Effects of saturated and monounsaturated fatty acids on cognitive impairment: evidence from Mendelian randomization study

Youjie Zeng; Si Cao; Juan Tang; Guoxin Lin

doi:10.1038/s41430-024-01437-5

Effects of saturated and monounsaturated fatty acids on cognitive impairment: evidence from Mendelian randomization study

Eur J Clin Nutr. 2024 Apr 17. doi: 10.1038/s41430-024-01437-5. Online ahead of print.

Authors

Youjie Zeng¹, Si Cao², Juan Tang³, Guoxin Lin⁴

Affiliations

¹ Department of Anesthesiology, Third Xiangya Hospital, Central South University, Changsha, 410013, Hunan, China.
² Clinical Research Center for Reproduction and Genetics in Hunan Province, Reproductive and Genetic Hospital of CITIC-XIANGYA, Changsha, 410205, Hunan, China.
³ Department of Nephrology, The Third Xiangya Hospital, The Critical Kidney Disease Research Center, Central South University, Changsha, 410013, China. csutj880109@163.com.
⁴ Department of Anesthesiology, Third Xiangya Hospital, Central South University, Changsha, 410013, Hunan, China. lgx_mzk@csu.edu.cn.

PMID: 38632331
DOI: 10.1038/s41430-024-01437-5

Abstract

Background: Prior observational studies have suggested correlations between saturated fatty acids (SFAs) and monounsaturated fatty acids (MUFAs) with cognitive function. However, causal relationships remains unclear.

Methods: We assessed the causal impact of two SFAs (palmitic acid [PA] and stearic acid [SA]) and two MUFAs (oleic acid [OA] and palmitoleic acid [POA]) on cognitive function-related traits, and dementia-related traits by univariable Mendelian randomization (UVMR) and multivariable Mendelian randomization (MVMR) analyses.

Results: UVMR indicated β of 0.060 (P = 4.05E-06) for cognitive performance score and 0.066 (P = 4.21E-04) for fluid intelligence per standard deviation (SD) increase in OA level. MVMR indicated: (i) β of -0.608 (P = 8.37E-05) for fluid intelligence score per SD increase in POA; (ii) β of 0.074 (P = 0.018) for fluid intelligence score per SD increase in OA; (iii) β of 0.029 (P = 0.033) for number of incorrect matches in round per SD increase in PA; and (iv) β of 0.039 (P = 0.032) for number of incorrect matches in round per SD increase in SA. In addition, a secondary MVMR analysis after excluding the effect of polyunsaturated fatty acids suggested that: (i) β of -0.043 (P = 1.97E-02) for cognitive performance score per SD increase in PA and (ii) β of -0.079 (P = 1.79E-03) for cognitive performance score per SD increase in SA.

Conclusions: Overall, UVMR and MVMR suggest that OA may be beneficial for cognitive function, while POA, PA, and SA may have detrimental effects on cognitive function.