A longitudinal study of blood folate levels and depressive symptoms among young women in the Southampton Women's Survey

SunGold Kiwifruit and Psychological Health (GoKiPH): A Randomised Controlled Crossover Trial

Background/Objectives: The consumption of SunGold kiwifruit, a fruit rich in vitamin C, has been associated with improved mood in healthy individuals with low vitamin C levels. However, no studies have examined this relationship in individuals with elevated mood disturbance. This study examined the potential for SunGold kiwifruit to improve psychological wellbeing in mood-disturbed adults. Methods: This study was a two-period, non-blinded crossover trial. Adults (n = 26) aged 18-60 years with mild to moderate mood disturbance were randomised with a two-week washout between periods. During each 4-week period, participants consumed either two SunGold kiwifruit daily or their usual diet. The primary outcome was mean change in total mood disturbance scores from the kiwifruit period compared to the diet-as-usual period. Secondary outcomes were blood plasma vitamin C concentration, wellbeing, vitality and gastrointestinal symptoms. Participants and researchers were unblinded to condition and intervention. Results: Scores for total mood disturbance (65.2%, p < 0.001), wellbeing (10.5%, p < 0.01) and vitality (17.3%, p = 0.001) significantly improved in the kiwifruit condition compared to the usual diet. Vitamin C (27.5%, p = 0.002) concentrations also improved and gastrointestinal symptom reduction was evident during kiwifruit consumption (16.2%, p = 0.003). There were no serious adverse events. SunGold kiwifruit consumption resulted in significant reductions in total mood disturbance scores and improvements in wellbeing, vitality and vitamin C concentrations. Gastrointestinal symptom severity also significantly reduced. Conclusions: Results provide preliminary evidence of the potential benefits of kiwifruit for reducing mood disturbance in adult populations. Further studies in diverse groups, including clinical populations, are warranted.

Folate supplementation as a beneficial add-on treatment in relieving depressive symptoms: A meta-analysis of meta-analyses

The results of meta-analyses investigating the role of folate on depression are conflicting. The aim of this umbrella meta-analysis was to obtain an overall effect and give a concise and resolving conclusion. International scientific databases including PubMed, Scopus, and Web of Science were searched up to Oct 2023. All observational and interventional meta-analyses investigating the role of folate in depression were included in the study. Random-effects model was employed to obtain pooled results. I 2 statistics and Cochrane Q test were used to assess the between-study heterogeneity. The quality of included meta-analyses was evaluated using the Assessing the Methodological Quality of Systematic Reviews 2 (AMSTAR2) questionnaire. Overall 11 studies were included, of which 8 studies went under quantitative evaluation. The results indicated that folate supplementation significantly relieved depression symptoms [(SMD: -0.42; 95% CI: -0.57, -0.27, p < .001; I 2 = 0.0%, p-heterogeneity = 0.554) (WMD: -3.20; 95% CI: -4.00, -2.41, p < .001, I 2 = 14.8%, p-heterogeneity = 0.318)] with low levels of heterogeneity. Also, based on observational studies, folate insufficiency significantly increased the odds ratio of depression by 35% (OR:1.35; 95% CI: 1.27, 1.42, p < .001, I 2 = 8.7%, p-heterogeneity = 0.350). The findings support the fact that folate supplementation could be suggested as an efficacious and adjuvant agent in the alleviation of depression symptoms along with routine medications.

Dietary methyl donor micronutrients intake in relation to psychological disorders in adults

Previous investigations have mostly studied an individual methyl donor nutrient in relation to psychological disorders and the findings were inconsistent. We investigated the association of methyl donor micronutrients (folate, B₆, B₁₂, choline, betaine and methionine) with psychological disorders in Iranian adults. In this cross-sectional study, dietary intakes of 3299 adults were collected using a validated food frequency questionnaire. Methyl donor micronutrient score (MDMS) was calculated based on energy-adjusted deciles of each nutrient. Hospital Anxiety and Depression Scale (HADS) and General Health Questionnaire (GHQ), validated for Iranians, have been applied to assess depression, anxiety and psychological distress. Participants had a mean age of 36·3 ± 7·9 years, of whom 58·5 % were women. After considering potential confounders, adults in the top quartile of MDMS, compared to the bottom one, had decreased odds of anxiety (OR: 0·53, 95 % CI: 0·37, 0·75), depression (OR: 0·75, 95 % CI: 0·58, 0·97) and psychological distress (OR: 0·61, 95 % CI: 0·46, 0·80). Among women, the top quartile of MDMS was protectively associated with anxiety (OR: 0·60, 95 % CI: 0·40, 0·90), depression (OR: 0·68, 95 % CI: 0·50, 0·93) and psychological distress (OR: 0·53, 95 % CI: 0·38, 0·74). Overweight and obese subjects in the highest quartile of MDMS had a 67 %, 35 % and 53 % lower odds of anxiety (95 % CI: 0·20, 0·56), depression (95 % CI: 0·44, 0·94) and psychological distress (95 % CI: 0·31, 0·70), respectively. We found that high consumption of methyl donor micronutrients was related to a reduced odds of psychological disorders, especially in women and overweight or obese individuals.

The association of folate and depression: A meta-analysis

BACKGROUND

Previous research suggested that folate levels play an important role in the etiology and course of depression. However, the literature has been inconsistent with regard to differences in folate level between individuals with and without depression. The present meta-analysis synthesized the results of previous studies to examine whether individuals with depression had lower levels of folate than individuals without depression.

METHODS

Meta-analytic procedures were conducted in accordance with PRISMA guidelines. Studies evaluating folate levels in individuals with and without depression via red blood cell folate, serum folate, or dietary intake of folate methods were identified via PsycINFO and PubMed. Random-effects meta-analysis was conducted using Hedge's g, and moderation analysis was used for both folate measurement method and population type. Study heterogeneity was assessed with I² and publication bias was qualitatively assessed via funnel plot and quantitatively assessed with the trim-and-fill method and Begg's adjusted rank test.

RESULTS

We found a significant, small effect size, such that individuals with depression had lower folate levels than those without depression, Hedge's g = -0.24 (95% CI = -0.31, -0.16), p < 0.001. Study heterogeneity was high (I² = 84.88%), and neither folate measurement method nor population accounted for study heterogeneity.

CONCLUSIONS

Individuals with depression have lower serum levels of folate and dietary folate intake than individuals without depression. Given that previous literature suggested folate supplementation improved the efficacy of traditional antidepressant medications, future research on folate supplementation in depression is warranted and clinicians may wish to consider folate supplementation for patients with depression.

A prospective evaluation of the depression–nutrient intake reverse causality hypothesis in a cohort of community-dwelling older Canadians

Studies have investigated the potential protective effects that diet may have on late-life depression incidence. This disorder can, however, affect the person’s food intake, widely known as the reverse causality hypothesis of depression. To test this hypothesis, we compared mean nutrient intakes from three 24-h recalls during the year depression was detected (Geriatric Depression Scale ≥11 or antidepressant medication) with intakes from 1 year earlier among community-dwelling older adults (67–83 years) followed up annually in the 4-year Québec Longitudinal Study on Nutrition and Aging, who were free of depression and cognitive impairment at baseline. Participants (n 158, 64·4 % female) who became depressed and had data available for all follow-up years were matched by age group and sex with non-depressed participants. General linear mixed models were adjusted for percentage changes in physical activity, functional autonomy and stressful life events reported at the time of positive screening. A significant group effect for the dietary intake of all three B-vitamins was observed, as depression cases had consistently lower dietary intakes than controls (P<0·01). Over time, intakes of dietary vitamin B12 declined within depressed participants in bivariate analysis, but there was no time×group effect for any nutrient tested in the multivariate analyses. Intakes of energy, protein, saturated fat and total dietary fibre did not change in cases v. controls. Among community-dwelling older adults, declines in dietary vitamins B6, B12 and folate may precede depression incidence. To help preventative efforts by programmes and practitioners, longitudinal cohorts of longer duration should investigate the extent of the decline in dietary intakes relative to the time of depression.

Folate Augmentation of Treatment--Evaluation for Depression (FolATED): randomised trial and economic evaluation

BACKGROUND

Folate deficiency is associated with depression. Despite the biological plausibility of a causal link, the evidence that adding folate enhances antidepressant treatment is weak.

OBJECTIVES

(1) Estimate the clinical effectiveness and cost-effectiveness of folic acid as adjunct to antidepressant medication (ADM). (2) Explore whether baseline folate and homocysteine predict response to treatment. (3) Investigate whether response to treatment depends on genetic polymorphisms related to folate metabolism.

DESIGN

FolATED (Folate Augmentation of Treatment - Evaluation for Depression) was a double-blind and placebo-controlled, but otherwise pragmatic, randomised trial including cost-utility analysis. To yield 80% power of detecting standardised difference on the Beck Depression Inventory version 2 (BDI-II) of 0.3 between groups (a 'small' effect), FolATED trialists sought to analyse 358 participants. To allow for an estimated loss of 21% of participants over three time points, we planned to randomise 453.

SETTINGS

Clinical - Three centres in Wales - North East Wales, North West Wales and Swansea. Trial management - North Wales Organisation for Randomised Trials in Health in Bangor University. Biochemical analysis - University Hospital of Wales, Cardiff. Genetic analysis - University of Liverpool.

PARTICIPANTS

Four hundred and seventy-five adult patients presenting to primary or secondary care with confirmed moderate to severe depression for which they were taking or about to start ADM, and able to consent and complete assessments, but not (1) folate deficient, vitamin B12 deficient, or taking folic acid or anticonvulsants; (2) misusing drugs or alcohol, or suffering from psychosis, bipolar disorder, malignancy or other unstable or terminal illness; (3) (planning to become) pregnant; or (4) participating in other clinical research.

INTERVENTIONS

Once a day for 12 weeks experimental participants added 5 mg of folic acid to their ADM, and control participants added an indistinguishable placebo. All participants followed pragmatic management plans initiated by a trial psychiatrist and maintained by their general medical practitioners.

MAIN OUTCOME MEASURES

Assessed at baseline, and 4, 12 and 25 weeks thereafter, and analysed by 'area under curve' (main); by analysis of covariance at each time point (secondary); and by multi-level repeated measures (sensitivity analysis): Mental health - BDI-II (primary), Clinical Global Impression (CGI), Montgomery-Åsberg Depression Rating Scale (MADRS), UKU side effects scale, and Mini International Neuropsychiatric Interview (MINI) suicidality subscale; General health - UK 12-item Short Form Health Survey (SF-12), European Quality of Life scale - 5 Dimensions (EQ-5D); Biochemistry - serum folate, B12, homocysteine; Adherence - Morisky Questionnaire; Economics - resource use.

RESULTS

Folic acid did not significantly improve any of these measures. For example it gained a mean of just 2.9 quality-adjusted life-days [95% confidence interval (CI) from -12.7 to 7.0 days] and saved a mean of just £48 (95% CI from -£292 to £389). In contrast it significantly reduced mental health scores on the SF-12 by 3.0% (95% CI from -5.2% to -0.8%).

CONCLUSIONS

The FolATED trial generated no evidence that folic acid was clinically effective or cost-effective in augmenting ADM. This negative finding is consistent with improving understanding of the one-carbon folate pathway suggesting that methylfolate is a better candidate for augmenting ADM. Hence the findings of FolATED undermine treatment guidelines that advocate folic acid for treating depression, and suggest future trials of methylfolate to augment ADM.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN37558856.

FUNDING

This project was funded by the NIHR Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 18, No. 48. See the HTA programme website for further project information.

Complementary and alternative medicine therapies for perinatal depression

Complementary and alternative medicine therapies are increasingly sought out by people with psychiatric disorders. In this chapter, we review the evidence for several commonly used CAM therapies (i.e. omega-3 fatty acids, folate, S-adenosyl-methionine, St John's Wort, bright light therapy, exercise, massage, and acupuncture) in the treatment of perinatal depression. A number of these treatments may be reasonable to consider for women during pregnancy or postpartum, but the safety and efficacy of these relative to standard treatments must still be systematically determined. Evidence-based use of complementary and alternative medicine therapies treatments for perinatal depression is discussed. Adequately powered systematic studies are necessary to determine the role of complementary and alternative medicine therapies in the treatment of perinatal depression.

Nutritional epidemiology of type 2 diabetes and depressive symptoms

In Japan, the prevalences of type 2 diabetes and depression are increasing, but evidence linking these diseases to diet is limited. The present study reviewed the association of type 2 diabetes with intakes of rice, fish/seafood, and soy product and isoflavone, and the association of depressive symptoms with folate, vitamin D, and dietary pattern, in the Japanese population. The analysis of type 2 diabetes comprised around 55 000 men and women aged 45 to 75 years who completed a questionnaire for the Japan Public Health Center-based Prospective Study and were free of type 2 diabetes at baseline. The odds ratio of self-reported physician-diagnosed type 2 diabetes during the subsequent 5 years increased with rice intake among women and among physically inactive men but decreased with total fish/seafood intake among men. In addition, risk tended to decrease with soy product and isoflavone intake among overweight and postmenopausal women. Depressive symptoms were assessed using the Center for Epidemiologic Studies Depression Scale. The participants were approximately 530 workers aged 21 to 67 years who participated in a health survey at the time of a periodic health check. A cross-sectional and prospective inverse association between serum folate and depressive symptoms was observed. Serum 25-hydroxyvitamin D level was suggestively associated with decreased prevalence of depressive symptoms in late autumn. In addition, a healthy Japanese pattern—characterized by high intakes of vegetables, fruit, mushrooms, and soy products—was inversely associated with depressive symptoms. The findings suggest that diet has a role in the development of type 2 diabetes and depression in Japanese.

Antioxidant status and its association with elevated depressive symptoms among US adults: National Health and Nutrition Examination Surveys 2005-6

We examined the relationship of elevated depressive symptoms with antioxidant status. Cross-sectional data from the National Health and Nutrition Examination Surveys 2005–6 on US adults aged 20–85 years were analysed. Depressive symptoms were measured using the Patient Health Questionnaire with a score cut-off point of 10 to define ‘elevated depressive symptoms’. Serum antioxidant status was measured by serum levels of carotenoids, retinol (free and retinyl esters), vitamin C and vitamin E. The main analyses consisted of multiple logistic and zero-inflated Poisson regression models, taking into account sampling design complexity. The final sample consisted of 1798 US adults with complete data. A higher total serum carotenoid level was associated with a lower likelihood of elevated depressive symptoms with a reduction in the odds by 37 % overall with each sd increase in exposure, and by 34 % among women (P< 0·05). A dose–response relationship was observed when total serum carotenoids were expressed as quartiles (Q4 (1·62–10·1 μmol/l) v. Q1 (0·06–0·86 μmol/l): OR 0·41; 95 % CI 0·23, 0·76, P< 0·001; P for trend = 0·035), though no significant associations were found with the other antioxidant levels. Among carotenoids, β-carotene (men and women combined) and lutein+zeaxanthins (women only, after control for dietary lutein+zeaxanthin intake and supplement use) had an independent inverse association with elevated depressive symptoms among US adults. None of the other serum antioxidants had a significant association with depressive symptoms, independently of total carotenoids and other covariates. In conclusion, total carotenoids (mainly β-carotene and lutein+zeaxanthins) in serum were associated with reduced levels of depressive symptoms among community-dwelling US adults.

Serum folate and depressive symptoms among Japanese men and women: a cross-sectional and prospective study

Although several studies have reported an association between blood folate concentrations and depressive symptoms, few studies have prospectively examined the association. This study aimed to investigate the cross-sectional and prospective associations between serum folate concentrations and depressive symptoms among Japanese. We analysed data among 545 subjects who participated in a health survey at the time of periodic check-up in 2009 for a cross-sectional association and among 272 subjects without depressive symptoms at baseline (in 2006) who responded to both baseline (2006) and follow-up (2009) surveys for prospective association. Depressive symptoms were assessed using the Center for Epidemiologic Studies Depression (CES-D) scale. In a cross-sectional analysis, serum folate concentrations were significantly associated with a decreased prevalence of depressive symptoms (CES-D scale of ≥16). Moreover, serum folate concentrations at baseline were significantly inversely associated with depressive symptoms after 3 years; the multivariate-adjusted odds ratios (95% confidence intervals) of depressive symptoms for the lowest through highest tertile categories of serum folate concentrations were 1.00 (reference), 0.66 (0.29-1.52) and 0.40 (0.16-0.99) (P for trend=0.047). Our findings suggest that a higher serum folate may be associated with decreased risk of depressive symptoms in Japanese.

Association between folate intake and melancholic depressive symptoms. A Finnish population-based study

BACKGROUND

An association between low blood folate levels and depressive symptoms (DS) has been reported in several epidemiological studies, but no studies have examined folate intake in melancholic or non-melancholic DS in population-based samples.

METHODS

The aim of the study was to evaluate folate intake in DS with or without melancholic characteristics as a part of the Finnish diabetes prevention program (FIN-D2D). Altogether, 4500 randomly selected subjects aged 45-74 years were selected from the National Population Register. The study population (N=2806, participation rate 62%) consisted of 1328 men and 1478 women. The health examinations were carried out in 2007 according to the WHO MONICA project. The assessment of DS was based on the Beck Depression Inventory (BDI, cut-off≥10 points). A summary score of melancholic items in the BDI was used in dividing the participants with DS (N=429) into melancholic (N=138) and non-melancholic DS (N=291) subgroups. Folate intake was assessed using a validated food frequency questionnaire (FFQ).

RESULTS

DS associated linearly with gender specific tertiles of folate intake (p for linearity=0.003). The OR for melancholic DS was 0.55 (95%CI 0.34 to 0.90) for the high tertile of folate intake versus the low (p for linearity=0.018), while the ORs for non-melancholic DS were nonsignificant.

LIMITATIONS

Assessment of DS was based on a self-rating scale, and the population was in advanced middle-aged.

CONCLUSIONS

A low folate intake was associated with DS through its effect on melancholic DS.

Low levels of food involvement and negative affect reduce the quality of diet in women of lower educational attainment

BACKGROUND

Women of lower educational attainment tend to have poorer quality diets and lower food involvement (an indicator of the priority given to food) than women of higher educational attainment. The present study reports a study of the role of food involvement in the relationship between educational attainment and quality of diet in young women.

METHODS

The first phase uses six focus group discussions (n = 28) to explore the function of food involvement in shaping the food choices of women of lower and higher educational attainment with young children. The second phase is a survey that examines the relationship between educational attainment and quality of diet in women, and explores the role of mediating factors identified by the focus group discussions.

RESULTS

The focus groups suggested that lower food involvement in women of lower educational attainment might be associated with negative affect (i.e. an observable expression of negative emotion), and that this might mean that they did not place a high priority on eating a good quality diet. In support of this hypothesis, the survey of 1010 UK women found that 14% of the effect of educational attainment on food involvement was mediated through the woman's affect (P ≤ 0.001), and that 9% of the effect of educational attainment on quality of diet was mediated through food involvement (P ≤ 0.001).

CONCLUSIONS

Women who leave school with fewer qualifications may have poorer quality diets than women with more qualifications because they tend to have a lower level of food involvement, partly attributed to a more negative affect. Interventions to improve women's mood may benefit their quality of diet.

Postpartum depressive symptoms: the B-vitamin link

Objective This study examined longitudinal relationships between maternal red-cell folate status and dietary intakes of vitamins B(6), B(12) and folate before and during pregnancy and subsequent postpartum depressive symptoms.Study design and setting Within a cohort study of women aged 20-34 years (the Southampton Women's Survey) dietary data were obtained before pregnancy and at 11 and 34 weeks' gestation. Red-cell folate was measured before pregnancy and at 11 weeks' gestation. We derived relative risks of postpartum depressive symptoms using an Edinburgh Postnatal Depression Scale (EPDS) score of ≥ 13 administered from 6 months to 1 year postpartum.Results No significant differences were found between those with postpartum depressive symptoms (n = 905) and those without (n = 1951) in relation to red-cell folate concentration or dietary intake of folate, vitamin B(12) and vitamin B(6), before or during pregnancy. A prior history of mental illness (relative risk (RR) 1.83; 95% confidence interval (CI) 1.53-2.19) was associated with postpartum depressive symptoms, and women who breastfed until 6 months were less likely to experience postpartum depressive symptoms (RR 0.68; 95% CI 0.55-0.84).Conclusion This study suggests that folate status and dietary folate, B(6) and B(12) intakes before and during pregnancy are not associated with postpartum depressive symptoms. A history of mental illness, however, was a strong risk factor.

Testing homocysteine-induced neurotransmitter deficiency, and depression of mood hypothesis in clinical practice

BACKGROUND

high total plasma homocysteine (tHcy) levels may cause neurotransmitter deficiency, and consequently depression of mood. We have recently shown that mixed oral nutritional supplements containing B-group vitamins led to a statistically significant benefit on depressive symptoms. The aim of this report was to examine the association between elevated plasma tHcy and symptoms of depression in older patients.

METHODS

two-hundred and thirty-six hospitalised acutely ill older patients, who were part of a randomised double-blind placebo-controlled trial, were assigned to receive daily mixed oral nutritional supplements containing B-group vitamins or a placebo for 6 weeks. Outcome measures included symptoms of depression measured using Geriatric Depression score and plasma tHcy levels.

RESULTS

the mean tHcy concentration fell by 22% among patients given the supplements compared with the placebo group (mean difference 4.1 µmol/l (95% CI: 0.14-8.03), P = 0.043). tHcy concentrations was divided into four quartiles and analysed against depression scores. tHcy concentrations in the first relative to the fourth quartile of the distribution were associated with a lower depression symptoms at the end of the supplement period (Geriatric depression score r = -0.20, P = 0.042).

CONCLUSIONS

lower plasma tHcy concentrations were associated with reduced depression symptoms in older patients recovering from acute illness.

Physical inactivity among adults with diabetes mellitus and depressive symptoms: results from two independent national health surveys

OBJECTIVE

To examine the association between depressive symptoms and physical inactivity in community samples of patients with diabetes mellitus (DM).

METHODS

Two representative samples of Israeli adults (age ≥21 years) were analyzed: The First Israeli National Health Interview Survey (INHIS-1) (n=9509) and the Israel National Health Survey (INHS) (n=4859). Information was obtained about past-month depressive symptoms, physician-diagnosed DM and physical activity. Multiple logistic regression models were used to examine the association between level of depressive symptoms and physical inactivity among individuals with DM, adjusting for potential confounders.

RESULTS

Prevalence of DM ranged from 7.2% (INHIS-1) to 8.7% (INHS). In both samples, physical inactivity was significantly more prevalent among persons with significant depressive symptoms, compared to those without depressive symptoms [INHIS-1: 67.0% vs. 50.6%; adjusted odds ratio (AOR): 1.57; 95% confidence interval (95% CI), 1.05-2.35, P=.03; INHS: 71.4% vs. 43.9%; AOR: 2.67; 95% CI, 1.67-4.27, P<.0001].

CONCLUSIONS

Depressive symptoms were associated with a higher likelihood of physical inactivity in persons with DM. Body mass index of patients reporting no regular physical activity was elevated compared to persons who were physically active. This finding supports the view that identification and management of depression should be part of interventions designed to improve self care behaviors in patients with DM.

Serum folate, vitamin B-12, and homocysteine and their association with depressive symptoms among U.S. adults

OBJECTIVE

To examine, in a nationally representative sample of U.S. adults, the associations of serum folate, vitamin B-12, and total homocysteine (tHcy) levels with depressive symptoms. Several nutritional and physiological factors have been linked to depression in adults, including low folate and vitamin B-12 and elevated tHcy levels.

METHODS

Data on U.S. adults (age, 20-85 years; n = 2524) from the National Health and Nutrition Examination Survey during the period 2005 to 2006 were used. Depressive symptoms were measured with the Patient Health Questionnaire (PHQ), and elevated symptoms were defined as a PHQ total score of ≥10. Serum folate, vitamin B-12, and tHcy were mainly expressed as tertiles. Multiple ordinary least square (OLS), logistic, and zero-inflated Poisson regression models were conducted in the main analysis.

RESULTS

Overall, mean PHQ score was significantly higher among women compared with men. Elevated depressive symptoms (PHQ score of ≥10) were inversely associated with folate status, particularly among women (fully adjusted odds ratio [tertiles T(3) versus T(1)] = 0.37; 95% confidence interval, 0.17-0.86), but not significantly related to tHcy or vitamin B-12. No interaction was noted between the three exposures in affecting depressive symptoms. In older adults (≥50 years) and both sexes combined, tHcy was positively associated with elevated depressive symptoms (fully adjusted odds ratio [tertiles T(2) versus T(1)] = 3.01; 95% confidence interval, 1.01-9.03), although no significant dose-response relationship was found.

CONCLUSIONS

Future interventions to improve mental health outcomes among U.S. adults should take into account dietary and other factors that would increase levels of serum folate.

The sex-specific role of plasma folate in mediating the association of dietary quality with depressive symptoms

Folate deficiency has been implicated in the etiology of unipolar depression. In this study, we attempted to cross-link plasma folate, depressive symptoms, and dietary quality (or dietary intake of folate) together in a comprehensive framework, while examining effect modification of those associations by sex. This was a cross-sectional, population-based study of 1681 participants aged 30-64 y (Healthy Aging in Neighborhoods of Diversity across the Lifespan Study). Participants were administered the Center for Epidemiologic Studies Depression scale (CES-D). Measures of plasma folate and dietary intakes (2 24-h recalls) from which the 2005-Healthy Eating Index (HEI) was computed were available. Multivariate logistic regression and structural equation modeling (SM) were conducted. Compared with the lowest tertile, the middle and uppermost tertiles of plasma folate were associated with a 39-40% reduced odds of elevated CES-D (> or =16) among women [adjusted odds ratio (T(3) vs. T(1)) = 0.60 (95% CI = 0.42-0.86); P = 0.006]. Confounding of this association by HEI(total) was noted among both men and women, although dietary folate did not confound this association appreciably. In SM, plasma folate completely mediated the inverse HEI(total)-CES-D association among men only, specifically for HEI(2) (higher intakes of whole fruits), HEI(3) (total vegetables), HEI(5) (total grains), HEI(6) (whole grains), HEI(7) (milk), and HEI(12) (lower discretionary energy). Among women, HEI(total) and 4 components had an inverse direct effect on CES-D score, suggesting a mechanism that is independent of plasma folate. Depressive symptoms in our study may be alleviated by improving overall dietary quality, with plasma folate playing a potential mediating role only among men.

Soft drink consumption and mental health problems among adults in Australia

OBJECTIVE

To examine the association between soft drink consumption and mental health problems, including self-reported doctor-diagnosed anxiety, stress-related problem and depression, suicidal ideation and psychological distress, among adults in South Australia.

DESIGN

Data were collected using a risk factor surveillance system. Each month a representative random sample of South Australians was selected from the Electronic White Pages with interviews conducted using computer-assisted telephone interviewing.

SETTING

South Australia.

SUBJECTS

Participants were aged 16 years and above.

RESULTS

Among 4741 participants, 12.5% reported daily soft drink consumption of more than half a litre. High levels of soft drink consumption were positively associated with depression, stress-related problem, suicidal ideation, psychological distress and a current mental health condition, but not anxiety. Overall, 24.0% of those having suicidal ideation reported consuming more than half a litre of soft drink per day. In the multivariate analysis, after adjusting for sociodemographic and lifestyle factors, those who consumed more than half a litre of soft drink per day had approximately 60% greater risk of having depression, stress-related problem, suicidal ideation, psychological distress or a current mental health condition, compared with those not consuming soft drinks. The soft drink to total fluid consumption ratio had similar associations with mental health problems.

CONCLUSIONS

There is a positive association between consumption of soft drinks and mental health problems among adults in South Australia.