Dietary Factors and Cognitive Health in Ethnic Chinese: A Systematic Review and Meta-analysis

Dementia is a group of neurological disorders affecting millions worldwide, placing substantial strain on healthcare systems. Although diet has been identified as a modifiable risk factor for cognitive health in aging, there is limited research on how dietary patterns affect cognitive outcomes in ethnic Chinese populations. Chinese populations, primarily in Mainland China, Hong Kong, Macao, Taiwan, and Singapore, have distinct genetic profiles and diverse dietary traditions. These genetic and cultural dietary factors may interact in specific ways to influence cognitive health.

This systematic review and meta-analysis critically evaluated the evidence on the dietary factors and cognitive health in the ethnic Chinese population.

A systematic search of PubMed, Web of Science, Scopus, and CNKI were conducted according to the PRISMA criteria.

Two reviewers independently extracted data using a standardized data extraction template. Information collected included study characteristics, participant demographics, dietary exposures or patterns, cognitive outcomes, and key findings. Study quality was assessed using the National Institutes of Health criteria for observational studies. Extracted data, including reported odds ratios (ORs) and corresponding 95% CIs, were summarized and used for subsequent analyses.

Meta-analyses were performed using random-effects models to pool ORs with corresponding 95% CIs. Between-study heterogeneity was assessed using τ2 and I2 statistics, with I2 values >50% indicating substantial heterogeneity. Statistical significance was set at P < .05.

Evidence from observational studies suggests that dietary patterns rich in vegetables, fruits, fish, and plant-based foods are associated with a lower risk of cognitive decline in ethnic Chinese adults, potentially influenced by unique genetic variations, traditional dietary practices, and cultural factors. Adherence to the Mediterranean, Dietary Approaches to Stop Hypertension (DASH), and Mediterranean-DASH Intervention for Neurodegenerative Delay (MIND) diets, as well as higher consumption of mushrooms and tea, was linked to better cognitive health, whereas diets high in red meat and low in fish and legumes were associated with increased risk. Meta-analysis showed a protective association for plant-based diets (OR: 0.78; 95% CI: 0.69-0.87).

PROSPERO NO. CRD42024575522.