Studies of single nutrients on depression have produced inconsistent results, and they have failed to consider the complex interactions between nutrients. An increasing number of studies in recent years are investigating the association of overall dietary patterns and depression. This study aimed to systematically review current literature and conduct meta-analyses of studies addressing the association between dietary patterns and depression. Six electronic databases were searched for articles published up to August 2013 that examined the association of total diet and depression among adults. Only studies considered methodologically rigorous were included. Two independent reviewers completed study selection, quality rating, and data extraction. Effect sizes of eligible studies were pooled by using random-effects models. A summary of the findings was presented for studies that could not be meta-analyzed. A total of 21 studies were identified. Results from 13 observational studies were pooled. Two dietary patterns were identified. The healthy diet pattern was significantly associated with a reduced odds of depression (OR: 0.84; 95% CI: 0.76, 0.92; P < 0.001). No statistically significant association was observed between the Western diet and depression (OR: 1.17; 95% CI: 0.97, 1.68; P = 0.094); however, the studies were too few for a precise estimate of this effect. The results suggest that high intakes of fruit, vegetables, fish, and whole grains may be associated with a reduced depression risk. However, more high-quality randomized controlled trials and cohort studies are needed to confirm this finding, specifically the temporal sequence of this association.
Type 2 diabetes is associated with significant morbidity and mortality. Modifiable risk factors have been found to contribute up to 60% of type 2 diabetes risk. However, type 2 diabetes continues to rise despite implementation of interventions based on traditional risk factors. There is a clear need to identify additional risk factors for chronic disease prevention. The aim of this study was to examine the relationship between perceived stress and type 2 diabetes onset, and partition the estimates into direct and indirect effects. Women born in 1946–1951 (n = 12,844) completed surveys for the Australian Longitudinal Study on Women’s Health in 1998, 2001, 2004, 2007 and 2010. The total causal effect was estimated using logistic regression and marginal structural modelling. Controlled direct effects were estimated through conditioning in the regression model. A graded association was found between perceived stress and all mediators in the multivariate time lag analyses. A significant association was found between hypertension, as well as physical activity and body mass index, and diabetes, but not smoking or diet quality. Moderate/high stress levels were associated with a 2.3-fold increase in the odds of diabetes three years later, for the total estimated effect. Results were only slightly attenuated when the direct and indirect effects of perceived stress on diabetes were partitioned, with the mediators only explaining 10–20% of the excess variation in diabetes. Perceived stress is a strong risk factor for type 2 diabetes. The majority of the effect estimate of stress on diabetes risk is not mediated by the traditional risk factors of hypertension, physical activity, smoking, diet quality, and body mass index. This gives a new pathway for diabetes prevention trials and clinical practice.
1 November 2012 in The American Journal of Clinical Nutrition
Background: The prenatal environment can induce permanent changes in offspring phenotype. Thinness at birth is associated with adult risk of cardiometabolic disease.
Objective: To investigate and report the diet quality of young Australian women by pregnancy status.Design: Pregnancy status was defined as pregnant (n606), trying to conceive (n454), had a baby in the last 12 months (n829) and other (n5597). The Dietary Questionnaire for Epidemiological Studies was used to calculate diet quality using the Australian Recommended Food Score (ARFS) methodology. Nutrient intakes were compared with the Nutrient Reference Values for Australia and New Zealand.Setting: A population-based cohort participating in the Australian Longitudinal Study on Women’s Health (ALSWH).Subjects: A nationally representative sample of Australian women, aged 25 to 30 years, who completed Survey 3 of the ALSWH. The 7486 women with biologically plausible energy intake estimates, defined as >4·5 but <20·0 MJ/d, were included in the analyses.Results: Pregnancy status was not significantly predictive of diet quality, before or after adjusting for area of residence and socio-economic status. Pregnant women and those who had given birth in the previous 12 months had marginally higher ARFS (mean (se): 30·2 (0·4) and 30·2 (0·3), respectively) than ‘other’ women (29·1 (0·1)). No single food group accounted for this small difference. Across all pregnancy categories there were important nutrients that did not meet the current nationally recommended levels of intake, including dietary folate and fibre.Conclusion: Women do not appear to consume a wider variety of nutritious foods when planning to become pregnant or during pregnancy. Many young Australian women are failing to meet key nutrient targets as nationally recommended.