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.
Associations of Dietary Intake on Biological Markers of Inflammation in Children and Adolescents: A Systematic Review.
Plain language summary
Inflammation is the normal physiological response to injury in the body and is designed to protect the host. However, in children and adolescents, chronic low-grade inflammation has been linked to a wide range of conditions. Certain markers in the blood can be measured and used to determine levels of inflammation in the body. This review of 53 studies provides the first evidence for the association between dietary intake and biological markers of inflammation in children and adolescents. Results show that adhering to a healthy way of eating such as the Mediterranean diet, are associated with decreased levels of pro-inflammatory biomarkers. The Western Dietary pattern, as well as intake of ultra-processed foods is associated with higher levels of the same pro-inflammatory markers. A good quality diet, high in fruit and vegetables, wholegrains, fibre and healthy fats ameliorates low-grade inflammation, and therefore represents a potential therapeutic approach. It is also an important element for disease prevention in both children and adolescents.
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.
The association between sedentary behaviour and indicators of stress: a systematic review.
BMC public health. 2019;(1):1357
BACKGROUND Emerging evidence shows sedentary behaviour may be associated with mental health outcomes. Yet, the strength of the evidence linking sedentary behaviour and stress is still unclear. This study aimed to synthesise evidence regarding associations between time spent in sedentary behaviour and stress in adults. METHODS A systematic search was conducted (January 1990 - September 2019). Following PRISMA guidelines, an evaluation of methodological quality, and best-evidence synthesis of associations between time in sedentary behaviour (including sitting time, TV viewing, computer use) and stress were presented. Twenty-six studies reporting on data from n = 72,795 people (age 18-98y, 62.7% women) were included. RESULTS Across the studies (n = 2 strong-, n = 10 moderate- and n = 14 weak-quality), there was insufficient evidence that overall time spent in sedentary behaviour and sitting time were associated with stress, particularly when using self-report measures of sedentary behaviour or stress. There was strong evidence of no association between TV viewing, or computer use and stress. Amongst studies using objective measures of sedentary behaviour and/or stress there was also strong evidence of no association. CONCLUSION Although previous research suggested sedentary behaviour may be linked to mental health outcomes such as depression and anxiety, the evidence for an association between various types of sedentary behaviour and stress is limited in quality, and associations are either inconsistent or null. High-quality longitudinal/interventional research is required to confirm findings and determine the direction of associations between different contexts (i.e. purpose) and domains (i.e. leisure, occupational, transport) of sedentary behaviour and stress.
Diet-Induced Weight Loss Has No Effect on Psychological Stress in Overweight and Obese Adults: A Meta-Analysis of Randomized Controlled Trials.
The effect of weight loss on psychological stress is unknown. The study aimed to investigate the effect of diet-induced weight loss in overweight and obese adults on psychological measures of stress through a meta-analysis of randomized controlled trials (RCTs). Databases including Medline Complete, Embase and PsycINFO were searched up to February 2018 for diet-induced weight loss RCTs, which included self-reported assessment of psychological stress. The mean difference between the intervention and control group of changes in stress (intervention-baseline) was used. Ten RCTs were included with 615 participants (502 women, age range 20⁻80 years). Overall, there was no change in stress (mean difference -0.06, 95% CI: -0.17, 0.06, p = 0.33) and no change in the five studies with a significant reduction in weight in the intervention group compared to a control group that lost no weight (mean difference in weight -3.9 Kg, 95% CI: -5.51, -2.29, p < 0.0001; mean difference in stress 0.04, 95% CI: -0.17, 0.25, p = 0.71). For all analyses, there was low heterogeneity. The benefits of weight loss for those who are overweight and obese do not appear to either increase or reduce psychological stress at the end of the weight loss period.
Does diet-induced weight change effect anxiety in overweight and obese adults?
Nutrition (Burbank, Los Angeles County, Calif.). 2014;(1):10-5
Anxiety is the most prevalent type of mental disorder and a significant health concern. Cross-sectional studies have detected a positive association between obesity and anxiety. What is less clear is whether weight loss can reduce anxiety. We sought to answer three questions: 1. Can weight loss improve symptoms of anxiety in the overweight and obese population? 2. Does the macronutrient content of energy-restricted diets that induce weight loss affect anxiety? 3. Is the change in anxiety related to the amount of weight lost? We investigated the findings from seven interventional studies, which induced weight loss by dietary intervention, in overweight and obese individuals, using established anxiety assessment tools. Mean weight loss ranged from 0.7 to 18.6 kg (SD 4.5) and in three of the studies, anxiety fell by 9.2% to 11.4% and did not change in four studies. When macronutrient content was considered, only one of four interventional studies and one pilot study reported a beneficial effect of a moderate-fat diet on anxiety. There appears to be no strong evidence to indicate that diet-induced weight loss has a beneficial effect on anxiety, however, none of the diet-induced weight loss studies assessed had a detrimental effect on anxiety.