Diet quality score is a predictor of type 2 diabetes risk in women: the Australian Longitudinal Study on Women's Health

Longitudinal analysis of the Alternative Healthy Eating Index-2010 and incident non-communicable diseases over 15 years in the 1973-1978 cohort of the Australian Longitudinal Study on Women's Health

In studies that contain repeated measures of variables, longitudinal analysis accounting for time-varying covariates is one of the options. We aimed to explore longitudinal association between diet quality (DQ) and non-communicable diseases (NCDs). Participants from the 1973-1978 cohort of the Australian Longitudinal Study on Women's Health (ALSWH) were included, if they; responded to survey 3 (S3, 2003, aged 25-30 years) and at least one survey between survey 4 (S4, 2006) and survey 8 (S8, 2018), were free of NCDs at or before S3, and provided dietary data at S3 or S5. Outcomes were coronary heart disease (CHD), hypertension (HT), asthma, cancer (except skin cancer), diabetes mellitus (DM), depression and/or anxiety, and multimorbidity (MM). Longitudinal modelling using generalised estimation equation (GEE) approach with time-invariant (S4), time-varying (S4-S8) and lagged (S3-S7) covariates were performed. The mean (± standard deviation) of Alternative Healthy Eating Index-2010 (AHEI-2010) of participants (n = 8022) was 51·6 ± 11·0 (range: 19-91). Compared to women with the lowest DQ (AHEI-2010 quintile 1), those in quintile 5 had reduced odds of NCDs in time-invariant model (asthma: OR (95 % CI): 0·77 (0·62-0·96), time-varying model (HT: 0·71 (0·50-0·99); asthma: 0·62 (0·51-0·76); and MM: 0·75 (0·58-0·97) and lagged model (HT: 0·67 (0·49-0·91); and asthma: 0·70 (0·57-0·85). Temporal associations between diet and some NCDs were more prominent in lagged GEE analyses. Evidence of diet as NCD prevention in women aged 25-45 years is evolving, and more studies that consider different longitudinal analyses are needed.

Gene-diet interaction analysis using novel weighted food scores discovers the adipocytokine signaling pathway associated with the development of type 2 diabetes

Introduction

The influence of dietary patterns measured using Recommended Food Score (RFS) with foods with high amounts of antioxidant nutrients for Type 2 diabetes (T2D) was analyzed. Our analysis aims to find associations between dietary patterns and T2D and conduct a gene-diet interaction analysis related to T2D.

Methods

Data analyzed in the current study were obtained from the Korean Genome and Epidemiology Study Cohort. The dietary patterns of 46 food items were assessed using a validated food frequency questionnaire. To maximize the predictive power of the RFS, we propose two weighted food scores, namely HisCoM-RFS calculated using the novel Hierarchical Structural Component model (HisCoM) and PLSDA-RFS calculated using Partial Least Squares-Discriminant Analysis (PLS-DA) method.

Results

Both RFS (OR: 1.11; 95% CI: 1.03- 1.20; P = 0.009) and PLSDA-RFS (OR: 1.10; 95% CI: 1.02-1.19, P = 0.011) were positively associated with T2D. Mapping of SNPs (P < 0.05) from the interaction analysis between SNPs and the food scores to genes and pathways yielded some 12 genes (CACNA2D3, RELN, DOCK2, SLIT3, CTNNA2, etc.) and pathways associated with T2D. The strongest association was observed with the adipocytokine signalling pathway, highlighting 32 genes (STAT3, MAPK10, MAPK8, IRS1, AKT1-3, ADIPOR2, etc.) most likely associated with T2D. Finally, the group of the subjects in low, intermediate and high using both the food scores and a polygenic risk score found an association between diet quality groups with issues at high genetic risk of T2D.

Conclusion

A dietary pattern of poor amounts of antioxidant nutrients is associated with the risk of T2D, and diet affects pathway mechanisms involved in developing T2D.

Diet quality in an ethnically diverse population of older men in Australia

BACKGROUND/OBJECTIVES

To compare the Australian Dietary Guideline Index (DGI-2013) and the Pyramid-based Mediterranean Diet Score (pyrMDS) as measures of diet quality in an ethnically diverse group of older men.

SUBJECTS/METHODS

Seven hundred and ninety-four older men aged ≥75 participated in wave 3 (2012-2013) of the Concord Health and Ageing in Men Project. Dietary intake was assessed using a validated diet history questionnaire. Ethnicity was based on self-reported country of birth and categorised as Australian-born (418 men), Italian or Greek migrants (188), and other migrants (188). Incident cardiovascular outcomes until March 2018 were measured using the composite of major adverse cardiovascular events (MACE), which comprises all-cause mortality, acute myocardial infarction, congestive cardiac failure, coronary revascularisation and/or ischaemic stroke. Ability to predict incident cardiovascular outcomes and all-cause mortality were compared between standardised DGI-2013 pyrMDS scores by comparison of hazard ratios, discrimination (Harrell's C-statistic) and calibration (calibration plots).

RESULTS

Italian and Greek migrant men had significantly lower DGI-2013 scores (91.7 vs. 93.9; p = 0.01) but significantly higher pyrMDS scores (8.8 vs. 8.2; p < 0.0001) than Australian-born men. In the whole sample (794 men), the pyrMDS was a better predictor of both MACE (age-adjusted HR = 0.84; 95% CI = 0.75-0.94 vs. HR = 0.92; 95% CI = 0.82-1.03 for DGI-2013) and all-cause mortality (age-adjusted HR = 0.69; 95% CI = 0.60-0.80 vs. HR = 0.86; 95% CI = 0.74-0.99). The pyrMDS also demonstrated superior discrimination for predicting all-cause mortality and superior calibration for MACE and all-cause mortality.

CONCLUSIONS

The DGI-2013 appears to underestimate diet quality in older Italian and Greek migrant men. The pyrMDS appears superior to the DGI-2013 for prediction of incident cardiovascular disease and mortality regardless of ethnic background.

Association of adherence to the Australian Dietary Guidelines with cognitive performance and cognitive decline in the Sydney Memory and Ageing Study: a longitudinal analysis

This study investigated associations of adherence to the Australian Dietary Guidelines (ADG) with cognitive performance and cognitive decline over 6 years. We used longitudinal data from the Sydney Memory and Aging Study comprising 1037 community-dwelling non-demented participants aged 70–90 years. Dietary intake was assessed at baseline using the Dietary Questionnaire for Epidemiological Studies Version 2. Adherence to the ADG was scored using the Dietary Guideline Index 2013 (DGI-2013). Cognition was assessed using neuropsychological tests in six cognitive domains and global cognition at baseline and 2, 4 and 6 years later. Linear mixed models analysed the association between adherence to the ADG and cognitive function and cognitive decline over 6 years. Results indicated that overall adherence to the ADG was suboptimal (DGI-2013 mean score 43⋅8 with a standard deviation of 10⋅1; median score 44, range 12–73 with an interquartile range of 7). The percent of participants attaining recommended serves for the five food groups were 30⋅2 % for fruits, 11⋅2 % for vegetables, 54⋅6 % for cereals, 28⋅9 % for meat and alternatives and 2⋅1 % for dairy consumption. Adherence to the ADG was not associated with overall global cognition over 6 years (β = 0⋅000; 95 % CI: −0⋅007, 0⋅007; P = 0⋅95). Neither were DGI-2013 scores associated with change in global cognitive performance over 6 years (β = 0⋅002; 95 % CI: −0⋅002, 0⋅005; P = 0⋅41) nor in any individual cognitive domains. In conclusion, adherence to the ADG was not associated with cognitive health over time in this longitudinal analysis of older Australians. Future research is needed to provide evidence to support specific dietary guidelines for neurocognitive health among Australian older adults.

Diet Quality Indices Used in Australian and New Zealand Adults: A Systematic Review and Critical Appraisal

Distilling the complexity of overall diet into a simple measure or summative score by data reduction methods has become a common practice in nutritional epidemiology. Recent reviews on diet quality indices (DQI) have highlighted the importance of sound construction criteria and validation. The aim of this current review was to identify and critically appraise all DQI used within Australian and New Zealand adult populations. Twenty-five existing DQI were identified by electronic searching in Medline and hand searching of reference lists. DQI were constructed based on the respective national dietary guidelines and condition-specific recommendations. For preferable features of DQI, six captured the dimensions of adequacy, moderation and balance; five had a nested structure; 12 consisted of foods, food groups and nutrients; 11 used metric scoring systems and most of those with metric scales used normative cutoff points. Food frequency questionnaires, either alone or with other methods, were the most common dietary assessment method used in 20 DQI. For evaluation of DQI, construct validity and relative validity are reported. Based on our critical appraisal, Dietary Guideline Index (DGI), Dietary Guideline Index-2013 (DGI-2013), Total Diet Score (TDS), Healthy Eating Index for Australian Adults-2013 (HEIFA-2013), and Aussie-Diet Quality Index (Aussie-DQI) were the preferred DQI used in Australian adults according to dimension, indicator selection, scoring criteria and evaluation. Further work is needed to enhance the construction of all Australian and New Zealand DQI, especially in terms of dimension and structure, for alignment with recommended construction criteria.

Adaptation and validity assessment of a diet quality index for patients with type 2 diabetes

PURPOSE

As diet quality indices (DQI) are likely to be influenced by disease background, adapting the existing indices for each disease is crucial. No study has been adapted a DQI for patients with type 2 diabetes. We aimed to adapt healthy eating index and assess its validity for Iranian patients with type 2 diabetes mellitus (T2DM).

METHODS

In this cross-sectional study, the analysis was conducted on 489 adults with T2DM. We adapted HEI and assessed its validity using construct validity. Construct validity was assessed using a 168-item semi-quantitative food-frequency questionnaire (FFQ). General linear model was used to assess associations between adapted HEI scores and demographic characteristics, anthropometric indices, physical activity and food and nutrient intakes.

RESULTS

Adapted HEI were examined on 489 subjects (163 men and 326 women). Findings showed that in older subjects the mean adapted HEI score was greater than the younger ones. However, it was significant only in women (p = 0.01). Women with higher education level obtained the greater score (p < 0.001). The greatest mean score of the adapted HEI score in men was related to non-smokers. The mean score in both genders were raised following the increase in physical activity level (p < 0.05). Moreover, a reduction in the mean score of adapted HEI was observed in men with higher BMI compared to those with the lower one (p = 0.001).

CONCLUSION

Adapted HEI could successfully discriminate diet quality in patients with T2DM. Older and high-educated women were adhered greatly to high quality diets. The adapted DQI linked with greater physical activity level and non-smokers diabetic men with lower BMI.

Education and lifestyle predict change in dietary patterns and diet quality of adults 55 years and over

Background

Diet is a key risk factor for chronic disease, and an increasing concern among older adults. We aim to examine the changes in dietary patterns using principal component analysis and a diet quality index among older adults and examine the predictors of dietary change over a 4 year period.

Methods

Data was obtained via a postal survey in a prospective cohort, the Wellbeing Eating and Exercise for a Long Life (WELL) study. Australian adults aged 55 years and over (n = 1005 men and n = 1106 women) completed a food frequency at three time points and provided self-reported personal characteristics. Principal component analysis was used to assess dietary patterns and diet quality was assessed using the 2013 Revised Dietary Guideline Index. The relationships between predictors and change in dietary patterns were assessed by multiple linear regression.

Results

Two dietary patterns were consistently identified in men and women at three time points over 4 years. One was characterised by vegetables, fruit and white meat, and the other was characterised by red and processed meat and processed foods. Reduced consumption of key food groups within the principal component analysis-determined dietary patterns was observed. An increase in diet quality over 4 years was observed in men only. Reported higher education levels and favourable lifestyle characteristics, including not smoking and physical activity, at baseline predicted an increase in healthier dietary patterns over 4 years.

Conclusions

There was stability in the main dietary patterns identified over time, however participants reported an overall decrease in the frequency of consumption of key food groups. Compliance with the Australian Dietary Guidelines remained poor and therefore targeting this population in nutritional initiatives is important. Design of nutrition promotion for older adults need to consider those with lower socioeconomic status, as having a lower level of education was a predictor of poorer dietary patterns. It is important to consider how nutrition behaviours can be targeted alongside other lifestyle behaviours, such as smoking and inadequate physical activity to improve health.

Strong adherence to dietary and lifestyle recommendations is associated with decreased type 2 diabetes risk in the AusDiab cohort study

We aimed to determine whether adherence to the Australian dietary guidelines and an index of healthy behavior was associated with a lower risk of type 2 diabetes (T2D) and to provide estimates of the proportion of preventable cases. Participants of the AusDiab cohort study were followed for 12 years (n = 6242), starting from May 1999, during which T2D cases were identified. The associations between T2D risk and a score of adherence to the dietary guidelines, its components, and a score of adherence to an index of healthy behaviors, (which included smoking, recreational physical activity, waist circumference and adherence to the dietary guidelines), were estimated using Cox proportional hazards ratios (HR) and 95% confidence intervals. The proportion of preventable cases was estimated using the population attributable fraction (PAF). Strong adherence to the dietary guidelines was not associated with T2D risk (HR = 0.64 [95% CI 0.39-1.06]), unless moderate alcohol consumption was considered as beneficial instead of no alcohol consumption (HR = 0.59 [0.36-0.96]). However, strong adherence to the guidelines regarding fruit and dairy intake were both associated with decreased risk of T2D (HR = 0.68 [0.51-0.91]; 0.56 [0.38-0.84], respectively) and could have prevented 23-37% of cases (PAF = 23.3% [7.3-38.2]; 37.1% [14.6-56.0], respectively). Strong adherence to the index of healthy behaviors was associated with decreased risk of T2D (HR = 0.30 [0.17-0.51]) and estimated to prevent almost 60% of T2D (PAF = 59.4% [34.3-76.6]). More than half of T2D cases could be preventable in Australia through modifying health behavior. These results could serve as a basis for prevention programs based on lifestyle modification.

Progression of diabetes, heart disease, and stroke multimorbidity in middle-aged women: A 20-year cohort study

BACKGROUND

The prevalence of diabetes, heart disease, and stroke multimorbidity (co-occurrence of two or three of these conditions) has increased rapidly. Little is known about how the three conditions progress from one to another sequentially through the life course. We aimed to delineate this progression in middle-aged women and to determine the roles of common risk factors in the accumulation of diabetes, heart disease, and stroke multimorbidity.

METHODS AND FINDINGS

We used data from 13,714 women aged 45-50 years without a history of any of the three conditions. They were participants in the Australian Longitudinal Study on Women's Health (ALSWH), enrolled in 1996, and surveyed approximately every 3 years to 2016. We characterized the longitudinal progression of the three conditions and multimorbidity. We estimated the accumulation of multimorbidity over 20 years of follow-up and investigated their association with both baseline and time-varying predictors (sociodemographic factors, lifestyle factors, and other chronic conditions). Over 20 years, 2,511 (18.3%) of the women progressed to at least one condition, of whom 1,420 (56.6%) had diabetes, 1,277 (50.9%) had heart disease, and 308 (12.3%) had stroke; 423 (16.8%) had two or three of these conditions. Over a 3-year period, the age-adjusted odds of two or more conditions was approximately twice that of developing one new condition compared to women who did not develop any new conditions. For example, the odds for developing one new condition between Surveys 7 and 8 were 2.29 (95% confidence interval [CI], 1.93-2.72), whereas the odds for developing two or more conditions was 6.51 (95% CI, 3.95-10.75). The onset of stroke was more strongly associated with the progression to the other conditions (i.e., 23.4% [95% CI, 16.3%-32.2%] of women after first onset of stroke progressed to other conditions, whereas the percentages for diabetes and heart disease were 9.9% [95% CI, 7.9%-12.4%] and 11.4% [95% CI, 9.1%-14.4%], respectively). Being separated, divorced, or widowed; being born outside Australia; having difficulty managing on their available income; being overweight or obese; having hypertension; being physically inactive; being a current smoker; and having prior chronic conditions (i.e., mental disorders, asthma, cancer, osteoporosis, and arthritis) were significantly associated with increased odds of accumulation of diabetes, heart disease, and stroke multimorbidity. The main limitations of this study were the use of self-reported data and the low number of events.

CONCLUSIONS

Stroke was associated with increased risk of progression to diabetes or heart disease. Social inequality, obesity, hypertension, physical inactivity, smoking, or having other chronic conditions were also significantly associated with increased odds of accumulating multimorbidity. Our findings highlight the importance of awareness of the role of diabetes, heart disease, and stroke multimorbidity among middle-aged women for clinicians and health-promotion agencies.

Exploring Diet Quality between Urban and Rural Dwelling Women of Reproductive Age

Health disparities, including weight gain and obesity exist between urban and rural dwelling women. The primary aim was to compare diet quality in urban and rural women of reproductive age, and secondary analyses of the difference in macronutrient and micronutrient intake in urban and rural women, and the predictors of diet quality. Diet quality was assessed in urban (n = 149) and rural (n = 394) women by a modified version of the Dietary Guideline Index (DGI) energy, macronutrient and micronutrient intake from a food frequency questionnaire (FFQ) and predictors of diet quality. Diet quality did not significantly differ between urban and rural women (mean ± standard deviation (SD), 84.8 ± 15.9 vs. 83.9 ± 16.5, p = 0.264). Rural women reported a significantly higher intake of protein, fat, saturated fat, monounsaturated fat, cholesterol and iron and a higher score in the meat and meat alternatives component of the diet quality tool in comparison to urban women. In all women, a higher diet quality was associated with higher annual household income (>$Australian dollar (AUD) 80,000 vs. <$AUD80,000 p = 0.013) and working status (working fulltime/part-time vs. unemployed p = 0.043). Total diet quality did not differ in urban and rural women; however, a higher macronutrient consumption pattern was potentially related to a higher lean meat intake in rural women. Women who are unemployed and on a lower income are an important target group for future dietary interventions aiming to improve diet quality.

Dietary Patterns and Type 2 Diabetes: A Systematic Literature Review and Meta-Analysis of Prospective Studies

Background: Different methodologic approaches for constructing dietary patterns and differences in their composition limit conclusions on healthful patterns for diabetes prevention.Objective: We summarized evidence from prospective studies that examined associations of dietary patterns with type 2 diabetes by considering different methodologic approaches.Methods: The literature search (MEDLINE and Web of Science) identified prospective studies (cohorts or trials) that associated dietary patterns with diabetes incidence in nondiabetic and apparently healthy participants. We summarized evidence by meta-analyses and distinguished different methodologic approaches.Results: The search resulted in 48 articles comprising 16 cohorts. Adherence to the Mediterranean diet (RR for comparing extreme quantiles: 0.87; 95% CI: 0.82, 0.93), Dietary Approaches to Stop Hypertension (DASH) (RR: 0.81; 95% CI: 0.72, 0.92), and Alternative Healthy Eating Index (AHEI) (RR: 0.79; 95% CI: 0.69, 0.90) was associated with significant risk reductions of incident diabetes. Patterns from exploratory factor and principal component analyses characterized by red and processed meat, refined grains, high-fat dairy, eggs, and fried products ("mainly unhealthy") were positively associated with diabetes (RR: 1.44; 95% CI: 1.27, 1.62), whereas patterns characterized by vegetables, legumes, fruits, poultry, and fish ("mainly healthy") were inversely associated with diabetes (RR: 0.84; 95% CI: 0.77, 0.91). Reduced rank regression (RRR) used diabetes-related biomarkers to identify patterns. These patterns were characterized by high intakes of refined grains, sugar-sweetened soft drinks, and processed meat and were all significantly associated with diabetes risk.Conclusions: Our meta-analysis suggests that diets according to the Mediterranean diet, DASH, and AHEI have a strong potential for preventing diabetes, although they differ in some particular components. Exploratory dietary patterns were grouped based on concordant food groups and were significantly associated with diabetes risk despite single-component foods having limited evidence for an association. Still, they remain population-specific observations. Consistent positive associations with diabetes risk were observed for 3 RRR patterns.

An Overview of Plant Phenolic Compounds and Their Importance in Human Nutrition and Management of Type 2 Diabetes

In this paper, the biosynthesis process of phenolic compounds in plants is summarized, which include the shikimate, pentose phosphate and phenylpropanoid pathways. Plant phenolic compounds can act as antioxidants, structural polymers (lignin), attractants (flavonoids and carotenoids), UV screens (flavonoids), signal compounds (salicylic acid, flavonoids) and defense response chemicals (tannins, phytoalexins). From a human physiological standpoint, phenolic compounds are vital in defense responses, such as anti-aging, anti-inflammatory, antioxidant and anti-proliferative activities. Therefore, it is beneficial to eat such plant foods that have a high antioxidant compound content, which will cut down the incidence of certain chronic diseases, for instance diabetes, cancers and cardiovascular diseases, through the management of oxidative stress. Furthermore, berries and other fruits with low-amylase and high-glucosidase inhibitory activities could be thought of as candidate food items in the control of the early stages of hyperglycemia associated with type 2 diabetes.

Diet qualities: healthy and unhealthy aspects of diet quality in preschool children

BACKGROUND

Diet quality indexes combine the healthy and unhealthy aspects of diet within a single construct, but few studies have evaluated their association. Emerging evidence suggests that predictors differ for the more and less healthy components of children's diets.

OBJECTIVES

Our objectives were to determine whether preschool-aged children's frequency of eating healthy foods was inversely related to their intake of unhealthy foods and to determine whether this differed by household income, maternal education, or child race-ethnicity.

DESIGN

We analyzed data from a representative sample of 8900 US children (mean age: 52.5 mo) who were born in 2001 and participated in the Early Childhood Longitudinal Study-Birth Cohort. Primary caregivers reported the frequency with which children consumed fruit, vegetables, milk, juice, sugar-sweetened beverages (SSBs), fast food, sweets, and salty snacks in the past week. Response options ranged from none to ≥4 times/d. We created healthy (fruit, vegetables, milk) and unhealthy (SSBs, fast food, sweets, salty snacks) diet scores. Healthy diet behaviors were defined as ≥2 daily servings of fruit, vegetables, and milk.

RESULTS

The prevalence of consuming fruit, vegetables, and milk ≥2 times/d (i.e., having 3 healthy diet behaviors) was 18.5%, and a similar proportion (17.6%) of children had none of these healthy behaviors. Contrary to our hypotheses, children with more healthy diet behaviors did not have lower unhealthy diet scores. The intake of healthy foods was not inversely associated with unhealthy foods overall or within any subgroup. Overall, the Spearman rank correlation between healthy and unhealthy diet scores was positive (r = 0.09). From the lowest to the highest strata of household income, these correlations were 0.12, 0.14, 0.14, 0.05, and 0.00, respectively.

CONCLUSIONS

No evidence was found in US preschool-aged children of an inverse association between eating healthy and unhealthy foods. The implications of combining healthy and unhealthy aspects of diet quality within an overall index should be considered by researchers.

Protective lifestyle behaviours and depression in middle-aged Irish men and women: a secondary analysis

Objective

To examine the association between protective lifestyle behaviours (PLB) and depression in middle-aged Irish adults.

Design

Secondary analysis of a cross-sectional study. PLB (non-smoker, moderate alcohol, physical activity, adequate fruit and vegetable intake) were assessed using a general health and lifestyle questionnaire and a validated FFQ. Depression was assessed using the Center for Epidemiologic Studies Depression Scale. A score of 15–21 indicates mild/moderate depression and a score of 22 or more indicates a possibility of major depression. Binary logistic regression was used to examine the association between PLB and depression.

Setting

Livinghealth Clinic, Mitchelstown, North Cork, Republic of Ireland.

Subjects

Men and women aged 50–69 years were selected at random from a list of patients registered at the clinic (n 2047, 67 % response rate).

Results

Over 8 % of participants engaged in zero or one PLB, 24 % and 39 % had two and three PLB respectively, while 28 % had four PLB. Those who practised three/four PLB were significantly more likely to be female, have a higher level of education and were categorised as having no depressive symptoms. Engaging in zero or one PLB was significantly associated with an increased odds of depression compared with four PLB. Results remained significant after adjusting for several confounders, including age, gender, education and BMI (OR=2·2; 95 % CI 1·2, 4·0; P for trend=0·001).

Conclusions

While causal inference cannot be established in a cross-sectional study, the findings suggest that healthy behaviours may play a vital role in the promotion of positive mental health or, at a minimum, are associated with lower levels of depression.

A Revised Australian Dietary Guideline Index and Its Association with Key Sociodemographic Factors, Health Behaviors and Body Mass Index in Peri-Retirement Aged Adults

The Dietary Guideline Index, a measure of diet quality, was updated to reflect the 2013 Australian Dietary Guidelines. This paper describes the revision of the index (DGI-2013) and examines its use in older adults. The DGI-2013 consists of 13 components reflecting food-based daily intake recommendations of the Australian Dietary Guidelines. In this cross-sectional study, the DGI-2013 score was calculated using dietary data collected via an 111-item food frequency questionnaire and additional food-related behaviour questions. The DGI-2013 score was examined in Australian adults (aged 55–65 years; n = 1667 men; 1801 women) according to sociodemographics, health-related behaviours and BMI. Women scored higher than men on the total DGI-2013 and all components except for dairy. Those who were from a rural area (men only), working full-time (men only), with lower education, smoked, did not meet physical activity guidelines, and who had a higher BMI, scored lower on the DGI-2013, highlighting a group of older adults at risk of poor health. The DGI-2013 is a tool for assessing compliance with the Australian Dietary Guidelines. We demonstrated associations between diet quality and a range of participant characteristics, consistent with previous literature. This suggests that the DGI-2013 continues to demonstrate convergent validity, consistent with the original Dietary Guideline Index.

Longitudinal diet quality is not associated with depressive symptoms in a cohort of middle-aged Australian women

There is increasing evidence for the role of nutrition in the prevention of depression. This study aims to describe changes in diet quality over 12 years among participants in the Australian Longitudinal Study on Women’s Health in relation to changes in depressive symptoms. Women born between 1946 and 1951 were followed-up for 12 years (2001–2013). Dietary intake was assessed using the Dietary Questionnaire for Epidemiological Studies (version 2) in 2001, 2007 and every 2–3 years after that until 2013. Diet quality was summarised using the Australian Recommended Food Score (ARFS). Depressive symptoms were measured using the ten-item Centre for Epidemiologic Depression Scale at every 2–3-year intervals during 2001–2013. Linear mixed models were used to examine trends in diet quality and its sub-components. The same model including time-varying covariates was used to examine associations between diet quality and depressive symptoms adjusting for confounders. Sensitivity analyses were carried out using the Mediterranean dietary pattern (MDP) index to assess diet quality. Minimal changes in overall diet quality and its sub-components over 12 years were observed. There was a significant association between baseline diet quality and depression (β=−0·24, P=0·001), but this was lost when time-varying covariates were added (β=−0·04, P=0·10). Sensitivity analyses showed similar performance for both ARFS and MDP in predicting depressive symptoms. In conclusion, initial associations seen when using baseline measures of diet quality and depressive symptoms disappear when using methods that handle time-varying covariates, suggesting that previous studies indicating a relationship between diet and depression may have been affected by residual confounding.

Prospective study on the association between diet quality and depression in mid-aged women over 9 years

PURPOSE

To examine the longitudinal association between diet quality and depression using prospective data from the Australian Longitudinal Study on Women's Health.

METHODS

Women born in 1946-1951 (n = 7877) were followed over 9 years starting from 2001. Dietary intake was assessed using the Dietary Questionnaire for Epidemiological Studies (version 2) in 2001 and a shortened form in 2007 and 2010. Diet quality was summarised using the Australian Recommended Food Score. Depression was measured using the 10-item Centre for Epidemiologic Depression Scale and self-reported physician diagnosis. Pooled logistic regression models including time-varying covariates were used to examine associations between diet quality tertiles and depression. Women were also categorised based on changes in diet quality during 2001-2007. Analyses were adjusted for potential confounders.

RESULTS

The highest tertile of diet quality was associated marginally with lower odds of depression (OR 0.94; 95 % CI 0.83, 1.00; P = 0.049) although no significant linear trend was observed across tertiles (OR 1.00; 95 % CI 0.94, 1.10; P = 0.48). Women who maintained a moderate or high score over 6 years had a 6-14 % reduced odds of depression compared with women who maintained a low score (moderate vs low score-OR 0.94; 95 % CI 0.80, 0.99; P = 0.045; high vs low score-OR 0.86; 95 % CI 0.77, 0.96; P = 0.01). Similar results were observed in analyses excluding women with prior history of depression.

CONCLUSION

Long-term maintenance of good diet quality may be associated with reduced odds of depression. Randomised controlled trials are needed to eliminate the possibility of residual confounding.