Soya–dairy protein blends can extend post-exercise muscle synthesis in young people more than whey protein control. Older adults differ metabolically from young people, and their ability to absorb amino acids from dietary protein is important for muscle function. The objective was to determine how protein source affects postprandial plasma amino acid response and/or metabolomic profile in older adults via a single-blind randomised crossover trial (n 16, males 50–70 years), using three nutritionally equivalent meal replacement drinks containing 30 g protein, from a 1:1 (mass ratio) soya:dairy blend, a 1:2 soya:dairy blend or whey protein. The outcome measures were plasma amino acid concentrations at 0–300 min postprandially and urine metabolomic fingerprint. Soya:dairy drinks gave similar amino acid response in plasma over time and similar urinary metabolite fingerprints. However, there were significant differences in plasma amino acid concentrations and AUC values for the soya:dairy drinks v. the whey protein drink. AUC for Leu, Trp and Lys was lower and AUC for Phe and Pro was higher for the soya:dairy drinks. Differences partly reflected the amino acid profiles of the drinks, but overall plasma amino acid response patterns were qualitatively unchanged. Plasma amino acid differences between the whey protein drink and the soya:dairy blends were reflected in urine metabolite patterns. In conclusion, postprandial plasma amino acid responses were broadly similar, irrespective of protein source (and soya:dairy ratio). There were significant differences for some plasma amino acid concentrations, reflecting different amino acid profiles of the protein source and influencing urine metabolite fingerprints.

Vitamin D deficiency is common in Irish adults, though there is limited research on its determinants, knowledge of vitamin D or indications for testing. We aimed to explore the determinants of vitamin D status in adults and examine knowledge and reasons for testing. The study population comprised adults who had serum 25-hydroxyvitamin D tested by general practitioners request at a Dublin Hospital in 2020. Questionnaires detailing dietary intake, sun exposure, ethnicity, biophysical factors and vitamin D knowledge were sent to a sample stratified by age, sex and vitamin D status. In total, there were 383 participants, mean age 56·0 (sd 16·6) years. Wintertime deficiency disproportionally affected non-white v. white (60 % v. 24 %, P < 0·001). The greatest predictors of deficiency were low vitamin D intake (< 10 μg/d) (P < 0·001) and non-white ethnicity (P = 0·006), followed by sun avoidance (P = 0·022). It was also more prevalent in those with lower body exposure when outdoors. The majority (86 %) identified vitamin D as important for bone health. However, 40 % were tested for non-clinical indications and half were not aware of the recommended daily allowance (RDA). Low vitamin D intake was the most important determinant of deficiency, but ethnicity and sun exposure habits were also significant predictors. The majority had no clear indication for testing and were not aware of the RDA. Public health policies to improve knowledge and vitamin D intake, especially for those of non-white ethnicity and with reduced sun exposure, should be considered.

Vitamin C-rich foods can improve mood; however, the timecourse of these benefits is unknown. This study utilised intensive longitudinal smartphone surveys from a three-armed placebo-controlled trial to determine mood-related changes following supplementation with vitamin C (250 mg tablet/d), kiwifruit (2 SunGold™ kiwifruit/d) or a placebo (1 tablet/d). Secondary data were analysed from the KiwiC for Vitality trial (Trial ID: ACTRN12617001031358). Adults (n 155, 63 % female, aged 18–35 years) with low plasma vitamin C (<40 μmol/l) completed a 14-d lead-in, 28-d intervention and 14-d washout. Participants self-reported vitality (SF-36), mood (POMS total mood disturbance), flourishing (flourishing scale), sleep quality, sleep quantity and physical activity every second day using smartphone surveys. Plasma vitamin C, measured fortnightly, reached saturation after 2 weeks of vitamin C or kiwifruit supplementation. Kiwifruit supplementation improved vitality and mood within 4 days, peaking around 14–16 days, and improved flourishing from day 14. Vitamin C marginally improved mood until day 12. Incremental AUC analyses revealed significant overall effects of kiwifruit consumption on vitality and mood compared with placebo, which were stronger than effects for vitamin C tablets, but attenuated when adjusting for covariates. Sensitivity analyses of participants with low baseline vitamin C status revealed improved mood (vitamin C and kiwifruit) and flourishing (kiwifruit only). This is the first study to use intensive smartphone surveys to model the day-to-day timecourse of mood-related states following vitamin C intervention and highlights the value of using smartphone surveys to reveal the temporal changes in mood-related outcomes following nutrient supplementation.

The associations of different lipid measures and related indices with incident hypertension during a median follow-up of 12·89 years were examined. Fasting levels of total cholesterol (TC), TAG, HDL-cholesterol and LDL-cholesterol, and related indices (TC/HDL-cholesterol and TAG/HDL-cholesterol) were determined in 7335 Iranian adults (men = 3270) free of hypertension, aged 39·0 (sd 13·2) years. Multivariate Cox proportional hazard regression was applied and lipid parameters were considered either as categorical or continuous variables. During follow-up, 2413 (men = 1126) participants experienced hypertension. Using the first quartile as reference, significant trends were found between quartiles of TAG, HDL-cholesterol, TC/HDL-cholesterol and TAG/HDL-cholesterol in multivariate models; moreover considering these measures as continuous variables, a 1 sd increase in each of these parameters was significantly associated with the risk of incident hypertension; the corresponding hazard ratios and CI were 1·06 (95 % CI 1·02, 1·10), 0·94 (95 % CI 0·89, 0·98), 1·04 (95 % CI 1·01, 1·09) and 1·04 (95 % CI 1·01, 1·07), respectively. The associations between lipid measures and incident hypertension did not change after excluding lipid lowering drug users and those with type 2 diabetes mellitus and these associations were independent of the categories of baseline blood pressure (P for interaction > 0·08). These findings indicate that TAG, TAG/HDL-cholesterol and TC/HDL-cholesterol were independently associated with higher risk, while HDL-cholesterol was associated with lower risk of incident hypertension.

This study examined differences in food groups consumed at eating occasions by the level of adherence to dietary guidelines in Australian adults (≤19 years) and whether consumption differed with respect to age, sex and education levels. Secondary analysis of the 2011–2012 National Nutrition and Physical Activity Survey (n 9054) was performed, using one 24-h dietary recall with self-reported eating occasions. Dietary Guideline Index scores were used to assess adherence to the 2013 Australian Dietary Guidelines. Mean differences (95 % CI) in servings of the five food groups and discretionary foods at eating occasions were estimated for adults with higher and lower diet quality, stratified by sex, age group and education. Using survey-based t-tests, differences of at least half a serving with P values < 0·05 were considered meaningful. Compared with adults with lower diet quality, women and men aged 19–50 years with higher diet quality consumed more serves of vegetables at dinner (mean difference (95 % CI), women; 1·0; 95 % CI (0·7, 1·2); men: 0·9; 95 % CI (0·6, 1·3)) and fewer serves of discretionary foods at snacks (women: −0·7; 95 % CI (−0·9, −0·5); men: −1·0; 95 % CI (−1·4, −0·7). Other food groups, such as grains, dairy products and alternatives, meats and alternatives, were not significantly different between adults with lower and higher diet quality, across any eating occasions and age groups. Discretionary food intake at lunch, dinner and snacks was consistently greater among adults with lower diet quality, regardless of education level. Our findings identify dinner and snacks as opportunities to increase vegetable intake and reduce discretionary food intake, respectively.

Nuts are an important component of a healthy diet, but little has been known about their effects on muscle health. Therefore, this study examined the association between nut consumption and low muscle strength among Korean adults. This cross-sectional analysis was conducted using single 24-h recall and handgrip strength data from 3962 younger adults 19–39 years, 6921 middle-aged adults 40–64 years and 3961 older adults ≥65 years participated in the seventh cycle (2016–2018) of the Korea National Health and Nutrition Examination Survey. Low muscle strength was defined as handgrip strength <28 kg for men and <18 kg for women. Sex-specific OR were obtained for younger, middle-aged and older adults using multivariable logistic regression analyses. About one in four Korean adults were consuming nuts (using a culinary definition) with peanut being the most frequently consumed type. After adjustment for age, BMI, total energy intake, household income, alcohol consumption, smoking, resistance exercise, medical history and dietary protein intake, nut consumption was associated with the lower risk of low muscle strength among older adults ≥65 years (men: OR 0·55, 95 % CI (0·38, 0·79); women: OR 0·69, 95 % CI (0·51, 0·93)); however, this association was not observed among younger adults 19–39 years or middle-aged adults 40–64 years. Our results suggest that consuming nuts might be beneficial in lowering the risk of low muscle strength among Korean older adults.

The purpose of this study was to determine whether n-3 PUFA result in an effect on endothelial function that is in addition to that of acute exercise. For 4 weeks, male Sprague–Dawley rats were subjected to a diet based on n-3 PUFA or a standard diet. In each diet group, ten rats were submitted to an acute treadmill exercise while the remaining ten acted as sedentary controls. The running speed was progressively increased until the animals were exhausted. Endothelial function was then assessed by measuring isometric tension in rings of the thoracic aorta. In vessels precontracted with 0·1 μm-phenylephrine, responses to acetylcholine (ACh) were significantly improved following acute exercise in all diet groups. When PUFA supplementation was compared to the standard diet no significant difference was found in response to ACh, either at rest or after an acute exercise. Pretreatment of rings with Nω-nitro-l-arginine methyl esther (50 μm) inhibited the ACh-mediated vasorelaxation in all groups. Response to 10 μm-nifedipine, an L-type Ca2+ channel antagonist, was similarly enhanced after acute exercise in both standard and PUFA diets. Furthermore, response to 0·01 μm-nifedipine was significantly higher after acute exercise only in the PUFA diet. In conclusion, in our ‘healthy’ rat model with ‘normal’ baseline endothelial function, acute exercise improves response to ACh while PUFA supplementation alone or in combination with acute exercise has no effect on endothelium-dependent vasorelaxation. However, PUFA may potentiate the acute exercise effect on smooth muscle cell relaxation via L-type Ca2+ channel modifications.

1. Sheep were injected with varying doses of urea into the rumen and changes in the amount of saliva secreted from one parotid gland were studied. When the dose of urea was 0.1–0.2 g/kg, the secretion under- went no change. When the dose was 0.3 g/kg. the secretion was inhibited. When the dose was 0.4 or 0.5 g/kg, there was a marked inhibition in the secretion.

2. There was a close relationship between the ammonia level of the jugular blood and the inhibition of salivary secretion. When the ammonia level exceeded approximately 0.28 mmol/l, the secretion was inhibited abruptly.

3. Salivary secretion and rumen movement were inhibited when the blood ammonia level exceeded 0.28 mmoljl, after injection of ammonium acetate into the jugular vein.

4. Based on the results mentioned previously, the mechanism of inhibition on the secretion of parotid saliva is discussed in relation to the domestic ruminant in which urea had been injected into the rumen.

The present study examines the effects of protein- and energy-type malnutrition in combination with Zn deficiency on the growth, serum insulin-like growth factor-1 (IGF-1), gastrocnemius muscle mass and fibre diameter of growing rats during a deficiency phase followed by nutritional rehabilitation. Rats (3-weeks old) were randomly assigned to baseline, or Zn-deficient (Z, < 1 mg Zn/kg), protein-deficient (P, 20 g protein/kg), combined Zn- and protein-deficient (ZP), energy-deficient (E, feed intake pair-fed to Z) or control (C, 30 mg Zn/kg and 170 g protein/kg) groups for a 3-week deficiency phase, followed by a 3-week repletion phase with the control diet. ATPase histochemical staining at pH 9·4 was used to differentiate type 1 and type 2 muscle fibres. After the deficiency phase, the ZP and P groups had lower body weight and smaller gastrocnemius muscle mass than the Z and E groups. Type 1 and 2 muscle fibre diameters (T1- and T2-MFD, respectively) were reduced in the ZP, P and Z groups compared with the E and C groups. Serum Zn was reduced in the ZP, P and Z groups, but serum IGF-1 was lowest in the Z and E groups. After the repletion phase, T1-MFD did not recover in the P and E groups nor T2-MFD in the P group, despite the P and E groups having a better recovery of body weight. In summary, previous protein deficiency, but not Zn deficiency, limited the recovery of both T1- and T2-MFD during nutritional repletion. The quality of skeletal muscle recovery in the malnourished groups was not associated with body weight, muscle mass, serum Zn or IGF-1 concentrations.

Given the dynamic characteristic of an individual’s drinking behaviours, comprehensive consideration of alcohol consumption variation using repeated measures may improve insight into the nature of its association with blood pressure (BP) change. We examined the association between longitudinal alcohol consumption (trajectory and quantity) and changes in BP and pulse pressure (PP) among Korean aged ≥ 40 years living in rural areas. Totally, 1682 hypertension-free participants who completed all three health examinations (median, 5·3 years) were included. All three visits were used to determine the cumulative trajectory of and quantity of alcohol consumption and the latest two visits and the last visit were used for the recent trajectory and the most recent quantity of alcohol consumption, respectively. Changes in BP and PP from the baseline to the third visit were used as outcome. In men, ≥30 ml/d cumulative average alcohol consumption was associated with the greatest increase in systolic BP (SBP) in both baseline outcome-unadjusted (2·9 mmHg, P = 0·032) and -adjusted models (3·6 mmHg, P = 0·001), and the given association for the most recent alcohol consumption was observed in the baseline outcome-adjusted model (3·9 mmHg, P = 0·003). For PP, similar associations were observed only in the baseline outcome-adjusted model. No meaningful associations in diastolic BP in men and any BP or PP in women existed. The quantity of alcohol consumption rather than the trajectory may be significantly related to raised SBP, and a possible short-term influence of the most recent alcohol consumption may exist when baseline SBP is adjusted in men.

The effectiveness of conjugated linoleic acid (CLA) as a weight-loss nutraceutical continues to be debatable, suggesting that there may be value in exploring the physiological effects of the lesser-known isomers. The effects of the minor isomer, trans-8, cis-10 (t8, c10)-CLA, in the form of an equimolar mixture with the cis-9, trans-11 (c9, t11) isomer, on body weight and body composition, circulating glucose and lipid concentrations, and liver weights were studied in sixty male Syrian golden hamsters. Animals were randomised to receive for 28 d a semi-purified, hypercholesterolaemic diet (5 % dietary fat and 0·25 % cholesterol) supplemented at the 2 % level with either the t8, c10+c9, t11-CLA mixture, c9, t11-CLA or trans-10, cis-12 (t10, c12)-CLA replacing lard and safflower-seed oil (control). Results show that compared with control, the t8, c10+c9, t11-CLA mixture and t10, c12-CLA-fed animals had lower (P < 0·0001) fat mass following supplementation. Animals consuming t10, c12-CLA also possessed higher lean mass compared with control and c9, t11-CLA groups (P < 0·001). However, the livers of these animals were larger (P < 0·0001) compared with those in the control and other CLA groups. Body weights of the hamsters did not differ across the experimental groups. CLA treatments had no effect on serum glucose or lipid profile, except for inducing higher (P < 0·05) non-HDL-cholesterol concentration with t10, c12-CLA compared with the c9, t11 isomer. Overall, these results indicate that in male hamsters fed a hypercholesterolaemic diet, the t8, c10+c9, t11-CLA mixture does not have an impact on blood lipid profile, but is able to effectively reduce fat mass, without incurring an accompanying liver enlargement.