Association of dietary pattern and cognitive function in the elderly: A systematic review and meta-analysis

Background: Cognitive dysfunction is one of the common geriatric syndromes, which is reported to be the fifth largest contributor to the global burden of disease. Whether specific dietary patterns are effective in improving cognitive function in the elderly remains controversial, therefore, this study will evaluate the relationship between healthy dietary patterns and cognitive function in older adults by means of Meta-analysis. Methods: As of June 2024, MEDLINE, Scopus, PubMed, Web of Science, and Embase databases were systematically searched. Inclusion criteria include the participants were 60 years and older, the dietary pattern studied was specified in the study, and the clear and valid outcome indicators were provided. Review and conference papers, articles published in languages other than English, repeated publication of literature with the same content, and inability to obtain the full text and valid data will be excluded. OR values and 95% confidence intervals were extracted, and statistical heterogeneity was determined using I-2 test. Publication bias was analyzed by Egger regression test. Due to high heterogeneity, sensitivity analysis, Meta-regression and Sub-group analysis were performed. The NOS and AHRQ scale were used to assess the quality of the study, and Stata17.0 was used for the Meta-analysis. Results: Fifteen papers were finally included, with a cumulative sample size of 62500 cases. All included literature had a score >= 6 after quality assessment. The pooled OR for the 15 studies was 0.60, with 95% confidence intervals ranging from 0.52 to 0.70. We found that a healthy dietary pattern can improve cognitive function in older people (z= 6.34, p<0.05). Discussion: Sub-group analyses in this study did not identify sources of heterogeneity, and there is still a need to include more studies for more comprehensive analyses in the future. Healthy dietary patterns can effectively improve or delay cognitive decline in older adults, which can not only provide a direct guidance for the rational arrangement of daily diet for the elderly, but also provide a reference for clinical staff to provide dietary guidance for elderly patients. Registration: The detailed study protocol can be found on the PROSPERO website. (CRD42024559851)