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.

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.

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.

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.

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.

Associations of Dietary Intake on Biological Markers of Inflammation in Children and Adolescents: A Systematic Review.

BACKGROUND: In children and adolescents, chronic low-grade inflammation has been implicated in the pathogenesis of co- and multi-morbid conditions to mental health disorders. Diet quality is a potential mechanism of action that can exacerbate or ameliorate low-grade inflammation; however, the exact way dietary intake can regulate the immune response in children and adolescents is still to be fully understood. METHODS: Studies that measured dietary intake (patterns of diet, indices, food groups, nutrients) and any inflammatory biomarkers in children and adolescents aged 2 to19 years and published until November 2020 were included in this systematic review, and were selected in line with PRISMA guidelines through the following databases: Academic Search Complete, CINAHL, Global Health, Medline COMPLETE and Web of Science-Core Collection. A total of 53 articles were identified. RESULTS: Results show that adequate adherence to healthful dietary patterns such as the Mediterranean diet, or food groups such as vegetables and fruit, or macro/micro nutrients such as fibre or vitamin C and E, are associated with decreased levels of pro-inflammatory biomarkers, mainly c-reactive protein (CRP), interleukin-6 (IL-6) and tumour necrosis factor-alpha (TNF-α), whereas adherence to a Western dietary pattern, as well as intake of food groups such as added sugars, macro-nutrients such as saturated fatty acids or ultra-processed foods, is associated with higher levels of the same pro-inflammatory biomarkers. CONCLUSIONS: This is the first systematic review examining dietary intake and biological markers of inflammation in both children and adolescents. A good quality diet, high in vegetable and fruit intake, wholegrains, fibre and healthy fats ameliorates low-grade inflammation, and therefore represents a promising therapeutic approach, as well as an important element for disease prevention in both children and adolescents.

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.

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.

Body, Brain, Life for Cognitive Decline (BBL-CD): protocol for a multidomain dementia risk reduction randomized controlled trial for subjective cognitive decline and mild cognitive impairment.

BACKGROUND: With no cure for dementia and the number of people living with the condition predicted to rapidly rise, there is an urgent need for dementia risk reduction and prevention interventions. Modifiable lifestyle risk factors have been identified as playing a major role in the development of dementia; hence, interventions addressing these risk factors represent a significant opportunity to reduce the number of people developing dementia. Relatively few interventions have been trialed in older participants with cognitive decline (secondary prevention). OBJECTIVES: This study evaluates the efficacy and feasibility of a multidomain lifestyle risk reduction intervention for people with subjective cognitive decline (SCD) and mild cognitive impairment (MCI). METHODS: This study is an 8-week, two-arm, single-blind, randomized controlled trial (RCT) of a lifestyle modification program to reduce dementia risk. The active control group receives the following four online educational modules: dementia literacy and lifestyle risk, Mediterranean diet (MeDi), cognitive engagement and physical activity. The intervention group also completes the same educational modules but receives additional practical components including sessions with a dietitian, online brain training and sessions with an exercise physiologist to assist with lifestyle modification. RESULTS: Primary outcome measures are cognition (The Alzheimer's Disease Assessment Scale-Cognitive-Plus [ADAS-Cog-Plus]) and a composite lifestyle risk factor score for Alzheimer's disease (Australian National University - Alzheimer's Disease Risk Index [ANU-ADRI]). Secondary outcome measures are motivation to change lifestyle (Motivation to Change Lifestyle and Health Behaviour for Dementia Risk Reduction [MCLHB-DRR]) and health-related quality of life (36-item Short Form Health Survey [SF-36]). Feasibility will be determined through adherence to diet (Mediterranean Diet Adherence Screener [MEDAS] and Australian Recommended Food Score [ARFS]), cognitive engagement (BrainHQ-derived statistics) and physical activity interventions (physical activity calendars). Outcomes are measured at baseline, immediately post-intervention and at 3- and 6-month follow-up by researchers blind to group allocation. DISCUSSION: If successful and feasible, secondary prevention lifestyle interventions could provide a targeted, cost-effective way to reduce the number of people with cognitive decline going on to develop Alzheimer's disease (AD) and other dementias.

Does personality affect dietary intake?

The purpose of this review is to evaluate the evidence for an association between the Big Five dimensions of personality, dietary intake, and compliance to dietary recommendations. Poor diet is a known risk factor for overweight and obesity and associated chronic lifestyle diseases and it has been proposed that personality may be linked to dietary choices. Findings from cross-sectional surveys from different countries and cultures show a positive association between Openness and consumption of fruits and vegetables and between Conscientiousness and healthy eating. Although no evidence has been found that personality dimensions are associated with adherence to dietary recommendations over time, Conscientiousness is associated with a number of prosocial and health-promoting behaviors that include avoiding alcohol-related harm, binge-drinking, and smoking, and adherence to medication regimens. With emerging evidence of an association between higher Conscientiousness and lower obesity risk, the hypothesis that higher Conscientiousness may predict adoption of healthy dietary and other lifestyle recommendations appears to be supported.