Nutrition constitutes an interesting approach for the prevention of age-related brain disorders. The objective of this review was to examine the most recent evidence on the association between ...adherence to a Mediterranean diet (MeDi) and cognitive health among elderly individuals.
Based on available epidemiological studies, two meta-analyses published in 2013 have underlined a protective effect of a greater MeDi adherence on cognitive health, including a reduced risk of Alzheimer's disease and cognitive impairment. Since then, six additional studies, from longitudinal cohorts or post-hoc analyses of randomized controlled trials conducted in the USA and Europe, have been published and provided mixed results. Potential reasons for such discrepancies include methodological limitations inherent to observational studies, and interactions between diet, environmental factors, such as those enhancing cognitive reserve, chronic diseases, and genetic factors.
Overall, available evidence suggests that the MeDi might exert a long-term beneficial effect on brain functioning. However, more high-powered observational studies with long-term follow-up for cognition and randomized controlled trials assessing the impact of shifting to a MeDi on cognitive functions are still needed in various populations.
Low-grade chronic inflammation associated with unhealthy diets may lead to cognitive aging.
We evaluated whether higher long-term adherence to an empirical dietary inflammatory pattern (EDIP) was ...associated with lower cognitive function after age 70 y in the Nurses’ Health Study.
A total of 16,058 older (mean ± SD age: 74 ± 2 y) highly educated (≥ bachelor degree) White women completed up to 5 validated 116-item food-frequency questionnaires. An EDIP score, previously derived with the use of reduced rank regression to predict circulating inflammatory markers (i.e., C-reactive protein, TNF-α receptor 2, and IL-6), was computed based on 9 anti-inflammatory and 9 proinflammatory components. A long-term EDIP score was calculated by averaging across 5 exams. The EDIP score was categorized into quintiles, taking the first (anti-inflammatory) quintile as the reference category. Cognitive testing was performed through telephone interviews over 4 follow-up exams (1995–2008). A composite global cognition score, a composite verbal memory score, and the Telephone Interview for Cognitive Status (TICS) were calculated and averaged across the 4 exams (6 y of follow-up). Multivariable linear regressions were used to examine longitudinal relations under study.
Higher long-term EDIP scores (i.e., more proinflammatory) were significantly associated with worse performance on global cognitive function (P-trend= 0.018) and TICS (P-trend= 0.004) after adjustment for demographic and lifestyle factors. The associations became nonsignificant after additional adjustments for disease (related) risk factors for dementia. No association was observed between the EDIP score and verbal memory.
We observed no relation between long-term EDIP scores and averaged global cognitive function and verbal memory among older women. Our findings suggest no relation between long-term adherence to a proinflammatory diet and cognitive function in a large population of mostly White and generally highly educated older women. Future studies are encouraged to investigate the relation between inflammatory diets and cognitive function in other races/ethnicities and men, and over a longer follow-up period.
Vascular risk factors have been proposed as important targets for the prevention of dementia. As lipid fractions represent easily modifiable targets, we examined the longitudinal relationship of ...baseline lipid fractions with 13-y incident dementia and its subtypes (Alzheimer disease AD and mixed or vascular dementia) in older community-dwelling persons.
Non-institutionalized persons aged 65+ y (n = 9,294) were recruited for the Three-City Study (3C Study), a population-based cohort study from the electoral rolls of the cities of Dijon, Bordeaux, and Montpellier, France, between March 1999 and March 2001. Follow-up examinations were performed every 2 y after the baseline assessment. The final study sample comprised 7,470 participants from the 3C Study (mean age ± standard deviation SD 73.8 ± 5.3 y, 61.0% women) who were prospectively followed up for up to 13 y. Fasting lipid fractions (triglycerides TGs, high-density lipoprotein cholesterol HDL-C, low-density lipoprotein cholesterol LDL-C, total cholesterol TC) were studied as continuous variables, and results are reported per SD increase of each lipid fraction. Incident dementia and its subtypes were studied as censored variables using Cox models with age as time scale. Analyses were adjusted for sex, study center, and educational level, as well as vascular risk factors and apolipoprotein E (APOE) ε4 genotype. We corrected for multiple testing, yielding a significance threshold of 0.0169. p-Values above the significance threshold but less than 0.05 were considered nominally significant. During a mean (± SD) follow-up period of 7.9 ± 3.6 y, 779 participants developed incident dementia (n = 532 AD and n = 154 mixed or vascular dementia). Higher LDL-C and TC concentrations at baseline were associated with an increased risk of AD (hazard ratio HR per SD increase = 1.13 95% CI 1.04-1.22, p = 0.0045, and HR = 1.12 1.03-1.22, p = 0.0072, respectively). These associations were largely unchanged after adjustment for vascular risk factors and were attenuated after adjustment for APOEε4 (HR per SD increase = 1.12 1.03-1.23, p = 0.0110, and HR = 1.12 1.02-1.23, p = 0.0171, respectively). Higher TG concentrations at baseline were associated with an increased risk of all dementia (HR per SD increase = 1.11 1.03-1.19, p = 0.0044) and mixed or vascular dementia (HR = 1.21 1.04-1.41, p = 0.0163). However, these associations disappeared after adjusting for vascular risk factors (HR = 1.07 0.98-1.17, p = 0.1374, and HR = 1.17 0.96-1.42, p = 0.1206, respectively). Main limitations of the study include interval censoring of incident dementia cases, potential selective survival bias, and the fact that variation in lipid concentrations during follow-up could not be accounted for in the analyses.
In a large population-based sample of older community-dwelling persons with up to 13 y of follow-up, we observed that higher LDL-C and TC concentrations were associated with an increased risk of AD. This result was independent of vascular risk factors and was attenuated after adjustment for APOEε4 carrier status. TG and HDL-C concentrations were not associated with risk of incident dementia or its subtypes after accounting for vascular risk factors.
Evidence is limited regarding the relation between cardiovascular health level and dementia risk.
To investigate the association between cardiovascular health level, defined using the 7-item tool ...from the American Heart Association (AHA), and risk of dementia and cognitive decline in older persons.
Population-based cohort study of persons aged 65 years or older from Bordeaux, Dijon, and Montpellier, France, without history of cardiovascular diseases or dementia at baseline who underwent repeated in-person neuropsychological testing (January 1999-July 2016) and systematic detection of incident dementia (date of final follow-up, July 26, 2016).
The number of the AHA's Life's Simple 7 metrics at recommended optimal level (nonsmoking, body mass index <25, regular physical activity, eating fish twice a week or more and fruits and vegetables at least 3 times a day, cholesterol <200 mg/dL untreated, fasting glucose <100 mg/dL untreated, and blood pressure <120/80 mm Hg untreated; score range, 0-7) and a global cardiovascular health score (range, 0-14; poor, intermediate, and optimal levels of each metric assigned a value of 0, 1, and 2, respectively).
Incident dementia validated by an expert committee and change in a composite score of global cognition (in standard units, with values indicating distance from population means, 0 equal to the mean, and +1 and -1 equal to 1 SD above and below the mean).
Among 6626 participants (mean age, 73.7 years; 4200 women 63.4%), 2412 (36.5%), 3781 (57.1%), and 433 (6.5%) had 0 to 2, 3 to 4, and 5 to 7 health metrics at optimal levels, respectively, at baseline. Over a mean follow-up duration of 8.5 (range, 0.6-16.6) years, 745 participants had incident adjudicated dementia. Compared with the incidence rate of dementia of 1.76 (95% CI, 1.38-2.15) per 100 person-years among those with 0 or 1 health metrics at optimal levels, the absolute differences in incident dementia rates for 2, 3, 4, 5, and 6 to 7 metrics were, respectively, -0.26 (95% CI, -0.48 to -0.04), -0.59 (95% CI, -0.80 to -0.38), -0.43 (95% CI, -0.65 to -0.21), -0.93 (95% CI, -1.18 to -0.68), and -0.96 (95% CI, -1.37 to -0.56) per 100 person-years. In multivariable models, the hazard ratios for dementia were 0.90 (95% CI, 0.84-0.97) per additional optimal metric and 0.92 (95% CI, 0.89-0.96) per additional point on the global score. Furthermore, the gain in global cognition associated with each additional optimal metric at baseline was 0.031 (95% CI, 0.009-0.053) standard units at inclusion, 0.068 (95% CI, 0.045-0.092) units at year 6, and 0.072 (95% CI, 0.042-0.102) units at year 12.
In this cohort of older adults, increased numbers of optimal cardiovascular health metrics and a higher cardiovascular health score were associated with a lower risk of dementia and lower rates of cognitive decline. These findings may support the promotion of cardiovascular health to prevent risk factors associated with cognitive decline and dementia.
Age-adjusted stroke incidence has decreased over the past 50 years, likely as a result of changes in the prevalence and impact of various stroke risk factors. An updated version of the Framingham ...Stroke Risk Profile (FSRP) might better predict current risks in the FHS (Framingham Heart Study) and other cohorts. We compared the accuracy of the standard (old) and of a revised (new) version of the FSRP in predicting the risk of all-stroke and ischemic stroke and validated this new FSRP in 2 external cohorts, the 3C (3 Cities) and REGARDS (Reasons for Geographic and Racial Differences in Stroke) studies.
We computed the old FSRP as originally described and a new model that used the most recent epoch-specific risk factor prevalence and hazard ratios for individuals ≥55 years of age and for the subsample ≥65 years of age (to match the age range in REGARDS and 3C studies, respectively) and compared the efficacy of these models in predicting 5- and 10-year stroke risks.
The new FSRP was a better predictor of current stroke risks in all 3 samples than the old FSRP (calibration χ
of new/old FSRP: in men: 64.0/12.1, 59.4/30.6, and 20.7/12.5; in women: 42.5/4.1, 115.4/90.3, and 9.8/6.5 in FHS, REGARDS, and 3C, respectively). In the REGARDS, the new FSRP was a better predictor among whites compared with blacks.
A more contemporaneous, new FSRP better predicts current risks in 3 large community samples and could serve as the basis for examining geographic and racial differences in stroke risk and the incremental diagnostic utility of novel stroke risk factors.
Dietary factors and brain health Lefèvre-Arbogast, Sophie; Thomas, Aline; Samieri, Cécilia
Current opinion in lipidology,
02/2022, Volume:
33, Issue:
1
Journal Article
Peer reviewed
Nutrition is a complex exposure (i.e., the food exposome) that influences brain function and health through multiple pathways. We review recent epidemiological studies that have improved the ...characterization of the food exposome and brain health in humans and have revealed promising nutrition-based strategies to prevent cognitive aging.
A selection of epidemiological research from the past 18 months of both observational and clinical studies is presented, with a focus on novel findings, including novel nutrient and diet patterns, diet-related approaches to rescue brain energetics defects in aging, and biomarker-based studies to decipher specific neurobiological pathways of nutrition and brain health.
Although healthy diets such as the Mediterranean diet promote brain health throughout life, specific diets, such as the Mediterranean-Dietary Approaches to Stop Hypertension Intervention for Neurodegenerative Delay diet, or specific nutrients (LC n-3 polyunsaturated fatty acids, carotenoids, vitamin D, B vitamins, polyphenols) alone or in combination, may prevent cognitive aging. Diet management approaches to rescue brain energetics defects such as the Modified Mediterranean-ketogenic diet may be promising to prevent neurodegenerative diseases. Expanding research also suggests that promotion of a healthy gut microbiome through prebiotic foods may preserve the diet-gut-brain axis with aging. Future studies should explore more individualized preventive approaches through a 'precision nutrition' framework.
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