The association between plant and animal protein intake with depression, anxiety, and stress

ABSTRACT

Background

Recent evidence suggests that diet composition is a key biological factor related to the development of depressive disorders. The present study was conducted to investigate the animal and plant protein intake and their replacement in association with depression, anxiety, and stress in Iranian adults.

Method

In this cross-sectional study, the dietary intake of 7169 subjects were assessed using a validated food frequency questionnaire. The depression, anxiety, and stress Scale – 21 (DASS-21) questionnaire was used to psychological disorders. Logistic regression was used to obtain odds ratios for depression, anxiety, and stress across quintiles of animal and plant protein.

Results

The participants’ age range was 20–69 years. Individuals with the highest animal protein consumption had a lower chance for developing depression compared to those with the lowest intakes (OR = 0.73, 95%CI: 0.59-0.90; P_trend< 0.01). Results also showed a significant association between animal protein intake and anxiety, such that subjects in the highest quintile of animal protein intake had 24% lower odds for anxiety compared to those in the lowest quintile (p < 0.05). We found a significant association between highest quintiles of animal protein intake and a 40% lower risk for stress among female individuals (P_trend= 0.05). The multivariable-adjusted non-linear analyses also revealed that the replacement of plant protein with animal protein was significantly associated with the likelihood of depression and anxiety (P < 0.05).

Conclusion

Animal protein intake might lower the odds of depression and anxiety particularly. Future prospective investigations are proposed to confirm these findings.

KEYWORDS:

• ‌Diet
• animal protein
• plant protein‌
• depression
• anxiety
• stress
• mental disorders
• cross-sectional studies

Ethics approval and consent to participate

The methodology of the present study was approved by the ethics committee of Shahid Sadoughi University of Medical Sciences, Yazd, Iran and written informed consents for entering the study and publication of study results were taken from all participants.

Consent for publication

No individual detail is presented in this manuscript; therefore, it is not applicable.

Authors’ contribution

BF and BS participated in drafting the initial version. ASA and BS designed the study and helped in the data analysis. BF implemented comments and suggestions of the co-authors. ASA and MM contributed to the conception, design, and data analysis. All authors reviewed the final version of the manuscript. ASA supervised the study.

Acknowledgments

We would like to express our special thanks to the participants, without whom the study would not have been possible.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

The data of the present study will be available for the corresponding author.

Additional information

Funding

This work was supported by Shahid Sadoughi University of Medical Sciences.

Notes on contributors

Bita Forootani

Bita Forootani is an MSc student in public health nutrition at Shahis Sadoughi University. Her research is focused on the effect of dietary oils on cardiovascular risk factors. She has recently published a paper entitled “The impact of a blend of Pistacia atlantica seed and canola oil compared with a blend of corn-canola oil with synthetic antioxidant and corn-canola oil without synthetic antioxidant on oxidative stress markers in patients with metabolic syndrome: protocol for a triple-blind, randomized, three-way cross-over clinical trial” (Trials, 2023).

Bahareh Sasanfar

Bahareh Sasanfar is a PhD student in nutrition at Shahid Sadoughi University of Medical Sciences. She has focused on nutritional epidemiology and has tried to investigate the association between diet and different chronic diseases in the context of observational studies. She has recently published a paper entitled “Association between a western diet and asthma among children and adolescents” (Scientific Reports, 2024).

Amin Salehi-Abargouei

Amin Salehi-Abargouei, as an associate professor of nutrition, has focused on the association between diet and cardiovascular diseases, mental health and cancer. One of his recent publications is entitled “The association between dietary meal intake habits and coronary artery stenosis and cardio-metabolic risk factors” (BMC Public Health, 2024).

Masoud Mirzaei

Masoud Mirzaei, as a professor of epidemiology. is the principal investigator of Yazd Health Study (YaHS) a population-based cohort conducted in Yazd city, Iran and is actively involved in research related to chronic diseases, particularly cardiovascular diseases. His recent paper is entitled “Electrocardiography Changes and Different Stages of Heart Failure in Central Iran: A cross-sectional Study from Yazd Health Study” (Health Science Reports, 2024).