low plasma vitamin B12 ( ≤ 257 pmol/l) concentrations (RRKOLT= 2·6, 95 % CI 1·1, 6·1; RRm-MMSE= 2·7, 95 % CI 1·1, 6·6; RRCOWAT= 3·1, 95 % CI 1·4, 7·2) or high methylmalonic acid (MMA) ( ≥ 3·95 μmol/l) concentrations (RRm-BD= 2·8, 95 % CI 1·3, 6·1). Low betaine ( ≤ 31·1 μmol/l) combined with high MMA was associated with elevated RR on KOLT (RRKOLT= 2·5, 95 % CI 1·0, 6·2). Low plasma free choline concentrations are associated with poor cognitive performance. There were significant interactions between low choline or betaine and low vitamin B12 or high MMA on cognitive performance.

Little is known about changes in dietary patterns over time. The present study aims to derive dietary patterns using cluster analysis at three ages in children and track these patterns over time. In all, 3 d diet diaries were completed for children from the Avon Longitudinal Study of Parents and Children at 7, 10 and 13 years. Children were grouped based on the similarities between average weight consumed (g/d) of sixty-two food groups using k-means cluster analysis. A total of four clusters were obtained at each age, with very similar patterns being described at each time point: Processed (high consumption of processed foods, chips and soft drinks), Healthy (high consumption of high-fibre bread, fruit, vegetables and water), Traditional (high consumption of meat, potatoes and vegetables) and Packed Lunch (high consumption of white bread, sandwich fillings and snacks). The number of children remaining in the same cluster at different ages was reasonably high: 50 and 43 % of children in the Healthy and Processed clusters, respectively, at age 7 years were in the same clusters at age 13 years. Maternal education was the strongest predictor of remaining in the Healthy cluster at each time point – children whose mothers had the highest level of education were nine times more likely to remain in that cluster compared to those with the lowest. Cluster analysis provides a simple way of examining changes in dietary patterns over time, and similar underlying patterns of diet at two ages during late childhood, that persisted through to early adolescence.

The validity of using FFQ to assess dietary lignans is uncertain. We aimed to validate the use of FFQ for the assessment of dietary intake of lignans compared to the serum biomarker enterolactone, the main product of dietary lignans' metabolism in human subjects. A random sample of women, aged 55–75 years, from the Swedish Mammography Cohort was selected. Information from two FFQ, the FFQ-87 (sixty-seven food items) and the FFQ-97 (ninety-three food items), and blood samples were collected. Dietary intake of lignans (secoisolariciresinol, matairesinol, lariciresinol, pinoresinol, medioresinol and syringaresinol) was assessed by the FFQ. Serum concentrations of enterolactone were analysed by time-resolved fluoroimmunoassay. The correlation coefficient between energy-adjusted lignan intake and serum enterolactone was estimated in crude and multivariable-adjusted models, taking into account the factors potentially influencing the serum enterolactone. Among the 135 participants aged 55–75 years, with a mean BMI of 26·7 kg/m2, the average energy-adjusted intake of total lignans was 1616 (sd 424) and 1516 (sd 409) μg/d according to the FFQ-87 (forty-five food items containing lignans) and the FFQ-97 (sixty-five food items containing lignans), respectively. The mean concentration of serum enterolactone was 23·2 (sd 15·4) nmol/l. The adjusted Pearson's correlation between dietary intake of lignans assessed by the FFQ-97 and serum enterolactone was statistically significant (r 0·22, P= 0·01). No significant correlation was observed for the FFQ-87 (r 0·09, P= 0·30). The present study indicates that the FFQ-97 might be better than the FFQ-87 for assessing dietary intake of lignans, although the correlation was low.

Oxidative stress is detrimental to animals. Previous studies have indicated that arginine (Arg) may function as a potential substance against oxidative stress. The present study was conducted to explore the potential mechanisms behind the Arg-induced protective effects against oxidative stress in piglets. A total of thirty-six piglets were randomly allocated to six groups with six replicates per group. Piglets were subjected to three dietary treatments (namely two groups per treatment) in week 1 and fed with a basal diet (ArgL) or the basal diet supplemented with 0·8 % (ArgM) or 1·6 % (ArgH) l-Arg, respectively. On day 8, piglets were injected intraperitoneally either with diquat (10 mg/kg body weight) or sterile saline. The whole trial lasted 11 d. Results showed that dietary Arg supplementation did not affect growth performance in week 1. Oxidative stress significantly decreased the growth performance of piglets (P< 0·05). However, ArgH attenuated the negative effects of oxidative stress on feed intake and significantly increased the total antioxidant capacity in the liver under oxidative stress (P< 0·05). Both ArgM and ArgH enhanced the activities of plasma glutathione peroxidases and superoxide dismutases and decreased the IL-6 and TNF-α mRNA level in the liver under oxidative stress (P< 0·05). The present study not only shows that Arg can function as a potential nutrient to alleviate oxidative stress responses through the enhancement of antioxidant capacity, and inhibition of the expression of inflammatory cytokines, but the results also suggest that alleviation of oxidative stress responses using dietary nutrient components deserves further attention in the future.