The association between intake of whole grain, rened grain, fast food and carbonated drinks with depression and quality of life in Iranian adolescent girls

Background: We evaluated the association between fast food, whole grain, rened grain and carbonated drink consumption with depression and QoL in Iranian adolescent girls. Methods: In this cross-sectional study, 733 adolescent girls were included from Mashhad and Sabzevar cities in northeastern Iran. The Beck Depression Inventory (BDI) and SF-12v2 questionnaire were used to assess depression and QoL, respectively. A valid and reliable food frequency questionnaire was used to obtained dietary intakes of the study participants. To explore the association between intake of food groups and depression and QoL, we used linear and logistic regression in crude and adjusted models. Results: There was a signi ﬁ cant decreasing trend in the odds of poor QOL and depression across increasing quartile intake of whole grain; but, there was no linear relationship between whole grain intake with depression and QoL score. In addition, subjects in the highest quartile of carbonated drink consumption had higher odds of poor QoL compared to the rst quartile (OR: 1.33; 95% CI: 1.00–2.32, P = 0.04). We found a positive association between intake of fast food and depression score (β= 0.09). Intake of fast food was inversely associated with QoL score (β= -0.081). However, there was no signicant relationship between intake of rened grains and carbonated drinks with depression, and between whole grain and rened grain intake with QoL.


Introduction
Recent evidence con rms the growing prevalence as well as socioeconomic costs of mental health disorders (1)(2)(3). Depression is a common mental health disorder, with two major symptoms including depressed mood and anhedonia, which are often accompanied with several other symptoms (3). The lifetime prevalence of depression is estimated to be 15% in the general population (4). Many patients suffering from depression experience depressive symptoms during adolescence (5). The prevalence of depression is affected by gender and is higher among adolescent females than males (6, 7). Obesity, oxidative stress, and in ammation are linked to the development and progression of depressive symptoms (8-10). Based on a meta-analysis the prevalence of depression among Iranian children and adolescents is reported to be 43.5% (11).
Several studies have suggested that depression has a negative effect on quality of life (QoL) (12,13).
QoL is a multidimensional concept (14). Based on the World Health Organization (WHO), QoL is de ned as follows: "the perception of individuals about their position in life in the context of the culture and value systems which is related to their goals, expectations, standards and concerns" (15).
Previous studies have proposed that diet can play an important role in the development or preventive of depression (16)(17)(18). Several studies have investigated the association between dietary patterns, intake of nutrients or speci c food groups with depression (16)(17)(18)(19)(20). Results of some studies reported that intake of copper, iron, zinc and selenium were inversely associated with depressive symptoms (19,20). Results of other studies showed that healthy dietary patterns which provide higher amounts of gruel, oatmeal, whole grains, fresh yellow or red vegetables, fruits, soya milk and sh, can decrease risk of depression among adolescents (16,17). Unhealthy dietary patterns like the western dietary pattern that are characterized by high intake of red and processed meats, re ned foods, saturated fatty acids (SFAs), noodles, white bread and coffee can increase the risk of depression (16, 18). Investigations suggested that intake of speci c food groups such as vegetables, fruits, nuts and legumes have an inverse association with the risk of depression (21,22). There are few studies investigating the relationship between speci c food groups with depression. A recent study has evaluated the relationship between diet and QoL (23); however, there no published investigations evaluating the association between speci c food groups and QoL. Accordingly, the present study aimed to investigate the association between intake of re ned grains, whole grains, fast foods and carbonated drinks with depression and QoL in adolescent girls.

Study population
This cross sectional study was conducted among 733 adolescent girls (aged 12-18 years) in January 2015. Participants were selected from several schools in the cities of Mashhad and Sabzevar, in northeastern Iran by a random cluster sampling method. Adolescents with history of autoimmune diseases, cancer, metabolic bone disease, hepatic or renal failure, cardiovascular disorders, malabsorption or thyroid, parathyroid, adrenal diseases and anorexia nervosa or bulimia were excluded from the study. In addition, participants who were included, did not receive anti-in ammatory, antidepressant, antidiabetic, or anti-obesity drugs, vitamin D or calcium supplement, and any hormone therapy within the last 6 months. Before the start of the study, written informed consent forms con rmed by the ethical committee of Mashhad University of Medical Sciences, in Mashhad, Iran (ethical code number: 931188) were completed by all participants and their parents.
Demographic and anthropometric assessments Demographic variables were assessed using a demographic questionnaire administered by trained interviewers. Demographic variables were age, smoking status, menstruation status, medical history, supplement intake, taking psychological treatment and chronic diseases. Participants' physical activity was assessed using a modi able activity questionnaire (MAQ) (20). Physical activity level was calculated based on metabolic equivalent task minutes per week. Anthropometric variables such as weight, height and waist circumference (WC) were measured by the trained investigators using the standard protocols.
Body mass index (BMI) computed as weight (kg) divided by square of height (m 2 ).

Dietary assessment
Dietary intakes were estimated by a validated food-frequency questionnaire (FFQ) with 147 food items. The validity and reliability of this FFQ were con rmed previously (24). To complete the FFQ, a face-to-face interview was performed by a trained dietitian. To evaluate the frequency of food items intake during the last year, the participants answered the questions about their daily, weekly, monthly and yearly intake. The reported portion sizes in the FFQ were converted to grams using household measures, and the energy and nutrient intakes were calculated using the Nutritionist IV software (25).

Assessment of depression
Depression was assessed via a Persian version of the Beck Depression Inventory (BDI). This questionnaire has 21 items evaluating various symptoms of depression including feelings of guilt, feelings of hopelessness, sadness, crying, sleep disturbance, fear and loss of appetite over the past 2 weeks. The range of scores for the BDI was between 0 and 63 points. scores 0-13, 14-19, 20-28 and 29-63 refer to no depression, mild depression, moderate depression, and severe depression respectively. The validity and reliability of this questionnaire were con rmed by previous studies (26, 27).

Quality of life assessment
To assess health-related QOL, the SF-12v2 questionnaire was used. This questionnaire is a short form of the SF-36 questionnaire and improved version of SF-12v1 (28). The validity and reliability of this questionnaire were approved in Iran (29). The questionnaire has 12 items which evaluate 8 domains of health including physical functioning, role limitations because of physical problems, bodily pain, general health, vitality, social functioning, role limitations because of emotional problems, and mental health. The range of QoL scores are between 0 (the worst QoL) to 100 (the best QoL). The median of the QoL score is 43. The subjects were categorized as high QoL if their scores were higher than 43.

Statistical analysis
Subjects were classi ed into four groups across quartiles of their food group scores including whole grain, re ned grain, carbonated drink and fast foods. General characteristics and nutrient intake across quartiles of food group score were expressed as means ± SDs for continuous variables, and as numbers and percentages for categorical variables. To examine the differences between quartiles, one-way-ANOVA and Chi square test were used for continuous and categorical variable respectively. To investigate the relationship between quartiles of food group scores with depression and poor QoL, multivariate regression was conducted in the crude and adjusted models. Multivariate linear regression was used to explore the association between QOL score and depression with fast food, carbonated drink, whole grain and re ned grain intake. Age and energy intake were adjusted in Model I. Additionally, BMI percentile was adjusted in Model II. Finally, physical activity, age, energy intake and BMI percentile were adjusted in the model III. All statistical analyses were conducted using the SPSS version 21. P-values less than 0.05 were considered as signi cant.

General characteristics study participants
The mean age of the participants was 14.5 years. The prevalence of depression and poor QoL were 24% and 49%, respectively. General characteristics and anthropometric indices of the participants across quartiles of food groups are demonstrated in Table 1. Participants in the lowest quartile of whole grain and the highest quartile of re ned grain were signi cantly younger (p=0.02 and p=0.01, respectively). Anthropometric variables and other general characteristics were not different among quartiles of food intake.

Dietary intake of study participants
Dietary intake of study participants across quartiles of food groups are shown in Table 2. Participants in the highest quartiles of food groups (whole grain, re ned grain, fast food and carbonated drink) compared with the participants who were in the lowest quartile had higher intake of energy, protein and carbohydrate. Vitamin B6 intake was signi cantly higher among participants in the last quartile of fast food intake (per 1000 kcal) compared to the rst quartile (p=0.04). Intake of Vitamin B12 was not signi cantly different between quartiles of food groups (per 1000 kcal). Participants in the rst quartile of carbonated drink as well as fast foods intake had higher intake of folate compare with the fourth quartile (per 1000 kcal) (p<0.001). The participants with a greater intake of re ned grain had a lower intake of vitamin A (p=0.01), vitamin C (p< 0.001), and calcium (per 1000 kcal) (p< 0.001). Participants in the highest quartile of food groups intake including fast foods, re ned grain and carbonated drink had higher intake of monounsaturated fatty acids (MUFA), polyunsaturated fatty acids (PUFAs) and SFAs. Association between food groups and depression, poor quality of life Multi-variable adjusted odds ratios (ORs) for depression and poor QoL categories across quartiles of food intake are represented in Table 3. Adolescent girls in the fourth quartile of whole grain intake compared with the subjects in the rst quartile had a 40% lower probability of having depressive symptoms (OR: 0.60; 95% CI: 0.37-0.98, p = 0.04). This association remained signi cant after adjustment for age, energy intake, BMI percentile, and physical activity (OR: 0.60; 95% CI:0.36-0.99, p = 0.04). There was a significant reduction trend in the odds of poor QoL across increasing quartile intake of whole grain in the crude (OR: 0.87; 95% CI: 0.76-0.99, p-trend = 0.04). This trend was not signi cant after adjustment for age, energy intake, BMI percentile, and physical activity (OR: 0.88; 95% CI: 0.76-1.00, p-trend = 0.06).
The correlations between intake of food groups with depression and QoL score are shown in Table 4.
There was a positive association between intake of fast food and depression score in the crude model (β= 0.09; P-value = 0.01). Likewise, this association remained signi cant after adjustment for age, energy intake, BMI percentile, and physical activity (β= 0.01; P-value <0.01). Intake of fast food was inversely associated with QoL score in the crude (β = -0.081; P-value = 0.02) and adjusted models (β= -0.090; Pvalue = 0.02). Carbonated drink, re ned grain and whole grain intake were not signi cantly associated with depression and QoL score.

Discussion
The high prevalence of depression and its outcomes like suicide ideation and suicide attempts in adolescents have become important challenges for public health (1,30,31). Modifying behaviors such as smoking, drinking, using drugs, physical activity, and diet may reduce the risk of depression and improve the QoL (32)(33)(34). Thus, evaluating the association of these modi able factors with depression and QoL can be helpful for public health organizations, physicians, and patients for the management of depression and increasing QoL. To the best of our knowledge, the present study was the rst crosssectional study evaluating the association between speci c food groups with depression and QoL among adolescent females.
We demonstrated that higher consumption of fast foods is positively associated with depression score.
In addition, although based on the logistic regression analysis, a higher intake of whole grain is associated with lower odds of depression (at a slightly signi cant level with P=0.04), according to linear regression analysis there was no association between whole grain intake and depression. Unlike linear regression analysis, in logistic regression analysis, individuals are categorized based their intakes and the linear relationship is not examined. Therefore, this nding must be interpreted with caution. However, we found no signi cant relationship between intake of re ned grain and carbonated drink with risk of depression. There is no cross-sectional study examining the association between depression with the above-mentioned food groups among adolescents. A cross-sectional study that was conducted in adults showed an inverse relationship between frequency of healthy food groups such as fruits and vegetables consumption with odds of depression (35). This study used logistic regression analysis, but not linear regression analysis. Moreover, a study found that subjects without depression consumed more legumes, fruits, and vegetables compared to patients with depression (36). In addition, it has been shown that intake of non-re ned grain is associated with lower odds of depression/anxiety disorders (37); but, high intake of re ned grains was associated with a higher risk of depression (38). Some inconsistencies between the results of mentioned studies and our ndings may be due to the differences in design, statistical analysis, methodology of the studies as well as age of participants. Our ndings showed that subjects in the highest quartile of fast food and re ned grain intake had higher energy intake which can On the other hand, the present study found that fast food consumption is inversely associated with the QoL score. Fast food is a component of unhealthy dietary patterns that can induce obesity, in ammation as well as oxidative stress (39)(40)(41), and subsequently increase the risk of depression (8-10). As mentioned, depression has a negative effect on QoL. Moreover, the logistic regression analysis showed higher carbonated drink consumption was associated with lower odds of poor QoL. However, linear model analysis demonstrated that there is no relationship between carbonated drink consumption and QoL score. As mentioned, unlike linear regression analysis, in the logistic regression analysis, subjects are categorized based their intakes and it cannot demonstrate the linear association. The results should be interpreted with caution. In addition, there was no signi cant association between intake of whole grain and re ned grain with QoL score. There is no similar study in this eld. A systematic review that conducted by Govindaraju et al. (46) con rmed that adherence to the healthy dietary patterns containing higher amounts of whole grains, fruits and vegetables as well as lower amounts of carbonated drinks and re ned foods and fast food is directly associated with QoL score.
Some important strengths of our study are as follows: 1) The rst study evaluating the association between speci c food groups with depression among a relatively large sample of adolescents; 2) The rst investigation examining the relationship between speci c food groups with QoL; 3) High quality of data collection; and 4) Modulating the effects of various important confounding factors. However, the present study has some limitations. Due to design of the study, we cannot show the causality. Furthermore, this study was conducted only among adolescent females. Finally, low response and misclassi cation are common in cross-sectional studies, which can increase the probability of recall bias.

Conclusion
We demonstrated an inverse association between fast food intake with depression and QOL. However, there is no signi cant relationship between intake of re ned grain and carbonated drink with depression. Furthermore, we found no association between intake of whole grain and re ned grain with QoL. Due to inconsistent ndings based on utilizing different analyses, the associations between intake of whole grain with depression as well as consumption of carbonated drink with QoL remained unclear. To better conclude, further studies evaluating the association of various food groups with depression and QoL.

Consent for publication
Not applicable.

Availability of supporting data
The data and materials of the current study is available from the corresponding author on reasonable request.