The association of plant-based dietary patterns and psychological disorders among Iranian adults

Plant-Based Diets and Risk of Multimorbidity: The Health and Retirement Study

BACKGROUND

Plant-based diets have gained attention due to their beneficial effects against major chronic diseases, although their association with multimorbidity is mostly unknown.

OBJECTIVES

We examined the association between the healthful (hPDI) and unhealthful plant-based diet indices (uPDI) with multimorbidity among middle-aged and older adults from the United States.

METHODS

Data on 4262 adults aged >50 y was obtained from the 2012-2020 Health and Retirement Study (HRS) and 2013 Health Care and Nutrition Study (HCNS). Food consumption was collected at baseline with a food frequency questionnaire and 2 PDIs were derived: the hPDI, with positive scores for healthy plant foods and reverse scores for less healthy plant foods and animal foods; and the uPDI, with only positive scoring for less healthy plant foods. Complex multimorbidity, defined as ≥3 coexistent conditions, was ascertained from 8 self-reported conditions: hypertension, diabetes, cancer, chronic lung disease, heart disease, stroke, arthritis, and depression. Cox proportional hazards models were used to estimate the hazard ratios (HRs) and 95% confidence intervals (CIs).

RESULTS

After a median follow-up of 7.8 y, we documented 1202 incident cases of multimorbidity. Compared with the lowest quartile, higher adherence to the hPDI was inversely associated with multimorbidity (HR for quartile 3: 0.77; 95% CI: 0.62, 0.96 and HR for quartile 4: 0.79; 95% CI, 0.63, 0.98; P-trend = 0.02). In addition, a 10-point increment in the hPDI was associated with a 11% lower incidence of multimorbidity (95% CI: 1, 20%). No significant associations were found for the uPDI after adjusting for sociodemographic and lifestyle factors.

CONCLUSIONS

Higher adherence to the hPDI was inversely associated with multimorbidity among middle-aged and older adults. Plant-based diets that emphasize consumption of high-quality plant foods may help prevent the development of complex multimorbidity.

The associations between plant-based dietary indices with depression and quality of life and insomnia among Iranian adolescent girls in 2015

Although previous research has explored the link between plant-based diets and mental health outcomes, there has been limited study on the quality levels of plant foods in this context. This study was conducted on 733 adolescent girls from cities in northeastern Iran. The validated Iranian version of the Insomnia Severity Index, SF-12v2 questionnaire and Persian version of the Beck Depression Inventory used to assess insomnia and poor quality of life (QoL) and depression, respectively. Dietary intakes assessed using a valid and reliable food frequency questionnaire. The association of scores of plant based dietary index (PDI) and poor QoL, depression and insomnia explored by binary logistic regression. The unadjusted model showed subjects in the highest quartile of healthy PDI had lower chances of insomnia than those in the lowest quartile (OR: 0.50; 95% CI 0.27-0.91, P = 0.024). The association persisted across various adjusted models. Subjects in the highest quartile of unhealthy PDI (uPDI) had higher chances of depression than those in the lowest quartile (OR: 1.83; 95% CI 1.09-3.08, P = 0.022). The significance of the association was maintained after adjusting for other confounders. A healthy plant-based dietary index is associated with a lower odds of insomnia. An unhealthy plant-based dietary index was associated to an increased chance of depression. Findings need to be confirmed by future studies.

Diet quality and anxiety: a critical overview with focus on the gut microbiome

Anxiety disorders disproportionally affect females and are frequently comorbid with eating disorders. With the emerging field of nutritional psychiatry, focus has been put on the impact of diet quality in anxiety pathophysiology and gut microbiome underlying mechanisms. While the relationship between diet and anxiety is bidirectional, improving dietary habits could better facilitate the actions of pharmacological and psychological therapies, or prevent their use. A better understanding of how gut bacteria mediate and moderate such relationship could further contribute to develop personalized programs and inform probiotics and prebiotics manufacturing. To date, studies that look simultaneously at diet, the gut microbiome, and anxiety are missing as only pairwise relationships among them have been investigated. Therefore, this study aims at summarizing and integrating the existing knowledge on the dietary effects on anxiety with focus on gut microbiome. Findings on the effects of diet on anxiety are critically summarized and reinterpreted in relation to findings on (i) the effects of diet on the gut microbiome composition, and (ii) the associations between the abundance of certain gut bacteria and anxiety. This novel interpretation suggests a theoretical model where the relationship between diet and anxiety is mediated and/or modulated by the gut microbiome through multiple mechanisms. In parallel, this study critically evaluates methodologies employed in the nutritional field to investigate the effects of diet on anxiety highlighting a lack of systematic operationalization and assessment strategies. Therefore, it ultimately proposes a novel evidence-based approach that can enhance studies validity, reliability, systematicity, and translation to clinical and community settings.

Association of plant-based dietary patterns with depression and anxiety symptoms in Chinese older adults: A nationwide study

BACKGROUND

The associations of plant-based dietary patterns with depression and anxiety symptoms among older adults have not been extensively studied. Therefore, the purpose of this study was to examine these associations in Chinese older adults.

METHODS

Data from the Chinese Longitudinal Healthy Longevity Survey (CLHLS) was employed in the present study. The simplified food frequency questionnaire was used to assess the overall plant-based diet index (PDI), healthful plant-based diet index (hPDI), and unhealthful plant-based diet index (uPDI). The Center for Epidemiologic Studies Depression Scale-10 (CES-D-10) was used to evaluate depression symptoms, and the Generalized Anxiety Disorder Scale-7 (GAD-7) was used to assess anxiety symptoms. This study employed logistic regression and linear regression to examine the associations between plant-based dietary patterns and symptoms of depression and anxiety.

RESULTS

This study included 11,971 older adults, with a mean age of 83.23 ± 11.10 years. The results indicated that PDI and hPDI were negative associated with depression symptoms (adjusted β -0.09, 95 % CI -0.11, -0.07) (adjusted β -0.09, 95 % CI -0.11, -0.07) and anxiety symptoms (adjusted β -0.03, 95 % CI -0.04, -0.02) (adjusted β -0.04, 95 % CI -0.05, -0.02), while uPDI was positive associated with depression symptoms (adjusted β 0.09, 95 % CI 0.07, 0.11) and anxiety symptoms (adjusted β 0.04, 95 % CI 0.03, 0.05).

CONCLUSIONS

The findings from this study have the potential to promote healthy dietary patterns in older adults, and may have implications for the prevention and management of depression and anxiety in this population.

Dietary eating patterns, dairy consumption, and anxiety: A systematic literature review

BACKGROUND

Nutrition affects both physical and mental health but evidence is mixed regarding potential associations between anxiety and diet, particularly dairy consumption. We conducted a systematic literature review (SLR) of dairy consumption and/or various dietary patterns and risk of anxiety.

METHODS

Literature searches were conducted in PubMed and Embase. All study designs except case reports, small case series, and SLRs were considered for inclusion. Reference lists of previously published SLRs were reviewed for any relevant additional studies. Studies of populations without dairy sensitivities exploring the association between dietary patterns and/or dairy consumption and anxiety published through May 2022 were identified using predefined eligibility criteria. Study quality was determined using the Academy of Nutrition and Dietetics Quality Criteria Checklist.

RESULTS

For this SLR, 132 studies were included; 80 were cross-sectional. Studies examined different dietary patterns (e.g., Mediterranean, gluten-free) and anxiety using various anxiety scales, with 19 studies specifically reporting on whole dairy consumption and anxiety. Dairy consumption was significantly associated with a lower risk of anxiety in 7 studies, while the remaining 12 studies showed no significant associations. Evidence was mixed for the association between various dietary patterns and anxiety, but more studies observed a lower risk of anxiety with greater adherence to "healthy" diets (e.g., Mediterranean, diet quality score, vegetarian/vegan) than a higher risk. Notable heterogeneity in study populations, time periods, geographical locations, dietary assessment methods, and anxiety scales was observed.

CONCLUSIONS

The results of this SLR suggest a potential link between diet including diary consumption and anxiety, but future studies, especially with longitudinal designs that measure diet and anxiety at several timepoints and comprehensively adjust for confounders, are needed to fully understand the relationship between diet and anxiety.

Scoping review of the association of plant-based diet quality with health outcomes

Introduction

The association of plant-based dietary patterns with health outcomes has traditionally been assessed without considering nutritional value. The plant-based dietary index (PDI), first published in 2016, overcomes this limitation with both a healthful PDI (hPDI) and an unhealthful PDI (uPDI), based on the quality of plant foods consumed plus the frequency of animal foods. We sought to summarize the breadth of research using the hPDI and uPDI to gain insight into how the quality of plant-based dietary patterns might be associated with health outcomes.

Methods

Scoping review of studies that used the PDI, hPDI, or uPDI to report associations with health outcomes. Multiple databases were searched from 2010 through April 2023 with 2 authors independently assessing eligibility and extracting data. In addition to assessing the association of the indices to health outcomes, we determined the frequency of concordant or discordant findings for hPDI versus PDI and for hPDI versus uPDI.

Results

We included 95 articles (54% longitudinal, 37% cross-sectional, and 9% case-control) with a median sample size of 3,646. Higher hPDI levels were associated with favorable health outcomes in 36% of comparisons (most often for obesity, mortality, diabetes, cardiovascular disease, and psychiatric disorders), compared to 25% for the PDI and only 2% for the uPDI. Conversely, higher levels of the uPDI were associated with unfavorable health outcomes in 33% of comparisons, in contrast to under 1% for the hPDI and 2% for the PDI. When the hPDI association to an outcome was discordant with the uPDI or PDI, the significance and directionality always favored the hPDI over the uPDI, and nearly always favored the hPDI over the PDI.

Discussion

Dietary indices that account for the quality of plant foods can show health benefits that might be missed by a generic plant-based index. A greater focus on the quality of plant foods could improve nutrition guidelines, raise awareness about the benefits of adding unrefined plant foods to the diet, and empower consumers to make incremental additions of such foods to displace unhealthy foods. We anticipate increasing use of indices that address food quality in future research.

Association of plant-based dietary patterns with the risk of osteoporosis in community-dwelling adults over 60 years: a cross-sectional study

Plant foods are rich in many important micronutrients that are beneficial for bone health. This cross-sectional study of 9613 community-dwelling older adults found that more consumption of healthy plant foods and less consumption of animal foods and unhealthy plant foods were associated with a lower risk of osteoporosis.

INTRODUCTION

Osteoporosis,a common chronic disease in older adults, threatens their health. Many nutrients in plant foods are important for preventing osteoporosis. However, the relationship between plant-based dietary patterns and osteoporosis remains unclear. This study aimed to investigate the cross-sectional association between plant-based dietary patterns and osteoporosis in older adults.

METHODS

This study was conducted among 9613 community-dwelling older adults in Liaoning Province, China. The effective food frequency questionnaire (FFQ) and plant-based diet index (PDI) were used to evaluate compliance with plant-based dietary patterns. Osteoporosis was defined based on heel ultrasound. We analyzed the association between healthy plant-based diet index (HPDI) and unhealthful plant-based diet index (UPDI) and the risk of osteoporosis.

RESULTS

A higher PDI was associated with higher bone mineral density (BMD) in older adults. In logistic regression models, the highest quartile of PDI and HPDI had a significantly lower risk of osteoporosis than the lowest quartile, whereas UPDI in the highest quartile was associated with a higher risk of osteoporosis. There was a dose-response relationship between the three indices and the risk of osteoporosis. Subgroup analysis revealed differences in the relationship between HPDI and the risk of osteoporosis according to gender and age.

CONCLUSIONS

Older adults, especially women, consume more healthy plant foods and reduce the consumption of animal foods and unhealthy plant foods, which was associated with a lower risk of osteoporosis.

The relationship between dietary patterns and aggressive behavior in adolescent girls: A cross-sectional study

BACKGROUND

There are few studies about the relationship between dietary patterns and aggression. The aim of this study was to assess the relationship between the main dietary patterns and aggression scores among adolescent girls in Iran.

METHODS

This cross-sectional study was conducted on 670 adolescent girls. The 168-item self-administered Semi-quantitative Food Frequency Questionnaire was used to evaluate dietary intake and to identify major dietary patterns, while factor analysis was applied. Aggression was evaluated by the validated Persian version of the Buss-Perry questionnaire. Statistical analysis was performed by crude and adjusted models.

RESULTS

Three main dietary patterns including healthy, fast food, and Western were identified. A significant positive association was found between more adherence to Western dietary pattern and the presence of a high aggression score (OR: 2.00; 95% CI: 1.32-3.05, p-_{trend =} .001); even after adjustment for potential confounders, these findings were significant.

CONCLUSION

Although Western dietary patterns were associated with increased aggression risk, there was no significant relationship between healthy and fast food dietary patterns and the prevalence of a high aggression score. Further studies, particularly longitudinal intervention studies, are required to clarify this relationship.