Association between the Erythrocyte Membrane Fatty Acid Profile and Cognitive Function in the Overweight and Obese Population Aged from 45 to 75 Years Old

Association of the serum levels of saturated fatty acids and mild cognitive impairment: a cross-sectional study

OBJECTIVES

To investigate the association of serum saturated fatty acids (SFAs) and prevalent mild cognitive impairment (MCI) among middle-aged and elderly Chinese.

METHODS

A total of 607 Chinese adults aged at least 45 years were included in the baseline survey of The Lifestyle and Healthy Aging of Chinese Square Dancer Study. Serum concentrations of individual SFAs including 6 even-chain SFAs (C14:0, C16:0, C18:0, C20:0, C22:0, and C24:0) and 4 odd-chain SFAs (C15:0, C17:0, C21:0, and C23:0), were quantified by Gas chromatography system with a mass spectrometer. According to Petersen's criteria, prevalent MCI was diagnosed by neurologists through uniformed neuropsychological tests, including trail-making test-part B (TMT-B), auditory verbal learning test (AVLT), digit symbol substitution test (DSST), and verbal fluency test (VFT).

RESULTS

The median age was 62 years with an interquartile range of 57.0 to 67.0 years, and 86 (14.17%) participants were living with MCI. Higher levels of either even-chain or odd-chain individual SFAs were associated with the higher odds of MCI, and their odds ratios (ORs) and 95% confidence intervals (95%CIs) were 2.054 (1.012 to 4.171) for C14:0, 2.246 (1.061 to 4.755) for C16:0, 2.789 (1.321 to 5.886) for C18:0, and 2.329 (1.136 to 4.778) for C15:0, and 2.761 (1.310 to 5.820) for C17:0, respectively.

CONCLUSIONS

The serum concentration of SFAs was positively related to the odds of MCI in middle-aged and elderly adults. Determining the link between SFAs profiles and MCI may inform a better understanding of the potential role of saturated fat intake on cognitive function.

Dietary Inflammatory Index and Cognitive Function: Findings from a Cross-Sectional Study in Obese Chinese Township Population from 45 to 75 Years

Background and Objective

Cognitive dysfunction is highly prevalent in obese people, and food is a key factor in obesity, and dietary inflammatory index (DII) can reflect whether diet has anti-inflammatory or pro-inflammatory potential. In addition, dietary fatty acid consumption is linked to inflammation, obesity, and cognitive impairment. Erythrocyte membrane fatty acids can reflect dietary fatty acid intake. Our hypothesis was that erythrocyte membrane fatty acids might have a significant impact on the relationship between DII and cognition in obese individuals, and we designed experiments to test the hypothesis.

Methods

In three villages in Beijing, we collected 579 respondents from individuals 45 to 75 years old and categorized them by body mass index. The Montreal Cognitive Assessment (MoCA) score and DII score was calculated and gas chromatography was used to measure the proportion of erythrocyte membrane fatty acids. The relationship between the DII score and cognition was examined using multiple linear regression and binary logistic regression. Mediation analysis can help to understand the causal chain between variables, deeply explore the internal relationship and mechanism of action between variables. So a multiple chain mediation model was developed to investigate the mediating factors between the DII score and cognitive association.

Results

According to adjusted linear regression, higher DII scores were linked to lower MoCA scores in the obese group. The negative correlation between DII score and cognitive function score remains in binary linear regression. We discovered through mediation analysis that erythrocyte membrane fatty acids mediate the detrimental link between DII and cognitive function in obese individuals.

Conclusion

We propose that higher DII scores in obese people are associated with a decline in cognitive function. In addition, this effect might be mediated via the fatty acids in the erythrocyte membrane.

Association between erythrocyte membrane fatty acids and gut bacteria in obesity-related cognitive dysfunction

Obesity increases the risk of cognitive impairment and dementia, and the gut microbiota can affect brain cognitive function and obesity through a variety of pathways such as the gut-brain axis. This study aimed to discover how fatty acid affect cognitive function by regulating intestinal flora in obesity. Obese subjects were recruited for cognitive function assessment, and participants were divided into obese group with cognitive impairment (MCI, n = 49) and obese cognitively normal group (Non_MCI, n = 55). In the erythrocyte membrane, the proportion of polyunsaturated fatty acids (PUFA), linoleic acid (C18:2 n-6) and arachidonic acid (C20:4 n-6) and n-6/n-3 ratio was higher in the MCI group than in the Non_MCI group. However, the α-linolenic acid (C18:3 n-3) percentage of the erythrocyte membrane was lower in the MCI group. We found that Coriobacteriales_Incertae_Sedis was positively correlated with erythrocyte membrane C20:4 n-6 and n-6 PUFA and negatively correlated with cognitive scores in obese patients. In addition, several of the functional pathways we predicted were significantly different in the MCI and Non_MCI groups. Higher levels of n-6/n-3 polyunsaturated fatty acids ratio in the erythrocyte membranes may influence the inflammatory response in the organism causing obesity induced cognitive damage. Moreover, high levels of n-6/n-3 polyunsaturated fatty acids ratio may also affect the intestinal flora of obese patients, which in turn may affect the cognitive function of obese patients.

Gut microbiota regulation of inflammatory cytokines and microRNAs in diabetes-associated cognitive dysfunction

Type 2 diabetes mellitus (T2DM) has a major comorbidity known as diabetes-associated cognitive dysfunction (DACD). Studies have demonstrated that the gut microbiota is crucial in mediating the cognitive abnormalities that occur in diabetic individuals. Additionally, changes in dietary fatty acid intake levels, inflammatory cytokines, and microRNAs (miRs) have an effect on cognitive performance. However, further studies are needed to identify the link between gut microbiota and cognition in T2DM patients and the role that the above indicators play in this process. In order to provide a new rationale for the treatment of cognitive dysfunction in diabetes, this study was conducted in the middle-aged and elderly Beijing population to examine the differences in gut microbiota between DACD and T2DM patients as well as to further explore the role of erythrocyte membrane fatty acids, inflammatory cytokines, and miRs in gut microbiota-mediated cognitive impairment. According to the results, the abundance of norank_f_Eubacterium_coprostanoligenes_group, Acidaminococcus, Enterorhabdus, and norank_f_Clostridium_methylpentosum_group was higher in DACD patients compared to T2DM patients at the genus level. Compared with T2DM patients, plasma interleukin-12 (IL-12) concentrations were significantly higher in DACD patients than in T2DM patients, and IL-12 was significantly positively correlated with norank_f_Eubacterium_coprostanoligenes_group. In addition, plasma miR-142-5p was significantly positively correlated with Enterorhabdus and norank_f_Eubacterium_coprostanoligenes_group. We therefore hypothesize that cognitive impairment in T2DM patients is associated with altered gut microbial composition and that the effect of microbiota on cognition may be mediated through IL-12 and miR-142-5p. KEY POINTS: • Type 2 diabetes with or without cognitive impairment differs in gut microbiota. • Differential genera of gut microbiota were associated with inflammatory cytokines. • Differential genera of gut microbiota were associated with plasma microRNAs.

Red Blood Cell Fatty Acid Profiles Are Significantly Altered in South Australian Mild Cognitive Impairment and Alzheimer's Disease Cases Compared to Matched Controls

Nutritional imbalances have been associated with a higher risk for cognitive impairment. This study determined the red blood cell (RBC) fatty acid profile of newly diagnosed mild cognitive impairment (MCI) and Alzheimer's disease (AD) patients compared to age and gender-matched controls. There was a significant increase in palmitic acid (p < 0.00001) for both MCI and AD groups. Saturated fatty acids were significantly elevated in the MCI group, including stearic acid (p = 0.0001), arachidic acid (p = 0.003), behenic acid (p = 0.0002), tricosanoic acid (p = 0.007) and lignoceric acid (p = 0.001). n-6 polyunsaturated fatty acids (PUFAs) were significantly reduced in MCI, including linoleic acid (p = 0.001), γ-linolenic acid (p = 0.03), eicosatrienoic acid (p = 0.009) and arachidonic acid (p < 0.00004). The n-3 PUFAs, α-linolenic acid and docosahexaenoic acid, were both significantly reduced in MCI and AD (p = 0.0005 and p = 0.00003). A positive correlation was evident between the Mini-Mental State Examination score and nervonic acid in MCI (r = 0.54, p = 0.01) and a negative correlation with γ-linolenic acid in AD (r = -0.43, p = 0.05). Differences in fatty acid profiles may prove useful as potential biomarkers reflecting increased risk for dementia.

The role of dietary patterns and erythrocyte membrane fatty acid patterns on mild cognitive impairment

Background

Dietary fatty acids have been shown to be associated with the development of cognition. However, research on the role of fatty acid intake in dietary patterns and fatty acid patterns (FAPs) in the development of cognitive function is limited. The aim of this study was to explore the correlation between dietary patterns and FAPs and to provide available evidence for preventing mild cognitive impairment (MCI) through these patterns.

Materials and methods

The 973 participants aged between 65 and 85 were recruited from 2020 to 2021 for this multicenter research in Beijing. Neuropsychological tests were used for cognitive evaluation, and data of dietary intake in the past 12 months were collected with semi-quantitative food frequency questionnaire. The erythrocyte membrane fatty acid profile was tested by chromatography and mass spectrometry lipid profiling. Factor analysis was used to derive the main dietary patterns and FAPs. Pearson’s correlation or Spearman’s correlation was used to explore the association between dietary patterns and FAPs. Binary logistic regression was applied to examine the relationship between patterns and cognitive function.

Results

Six dietary patterns and six FAPs were identified, explaining 53.4 and 80.9% of the total variance separately. After adjusting all potential confounders, T3 of the pattern 1 and FAP2 were the independent protect factors for MCI, respectively (OR 0.601, 95% CI [0.395, 0.914]; OR 0.108, 95% CI [0.019, 0.623]). Rich of SM (26:0), SM (24:1), and SM (26:1) is the characteristic of FAP2. A positive correlation was found between component scores of dietary pattern1 and FAP2 (r = 0.441, p = 0.001). People who adhered to a reasonable intake of animal flesh consumed more various long-chain fatty acids as well.

Conclusion

The erythrocyte membrane metabolites, SM (26:0), SM (24:1), and SM (26:1), might function as early biomarkers for predicting or monitoring of cognitive aging in the elderly. The dietary pattern with recommended animal flesh consumption was significantly associated with FAP characterized by very long-chain SMs. This dietary pattern affected FAP, which might achieve the ultimate goal of neuroprotection through the very long-chain SMs. A rational intake of dietary fatty acids might be an effective way on preventing MCI in the elderly.