Poor diet can be detrimental to mental health. However, the overall evidence for the effects of dietary interventions on mood and mental well-being has yet to be assessed. We conducted a systematic ...review and meta-analysis examining effects of dietary interventions on symptoms of depression and anxiety.
Major electronic databases were searched through March 2018 for all randomized controlled trials of dietary interventions reporting changes in symptoms of depression and/or anxiety in clinical and nonclinical populations. Random-effects meta-analyses were conducted to determine effect sizes (Hedges' g with 95% confidence intervals CI) for dietary interventions compared with control conditions. Potential sources of heterogeneity were explored using subgroups and meta-regression analyses.
Sixteen eligible randomized controlled trials (published in English) with outcome data for 45,826 participants were included; the majority of which examined samples with nonclinical depression (n = 15 studies). Nonetheless, dietary interventions significantly reduced depressive symptoms (g = 0.275, 95% CI = 0.10 to 0.45, p = .002). Similar effects were observed among high-quality trials (g = 0.321, 95% CI = 0.12 to 0.53, p = .002) and when compared with both inactive (g = 0.308, 95% CI = 0.02 to 0.60, p = .038) and active controls (g = 0.174, 95% CI = 0.01 to 0.34, p = .035). No effect of dietary interventions was observed for anxiety (k = 11, n = 2270, g = 0.100, 95% CI = -0.04 to 0.24, p = .148). Studies with female samples observed significantly greater benefits from dietary interventions, for symptoms of both depression and anxiety.
Dietary interventions hold promise as a novel intervention for reducing symptoms of depression across the population. Future research is required to determine the specific components of dietary interventions that improve mental health, explore underlying mechanisms, and establish effective schemes for delivering these interventions in clinical and public health settings.
PROSPERO Online Protocol: CRD42018091256.
The possible therapeutic impact of dietary changes on existing mental illness is largely unknown. Using a randomised controlled trial design, we aimed to investigate the efficacy of a dietary ...improvement program for the treatment of major depressive episodes.
'SMILES' was a 12-week, parallel-group, single blind, randomised controlled trial of an adjunctive dietary intervention in the treatment of moderate to severe depression. The intervention consisted of seven individual nutritional consulting sessions delivered by a clinical dietician. The control condition comprised a social support protocol to the same visit schedule and length. Depression symptomatology was the primary endpoint, assessed using the Montgomery-Åsberg Depression Rating Scale (MADRS) at 12 weeks. Secondary outcomes included remission and change of symptoms, mood and anxiety. Analyses utilised a likelihood-based mixed-effects model repeated measures (MMRM) approach. The robustness of estimates was investigated through sensitivity analyses.
We assessed 166 individuals for eligibility, of whom 67 were enrolled (diet intervention, n = 33; control, n = 34). Of these, 55 were utilising some form of therapy: 21 were using psychotherapy and pharmacotherapy combined; 9 were using exclusively psychotherapy; and 25 were using only pharmacotherapy. There were 31 in the diet support group and 25 in the social support control group who had complete data at 12 weeks. The dietary support group demonstrated significantly greater improvement between baseline and 12 weeks on the MADRS than the social support control group, t(60.7) = 4.38, p < 0.001, Cohen's d = -1.16. Remission, defined as a MADRS score <10, was achieved for 32.3% (n = 10) and 8.0% (n = 2) of the intervention and control groups, respectively (χ
(1) = 4.84, p = 0.028); number needed to treat (NNT) based on remission scores was 4.1 (95% CI of NNT 2.3-27.8). A sensitivity analysis, testing departures from the missing at random (MAR) assumption for dropouts, indicated that the impact of the intervention was robust to violations of MAR assumptions.
These results indicate that dietary improvement may provide an efficacious and accessible treatment strategy for the management of this highly prevalent mental disorder, the benefits of which could extend to the management of common co-morbidities.
Australia and New Zealand Clinical Trials Register (ANZCTR): ACTRN12612000251820 . Registered on 29 February 2012.
Australia experienced significant COVID-19 lockdown restrictions throughout 2020 that had an impact on mental health and disrupted health-promoting lifestyle behaviours. Lockdowns may have ...exacerbated existing mental health concerns among tertiary students, who experience higher levels of mental health concerns compared to the wider community. This study aimed to investigate the association between modifiable lifestyle factors and wellbeing of students at a Melbourne-based tertiary education institution during COVID-19 lockdown.
This quantitative, cross-sectional study was conducted across campuses in Melbourne and Sydney. Data was collected via online questionnaire during the 7th week of a second-wave lockdown. Descriptive statistics were calculated for demographic variables (n = 239). Linear regression models were estimated to determine multivariate associations between lifestyle variables and psychological distress.
Participants were on average 30.98 years old (SD = 9.78), predominantly female, domestic students, undergraduate, not the first member of their family to attend university and living out of family home. Mindfulness, diet quality, sleep quality and moderate-vigorous physical activity (MVPA) were all inversely correlated with psychological distress. Unadjusted and adjusted models show that mindfulness, sleep quality, and MVPA were all independently inversely related to psychological distress. Greater mindfulness, sleep quality and engagement in MVPA were associated with lower psychological distress during COVID-19 lockdowns.
As this study is cross-sectional and we cannot rule out reverse causality.
This study highlights the potential for lifestyle focused mental-health promotion delivered through tertiary education institutions to support students in times of crisis as well as more generally.
•Australia had strict COVID-19 lockdowns that impacted mental health and daily life.•Among students lifestyle factors were related to psychological distress.•This shows the potential to use lifestyle strategies used to support mental health.
Recently, the efficacy of dietary improvement as a therapeutic intervention for moderate to severe depression was evaluated in a randomised controlled trial. The SMILES trial demonstrated a ...significant improvement in Montgomery-Åsberg Depression Rating Scale scores favouring the dietary support group compared with a control group over 12 weeks. We used data collected within the trial to evaluate the cost-effectiveness of this novel intervention.
In this prospective economic evaluation, sixty-seven adults meeting DSM-IV criteria for a major depressive episode and reporting poor dietary quality were randomised to either seven sessions with a dietitian for dietary support or to an intensity matched social support (befriending) control condition. The primary outcome was Quality Adjusted Life Years (QALYs) as measured by the AQoL-8D, completed at baseline and 12 week follow-up (endpoint) assessment. Costs were evaluated from health sector and societal perspectives. The time required for intervention delivery was costed using hourly wage rates applied to the time in counselling sessions. Food and travel costs were also included in the societal perspective. Data on medications, medical services, workplace absenteeism and presenteesim (paid and unpaid) were collected from study participants using a resource-use questionnaire. Standard Australian unit costs for 2013/2014 were applied. Incremental cost-effectiveness ratios (ICERs) were calculated as the difference in average costs between groups divided by the difference in average QALYs. Confidence intervals were calculated using a non-parametric bootstrap procedure.
Compared with the social support condition, average total health sector costs were $856 lower (95% CI -1247 to - 160) and average societal costs were $2591 lower (95% CI -3591 to - 198) for those receiving dietary support. These differences were driven by lower costs arising from fewer allied and other health professional visits and lower costs of unpaid productivity. Significant differences in mean QALYs were not found between groups. However, 68 and 69% of bootstrap iterations showed the dietary support intervention was dominant (additional QALYs at less cost) from the health sector and societal perspectives.
This novel dietary support intervention was found to be likely cost-effective as an adjunctive treatment for depression from both health sector and societal perspectives.
Australia and New Zealand Clinical Trials Register (ANZCTR): ACTRN12612000251820 . Registered on 29 February 2012.
Global assessments of burden of disease suggests there are sex differences in risk factors for chronic disease, including overweight/obesity, dietary patterns and habitual physical activity. Given ...that prevention efforts aim to target such factors to reduce disease risk, the age at which sex differences may occur is of particular interest. Early life to young adulthood is the optimal time for intervention, with lifestyle habits typically forming during this period. This study aimed to identify the sex differences in risk factors for chronic disease during childhood (5-9 years), adolescence (10-17 years) and emerging adulthood (18-25 years) in a large population-representative Australian sample. Among children in this study (
= 739), no sex-related differences were observed. Among adolescents (
= 1304), females were more likely than males to meet daily fruit and vegetable recommendations (12.9% vs. 7.5%; OR = 1.84, 95% CI = 1.16, 2.93,
< 0.05). Among emerging adults (
= 909), females were less likely to be overweight/obese (30.1% vs. 39.8%; OR = 0.65, 95% CI = 0.44, 0.95,
< 0.05) and more likely to meet physical activity recommendations (52.1% vs. 42.3%; OR = 1.44, 95% CI = 1.01, 2.06,
< 0.05). These findings suggest that sex differences for risk factors of chronic disease occur during adolescence and emerging adulthood, although the differences are not consistent across age periods. From adolescence onwards, it appears that females exhibit lower risk factors than males and a life span approach to risk factor monitoring is warranted.
Depression and type 2 diabetes (T2D) contribute significantly to global burden of disease and often co-occur. Underpinning type 2 diabetes is poor glycaemic control and glucose is also an obligatory ...substrate for brain metabolism, with potential implications for cognition, motivation and mood. This research aimed to examine the relationships between fasting plasma glucose and depressive symptoms in a large, population representative sample of US adults, controlling for other demographic and lifestyle behavioural risk factors. Using the 2013-2014 National Health and Nutrition Examination Survey (NHANES) data, this study first investigated the relationship between fasting plasma glucose and mental disorders at a population-level, accounting for demographic, health behavioural and weight-related factors known to co-occur with both type 2 diabetes and mental disorders. Depressive symptoms were derived from the 9-item Patient Health Questionnaire. Fasting plasma glucose was obtained through medical examination and demographic (age, household income, sex) and health characteristics (perceived diet quality, daily time sedentary) were self-reported. Body mass index was calculated from objectively measured height and weight. In the univariate model, higher fasting plasma glucose was associated with greater depressive symptoms among females (
= 0.24, 95% CI = 0.05, 0.43,
< 0.05), but not males. In the final fully adjusted model, the relationship between fasting plasma glucose and depressive symptoms was non-significant for both males and females. Of all independent variables, self-appraised diet quality was strongly and significantly associated with depressive symptoms and this remained significant when individuals with diabetes were excluded. Although diet quality was self-reported based on individuals' perceptions, these findings are consistent with a role for poor diet in the relationship between fasting plasma glucose and depressive symptoms.
Evidence suggests age and sex differences in risk factors for chronic disease. This study examined lifestyle and biomedical risk factors among men (m) and women (w) in early-middle (25⁻51 years), ...middle (52⁻64) and older (65+) adulthood. Cross-sectional data from the 2011⁻2012 Australian Health Survey (n = 3024) were analysed. Self-reported dietary, activity, sleep behaviours and collected biomedical data were analysed. Early-middle adults failed to meet fruit, vegetable (95.3%) and sugar-sweetened beverage (SSB, 34.9%) recommendations. Older adults had higher prevalence of overweight/obesity (70%), high blood pressure (38.0%) and fewer met physical activity guidelines (36.3%). Prior to older adulthood, more men consumed SSBs (early-middle m 45.6%, w 24.4%; middle m 26.0%, w 19.3%), and fewer met sedentary behaviour recommendations (early-middle m 43.2%, w 62.1%; middle m 46.4%, w 63.9%). Differences in overweight/obese women in early-middle (44.8%) to middle adulthood (64.7%) were significant. Biomedical risk was greatest in middle age; abnormal cholesterol/lipids increased specifically for women (total cholesterol early-middle 24.9% middle 56.4%; abnormal LDL-cholesterol early-middle 23.1% middle 53.9%). Adherence to lifestyle guidelines was low; particularly among men. While men exhibited greater clinical risk overall, this significantly increased among women in middle-adulthood. Public health strategies to improve lifestyle, monitor and intervene among middle-aged women are warranted.
Aims:
We aimed to explore the relationships between diet quality, dietary inflammatory potential or body mass index and outcomes of a clinical trial of nutraceutical treatment for bipolar depression.
...Methods:
This is a sub-study of a randomised controlled trial of participants with bipolar depression who provided dietary intake data (n = 133). Participants received 16 weeks adjunctive treatment of either placebo or N-acetylcysteine-alone or a combination of mitochondrial-enhancing nutraceuticals including N-acetylcysteine (combination treatment). Participants were followed up 4 weeks post-treatment discontinuation (Week 20). Diet was assessed by the Cancer Council Victoria Dietary Questionnaire for Epidemiological Studies, Version 2, converted into an Australian Recommended Food Score to measure diet quality, and energy-adjusted dietary inflammatory index score to measure inflammatory potential of diet. Body mass index was also measured. Generalised estimating equation models were used to assess whether diet quality, energy-adjusted dietary inflammatory index score and/or body mass index were predictors of response to significant outcomes of the primary trial: depression symptoms, clinician-rated improvement and functioning measures.
Results:
In participants taking combination treatment compared to placebo, change in depression scores was not predicted by Australian Recommended Food Score, dietary inflammatory index or body mass index scores. However, participants with better diet quality (Australian Recommended Food Score) reported reduced general depression and bipolar depression symptoms (p = 0.01 and p = 0.03, respectively) and greater clinician-rated improvement (p = 0.02) irrespective of treatment and time. Participants who had a more anti-inflammatory dietary inflammatory index had less impairment in functioning (p = 0.01). Combination treatment may attenuate the adverse effects of pro-inflammatory diet (p = 0.03) on functioning. Participants with lower body mass index who received combination treatment (p = 0.02) or N-acetylcysteine (p = 0.02) showed greater clinician-rated improvement.
Conclusion:
These data support a possible association between diet (quality and inflammatory potential), body mass index and response to treatment for bipolar depression in the context of a nutraceutical trial. The results should be interpreted cautiously because of limitations, including numerous null findings, modest sample size and being secondary analyses.
The original version of this paper 1 did not specify that a website was used in the final year of recruitment, in addition to the other stated recruitment methods.