Do high-protein diets have the potential to reduce gut barrier function in a sex-dependent manner?

PURPOSE: Impaired gut barrier function is associated with systemic inflammation and many chronic diseases. Undigested dietary proteins are fermented in the colon by the gut microbiota which produces nitrogenous metabolites shown to reduce barrier function in vitro. With growing evidence of sex-based differences in gut microbiotas, we determined whether there were sex by dietary protein interactions which could differentially impact barrier function via microbiota modification. METHODS: Fermentation systems were inoculated with faeces from healthy males (n = 5) and females (n = 5) and supplemented with 0.9 g of non-hydrolysed proteins sourced from whey, fish, milk, soya, egg, pea, or mycoprotein. Microbial populations were quantified using fluorescence in situ hybridisation with flow cytometry. Metabolite concentrations were analysed using gas chromatography, solid phase microextraction coupled with gas chromatography-mass spectrometry and ELISA. RESULTS: Increased protein availability resulted in increased proteolytic Bacteroides spp (p < 0.01) and Clostridium coccoides (p < 0.01), along with increased phenol (p < 0.01), p-cresol (p < 0.01), indole (p = 0.018) and ammonia (p < 0.01), varying by protein type. Counts of Clostridium cluster IX (p = 0.03) and concentration of p-cresol (p = 0.025) increased in males, while females produced more ammonia (p = 0.02), irrespective of protein type. Further, we observed significant sex-protein interactions affecting bacterial populations and metabolites (p < 0.005). CONCLUSIONS: Our findings suggest that protein fermentation by the gut microbiota in vitro is influenced by both protein source and the donor's sex. Should these results be confirmed through human studies, they could have major implications for developing dietary recommendations tailored by sex to prevent chronic illnesses.

Saturated fat and CVD: importance of inter-individual variation in the response of serum low-density lipoprotein cholesterol.

The aim of this review is to provide an overview of the history in support of the role of dietary saturated fatty acids (SFA) in the development of cardiovascular disease (CVD), and the controversy and consensus for the evidence in support of guidelines to remove and replace SFA with unsaturated fatty acids. The review will also examine the existence, origins, and implications for CVD risk of variability in serum LDL-cholesterol in response to these guidelines. While the quality of supporting evidence for the efficacy of restricting SFA on CVD risk has attracted controversy, this has helped to increase understanding of the inter-relationships between SFA, LDL-cholesterol and CVD, and reinforce confidence in this dietary recommendation. Nevertheless, there is significant inter-individual variation in serum LDL-C in response to this dietary change. The origins of this variation are multi-factorial and involve both dietary and metabolic traits. If serum biomarkers of more complex metabolic traits underlying LDL-responsiveness can be identified, this would have major implications for the targeting of these dietary guidelines to LDL-responders, to maximise the benefit to their cardiovascular health.

Time-Resolved Structural Measurement of Thermal Resistance across a Buried Semiconductor Heterostructure Interface.

The precise control and understanding of heat flow in heterostructures is pivotal for advancements in thermoelectric energy conversion, thermal barrier coatings, and efficient heat management in electronic and optoelectronic devices. In this study, we employ high-angular-resolution time-resolved X-ray diffraction to structurally measure thermal resistance in a laser-excited AlGaAs/GaAs semiconductor heterostructure. Our methodology offers femtometer-scale spatial sensitivity and nanosecond time resolution, enabling us to directly observe heat transport across a buried interface. We corroborate established Thermal Boundary Resistance (TBR) values for AlGaAs/GaAs heterostructures and demonstrate that TBR arises from material property discrepancies on either side of a nearly flawless atomic interface. This work not only sheds light on the fundamental mechanisms governing heat flow across buried interfaces but also presents a robust experimental framework that can be extended to other heterostructure systems, paving the way for optimized thermal management in next-generation devices.

Impact of a food-based dietary fat exchange model for replacing dietary saturated with unsaturated fatty acids in healthy men on plasma phospholipids fatty acid profiles and dietary patterns.

PURPOSE: UK guidelines recommend dietary saturated fatty acids (SFAs) should not exceed 10% total energy (%TE) for cardiovascular disease prevention, with benefits observed when SFAs are replaced with unsaturated fatty acids (UFAs). This study aimed to assess the efficacy of a dietary exchange model using commercially available foods to replace SFAs with UFAs. METHODS: Healthy men (n = 109, age 48, SD 11 year) recruited to the Reading, Imperial, Surrey, Saturated fat Cholesterol Intervention-1 (RISSCI-1) study (ClinicalTrials.Gov n°NCT03270527) followed two sequential 4-week isoenergetic moderate-fat (34%TE) diets: high-SFA (18%TE SFAs, 16%TE UFAs) and low-SFA (10%TE SFAs, 24%TE UFAs). Dietary intakes were assessed using 4-day weighed diet diaries. Nutrient intakes were analysed using paired t-tests, fasting plasma phospholipid fatty acid (PL-FA) profiles and dietary patterns were analysed using orthogonal partial least square discriminant analyses. RESULTS: Participants exchanged 10.2%TE (SD 4.1) SFAs for 9.7%TE (SD 3.9) UFAs between the high and low-SFA diets, reaching target intakes with minimal effect on other nutrients or energy intakes. Analyses of dietary patterns confirmed successful incorporation of recommended foods from commercially available sources (e.g. dairy products, snacks, oils, and fats), without affecting participants' overall dietary intakes. Analyses of plasma PL-FAs indicated good compliance to the dietary intervention and foods of varying SFA content. CONCLUSIONS: RISSCI-1 dietary exchange model successfully replaced dietary SFAs with UFAs in free-living healthy men using commercially available foods, and without altering their dietary patterns. Further intervention studies are required to confirm utility and feasibility of such food-based dietary fat replacement models at a population level.

Patient activation and patient-reported outcomes of men from a community pharmacy lifestyle intervention after prostate cancer treatment.

PURPOSE: To report patient activation, which is the knowledge, skills, and confidence in self-managing health conditions, and patient-reported outcomes of men after prostate cancer treatment from a community pharmacy lifestyle intervention. METHODS: The 3-month lifestyle intervention was delivered to 116 men in nine community pharmacies in the UK. Patient Activation Measure (PAM) was assessed at baseline, 3 and 6 months. Prostate cancer-related function and quality of life were assessed using the European Prostate Cancer Index Composite (EPIC-26) and EuroQOL 5-dimension 5-level (EQ5D-5L) questionnaires at baseline and 6 months. Lifestyle assessments included Mediterranean Diet Adherence Screener (MEDAS) at baseline, 3 and 6 months and Godin Leisure Time Exercise Questionnaire (GLTEQ) at baseline and 3 months. RESULTS: PAM score increased from 62 [95% CI 59-65] at baseline to 66 [64-69] after the intervention (p = 0.001) and remained higher at 6 months (p = 0.008). Scores for all the EPIC-26 domains (urinary, bowel and hormonal) were high at both assessments, indicating good function (between 74 [70-78] and 89 [86-91]), except sexual domain, where scores were much lower (21 [17-25] at baseline, increasing to 24 [20-28] at 6 months (p = 0.012)). In EQ5D-5L, 3% of men [1-9] reported self-care problems, while 50% [41-60] reported pain and discomfort, and no significant changes over time. Men who received androgen deprivation therapy, compared with those who did not, reported higher (better) urinary incontinence scores (p < 0.001), but lower (worse) scores in the urinary irritative/obstructive (p = 0.003), bowel (p < 0.001) and hormonal (p < 0.001) domains. Poor sexual function was common across all age groups irrespective of prostate cancer treatment. CONCLUSIONS: The intervention led to significant improvements in patient activation, exercise and diet. Community pharmacy could deliver effective services to address sexual dysfunction, pain and discomfort which are common after prostate cancer.

Effects of Maternal Nightshift Work on Evening Energy Intake, Diet Quality and Meal Timing in the Family: An Observational Study.

The percentage of women working regular nightshift work has increased in the past decade. While nightshift work has the potential to exert adverse effects on dietary habits, little is known about the impact of a parent working nightshifts on dietary habits in the family. We analysed energy intake, meal timing, and diet quality among dependent children and male partners of 20 female UK National Health Service (NHS) nurses working rotational nightshifts. Comparing nightshift against non-nightshift conditions, we hypothesised that maternal nightshift work would affect the evening energy intake, diet quality and time of eating of dependent children and adult partners. Primary outcomes were absolute energy intake and the proportion of daily energy intake consumed in the evening (16:00-23:59 h). Our results show that in pre-teen children aged 8-12 years (n = 13, mean ± SD, 9.9 ± 1.6 yrs; 9 males), the proportion of total daily energy intake consumed during periods of nightshift work was significantly greater compared to periods of non-nightshifts (45.7% ± 8.8% vs. 39.7% ± 7.0%, mean ± SD, p = 0.012). There was no effect of nightshift work on dietary habits in teenage children or partners. The finding of a greater proportion of daily energy consumed in the evening period in pre-teen children is noteworthy, as it suggests that pre-teen children more dependent than older teenage children may be more vulnerable to disruptions to dietary patterns associated with maternal nightshift work.

Obesity and low levels of physical activity impact on cardiopulmonary fitness in older men after treatment for prostate cancer.

The purpose of this study was to compare fitness parameters and cardiovascular disease risk of older and younger men with prostate cancer (PCa) and explore how men's fitness scores compared to normative age values. 83 men were recruited post-treatment and undertook a cardiopulmonary exercise test (CPET), sit-to-stand, step-and-grip strength tests and provided blood samples for serum lipids and HbA1c. We calculated waist-to-hip ratio, cardiovascular risk (QRISK2), Charlson comorbidity index (CCI) and Godin leisure-time exercise questionnaire [GLTEQ]. Age-group comparisons were made using normative data. Men > 75 years, had lower cardiopulmonary fitness, as measured by VO2 Peak (ml/kg/min) 15.8 + 3.8 p < 0.001, and lower grip strength(28.6+5.2 kg p < 0.001) than younger men. BMI ≥30kg/m2 and higher blood pressure all contributed to a QRisk2 score indicative of 20% chance of cardiovascular risk within 10 years (mean: 36.9-6.1) p < 0.001. Age, BMI and perceived physical activity were significantly associated with lower cardiopulmonary fitness. Men with PCa > 75 years had more cardiovascular risk factors compared to normative standards for men of their age. Although ADT was more frequent in older men, this was not found to be associated with cardiopulmonary fitness, but obesity and low levels of physical activity were. Secondary prevention should be addressed in men with PCa to improve men's overall health.

Does variation in serum LDL-cholesterol response to dietary fatty acids help explain the controversy over fat quality and cardiovascular disease risk?

Controversy over fat quality and cardiovascular disease risk stems from a series of meta-analyses of prospective cohort and randomised intervention trials, which found little evidence for a significant relationship between the intake of saturated fat and disease endpoints. Possible explanations for these null findings include difficulties inherent in estimating true food intake, the confounding effects of macronutrient replacement and food composition, and marked inter-individual variation in the response of serum LDL-cholesterol. The aim of this narrative review was to present evidence for the existence and origins of variation in serum LDL-cholesterol response to the replacement of dietary saturated fat, and its potential to explain the controversy over the latter. The review provides evidence to suggest that variation in LDL-responsiveness may harbour significant potential to confound the relationship between saturated fat and atherosclerotic cardiovascular disease risk, thus undermining the effectiveness of the dietary guideline to replace saturated fat with unsaturated fat. It concludes that the identification and application of a simple biomarker of this phenomenon, would make it possible to tailor dietary guidelines to LDL responsive individuals, who stand to gain a greater benefit to their cardiovascular health.

Musculoskeletal pain in lacrosse officials impacts function on the field.

This study determined the prevalence of joint pain among lacrosse officials and described the impact of pain thereof on current officiating duties on the field. Members of the US Lacrosse Officials Development Programme were provided with an electronic survey (a 15.7% response rate resulted in N = 1,441 of completed surveys). Pain sites and severity, previous injuries and current impact of musculoskeletal pain on officiating duties were captured. Pain was present in 18.1-40.1% of respondents at the foot, shoulder, back and knee. A total of 437 officials reported diagnoses of osteoarthritis ([OA]; knee 48.7%, hip 10.5%, spine 10.1%, shoulder 8.0%) and 247 reported OA in more than one joint (p < .05). Officials with OA or previous lacrosse-related injuries reported frequent difficulty with running the entire field distance (p < 0.0001), starting and stopping on the field (p < 0.0001), keeping pace (p < 0.0001), focusing on multiple actions of players at once (p < 0.0001), and enjoyment (all p < 0.0001). Musculoskeletal pain is a common, unrecognized issue in this population that interferes with sport officiating functions. Additional study is needed to objectively determine the impact of OA pain and musculoskeletal injuries on measurable performance outcomes on the field and subjective measures of focus, attention and enjoyment.

Report of a member-led meeting: how stable isotope techniques can enhance human nutrition research.

A Nutrition Society member-led meeting was held on 9 January 2020 at The University of Surrey, UK. Sixty people registered for the event, and all were invited to participate, either through chairing a session, presenting a '3 min lightning talk' or by presenting a poster. The meeting consisted of an introduction to the topic by Dr Barbara Fielding, with presentations from eight invited speakers. There were also eight lightning talks and a poster session. The meeting aimed to highlight recent research that has used stable isotope tracer techniques to understand human metabolism. Such studies have irrefutably shaped our current understanding of metabolism and yet remain a mystery to many. The meeting aimed to de-mystify their use in nutrition research.

Dietary Patterns of Nurses on Rotational Shifts Are Marked by Redistribution of Energy into the Nightshift.

Nightshift work is associated with adverse health outcomes, which may be related to eating during the biological night, when circadian rhythms and food intake are misaligned. Nurses often undertake nightshift work, and we aimed to investigate patterns of energy distribution and dietary intake across 14 days in 20 UK National Health Service (NHS) nurses working rotational shifts. We hypothesised that the proportion of daily energy consumed during the nightshift would increase over consecutive nights. Primary and secondary outcome measures included intakes of energy and macronutrients. Our results show that nurses consumed the same total daily energy on nightshifts and non-nightshifts, but redistributed energy to the nightshift period in increasing proportions with a significant difference between Night 1 and 2 in the proportion of total daily energy consumed (26.0 ± 15.7% vs. 33.5 ± 20.2%, mean ± SD; p < 0.01). This finding indicates that, rather than increasing total energy intake, nurses redistribute energy consumed during nightshifts as a behavioural response to consecutive nightshifts. This finding informs our understanding of how the intake of energy during the biological night can influence adverse health outcomes of nightshift work.

Impact of the occupational environment of a submerged submarine on cardiometabolic health of Royal Navy submariners.

OBJECTIVE: To determine the effect of prolonged exposure to a submarine environment on biomarkers of cardiometabolic risk in Royal Navy (RN) submariners. METHODS: Serum lipids (cholesterol (C), triglyceride (TG), low-density lipoprotein cholesterol, high-density lipoprotein cholesterol (HDL-C), non-HDL-C), glucose, insulin and anthropometrics were compared within three RN submarine crews before and after submerged patrols of 12 or 6 weeks, and with a crew that remained ashore (SUB-HOME). Dietary intake and activity patterns were self-reported during each patrol. Differences were assessed in crew characteristics using one-way analysis of variance and in serum lipids using paired t-tests. RESULTS: Postpatrol, the mean body weight of submerged crews decreased (-1.4±4.2 kg, p=0.0001), but increased in SUB-HOME (1.9±1.8 kg, p=0.0001). Modest improvements in serum lipids (mean individual change (mmol/L); C=-0.3±0.7, p=0.0001; TG=-0.3±0.7, p=0.0001; HDL-C=-0.1±0.3, p=0.0001; non-HDL-C=-0.2±0.6, p=0.012), glucose (-0.2±0.5, p=0.0001) and insulin (-1.5±4.6 mU/L, p=0.001) were observed in submerged crews. Changes in serum lipids were positively associated with changes in body weight within crews combined. Energy intake was maintained during submerged patrols but was lower compared with non-submerged (11 139±2792 vs. 9617±2466 kJ, p=0.001; 11 062±2775 vs. 9632±2682 kJ, p=0.003). CONCLUSIONS: The environment of a submerged submarine produced no adverse effects on serum biomarkers of cardiometabolic risk in crew. Conversely, modest improvements in these biomarkers were associated with a decrease in body weight.

Waist circumference as a vital sign in clinical practice: a Consensus Statement from the IAS and ICCR Working Group on Visceral Obesity.

Despite decades of unequivocal evidence that waist circumference provides both independent and additive information to BMI for predicting morbidity and risk of death, this measurement is not routinely obtained in clinical practice. This Consensus Statement proposes that measurements of waist circumference afford practitioners with an important opportunity to improve the management and health of patients. We argue that BMI alone is not sufficient to properly assess or manage the cardiometabolic risk associated with increased adiposity in adults and provide a thorough review of the evidence that will empower health practitioners and professional societies to routinely include waist circumference in the evaluation and management of patients with overweight or obesity. We recommend that decreases in waist circumference are a critically important treatment target for reducing adverse health risks for both men and women. Moreover, we describe evidence that clinically relevant reductions in waist circumference can be achieved by routine, moderate-intensity exercise and/or dietary interventions. We identify gaps in the knowledge, including the refinement of waist circumference threshold values for a given BMI category, to optimize obesity risk stratification across age, sex and ethnicity. We recommend that health professionals are trained to properly perform this simple measurement and consider it as an important 'vital sign' in clinical practice.

Optimal diet and lifestyle strategies for the management of cardio-metabolic risk.

Cardio-metabolic risk (CMR) embodies a clustering of metabolic abnormalities that increase the likelihood of developing CVD in the large arteries of the heart, peripheral tissues and brain. These abnormalities share a common origin of insulin resistance, which manifests typically as excess visceral adipose tissue in the abdominal cavity, and within cells of key metabolic tissues (ectopic fat), including the liver, pancreas, heart and skeletal muscle. As expected, the increased risk of CVD that can be attributed to CMR factors is alarmingly high in overweight and obese populations, but this risk can be reduced by reversing many of the inappropriate diet and lifestyle behaviours that underlie its development. The Nutrition Society's 2018 Winter Meeting at the Royal Society of Medicine addressed the topic of the 'Optimal diet and lifestyle for managing cardio-metabolic risk', with the aim of providing mechanistic insights into the impact of macronutrients, dietary patterns and meal timing in key metabolic tissues. The 2-d programme concluded with a summary of its main outcomes, and an overview of their implications for dietary policy in the UK.