Is high salt intake inducing obesity via production of cortisol? A novel working hypothesis and pilot study.

PURPOSE: Evidence is growing that high salt intake is an independent risk factor for obesity, but the mechanisms are unknown. Our novel working hypothesis is that high salt intake drives cortisol production, which in turn, drives obesity. The current study aimed to demonstrate an acute cortisol response following a single high salt meal. METHODS: Eight participants (age 30.5 ± 9.8 years [mean ± SD], 50% female), consumed high salt (3.82 g; 1529 mg sodium) and low salt (0.02 g; 9 mg sodium) meals in a randomized cross-over design. RESULTS: Urinary and salivary cortisol and plasma adrenocorticotropic hormone (ACTH) demonstrated order effects. When high salt was given second, there was a peak above baseline for urinary cortisol (26.3%), salivary cortisol (9.4%) and plasma ACTH (4.1%) followed by a significant decline in each hormone (treatment*time, F[9, 18] = 2.641, p = 0.038, partial η2 = 0.569; treatment*time, F[12, 24] = 2.668, p = 0.020, partial η2 = 0.572; treatment*time, F[12, 24] = 2.580, p = 0.023, partial η2 = 0.563, respectively), but not when high salt was given first (p > 0.05 for all). CONCLUSION: These intriguing findings provide partial support for our hypothesis and support a need for further research to elucidate the role of high salt intake in cortisol production and, in turn, in the aetiology of obesity. TRIAL REGISTRATION NUMBER: ACTRN12623000490673; date of registration 12/05/2023; retrospectively registered.

Data-driven lifestyle patterns and risk of dementia in older Australian women.

INTRODUCTION: Many lifestyle factors have been associated with dementia, but there is limited evidence of how these group together. The aim of this study was to examine the clustering of lifestyle behaviors and associations with dementia. METHODS: This population-based study included 9947 older Australian women. Latent class analysis was employed to identify distinct lifestyle classes, and Cox proportional hazard regression compared these with incident dementia over 17 years. RESULTS: Three classes were identified: (1) "highly social and non-smokers" (54.9%), (2) "highly social, smokers, and drinkers" (25.1%), and (3) "inactive and low socializers" (20.0%). Women in Class 3 exhibited a higher risk of dementia compared to both Class 1 (hazard ratio [HR] = 1.19, 95% confidence interval [CI]: 1.08 to 1.30) and Class 2 (HR = 1.12, 95% CI: 1.00 to 1.25). DISCUSSION: A lifestyle pattern characterized by physical inactivity and low social engagement may be particularly detrimental for dementia risk in older women and should be prioritized in preventive strategies. HIGHLIGHTS: Latent class analysis was employed to identify distinct lifestyle clusters. Three lifestyle-related clusters were differentially associated with dementia risk. Inactive and low socializers exhibited the greatest risk of dementia. Targeting physical inactivity and low social engagement in prevention is vital.

Prospective associations between diet quality and health-related quality of life in the Australian Diabetes, Obesity and Lifestyle (AusDiab) study.

Changes between diet quality and health-related quality of life (HR-QoL) over 12 years were examined in men and women, in 2844 adults (46 % males; mean age 47·3 (sd 9·7) years) from the Australian Diabetes, Obesity and Lifestyle study with data at baseline, 5 and 12 years. Dietary intake was assessed with a seventy-four-item FFQ. Diet quality was estimated with the Dietary Guideline Index, Mediterranean-Dietary Approaches to Stop Hypertension Diet Intervention for Neurological Delay Index (MIND) and Dietary Inflammatory Index. HR-QoL in terms of global, physical component summary (PCS) and mental component summary (MCS) was assessed with the Short-Form Health Survey-36. Fixed effects regression models adjusted for confounders were performed. Mean MCS increased from baseline (49·0, sd 9·3) to year 12 (50·7, sd 9·1), whereas mean PCS decreased from baseline (51·7, sd 7·4) to year 12 (49·5, sd 8·6). For the total sample, an improvement in MIND was associated with an improvement in global QoL (ß = 0·28, 95 % CI (0·007, 0·55)). In men, an improvement in MIND was associated with an improvement in global QoL (ß = 0·28, 95 % CI (0·0004, 0·55)). In women, improvement in MIND was associated with improvements in global QoL (ß = 0·62 95 % CI (0·38, 0·85)), MCS (ß = 0·75, 95 % CI (0·29, 1·22)) and PCS (ß = 0·75, 95 % CI (0·29, 1·22)). Positive changes in diet quality were associated with broad improvements in HR-QoL, and most benefits were observed in women when compared to men. These findings support the need for strategies to assist the population in consuming healthy dietary patterns to lead to improvements in HR-QoL.

Nineteen-Year Associations between Three Diet Quality Indices and All-Cause and Cardiovascular Disease Mortality: The Australian Diabetes, Obesity, and Lifestyle Study.

BACKGROUND: Examining a variety of diet quality methodologies will inform best practice use of diet quality indices for assessing all-cause and cardiovascular disease (CVD) mortality. OBJECTIVES: To examine the association between 3 diet quality indices (Australian Dietary Guideline Index, DGI; Dietary Inflammatory Index, DII; Mediterranean-DASH (Dietary Approaches to Stop Hypertension) Intervention for Neurodegenerative Delay, MIND) and risk of all-cause mortality, CVD mortality, and nonfatal CVD events ≤19 y later. METHODS: Data on 10,009 adults (mean age 51.8 y; 52% female) from the Australian Diabetes, Obesity, and Lifestyle study were used. An FFQ was used to calculate DGI, DII, and MIND at baseline. Cox proportional hazard models were used to estimate HRs and 95% CI of all-cause mortality, CVD mortality, and nonfatal CVD events (stroke; myocardial infarction) according to 1 SD increase in diet quality, adjusted for age, sex, education, smoking, physical activity, energy intake, history of stroke or heart attack, and diabetes and hypertension status. RESULTS: Deaths due to all-cause (n = 1955) and CVD (n = 520), and nonfatal CVD events (n = 264) were identified during mean follow-ups of 17.7, 17.4, and 9.6 y, respectively. For all-cause mortality, HRs associated with higher DGI, DII, and MIND were 0.94 (95% CI: 0.89, 0.99), 1.08 (95% CI: 1.02, 1.15), and 0.93 (95% CI: 0.89, 0.98), respectively. For CVD mortality, HRs associated with higher DGI, DII, and MIND were 0.93 (95% CI: 0.85, 0.99), 1.10 (95% CI: 1.00, 1.24), and 0.90 (95% CI: 0.82, 0.98), respectively. There was limited evidence of associations between diet quality and nonfatal CVD events. CONCLUSIONS: A better quality diet predicted lower risk of all-cause and CVD mortality in Australian adults, whereas a more inflammatory diet predicted higher mortality risk. These findings highlight the applicability of following Australian dietary guidelines, a Mediterranean-style diet, and a low-inflammatory diet for the reduction of all-cause and CVD mortality risk.

Association between dietary protein intake and changes in health-related quality of life in older adults: findings from the AusDiab 12-year prospective study.

BACKGROUND: Adequate dietary protein intake is recommended for older adults to optimise muscle health and function, and support recovery from illness, however, its effect on health-related quality of life (HRQoL) is unclear. The aim of this study was to examine the association between total protein intake and different sources of dietary protein and HRQoL in Australians aged 60 years and older over a 12-year period. METHODS: This study used data from the Australian Diabetes, Obesity and Lifestyle study (AusDiab), a 12-year population-based prospective study. The sample included 752 (386 females) adults aged 60 years and older. Protein intake was estimated at baseline (1999/2000) from a 74-item Food Frequency Questionnaire, and HRQoL using the 36-item Short-form Health Survey assessed at baseline (1999/2000) and after 12 years (2011/12). The association between protein intake and change in HRQoL was evaluated using multivariate regression analysis adjusted for relevant confounders. The difference in change in HRQoL between participants with total protein intakes of < 1.0 g/kg/day, intakes of between 1.0-1.2 g/kg/day and intakes of > 1.2 g/kg/day were assessed using one-way ANCOVA. RESULTS: Total protein intake at baseline was not associated with 12-year changes in physical component summary (PCS) or mental component summary (MCS) scores of HRQoL. Higher animal, red meat and processed animal protein intakes were associated with deteriorations in PCS scores after adjusting for relevant confounders (ß = - 0.04; 95% CI: - 0.07, -0.01 ; p = 0.009; ß = - 0.05; 95% CI: - 0.08, - 0.01; p = 0.018; ß = - 0.17; 95% CI: - 0.31, - 0.02; p = 0.027 respectively). Higher red meat protein intake was associated with deteriorations in MCS scores after adjusting for relevant confounders (ß = - 0.04; 95% CI: - 0.08, - 0.01; p = 0.011). There was no difference in 12-year changes in PCS or MCS between participants consuming total protein of < 1.0 g/kg/day, 1.0-1.2 g/kg/day and intakes of > 1.2 g/kg/day. CONCLUSION: There was no relationship between total dietary protein intake and HRQoL, but higher protein intakes from animal, red meat and processed animal sources were associated with a deterioration in HRQoL scores over 12 years. Due to the number of associations examined and high drop out of older less healthy participants, further research is required to confirm the associations detected in healthy and less healthy participants, with a view to making protein intake recommendations for older adults.

Associations between data-driven lifestyle profiles and cognitive function in the AusDiab study.

BACKGROUND: Mounting evidence highlights the importance of combined modifiable lifestyle factors in reducing risk of cognitive decline and dementia. Several a priori additive scoring approaches have been established; however, limited research has employed advanced data-driven approaches to explore this association. This study aimed to examine the association between data-driven lifestyle profiles and cognitive function in community-dwelling Australian adults. METHODS: A cross-sectional study of 4561 Australian adults (55.3% female, mean age 60.9 ± 11.3 years) was conducted. Questionnaires were used to collect self-reported data on diet, physical activity, sedentary time, smoking status, and alcohol consumption. Cognitive testing was undertaken to assess memory, processing speed, and vocabulary and verbal knowledge. Latent Profile Analysis (LPA) was conducted to identify subgroups characterised by similar patterns of lifestyle behaviours. The resultant subgroups, or profiles, were then used to further explore associations with cognitive function using linear regression models and an automatic Bolck, Croon & Hagenaars (BCH) approach. RESULTS: Three profiles were identified: (1) "Inactive, poor diet" (76.3%); (2) "Moderate activity, non-smokers" (18.7%); and (3) "Highly active, unhealthy drinkers" (5.0%). Profile 2 "Moderate activity, non-smokers" exhibited better processing speed than Profile 1 "Inactive, poor diet". There was also some evidence to suggest Profile 3 "Highly active, unhealthy drinkers" exhibited poorer vocabulary and verbal knowledge compared to Profile 1 and poorer processing speed and memory scores compared to Profile 2. CONCLUSION: In this population of community-dwelling Australian adults, a sub-group characterised by moderate activity levels and higher rates of non-smoking had better cognitive function compared to two other identified sub-groups. This study demonstrates how LPA can be used to highlight sub-groups of a population that may be at increased risk of dementia and benefit most from lifestyle-based multidomain intervention strategies.

A Dietary Inflammatory Index and associations with C-reactive protein in a general adult population.

PURPOSE: Chronic low-grade inflammation is implicated in many of the diseases of ageing. Lifestyle factors, including diet may alter low-grade inflammation. This study aimed to assess cross-sectional associations between the Dietary Inflammatory Index (DII) score and the inflammatory marker C-reactive protein (CRP); and determine if any association differs according to age (< 50 vs ≥ 50 years). METHODS: DII scores were calculated for respondents of the Australian Health Survey 2011-2012 using data from two 24-h recalls. Serum CRP was measured using ultrasensitive immunoturbidimetric assay. Associations between DII and CRP were assessed using multivariate linear regression adjusting for confounders (age education, physical activity, sex and smoking). Associations were assessed for the whole cohort and stratified at age 50 years. RESULTS: The analysis included 2558 respondents with a mean BMI of 26.8 kg/m2 (< 50 years n = 1099; ≥ 50 years n = 1459). Respondents in the lowest DII quartile (anti-inflammatory diet) reportedly consumed more grains, vegetables and legumes, fruit, milk products, meat, poultry, fish and eggs, unsaturated oils and alcohol compared to respondents in DII quartile 4. No associations were seen between DII and CRP after adjustment for confounders in the whole cohort or when stratified < 50 or ≥ 50 years. CONCLUSIONS: The DII was not associated with CRP in this cross-sectional study. Inflammation is complex characterised by a cascade of the multiple inflammatory markers and understanding the temporal relationship between diet and the inflammatory process is an important area for future research.

Dietary patterns and associations with biomarkers of inflammation in adults: a systematic review of observational studies.

BACKGROUND: Evidence indicates that low-grade inflammation is involved in manychronic diseases of ageing. Modifiable lifestyle factors including dietcan affect low-grade inflammation. Dietary patterns allow assessment of the complex interactions of food nutrients and health and may be associated with inflammatory status. This systematic review aimed to summarises current evidence from observational studies for associations between dietary patterns and inflammatory biomarkers in the general adult population. This review followed the PRISMA guidelines. METHODS: We conducted a systematic search in Embase, CINAHL Complete, Global Health and MEDLINE complete databases. Search terms included terms for diet ("dietary patterns", "diet scores") and inflammation ("inflammation", "c-reactive protein", "interleukin"). RESULTS: The search produced 7161 records. Duplicates were removed leaving 3164 for screening. There were 69 studies included (60 cross-sectional, 9 longitudinal). Papers included studies that were: 1) observational studies; 2) conducted in community-dwelling adults over 18 years of age; 3) assessed dietary patterns; 4) measured specified biomarkers of inflammation and 5) published in English. Dietary patterns were assessed using diet scores (n = 45), data-driven approaches (n = 22), both a data-driven approach and diet score (n = 2). The most frequently assessed biomarkers were CRP (n = 64) and/or IL-6 (n = 22). Cross-sectionally the majority of analyses reported an association between higher diet scores (mostly Mediterranean and anti-inflammatory diet scores) and lower inflammatory markers with 82 significant associations from 133 analyses. Only 22 of 145 cross-sectional analyses using data-driven approaches reported an association between a dietary patterns and lower inflammatory markers; the majority reported no association. Evidence of an association between dietary patterns and inflammatory markers longitudinally is limited, with the majority reporting no association. CONCLUSIONS: Adherence to healthy, Mediterranean and anti-inflammatory dietary scores, appear to be associated with lower inflammatory status cross-sectionally. Future research could focus on longitudinal studies using a potential outcomes approach in the data analysis. TRIAL REGISTRATION: PROSPERO Registration Number CRD42019114501 .

Effects of a multicomponent exercise program combined with calcium-vitamin D3-enriched milk on health-related quality of life and depressive symptoms in older men: secondary analysis of a randomized controlled trial.

PURPOSE: Osteoporosis is associated with both lower health-related quality of life and depression in older people. We examined the independent and combined effects of a multi-component exercise program and calcium-vitamin D3 fortified milk on health-related quality of life (HR-QoL) and depression in older men. METHODS: In this 12-month, factorial design randomized controlled trial, 180 healthy community-dwelling men aged 50-79 years with normal to below average bone mineral density were allocated into one of four groups: exercise + fortified milk; exercise; fortified milk; or controls. Exercise consisted of high-intensity resistance training with weight-bearing exercise (3 days per week; 60-75 min per session). Men assigned to fortified milk consumed 400 ml/day of low-fat milk containing 1000 mg/day calcium and 800IU/day vitamin D3. Questionnaires were used to assess HR-QoL (SF-36) and depressive symptoms (Center for Epidemiologic Studies Depression Scale) at baseline, and 6 and 12 months. A linear mixed model analysis was used to test whether there was a synergistic interaction between exercise and calcium-vitamin D3. If no significant interactions were detected, the main effects of exercise and fortified milk were examined. RESULTS: Mean adherence to the exercise program and fortified milk was 67% (95% CI 61, 73%) and 90% (95% CI 86, 93%), respectively. There were no exercise-by-fortified milk interactions nor main effects of exercise or calcium-vitamin D for any of the HR-QoL measures or depressive symptoms. CONCLUSION: In healthy community-dwelling older men, exercise training and/or calcium-vitamin D fortified milk did not improve HR-QoL or depressive symptoms.

An Internet-Based Intervention Augmented With a Diet and Physical Activity Consultation to Decrease the Risk of Dementia in At-Risk Adults in a Primary Care Setting: Pragmatic Randomized Controlled Trial.

BACKGROUND: There is a need to develop interventions to reduce the risk of dementia in the community by addressing lifestyle factors and chronic diseases over the adult life course. OBJECTIVE: This study aims to evaluate a multidomain dementia risk reduction intervention, Body Brain Life in General Practice (BBL-GP), targeting at-risk adults in primary care. METHODS: A pragmatic, parallel, three-arm randomized trial involving 125 adults aged 18 years or older (86/125, 68.8% female) with a BMI of ≥25 kg/m2 or a chronic health condition recruited from general practices was conducted. The arms included (1) BBL-GP, a web-based intervention augmented with an in-person diet and physical activity consultation; (2) a single clinician-led group, Lifestyle Modification Program (LMP); and (3) a web-based control. The primary outcome was the Australian National University Alzheimer Disease Risk Index Short Form (ANU-ADRI-SF). RESULTS: Baseline assessments were conducted on 128 participants. A total of 125 participants were randomized to 3 groups (BBL-GP=42, LMP=41, and control=42). At immediate, week 18, week 36, and week 62 follow-ups, the completion rates were 43% (18/42), 57% (24/42), 48% (20/42), and 48% (20/42), respectively, for the BBL-GP group; 71% (29/41), 68% (28/41), 68% (28/41), and 51% (21/41), respectively, for the LMP group; and 62% (26/42), 69% (29/42), 60% (25/42), and 60% (25/42), respectively, for the control group. The primary outcome of the ANU-ADRI-SF score was lower for the BBL-GP group than the control group at all follow-ups. These comparisons were all significant at the 5% level for estimates adjusted for baseline differences (immediate: difference in means -3.86, 95% CI -6.81 to -0.90, P=.01; week 18: difference in means -4.05, 95% CI -6.81 to -1.28, P<.001; week 36: difference in means -4.99, 95% CI -8.04 to -1.94, P<.001; and week 62: difference in means -4.62, 95% CI -7.62 to -1.62, P<.001). CONCLUSIONS: A web-based multidomain dementia risk reduction program augmented with allied health consultations administered within the general practice context can reduce dementia risk exposure for at least 15 months. This study was limited by a small sample size, and replication on a larger sample with longer follow-up will strengthen the results. TRIAL REGISTRATION: Australian clinical trials registration number (ACTRN): 12616000868482; https://anzctr.org.au/ACTRN12616000868482.aspx.

Fruit and vegetable consumption and psychological distress in Australian pregnant and breastfeeding women.

BACKGROUND AND OBJECTIVES: Mental health disorders amongst pregnant and postpartum women are an increasing public health concern. Our aim was to determine the association between fruit and vegetable intake and psychological distress in a nationally representative sample of Australian pregnant and breastfeeding women. METHODS AND STUDY DESIGN: This study used cross-sectional data collected by the Australian Bureau of Statistics in the 2014 to 2015 Australian National Health Survey. Participants included 166 pregnant and 207 breastfeeding women >18 years old. Number of serves of fruit and vegetables usually consumed each day was reported. The Kessler Psychological Distress Scale (K10) measured levels of global non-specific psychological distress. The association between fruit and vegetable intake and psychological distress was investigated using linear regression adjusted for available known covariates (age, education, physical activity). RESULTS: Mean±SD fruit intake was greater in pregnant compared to breastfeeding women (2.0±1.0 versus 1.7±1.0, p<0.05). The mean K10 score for both the pregnant and breastfeeding women was in the 10-15 'little or no psychological distress" range. In pregnant women, combined fruit and vegetable intake was inversely associated with psychological distress in the fully adjusted model (ß=-0.37, 95% CI -0.72, -0.02). There was no association between fruit and vegetable intake and psychological distress in breastfeeding women. CONCLUSIONS: A higher intake of combined fruit and vegetables was found to be associated with less psychological distress in pregnant women. Further research, including longitudinal and intervention studies, are required to determine causality between fruit and vegetable intake and psychological distress in this population group.

Dietary patterns are associated with depressive symptoms in older Australian women but not men.

Studies have examined the association between depressive symptoms and dietary patterns; however, only few studies focused on older adults. The present study examines the association between current and past dietary patterns and depression in a community-dwelling adult population aged 55 years and over. Adults (n 4082) were recruited into the Wellbeing, Eating and Exercise for a Long Life study in Victoria, Australia. In 2010 and 2014, data were collected using self-administered questionnaires including a 111-item FFQ, the RAND thirty-six-item Short Form Health Survey of health-related quality of life and the International Physical Activity Questionnaire. Depressive symptoms were assessed using the Geriatric Depression Scale in 2014. Current (2014) and past (2010) dietary patterns were determined using principal component analysis. Association between dietary patterns and depressive symptoms was assessed using a mixed model analysis with adjustment for covariates. Two similar dietary patterns were identified in men and women (n 2142). In women, a healthy dietary pattern (characterised by frequent intake of vegetables, fruits and fish) was associated with lower levels of depressive symptoms (current diet: ß = -0·260, 95 % CI -0·451, -0·070; past diet: ß = -0·201, 95 % CI -0·390, -0·013). A current unhealthy dietary pattern in women (characterised by frequent intake of red and processed meat, potatoes, hot chips, cakes, deserts and ice cream) was associated with higher levels of depressive symptoms (ß = 1·367, 95 % CI 0·679, 2·056). No associations were identified in men. Further research is needed to confirm these findings and to understand the differences that may occur by sex.

Diet quality and well-being in children and adolescents: the UP&DOWN longitudinal study.

The present study examined the association between high-quality diet (using the Mediterranean diet (MD) as an example) and well-being cross-sectionally and prospectively in Spanish children and adolescents. Participants included 533 children and 987 adolescents at baseline and 527 children and 798 adolescents at 2-year follow-up, included in the UP&DOWN study (follow-up in schoolchildren and adolescents with and without Down's syndrome). The present study excluded participants with Down's syndrome. Adherence to an MD was assessed using the KIDMED index. Well-being was measured using the Positive and Negative Affect Schedule and the KIDSCREEN-10 questionnaire. Associations between MD adherence and well-being were assessed using multi-level, mixed-effects linear regression. At baseline, MD adherence was positively related to health-related quality of life in secondary school girls and boys (ß=0·41, se 0·10, P<0·001; ß=0·46, se 0·10, P<0·001, respectively) and to positive affect in secondary school girls and boys (ß=0·16, se 0·05, P=0·006; ß=0·20, se 0·05, P<0·001, respectively) and in primary school boys (ß=0·20, se 0·08, P=0·019). At 2-year follow-up, MD adherence was negatively related to negative affect in secondary school adolescent girls and boys (ß=-0·15, se 0·07, P=0·047; ß=-0·16, se 0·06, P=0·019, respectively), and MD adherence was associated with higher positive affect scores in secondary school girls (ß=0·30, se 0·06, P<0·001) and in primary school boys (ß=0·20, se 0·09, P=0·023). However, MD adherence at baseline did not predict well-being indicators at 2-year follow-up. In conclusion, higher MD adherence was found to behave as a protective factor for positive well-being in cross-sectional analysis.

Urinary sodium is positively associated with urinary free cortisol and total cortisol metabolites in a cross-sectional sample of Australian schoolchildren aged 5-12 years and their mothers.

High Na intake and chronically elevated cortisol levels are independently associated with the development of chronic diseases. In adults, high Na intake is associated with high levels of urinary cortisol. We aimed to determine the association between urinary Na and K and urinary cortisol in a cross-sectional sample of Australian schoolchildren and their mothers. Participants were a sample of Australian children (n 120) and their mothers (n 100) recruited through primary schools. We assessed Na, K, free cortisol and cortisol metabolites in one 24 h urine collection. Associations between 24 h urinary electrolytes and 24 h urinary cortisol were assessed using multilevel mixed-effects linear regression models. In children, urinary Na was positively associated with urinary free cortisol (ß=0·31, 95 % CI 0·19, 0·44) and urinary cortisol metabolites (ß=0·006, 95 % CI 0·002, 0·010). Positive associations were also observed between urinary K and urinary free cortisol (ß=0·65, 95 % CI 0·23, 1·07) and urinary cortisol metabolites (ß=0·02, 95 % CI 0·03, 0·031). In mothers, urinary Na was positively associated with urinary free cortisol (ß=0·23, 95 % CI 0·01, 0·50) and urinary cortisol metabolites (ß=0·008, 95 % CI 0·0007, 0·016). Our findings show that daily Na and K intake were positively associated with cortisol production in children and their mothers. Investigation of the mechanisms involved and the potential impact of Na reduction on cortisol levels in these populations is warranted.

Effects of progressive resistance training combined with a protein-enriched lean red meat diet on health-related quality of life in elderly women: secondary analysis of a 4-month cluster randomised controlled trial.

Resistance training (RT) and increased dietary protein are recommended to attenuate age-related muscle loss in the elderly. This study examined the effect of a lean red meat protein-enriched diet combined with progressive resistance training (RT+Meat) on health-related quality of life (HR-QoL) in elderly women. In this 4-month cluster randomised controlled trial, 100 women aged 60-90 years (mean 73 years) from self-care retirement villages participated in RT twice a week and were allocated either 160 g/d (cooked) lean red meat consumed across 2 meals/d, 6 d/week or ≥1 serving/d (25-30 g) carbohydrates (control group, CRT). HR-QoL (SF-36 Health Survey questionnaire), lower limb maximum muscle strength and lean tissue mass (LTM) (dual-energy X-ray absorptiometry) were assessed at baseline and 4 months. In all, ninety-one women (91 %) completed the study (RT+Meat (n 48); CRT (n 43)). Mean protein intake was greater in RT+Meat than CRT throughout the study (1·3 (sd 0·3) v. 1·1 (sd 0·3) g/kg per d, P<0·05). Exercise compliance (74 %) was not different between groups. After 4 months there was a significant net benefit in the RT+Meat compared with CRT group for overall HR-QoL and the physical component summary (PCS) score (P<0·01), but there were no changes in either group in the mental component summary (MCS) score. Changes in lower limb muscle strength, but not LTM, were positively associated with changes in overall HR-QoL (muscle strength, ß: 2·2 (95 % CI 0·1, 4·3), P<0·05). In conclusion, a combination of RT and increased dietary protein led to greater net benefits in overall HR-QoL in elderly women compared with RT alone, which was because of greater improvements in PCS rather than MCS.

The influence of a high-fat meal on fat taste thresholds.

A high-fat diet for four weeks has been shown to attenuate fat taste sensitivity in healthy weight individuals. However, there is minimal evidence as to whether a single high-fat meal immediately prior to fat taste threshold testing has an effect on thresholds. Therefore, the aim of the study was to determine the effect of a high-fat meal immediately prior to detection threshold testing for oleic acid (C18:1). Thirty-two participants (15 males, 17 females, aged 39.1 ± 3.1 years, Body Mass Index 23.1 ± 0.7 kg/m(2)) attended three laboratory sessions. In each session, participants were randomly assigned to one of three different types of breakfast: a high-fat (60% energy from fat), or low-fat (20% energy from fat) or macronutrient balanced (33% energy from fat) frittata. Fat taste thresholds were evaluated using ascending forced choice triangle tests on two occasions each day; once one-hour post breakfast and then one-hour post the completion of the first threshold test. There was no effect of breakfast type on fat taste detection thresholds for the first testing session of each day (P = 0.288), or the second testing session of each day (P = 0.754). There was also no effect of breakfast within each day (day 1: P = 0.198, day 2: P = 0.199, day 3: P = 0.125). There was no effect of macronutrient composition on the ability of participants to rank the level of fat in food (P = 0.345), or preference for the level of fat in food (P = 0.187-0.868). This study provides preliminary evidence that the composition of the meal consumed by a participant immediately prior to testing does not affect fat taste thresholds.

Attitudes and Considerations for Multidomain Lifestyle Approaches to Dementia Prevention: A Qualitative Study.

BACKGROUND: Dementia, with the most common form being Alzheimer's disease, is a global health issue and lifestyle-based strategies may reduce risk. Individuals with a family history of dementia are an important target group, but little is known about their attitudes and perceptions of dementia risk reduction. OBJECTIVE: To elucidate the attitudes to and key considerations for multidomain lifestyle-based dementia prevention strategies in middle-aged Australians with a family history of dementia. METHODS: Twenty participants (80% female; age range 47-65 years), undertook semi-structured phone-based interviews. Inductive thematic analysis of interview transcripts was conducted. Hierarchical coding frames and illustrative quotes were compiled and critically challenged until a final set of themes was produced. RESULTS: Some participants expressed a positive attitude toward lifestyle-based dementia prevention. Reasons related to wanting to future proof, believing that risk reduction is relevant at all life stages and/or that there is always room for improvement. Other participants had a negative attitude, expressing that they were already following a healthy lifestyle, did not feel it was relevant to them yet, and/or held a deterministic view that dementia is random. Important considerations congregated on the themes of being tailored/personalized, taking a holistic approach, and involving small, achievable steps. CONCLUSIONS: In individuals with a family history of dementia, a positive attitude to dementia prevention holds promise for intervention efforts, but in individuals expressing negative attitudes, further education and individual-level counselling may be warranted. Multidomain lifestyle-based preventive strategies also need to be tailored to the needs of key target groups to optimize appeal and effectiveness.

Statistical Approaches for the Analysis of Combined Health-Related Factors in Association with Adult Cognitive Outcomes: A Scoping Review.

BACKGROUND: Dementia prevention is a global health priority, and there is emerging evidence to support associations between individual modifiable health behaviors and cognitive function and dementia risk. However, a key property of these behaviors is they often co-occur or cluster, highlighting the importance of examining them in combination. OBJECTIVE: To identify and characterize the statistical approaches used to aggregate multiple health-related behaviors/modifiable risk factors and assess associations with cognitive outcomes in adults. METHODS: Eight electronic databases were searched to identify observational studies exploring the association between two or more aggregated health-related behaviors and cognitive outcomes in adults. RESULTS: Sixty-two articles were included in this review. Fifty articles employed co-occurrence approaches alone to aggregate health behaviors/other modifiable risk factors, eight studies used solely clustering-based approaches, and four studies used a combination of both. Co-occurrence methods include additive index-based approaches and presenting specific health combinations, and whilst simple to construct and interpret, do not consider the underlying associations between co-occurring behaviors/risk factors. Clustering-based approaches do focus on underlying associations, and further work in this area may aid in identifying at-risk subgroups and understanding specific combinations of health-related behaviors/risk factors of particular importance in the scope of cognitive function and neurocognitive decline. CONCLUSION: A co-occurrence approach to aggregating health-related behaviors/risk factors and exploring associations with adult cognitive outcomes has been the predominant statistical approach used to date, with a lack of research employing more advanced statistical methods to explore clustering-based approaches.

The role of combined modifiable lifestyle behaviors in the longitudinal association between stressful life events and allostatic load in Australian adults.

Allostatic load is a model that is used to quantify the physiological damage from exposure to stressors. Stressful life events are chronic stressors that can lead to an elevated allostatic load through the physiological and behavioral stress responses. However, there is limited empirical studies that has tested the proposed behavioural pathway. Our study addresses this gap by examining the mediating role of combined modifiable lifestyle behaviors in the 12-years longitudinal association between stressful life events and allostatic load among participants from the Australian Diabetes, Obesity and Lifestyle (AusDiab) Study cohort. A latent profile analysis was performed to identify latent subgroups with distinct behavioral clusters based on five modifiable lifestyle behaviors (smoking, sedentary behavior, physical activity, alcohol consumption, and diet quality). We then used a sequential mediation model design with path analysis to test the mediating effect of these latent subgroups in the associations between stressful life events and three measures of allostatic load. Indirect effects were estimated using the product of coefficient approach and the statistical significance was determined by the 95% bias-corrected bootstrap confidence intervals with 1000 replications. We identified three latent subgroups: "least healthy lifestyle" (12%; n = 396), "moderately healthy lifestyle" (78.7%; n = 2599), and "most healthy lifestyle" (9.2%; n = 306). Exposure to stressful life events was not associated with the allocation of participants in latent subgroups. Compared to the "moderately healthy lifestyle" subgroups, we found that the "least healthy lifestyle" behavioral cluster was not associated with allostatic load. However, there was a significant inverse association between the "most healthy lifestyle" behavioral cluster and allostatic load. Overall, we did not find significant indirect effects between stressful life events and three measures of allostatic load via the "least healthy lifestyle" and the "most healthy lifestyle" groups. In summary, the combinations of modifiable lifestyle behaviors did not explain the association between stressful life events and allostatic load. More longitudinal studies are needed to replicate our study to confirm this finding.

The role of combined modifiable lifestyle behaviors in the association between exposure to stressors and allostatic load: A systematic review of observational studies.

BACKGROUND: Exposure to stressors can evoke psychological, physiological, and behavioral stress responses, which may lead to the adoption of health-damaging behaviors that dysregulate multiple biological systems contributing to a high allostatic load. This review explored the role of combined modifiable lifestyle behaviors in the relationship between stressors and allostatic load among healthy adults. METHODS: A systematic search was conducted in Medline Complete, PsycINFO, CINAHL, and Embase databases up to September 2021. The PRISMA guidelines guided reporting and study quality was assessed using the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) Checklist. RESULTS: Database searches identified 319 papers. Eight cross-sectional and two longitudinal studies met our inclusion criteria. Among the ten studies, combined modifiable lifestyle behaviors partly explained the association between exposure to stressors and elevated allostatic load in four cross-sectional and two longitudinal studies. CONCLUSION: Some evidence suggests that combined modifiable lifestyle behaviors may help explain the relationship between stressors and an elevated allostatic load. Further longitudinal studies with mediation analyses would strengthen these findings and help to confirm the mechanistic role of combined modifiable lifestyle behaviors underlying the relationship between stress exposure and allostatic load.