The association of ultra-processed food intake with neurodegenerative disorders: a systematic review and dose-response meta-analysis of large-scale cohorts

ABSTRACT

Objectives

Our systematic review and meta-analysis aimed to uncover the relationship between UPFs intake and neurodegenerative disorders, including multiple sclerosis (MS), Parkinson’s disease (PD), Alzheimer’s disease (AD), cognitive impairment, and dementia.

Setting

A systematic search was conducted using the Scopus, PubMed/MEDLINE, and ISI Web of Science databases without any limitation until June 24, 2023. Relative risk (RR) and 95% confidence interval (CI) were pooled by using a random-effects model, while validated methods examined quality and publication bias via Newcastle-Ottawa Scale, Egger’s regression asymmetry, and Begg’s rank correlation tests, respectively.

Results

Analysis from 28 studies indicated that a higher UPFs intake was significantly related to an enhanced risk of MS (RR = 1.15; 95% CI: 1.00, 1.33; I²= 37.5%; p = 0.050; n = 14), PD (RR = 1.56; 95% CI: 1.21, 2.02; I²= 64.1%; p = 0.001; n = 15), and cognitive impairment (RR = 1.17; 95% CI: 1.06, 1.30; I²= 74.1%; p = 0.003; n = 17), although not AD or dementia. We observed that a 25 g increment in UPFs intake was related to a 4% higher risk of MS (RR = 1.04; 95% CI: 1.01, 1.06; I²= 0.0%; p = 0.013; n = 7), but not PD. The non-linear dose–response relationship indicated a positive non-linear association between UPF intake and the risk of MS (P_nonlinearity = 0.031, P_{dose-response}= 0.002). This association was not observed for the risk of PD (P_nonlinearity = 0.431, P_{dose-response}= 0.231).

Conclusion

These findings indicate that persistent overconsumption of UPFs may have an adverse impact on neurodegenerative conditions, potentially leading to a decline in quality of life and reduced independence as individuals age.

GRAPHICAL ABSTRACT

KEYWORDS:

• Ultra-processed foods
• neurodegenerative disorders
• multiple sclerosis
• Parkinson’s disease
• Alzheimer’s disease
• cognitive impairment
• dementia
• meta-Analysis‌

Disclosure statement

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

Additional information

Funding

The author(s) reported there is no funding associated with the work featured in this article.

Notes on contributors

Ali Pourmotabbed

Dr. Ali Pourmotabbed is a professor of the department of physiology, school of medicine, Kermanshah University of Medical Sciences, Kermanshah, Iran. Her work focuses on neuromuscular system disorders. He has published many articles and books in the field of neurology.

Sepide Talebi

Sepide Talebi is a PhD candidate of the department of clinical nutrition, school of nutritional sciences and dietetics, Tehran University of Medical Sciences, Tehran, Iran. She works focuses on epidemiological studies related to nutrition and neurological disorders.

Sanaz Mehrabani

Dr. Sanaz Mehrabani is a PhD of the department of clinical nutrition, school of nutritional sciences and dietetics, Isfahan University of Medical Sciences, Isfahan, Iran. Her research interests include nutritional studies related to neurological disorders.

Atefeh Babaei

Dr Atefeh Babaei is a PhD of the department of physiology, school of medicine, Kermanshah University of Medical Sciences, Kermanshah, Iran. Her work focuses on reproductive science.

Reza Amiri Khosroshahi

Reza Amiri Khosroshahi is a PhD candidate of the department of clinical nutrition, school of nutritional sciences and dietetics, Tehran University of Medical Sciences, Tehran, Iran. He works focuses on epidemiological studies related to neurological disorders.

Reza Bagheri

Dr. Reza Bagheri is a PhD of the department of department of exercise physiology, University of Isfahan, Isfahan, Iran. Her work focuses on neuromuscular system disorders.

Alexei Wong

Dr. Alexei Wong is a PhD of the department of health and human performance, Marymount University, Arlington, VA, USA. Her work focuses on neuromuscular system disorders.

Seyed Mojtaba Ghoreishy

Seyed Mojtaba Ghoreishy is a PhD candidate of the department of clinical nutrition, school of nutritional sciences and dietetics, Iran University of Medical Sciences, Tehran, Iran. She works focuses on epidemiological studies related to neurological disorders.

Parsa Amirian

Dr. Parsa Amirian is MD of the General Practitioner, Kermanshah University of Medical Sciences (KUMS), Kermanshah, Iran.

Mahsa Zarpoosh

Dr. Mahsa Zarpoosh is MD of the General Practitioner, Kermanshah University of Medical Sciences (KUMS), Kermanshah, Iran.

Mohammad Ali Hojjati Kermani

Mohammad Ali Hojjati Kermani is Phd candidate of the of clinical nutrition, school of nutritional sciences and dietetics, Isfahan University of Medical Sciences, Isfahan, Iran. He works at Clinical Tuberculosis and Epidemiology Research Center, National Research Institute of Tuberculosis and Lung Diseases (NRITLD), Masih Daneshvari Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran.

Sajjad Moradi

Dr. Sajjad Moradi is PhD of nutrition of the clinical nutrition, school of nutritional sciences and dietetics, Isfahan University of Medical Sciences, Isfahan, Iran. He works at department of nutrition and food sciences, Maragheh University of Medical Sciences, Maragheh, Iran. He works focuses on epidemiological studies related to nutrition and neurological disorders.