Midlife Dietary Intakes of Monounsaturated Acids, n-6 Polyunsaturated Acids, and Plant-Based Fat Are Inversely Associated with Risk of Cognitive Impairment in Older Singapore Chinese Adults

APOE Genotype Modifies the Association between Midlife Adherence to the Planetary Healthy Diet and Cognitive Function in Later Life among Chinese Adults in Singapore

BACKGROUND

It remains unclear if adherence to the planetary healthy diet (PHD), designed to improve human and environmental health, is associated with better cognitive function in aging, and if this association differs by apolipoprotein E (APOE) genotype.

OBJECTIVES

We aimed to examine the association between the PHD pattern and risk of poor cognitive function, and to further assess whether the APOE ε4 allele could modify this association.

METHODS

The study included 16,736 participants from the Singapore Chinese Health Study. The PHD score was calculated using data from a validated 165-item food frequency questionnaire at baseline (1993-1998), with higher scores indicating greater adherence to the PHD. Cognitive function was assessed by the Singapore-modified Mini-Mental State Examination at follow-up 3 visits (2014-2016). A subset of 9313 participants had APOE genotype data. Logistic regression models were used to estimate the odds ratios (ORs) and 95% confidence intervals (CIs), with adjustment for potential confounders.

RESULTS

We identified 2397 (14.3%) cases of poor cognitive function. In the total population, OR (95% CI) of poor cognitive function for each one-SD increment in the PHD score was 0.89 (0.85, 0.93). Carriers of APOE ε4 allele had increased risk of poor cognitive function (OR: 1.36, 95% CI: 1.15, 1.61). There was a significant interaction between the PHD score and the APOE ε4 allele (P-interaction = 0.042). Each one-SD increment in the PHD score was significantly associated with lower risk of poor cognitive function (OR: 0.89; 95% CI: 0.83, 0.96) in non-carriers of APOE ε4 allele, but not in APOE ε4 allele carriers (OR: 1.04, 95% CI: 0.89, 1.23).

CONCLUSIONS

Midlife adherence to the PHD was associated with reduced risk of poor cognitive function in later life. However, this was not observed in carriers of APOE ε4 allele who had higher risk of poor cognitive function.

Association between nutrition and cognition in a multi-ethnic cohort from Singapore

BACKGROUND

Nutrition, a modifiable risk factor, presents a low-cost prevention strategy to reduce the burden of cognitive impairment and dementia. However, studies examining the effects of dietary patterns on cognition are lacking in multi-ethnic Asian populations. We investigate the association between diet quality, measured with the Alternative Healthy Eating Index (AHEI)-2010, and cognitive impairment in middle-aged and older adults of different ethnicities (Chinese, Malay, Indian) in Singapore.

METHODS

This cross-sectional study (n = 3138; mean age: 50.4 ± 9.8, 58.4% women) was based on data from the Singapore Multi-Ethnic Cohort. Dietary intake collected with a validated semi-quantitative Food Frequency Questionnaire was converted into AHEI-2010 scores. Cognition, assessed with the Mini-Mental State Examination (MMSE), was analysed as a continuous or binary outcome (cognitively impaired or not, using cut-offs of ≥ 24, 26 or 28 for no education, primary school education and secondary school education and above). Multivariable linear and logistic regression models were used to examine associations between AHEI-2010 and cognition, adjusting for covariates.

RESULTS

A total of 988 (31.5%) participants had cognitive impairment. Higher AHEI-2010 scores were significantly associated with higher MMSE scores [β = 0.44; 95% confidence interval (CI) 0.22-0.67 highest vs. lowest quartile; p-trend < 0.001] and lower odds of cognitive impairment [OR 0.69; 95% CI 0.54-0.88; p-trend = 0.01] after adjusting for all the covariates. No significant associations were observed for individual dietary components of the AHEI-2010 with MMSE or cognitive impairment.

CONCLUSION

Healthier dietary patterns were associated with better cognitive function in middle-aged and older Singaporeans. These findings could inform better support to promote healthier dietary patterns in Asian populations.

Nutrition and Healthy Ageing in Asia: A Systematic Review

BACKGROUND

Nutrition plays a key role in modulating the likelihood of healthy ageing. In the present study, we aimed to conduct a systematic review to assess the impact of nutrition on healthy ageing in Asia.

METHODS

The systematic review was registered in the International Prospective Register of Systematic Reviews database (CRD42023408936) and conducted based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The PubMed, Web of Science, and Embase databases were searched up to February 2023 without language restrictions. We included prospective cohort studies that evaluated the associations of intake of a single food or consumption of a single nutrient at midlife; adherence to various dietary patterns at midlife; and improved adherence to dietary patterns from mid- to late life with the likelihood of healthy ageing and its components.

RESULTS

Out of 16,373 records, we included 71 papers comprising 24 cohorts from Singapore, China, Japan, and Thailand. The healthy ageing components included cognitive function, physical function, and depression. The majority of studies supported the observation that the likelihood of healthy ageing and its components in late life was positively increased by a higher consumption of healthy foods, such as vegetables, fruits, fish, nuts, legumes, tea, milk, and dairy, at midlife, and also by greater adherence to dietary patterns with high diversity scores or high total antioxidant capacities. Furthermore, improved adherence to healthy dietary patterns from mid- to late life also increased the likelihood of healthy ageing in late life.

CONCLUSION

Consuming healthy foods and adhering to healthy dietary patterns at midlife can promote the likelihood of healthy ageing. Moreover, improving diet quality from mid- to late life can still be beneficial.

The Relationship of Omega-3 Fatty Acids with Dementia and Cognitive Decline: Evidence from Prospective Cohort Studies of Supplementation, Dietary Intake, and Blood Markers

Previous data have linked omega-3 fatty acids with risk of dementia. We aimed to assess the longitudinal relationships of omega-3 polyunsaturated fatty acid intake as well as blood biomarkers with risk of Alzheimer's disease (AD), dementia, or cognitive decline. Longitudinal data were derived from 1135 participants without dementia (mean age = 73 y) in the Alzheimer's Disease Neuroimaging Initiative (ADNI) cohort to evaluate the associations of omega-3 fatty acid supplementation and blood biomarkers with incident AD during the 6-y follow-up. A meta-analysis of published cohort studies was further conducted to test the longitudinal relationships of dietary intake of omega-3 and its peripheral markers with all-cause dementia or cognitive decline. Causal dose-response analyses were conducted using the robust error meta-regression model. In the ADNI cohort, long-term users of omega-3 fatty acid supplements exhibited a 64% reduced risk of AD (hazard ratio: 0.36, 95% confidence interval: 0.18, 0.72; P = 0.004). After incorporating 48 longitudinal studies involving 103,651 participants, a moderate-to-high level of evidence suggested that dietary intake of omega-3 fatty acids could lower risk of all-cause dementia or cognitive decline by ∼20%, especially for docosahexaenoic acid (DHA) intake (relative risk [RR]: 0.82, I2 = 63.6%, P = 0.001) and for studies that were adjusted for apolipoprotein APOE ε4 status (RR: 0.83, I2 = 65%, P = 0.006). Each increment of 0.1 g/d of DHA or eicosapentaenoic acid (EPA) intake was associated with an 8% ∼ 9.9% (Plinear < 0.0005) lower risk of cognitive decline. Moderate-to-high levels of evidence indicated that elevated levels of plasma EPA (RR: 0.88, I2 = 38.1%) and erythrocyte membrane DHA (RR: 0.94, I2 = 0.4%) were associated with a lower risk of cognitive decline. Dietary intake or long-term supplementation of omega-3 fatty acids may help reduce risk of AD or cognitive decline.

The Role of Dietary Lipids in Cognitive Health: Implications for Neurodegenerative Disease

Neurodegenerative diseases are a group of disorders characterised by progressive loss of brain function. The most common of these is Alzheimer's disease, a form of dementia. Intake of macro- and micro-nutrients impacts brain function, including memory, learning, mood, and behaviour. Lipids, particularly phospholipids and sphingolipids, are crucial structural components of neural tissues and significantly affect cognitive function. The importance of functional foods in preventing cardiovascular disease is well-documented in the current literature. However, the significance of such foods for central nervous system health and neurodegenerative diseases is less recognized. Gut microbiome composition affects cognitive health and function, and dietary lipids are known to influence gut health. Thus, this review will discuss different sources of dietary lipids and their effect on cognitive functioning and their interaction with the gut microbiome in the context of neurodegenerative disease.

A gene-environment interplay between omega-3 supplementation and APOE ε4 provides insights for Alzheimer's disease precise prevention amongst high-genetic-risk population

BACKGROUND AND PURPOSE

The present study aimed to explore whether and how omega-3 (ω-3) supplementation could interact with genetic factors to modulate cognitive functions, amyloid pathologies, and Alzheimer's disease (AD) risk.

METHODS

A total of 1,670 non-demented participants (mean age 73 years, 47% females, 41% APOE ε4 carriers) were followed up for 10 years. Hierarchical regressions, linear mixed-effects models, and Cox proportional hazards models were used to examine the interaction effects of ω-3 supplementation with APOE ε4 and polygenic hazard scores, after adjusting for age, gender, education, cognitive diagnosis, insomnia, depression, anxiety, and cardiovascular risk score.

RESULTS

Individuals who progress to AD during the follow-up tend to take a shorter duration of ω-3 at baseline than those stable, for whom the difference remained significant only amongst APOE ε4 carriers (p < 0.01). The interaction term (APOE ε4 × ω-3) accounted for a significant amount of variance in cognition and cerebral amyloid burden. Long-term ω-3 use protected cognition (especially memory function) and lowered amyloid burden and AD risk only amongst APOE ε4 carriers. Mediation analysis suggested that amyloid pathologies, brain reserve capacities, and brain metabolism mediated the relationships of ω-3 use with memory and global cognition for APOE ε4 (+) carriers. Similar interaction and mediation effects were also indicated amongst high-risk subjects defined by polygenic hazard scores.

CONCLUSIONS

Long-term ω-3 intake may have a role in AD prevention in genetically at-risk populations.

The Effect and Mechanism of Cholesterol and Vitamin B12 on Multi-Domain Cognitive Function: A Prospective Study on Chinese Middle-Aged and Older Adults

Background: Nutrients are associated with cognitive function, but limited research studies have systematically evaluated on multi-domain cognitive function. The aim of this study was to investigate the effect and mechanism of specific nutrient on multi-domain cognitive function, and provide nutrition guidance for improving cognitive function.

Methods: Participants were selected based on a multicenter prospective study on middle-aged and older adults in China. Global cognitive function was evaluated by the Mini-Mental State Examination (MMSE). Nutrients intake was assessed according to food frequency questionnaire and China Food Composition Database, and principal component analysis was performed to extract nutrient patterns. Associations between specific nutrients and cognitive function were assessed using log-binomial regression. Restricted cubic spline was used to illustrate the dose-response relationship of nutrients with multi-domain cognitive function. Mediation analysis was used to determine the mechanism of nutrients in cognitive function.

Results: Four nutrient patterns were identified (vitamin-mineral, protein-carbohydrate, fatty acid-vitamin E, and cholesterol-vitamin B₁₂), and only a nutrient pattern rich in cholesterol and vitamin B₁₂ was found associated with cognitive function (RR = 0.891, 95%CI = 0.794–0.999). In multi-domain cognitive function, dietary cholesterol and vitamin B₁₂ were related to better performance of visual memory function (P = 0.034, P = 0.02). In dose-response relationship, it suggested a U-shaped association between vitamin B₁₂ and MMSE (P = 0.02) within a certain range.

Conclusions: Dietary intake rich in cholesterol and vitamin B₁₂ was associated with better cognitive function, and vitamin B₁₂ had a U-shaped dose-response relation with MMSE. Thus, ensuring moderate cholesterol and vitamin B₁₂intake may be an advisable strategy to improve cognitive function in middle-aged and older adults.

Clinical Trial Registration: EMCOA, ChiCTR-OOC-17011882, Registered 5th, July 2017-Retrospectively registered, http://www.medresman.org/uc/project/projectedit.aspx?proj=2610

Consumption of dietary nuts in midlife and risk of cognitive impairment in late-life: the Singapore Chinese Health Study

BACKGROUND

evidence from prospective studies investigating the association between consumption of nuts in midlife and risk of cognitive impairment in late life is limited.

METHODS

this study analysed data from 16,737 participants in a population-based cohort, the Singapore Chinese Health Study. Intake of nuts was assessed using a validated food-frequency questionnaire at baseline (1993-1998), when participants were 45-74 years old (mean age = 53.5 years). Cognitive function was tested using the Singapore modified Mini-Mental State Examination during the third follow-up visit (2014-2016), when participants were 61-96 years old (mean age = 73.2 years). Cognitive impairment was defined using education-specific cut-off points. Logistic regression models were used to estimate the odds ratio (OR) and the 95% confidence interval (CI) for the association between intake and risk of cognitive impairment.

RESULTS

cognitive impairment was identified in 2,397 (14.3%) participants. Compared with those who consumed <1 serving/month of nuts, participants who consumed 1-3 servings/month, 1 serving/week and ≥2 servings/week had 12% (95% CI 2-20%), 19% (95% CI 4-31%) and 21% (2-36%) lower risk of cognitive impairment, respectively (P-trend = 0.01). Further adjustment for intake of unsaturated fatty acids attenuated the association to non-significance. Mediation analysis showed that the 50.8% of the association between nuts and risk of cognitive impairment was mediated by the intake of total unsaturated fatty acids (P < 0.001).

CONCLUSION

higher intake of nuts in midlife was related to a lower risk of cognitive impairment in late life, which was partly mediated by unsaturated fatty acids.

Dietary fatty acids and risk for Alzheimer's disease, dementia, and mild cognitive impairment: A prospective cohort meta-analysis

The association between dietary fatty acid intake and Alzheimer's disease (AD), dementia, and mild cognitive impairment (MCI) risk is inconsistent. This meta-analysis examined the effect of dietary fatty acid intake in prospective cohort studies including patients with AD, dementia, and MCI. PubMed, China Biology Medicine (CBM), China National Knowledge Infrastructure (CNKI), Wanfang Data, and VIP Database were systematically searched through September 2020. The random-effects model was used to combine the highest and lowest categories of multivariable adjusted relative risk (RR). Prospective cohort studies that included associations between dietary fatty acid intake and the risk for AD, dementia, or MCI were included. Fourteen studies were included, comprising 54 177 participants: 1696 patients with AD, 1118 patients with dementia, and 2889 with MCI. The pooled RR showed a significant association only between ω-3 polyunsaturated fatty acid (PUFA) intake and MCI risk (RR, 0.86; 95% CI, 0.75-0.98), with no heterogeneity between studies (I² = 0%). The intake of total fatty acids, saturated fatty acids (SFAs), cholesterol, monounsaturated fatty acids (MUFAs), PUFAs, ω-3 PUFAs, ω-6 PUFAs, docosahexaenoic acids (DHAs), and eicosapentaenoic acids (EPAs) was not significantly associated with AD risk. The intake of total fatty acids, SFAs, MUFAs, PUFAs, and ω-3 PUFAs was not significantly associated with dementia risk. This meta-analysis provided evidence that ω-3 PUFA intake may be negatively associated with MCI risk.

Development of Fatty Acid Reference Ranges and Relationship with Lipid Biomarkers in Middle-Aged Healthy Singaporean Men and Women

Dietary fatty acids (FA) are essential for overall human health, yet individual FA reference ranges have yet to be established. Developing individual FA reference ranges can provide context to reported concentrations and whether an individual displays deficient, or excess amounts of FA. Reference ranges of sixty-seven individual FA (μmol/L) were profiled and analyzed using gas chromatography with a flame ionization detector from serum samples collected from 476 middle-aged Singaporean males (BMI:23.3 ± 2.9) and females (BMI:21.8 ± 3.6). Measures of triglycerides (TG), high-density lipoprotein (HDL), low-density lipoprotein (LDL), and total cholesterol (TC) (mmol/L) were also collected. The mean FA concentration seen in this cohort (11,458 ± 2478 was similar to that of overweight North American cohorts assessed in past studies. Ten biologically relevant FA were compared between sexes, with females exhibiting significantly higher concentrations in four FA (p < 0.05). A multiple regression model revealed the ten FA contributed significantly to nearly all lipid biomarkers (p < 0.05). A majority of participants who had FA concentrations in the ≥95th percentile also exhibited TG, HDL, LDL, and TC levels in the “high” risk classification of developing cardiovascular disease. Future studies profiling individual FA reference ranges in many unique, global cohorts are necessary to develop cut-off values of individual FA concentrations highly related to disease-risk.