Validity of estimated dietary eicosapentaenoic acid and docosahexaenoic acid intakes determined by interviewer-administered food frequency questionnaire among older adults with mild-to-moderate cognitive impairment or dementia

Association of adherence to the Chinese version of the MIND diet with reduced cognitive decline in older Chinese individuals: Analysis of the Chinese Longitudinal Healthy Longevity Survey

BACKGROUND

Current evidence suggests that the Mediterranean-Dietary Approaches to Stop Hypertension (DASH) diet intervention for Neurodegenerative Delay (MIND) is associated with a reduced risk of cognitive impairment among North American and Oceanian populations. However, there has been limited exploration of whether this association extends to the Asian population. This study aimed to assess the correlation between the Chinese version of the MIND (cMIND) diet and cognitive impairment in older Chinese individuals.

METHODS

We utilized data from the 2008 wave of the Chinese Longitudinal Healthy Longevity Survey. Participants aged ≥65 years with normal cognitive function at baseline were enrolled. The cMIND diet score (cMINDDS) was calculated by assessing dietary patterns based on survey responses. The Chinese version of the Mini-Mental State Examination (MMSE) was employed to diagnose cognitive impairment in participants. We stratified the analysis by cMINDDS and conducted additional sensitivity analyses.

RESULTS

The cohort consisted of 6411 participants. Over a 3-year follow-up, 1165 (18.6%) individuals who initially had normal cognitive function developed cognitive impairment. A linear association was observed between cMINDDS and cognitive impairment. The increased cMINDDS was associated with a reduced risk of cognitive impairment (quartile 1 vs. quartile 4: the adjusted odds ratio [OR] = 0.77, 95% confidence interval [CI]: [0.60, 0.97], p trend = 0.023). Regarding food composition, higher consumption of fresh fruits and nuts was associated with a decreased risk of cognitive impairment (OR = 0.77, 95% CI: [0.66, 0.89] and OR = 0.70, 95% CI [0.58, 0.86], respectively).

CONCLUSIONS

Adherence to the cMIND diet was associated with lower risks of cognitive impairment in older Chinese individuals. The cMIND diet, based on the MIND dietary pattern, could serve as a preventive measure against cognitive impairment.

The relationship between plasma free fatty acids, cognitive function and structural integrity of the brain in middle-aged healthy humans

Background: The cerebral composition of ω-3 and ω-6 polyunsaturated fatty acids (PUFAs) is believed to influence cognitive function and structural damage of the aging brain. However, existing data is inconsistent.

Materials and Methods: This retrospective study explored the association between free plasma PUFA concentrations, cognitive function and brain structure atrophy in a well-characterized community-dwelling cohort of elderly individuals without stroke and dementia. Ten different fatty acids were analyzed in stored plasma samples from 391 non-demented elderly individuals by gas chromatography mass spectrometry. Neuropsychiatric tests capturing memory, executive function and visuopractical skills were performed in all participants. Brain atrophy was assessed by MRI in a subset of 167 individuals.

Results: Higher plasma concentrations of free ω-6 PUFAs (p = 0.042), and, in particular, linoleic acid (p = 0.01), were significantly associated with lower executive function. No significant association existed between ω-3 PUFA concentrations and cognitive functioning. The volume of the frontal lobes was inversely associated with ω-6 PUFAs, whereas ω-3 PUFAs were positively related with temporal lobe volumes. All associations did not withstand correction for multiple comparisons.

Conclusions: Our study suggests subtle effects of PUFA imbalances on cognition and brain structure. Yet the observed associations are weak and unlikely to be of clinical relevance. The brain regions that seem to be most sensitive to imbalances of ω-3 and ω-6 PUFAs are the frontal and temporal lobes.

Association between methionine cycle metabolite-related diets and mild cognitive impairment in older Chinese adults: a population-based observational study

BACKGROUND

Homocysteine (Hcy) and folate, involved in a common metabolic pathway supplying essential methyl groups for DNA and protein synthesis, have been found to be associated with cognitive function. Moreover, diet may influence methionine cycle metabolites (MCM) as well as mild cognitive impairment (MCI), but MCM-related dietary patterns are unclear in an older population.

OBJECTIVE

The study aimed to identify MCM-related dietary patterns of older Chinese adults, and examine their association with the prevalence of MCI in a large population-based study.

METHODS

This study included 4457 participants ≥ 60 years of age from the Tianjin Elderly Nutrition and Cognition Cohort study. Dietary data were collected using a valid self-administered food frequency questionnaire, and factor analysis was used to identify major dietary patterns in the population. MCM-based dietary patterns were derived using reduced rank regression (RRR) based on serum folate and Hcy as response variables.

RESULTS

Compared with the participants in the lowest quartile of vegetarian pattern and processed foods pattern, the odds ratios (ORs) of MCI in the highest quartile were 0.72 (95% CI 0.53-0.98) and 1.39 (95% CI 1.03-1.88), respectively. In the MCM-based dietary patterns derived using RRR, the ORs for MCI for the highest quartile of MCM patterns I and II were 0.58 (95% CI 0.44-0.78) and 1.38 (95% CI 1.04-1.83), respectively, compared with participants in the lower quartile.

CONCLUSIONS

Findings from this large population-based study suggested that adopting an MCM-related dietary pattern, especially avoiding processed foods, can decrease the occurrence of MCI.

Dietary patterns are related to cognitive functioning in elderly enriched with individuals at increased risk for Alzheimer's disease

Purpose

To investigate cross-sectional associations between dietary patterns and cognitive functioning in elderly free of dementia.

Methods

Data of 389 participants from the German DELCODE study (52% female, 69 ± 6 years, mean Mini Mental State Score 29 ± 1) were included. The sample was enriched with elderly at increased risk for Alzheimer’s disease (AD) by including participants with subjective cognitive decline, mild cognitive impairment (MCI) and siblings of AD patients. Mediterranean and MIND diets were derived from 148 Food Frequency Questionnaire items, and data-driven patterns by principal component analysis (PCA) of 39 food groups. Associations between dietary patterns and five cognitive domain scores were analyzed with linear regression analyses adjusted for demographics (model 1), and additionally for energy intake, BMI, other lifestyle variables and APOe4-status (model 2). For PCA-derived dietary components, final model 3 included all other dietary components.

Results

In fully adjusted models, adherence to Mediterranean and MIND diet was associated with better memory. The ‘alcoholic beverages’ PCA component was positively associated with most cognitive domains. Exclusion of MCI subjects (n = 60) revealed that Mediterranean and MIND diet were also related to language functions; associations with the alcoholic beverages component were attenuated, but most remained significant.

Conclusion

In line with data from elderly population samples, Mediterranean and MIND diet and some data-derived dietary patterns were related to memory and language function. Longitudinal data are needed to draw conclusions on the putative effect of nutrition on the rate of cognitive decline, and on the potential of dietary interventions in groups at increased risk for AD.

Electronic supplementary material

The online version of this article (10.1007/s00394-020-02257-6) contains supplementary material, which is available to authorized users.

Validation of Nutrient Intake Estimates Derived Using a Semi-Quantitative FFQ against 3 Day Diet Records in the Baltimore Longitudinal Study of Aging

OBJECTIVE

To examine the relative validity of a multicultural FFQ used to derive nutrient intake estimates in a community dwelling cohort of younger and older men and women compared with those derived from 3 day (3d) diet records during the same time-frame.

DESIGN

Cross-sectional analyses.

SETTING

The Baltimore Longitudinal Study of Aging (BLSA) conducted in the Baltimore, MD and District of Columbia areas.

PARTICIPANTS

A subset (n=468, aged 26 to 95 years (y), 47% female, 65% non-Hispanic white) from the BLSA, with complete data for nutrient estimates from a FFQ and 3d diet records.

MEASUREMENTS

Pearson's correlation coefficients (energy adjusted and de-attenuated) for intakes of energy and 26 nutrients estimated from the FFQ and the mean of 3d diet records were calculated in a cross-sectional analysis. Rankings of individuals based on FFQ for various nutrient intakes were compared to corresponding rankings based on the average of the 3d diet records. Bland Altman plots were examined for a visual representation of agreement between both assessment methods. All analyses were stratified by sex and age (above and below 65 y).

RESULTS

Median nutrient intake estimates tended to be higher from the FFQ compared to average 3d diet records. Energy adjusted and de-attenuated correlations between FFQ intake estimates and records ranged from 0.23 (sodium intake in men) to 0.81 (alcohol intake in women). The FFQ classified more than 70 percent of participants in either the same or adjacent quartile categories for all nutrients examined. Bland Altman plots demonstrated good agreement between the assessment methods for most nutrients.

CONCLUSIONS

This FFQ provides reasonably valid estimates of dietary intakes of younger and older participants of the BLSA.

A Correlation Study of DHA Dietary Intake and Plasma, Erythrocyte and Breast Milk DHA Concentrations in Lactating Women from Coastland, Lakeland, and Inland Areas of China

We aimed to assess the correlation between docosahexaenoic acid (DHA) dietary intake and the plasma, erythrocyte and breast milk DHA concentrations in lactating women residing in the coastland, lakeland and inland areas of China. A total of 408 healthy lactating women (42 ± 7 days postpartum) were recruited from four hospitals located in Weihai (coastland), Yueyang (lakeland) and Baotou (inland) city. The categories of food containing DHA, the average amount consumed per time and the frequency of consumption in the past month were assessed by a tailored DHA food frequency questionnaire, the DHA Intake Evaluation Tool (DIET). DHA dietary intake (mg/day) was calculated according to the Chinese Food Composition Table (Version 2009). In addition, fasting venous blood (5 mL) and breast milk (10 mL) were collected from lactating women. DHA concentrations in plasma, erythrocyte and breast milk were measured using capillary gas chromatography, and were reported as absolute concentration (μg/mL) and relative concentration (weight percent of total fatty acids, wt. %). Spearman correlation coefficients were used to assess the correlation between intakes of DHA and its concentrations in biological specimens. The study showed that the breast milk, plasma and erythrocyte DHA concentrations were positively correlated with DHA dietary intake; corresponding correlation coefficients were 0.36, 0.36 and 0.24 for relative concentration and 0.33, 0.32, and 0.18 for absolute concentration (p < 0.05). The median DHA dietary intake varied significantly across areas (p < 0.05), which was highest in the coastland (24.32 mg/day), followed by lakeland (13.69 mg/day), and lowest in the inland (8.84 mg/day). The overall relative and absolute DHA concentrations in breast milk were 0.36% ± 0.23% and 141.49 ± 107.41 μg/mL; the concentrations were significantly lower in inland women than those from coastland and lakeland. We conclude that DHA dietary intake is positively correlated with DHA concentrations in blood and breast milk in Chinese lactating women, suggesting that the tailored DHA food frequency questionnaire, DIET, is a valid tool for the assessment of DHA dietary intake.

Considerations in selection of diet assessment methods for examining the effect of nutrition on cognition

Older adults are the most rapidly growing age group in the United States, and it is estimated that 22.2 % of U.S. adults over 71 years of age have cognitive impairments without dementia and 13.9% have dementia. Cognitive impairment is associated with reduced quality of life, increased risk of hospitalization, inability to live independently, and increased health care costs; therefore, identification of modifiable risk factors for prevention and delay of cognitive decline is of increasing importance. There is a growing body of research and interest in the relationship between diet and cognitive function. Epidemiologic studies suggest that cognitive function may be improved and cognitive decline prevented as a function of a particular nutrient, food group or dietary pattern; however, results from these trials have failed to be replicated in randomized controlled trials. One possible reason for the equivocality of findings in the diet and cognitive function literature may be the methodological issues and limitations in the assessment of dietary patterns and nutritional intake. Self-reported dietary data can be biased by many factors such as age, gender, socioeconomic status, and education; yet, there is limited research on the impact of cognitive function on the integrity of self-reported dietary data. Cognitive function itself may bias diet assessment methods, subsequently obscuring the evaluation of the nutrition-cognition relationship. The present review summarizes methodological validation studies that provide insight into potential errors of diet assessment methods due to cognitive function, identifies research gaps and provides recommendations for improving diet assessment accuracy in studies of individuals with cognitive impairments.

The food metabolome: a window over dietary exposure

The food metabolome is defined as the part of the human metabolome directly derived from the digestion and biotransformation of foods and their constituents. With >25,000 compounds known in various foods, the food metabolome is extremely complex, with a composition varying widely according to the diet. By its very nature it represents a considerable and still largely unexploited source of novel dietary biomarkers that could be used to measure dietary exposures with a high level of detail and precision. Most dietary biomarkers currently have been identified on the basis of our knowledge of food compositions by using hypothesis-driven approaches. However, the rapid development of metabolomics resulting from the development of highly sensitive modern analytic instruments, the availability of metabolite databases, and progress in (bio)informatics has made agnostic approaches more attractive as shown by the recent identification of novel biomarkers of intakes for fruit, vegetables, beverages, meats, or complex diets. Moreover, examples also show how the scrutiny of the food metabolome can lead to the discovery of bioactive molecules and dietary factors associated with diseases. However, researchers still face hurdles, which slow progress and need to be resolved to bring this emerging field of research to maturity. These limits were discussed during the First International Workshop on the Food Metabolome held in Glasgow. Key recommendations made during the workshop included more coordination of efforts; development of new databases, software tools, and chemical libraries for the food metabolome; and shared repositories of metabolomic data. Once achieved, major progress can be expected toward a better understanding of the complex interactions between diet and human health.

Ageing and apoE change DHA homeostasis: relevance to age-related cognitive decline

Epidemiological studies fairly convincingly suggest that higher intakes of fatty fish and n-3 fatty acids are associated with reduced risk of Alzheimer's disease (AD). DHA in plasma is normally positively associated with DHA intake. However, despite being associated with lower fish and DHA intake, unexpectedly, plasma (or brain) DHA is frequently not lower in AD. This review will highlight some metabolic and physiological factors such as ageing and apoE polymorphism that influence DHA homeostasis. Compared with young adults, blood DHA is often slightly but significantly higher in older adults without any age-related cognitive decline. Higher plasma DHA in older adults could be a sign that their fish or DHA intake is higher. However, our supplementation and carbon-13 tracer studies also show that DHA metabolism, e.g. transit through the plasma, apparent retroconversion and β-oxidation, is altered in healthy older compared with healthy young adults. ApoE4 increases the risk of AD, possibly in part because it too changes DHA homeostasis. Therefore, independent of differences in fish intake, changing DHA homeostasis may tend to obscure the relationship between DHA intake and plasma DHA which, in turn, may contribute to making older adults more susceptible to cognitive decline despite older adults having similar or sometimes higher plasma DHA than in younger adults. In conclusion, recent development of new tools such as isotopically labelled DHA to study DHA metabolism in human subjects highlights some promising avenues to evaluate how and why DHA metabolism changes during ageing and AD.

Plasma levels of n-3 fatty acids in bipolar patients: deficit restricted to DHA

Epidemiological studies suggest that n-3 polyunsaturated fatty acid (n-3 FA) deficiency is a risk factor for bipolar disorders (BDs). The aim of this study was to determine whether such a deficit does exist in patients with BD and to characterize the overall plasma fatty acid (FA) profile in these patients. Using gas chromatography/mass spectrometry, we measured fasting plasma levels of 15 FAs in 42 patients diagnosed with BD according to DSM-IV criteria and in 57 age- and gender-matched healthy controls. Plasma docosahexaenoic acid (DHA) levels were significantly decreased in bipolar patients (p < 0.001 versus healthy controls). Compared with controls, patients had higher plasma levels of all other FAs, including arachidonic acid (AA, p < 0.001), alpha-linolenic acid (ALA, p < 0.001), and eicosapentaenoic acid (EPA) (p < 0.001). Although in the present study we observed significant DHA deficits in the plasma of bipolar patients our findings do not support the therapeutic use of ALA and/or EPA supplementation. DHA may provide a basis for possible pharmacological intervention in psychiatric disorders at the level of second messengers linked to the phosphatidylinositol cycle. Finally, measurement of FA levels in plasma seems to be more reliable and reproducible than assays of erythrocyte FA content.

A Taiwanese food frequency questionnaire correlates with plasma docosahexaenoic acid but not with plasma eicosapentaenoic acid levels: questionnaires and plasma biomarkers

Background

Little evidence is available for the validity of dietary fish and polyunsaturated fatty acid intake derived from interviewer-administered questionnaires and plasma docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) concentration.

Methods

We estimated the correlation of DHA and EPA intake from both questionnaires and biochemical measurements. Ethnic Chinese adults with a mean (± SD) age of 59.8 (±12.8) years (n = 297) (47% women) who completed a 38-item semi-quantitative food-frequency questionnaire and provided a plasma sample were enrolled. Plasma fatty acids were analyzed by capillary gas chromatography.

Results

The Spearmen rank correlation coefficients between the intake of various types of fish and marine n-3 fatty acids as well as plasma DHA were significant, ranging from 0.20 to 0.33 (P < 0.001). In addition, dietary EPA, C22:5 n-3 and DHA were significantly correlated with the levels of marine n-3 fatty acids and DHA, with the Spearman rank correlation coefficients ranging from 0.26 to 0.35 (P < 0.001). Moreover, compared with those in the lowest fish intake quintile, participants in the highest quintile had a significantly higher DHA level (adjusted mean difference, 0.99 ± 0.10%, test for trend, P < 0.001). Similar patterns between dietary DHA intake and plasma DHA levels were found. However, the association between dietary fish intake and plasma EPA was not significant (test for trend, P = 0.69).

Conclusions

The dietary intakes of fish and of long chain n-3 fatty acids, as determined by the food frequency questionnaire, were correlated with the percentages of these fatty acids in plasma, and in particular with plasma DHA. Plasma DHA levels were correlated to dietary intake of long-chain n-3 fatty acids.

Association of marine-origin n-3 polyunsaturated fatty acids consumption and functional mobility in the community-dwelling oldest old

OBJECTIVE

To examine whether habitual dietary intake of marine-origin n-3 polyunsaturated fatty acids (MOPUFA), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), are associated with functional mobility in the community-dwelling oldest old, 85 years or older, who are at high risk for physical disability.

DESIGN

A cross-sectional study.

SETTING

A community-based survey conducted at university research center or home-based.

PARTICIPANTS

Four hundred seventeen (189 men, 228 women) out of 542 participants in the baseline examination of the Tokyo Oldest Old Survey on Total Health, a community-based ongoing longitudinal study among the oldest old living in the center of Japan.

MEASUREMENTS

Habitual dietary intake of MOPUFA was assessed by the brief-type self-administered diet history questionnaire (BDHQ), and functional mobility was assessed by the timed up and go test. Plasma inflammatory biomarkers (C-reactive protein, interleukin-6 and tumor necrosis factor-α) were measured. We evaluated the cross-sectional association between habitual intake of MOPUFA and functional mobility using multivariate logistic regression analysis. Prior to the analysis, validation of BDHQ in this study was confirmed among 190 participants (96 men, 94 women) based on the EPA and DHA concentrations in the erythrocyte membrane phospholipids as reference.

RESULTS

Moderate correlation between estimated dietary intake of EPA/DHA and concentration of EPA/DHA in the erythrocyte membrane phospholipids was obtained (Spearman's r=0.29-0.58, p<0.01). Multivariate logistic regression analysis revealed that a lower habitual intake of EPA+DHA was significantly associated with poor functional mobility in men but not in women (OR (95% CI) per 1 SD increase of EPA+DHA intake; 0.55 (0.33-0.91), 0.88 (0.59-1.32), men and women respectively).

CONCLUSIONS

Habitual intake of MOPUFA was associated with functional mobility in community-dwelling oldest old men.

Omega-3 fatty acids status in human subjects estimated using a food frequency questionnaire and plasma phospholipids levels

BACKGROUND

Intakes of omega-3 (n-3) fatty acids (FA) are associated with several health benefits. The aim of this study was to verify whether intakes of n-3 FA estimated from a food frequency questionnaire (FFQ) correlate with n-3 FA levels measured in plasma phospholipids (PL).

METHODS

The study sample consisted of 200 French-Canadians men and women aged between 18 to 55 years. Dietary data were collected using a validated FFQ. Fasting blood samples were collected and the plasma PL FA profile was measured by gas chromatography.

RESULTS

Low intakes of n-3 long-chain FA together with low percentages of n-3 long-chain FA in plasma PL were found in French-Canadian population. Daily intakes of eicosapentaenoic acid (EPA), docosapentaenoic acid (DPA) and docosahexaenoic acid (DHA) were similar between men and women. Yet, alpha-linolenic acid (ALA) and total n-3 FA intakes were significantly higher in men compared to women (ALA: 2.28 g and 1.69 g, p < 0.0001, total n-3 FA: 2.57 g and 1.99 g, p < 0.0001; respectively). In plasma PL, DPA and DHA percentages were significantly different between men and women (DPA: 1.03% and 0.88%, p < 0.0001, DHA: 3.00% and 3.43%, p = 0.0005; respectively). Moreover, DHA (men: r = 0.52, p < 0.0001; women: r = 0.57, p < 0.0001) and total n-3 FA (men: r = 0.47, p < 0.0001; women: r = 0.52, p < 0.0001) intakes were positively correlated to their respective plasma PL FA levels. In women, EPA (r = 0.44, p < 0.0001) and DPA (r = 0.23, p = 0.02) intakes were also correlated respectively with EPA and DPA plasma PL FA percentages.

CONCLUSION

Estimated n-3 long-chain FA intake among this young and well-educated French-Canadian population is lower than the recommendations. Further, FFQ data is comparable to plasma PL results to estimate DHA and total n-3 FA status in healthy individuals as well as to evaluate the EPA and DPA status in women. Overall, this FFQ could be used as a simple, low-cost tool in future studies to rank n-3 FA status of individuals.

Relative validity of the Geisinger Rural Aging Study food frequency questionnaire

OBJECTIVE

To determine the relative validity of a population specific food frequency questionnaire (FFQ) and evaluate the effectiveness of the instrument for assessing nutritional risk in older adults.

DESIGN

A cross-over design with participants completing two different dietary assessment instruments in random order.

SETTING

The Geisinger Rural Aging Study (GRAS), a longitudinal study of over 20,000 adults living in the central, northern and eastern counties of Pennsylvania.

PARTICIPANTS

A subset of GRAS consisting of 245 older adults (60% women) ranging in age from 70 to 95 years.

MEASUREMENTS

Energy and nutrient intakes were assessed from two instruments: a population specific food frequency questionnaire (FFQ) and four 24-hour dietary recalls conducted over a two week period.

RESULTS

Pearson correlation coefficients between the FFQ and dietary recalls for most nutrients were 0.5 or higher which suggests that the FFQ provided relatively valid estimates of macro and micronutrient intakes examined. Bland-Altman plots were generated to examine the agreement between instruments. Data are shown for energy, folate and zinc with close agreement at lower intakes indicative of risk for folate and zinc. Sensitivity results also showed that the FFQ was able to correctly classify individuals adequately at risk for most nutrients examined.

CONCLUSION

This population specific FFQ appears to be a valid instrument for use in in evaluating risk for many nutrients that are of particular concern in older adults residing throughout many predominately rural counties in Pennsylvania.

Nutrient intake and plasma β-amyloid

OBJECTIVE

The widely reported associations between various nutrients and cognition may occur through many biologic pathways including those of β-amyloid (Aβ). However, little is known about the possible associations of dietary factors with plasma Aβ40 or Aβ42. The aim of the current study was to evaluate the association between nutrient intake and plasma Aβ levels.

METHODS

In this cross-sectional study, plasma Aβ40 and Aβ42 and dietary data were obtained from 1,219 cognitively healthy elderly (age >65 years), who were participants in a community-based multiethnic cohort. Information on dietary intake was obtained 1.2 years, on average, before Aβ assay. The associations of plasma Aβ40 and Aβ42 levels and dietary intake of 10 nutrients were examined using linear regression models, adjusted for age, gender, ethnicity, education, caloric intake, apolipoprotein E genotype, and recruitment wave. Nutrients examined included saturated fatty acid, monounsaturated fatty acid, ω-3 polyunsaturated fatty acid (PUFA), ω-6 PUFA, vitamin E, vitamin C, β-carotene, vitamin B(12), folate, and vitamin D.

RESULTS

In unadjusted models that simultaneously included all nutrients, higher intake of ω-3 PUFA was associated with lower levels of Aβ40 (β = -24.7, p < 0.001) and lower levels of Aβ42 (β = -12.3, p < 0.001). In adjusted models, ω-3 PUFA remained a strong predictor of Aβ42 (β = -7.31, p = 0.02), whereas its association with Aβ40 was attenuated (β = -11.96, p = 0.06). Other nutrients were not associated with plasma Aβ levels.

CONCLUSIONS

Our data suggest that higher dietary intake of ω-3 PUFA is associated with lower plasma levels of Aβ42, a profile linked with reduced risk of incident AD and slower cognitive decline in our cohort.

Dietary methods and biomarkers of omega 3 fatty acids: a systematic review

The aims of the present study were to review the validity of dietary methods used to measure the usual long chain (LC) omega-3 polyunsaturated fatty acid (n-3 PUFA) intake of a population and to assess the usefulness of different biomarkers of n-3 PUFA in healthy humans. Two systematic literature searches were conducted until May 2011 to update previous systematic reviews. The first literature search aimed to find studies validating the methodology used for measuring the dietary intake of n-3 PUFA. The second search aimed to find human intervention studies in which n-3 PUFA status changed after 2 weeks of n-3 PUFA supplementation. Sixteen studies were identified for inclusion in the first review. Correlation coefficients between fatty acids in subcutaneous fat or blood lipids and dietary intake of n-3 PUFA from different questionnaires were similar. Subcutaneous fat has been reported as the best reference method for some authors, and these studies showed moderate correlation coefficients with no dietary intake method being superior to any other. As for the evaluation of biomarkers of docosahexaenoic acid (DHA, 22 : 6 n-3) and eicosapentaenoic acid (EPA, 20 : 5n-3) status in response to supplementation, the new search reaffirmed and reinforced the evidence supporting that plasma phospholipid DHA, erythrocyte DHA, and platelet DHA were all effective and robust biomarkers of DHA status. Our findings only confirmed earlier studies and did not provide evidence for reaching new conclusions.

Variety in fruit and vegetable intake and cognitive function in middle-aged and older Puerto Rican adults

Higher variety in fruit and vegetable intake has been associated with a lower risk of several chronic diseases. It remains unclear whether such associations exist relating to cognition. The authors examined associations between total quantity and variety in fruit and vegetable intake and cognitive function in a cross-sectional sample of 1412 Puerto Rican adults, aged 45-75 years from the Boston Puerto Rican Health Study, 2004-9. Fruit and vegetable intake was assessed with a FFQ. Cognitive function was measured with a battery of seven tests; the Mini Mental State Examination (MMSE) was administrated to assess global cognitive function. Greater variety, but not total quantity, of fruit and vegetable intake was associated with a higher MMSE score after multivariate adjustment (P for trend = 0·012). This association remained significant after further adjusting for total quantity of fruit and vegetable intake (P for trend = 0·018). High variety of fruit and vegetable intake was also associated with individual cognitive domains, including executive function, memory and attention (all P for trend < 0·05). Variety, more than total quantity, of fruit and vegetable intake may offer cognitive protection in middle-aged and older adults, but longitudinal studies are needed to clarify direction of causality.

Differences in diet pattern adherence by nativity and duration of US residence in the Mexican-American population

Literature on the diet of the Mexican-American population suggests that food consumption differs by nativity and duration of residence in the United States. However, no studies have used dietary pattern analysis to investigate these differences. To create dietary patterns, we used principal components analysis on food frequency questionnaire data for all adult respondents of the National Health and Nutrition Examination Survey years 2003-2006. Four dietary patterns were identified: Western, Healthy, Tomato/Tortilla, and Coffee/Sugar. Least squares means regression was used to test differences in adjusted mean dietary adherence scores among Mexico-born Mexican-American adults residing in the United States for <15 years (n=302), Mexico-born Mexican-American adults residing in the United States for ≥15 years (n=234), US-born Mexican-American adults (n=509), and US-born non-Hispanic whites (n=2,530) aged 18 to 69 years. Mean score for each diet pattern did not differ significantly by duration of US residence category in the Mexico-born Mexican-American population. However, in comparison to all Mexico-born Mexican Americans, US-born Mexican Americans had significantly lower score for the Tomato/Tortilla pattern, and significantly higher score for the Western pattern. Scores for the Healthy pattern were relatively low in all Mexican-American subgroups, indicating low adherence to the Healthy diet. However, Healthy diet scores of Mexico-born Mexican Americans among those aged ≤41 years appeared more similar to those of US-born non-Hispanic whites than US-born Mexican Americans. Education and policy action promoting healthy food access in Hispanic neighborhoods could help limit consumption of Western and Coffee/Sugar diet patterns and promote healthier choices in the Mexican-American population.

Vascular contributions to cognitive impairment and dementia: a statement for healthcare professionals from the american heart association/american stroke association

BACKGROUND AND PURPOSE

This scientific statement provides an overview of the evidence on vascular contributions to cognitive impairment and dementia. Vascular contributions to cognitive impairment and dementia of later life are common. Definitions of vascular cognitive impairment (VCI), neuropathology, basic science and pathophysiological aspects, role of neuroimaging and vascular and other associated risk factors, and potential opportunities for prevention and treatment are reviewed. This statement serves as an overall guide for practitioners to gain a better understanding of VCI and dementia, prevention, and treatment.

METHODS

Writing group members were nominated by the writing group co-chairs on the basis of their previous work in relevant topic areas and were approved by the American Heart Association Stroke Council Scientific Statement Oversight Committee, the Council on Epidemiology and Prevention, and the Manuscript Oversight Committee. The writing group used systematic literature reviews (primarily covering publications from 1990 to May 1, 2010), previously published guidelines, personal files, and expert opinion to summarize existing evidence, indicate gaps in current knowledge, and, when appropriate, formulate recommendations using standard American Heart Association criteria. All members of the writing group had the opportunity to comment on the recommendations and approved the final version of this document. After peer review by the American Heart Association, as well as review by the Stroke Council leadership, Council on Epidemiology and Prevention Council, and Scientific Statements Oversight Committee, the statement was approved by the American Heart Association Science Advisory and Coordinating Committee.

RESULTS

The construct of VCI has been introduced to capture the entire spectrum of cognitive disorders associated with all forms of cerebral vascular brain injury-not solely stroke-ranging from mild cognitive impairment through fully developed dementia. Dysfunction of the neurovascular unit and mechanisms regulating cerebral blood flow are likely to be important components of the pathophysiological processes underlying VCI. Cerebral amyloid angiopathy is emerging as an important marker of risk for Alzheimer disease, microinfarction, microhemorrhage and macrohemorrhage of the brain, and VCI. The neuropathology of cognitive impairment in later life is often a mixture of Alzheimer disease and microvascular brain damage, which may overlap and synergize to heighten the risk of cognitive impairment. In this regard, magnetic resonance imaging and other neuroimaging techniques play an important role in the definition and detection of VCI and provide evidence that subcortical forms of VCI with white matter hyperintensities and small deep infarcts are common. In many cases, risk markers for VCI are the same as traditional risk factors for stroke. These risks may include but are not limited to atrial fibrillation, hypertension, diabetes mellitus, and hypercholesterolemia. Furthermore, these same vascular risk factors may be risk markers for Alzheimer disease. Carotid intimal-medial thickness and arterial stiffness are emerging as markers of arterial aging and may serve as risk markers for VCI. Currently, no specific treatments for VCI have been approved by the US Food and Drug Administration. However, detection and control of the traditional risk factors for stroke and cardiovascular disease may be effective in the prevention of VCI, even in older people.

CONCLUSIONS

Vascular contributions to cognitive impairment and dementia are important. Understanding of VCI has evolved substantially in recent years, based on preclinical, neuropathologic, neuroimaging, physiological, and epidemiological studies. Transdisciplinary, translational, and transactional approaches are recommended to further our understanding of this entity and to better characterize its neuropsychological profile. There is a need for prospective, quantitative, clinical-pathological-neuroimaging studies to improve knowledge of the pathological basis of neuroimaging change and the complex interplay between vascular and Alzheimer disease pathologies in the evolution of clinical VCI and Alzheimer disease. Long-term vascular risk marker interventional studies beginning as early as midlife may be required to prevent or postpone the onset of VCI and Alzheimer disease. Studies of intensive reduction of vascular risk factors in high-risk groups are another important avenue of research.

Vascular contributions to cognitive impairment and dementia: a statement for healthcare professionals from the american heart association/american stroke association

BACKGROUND AND PURPOSE

This scientific statement provides an overview of the evidence on vascular contributions to cognitive impairment and dementia. Vascular contributions to cognitive impairment and dementia of later life are common. Definitions of vascular cognitive impairment (VCI), neuropathology, basic science and pathophysiological aspects, role of neuroimaging and vascular and other associated risk factors, and potential opportunities for prevention and treatment are reviewed. This statement serves as an overall guide for practitioners to gain a better understanding of VCI and dementia, prevention, and treatment.

METHODS

Writing group members were nominated by the writing group co-chairs on the basis of their previous work in relevant topic areas and were approved by the American Heart Association Stroke Council Scientific Statement Oversight Committee, the Council on Epidemiology and Prevention, and the Manuscript Oversight Committee. The writing group used systematic literature reviews (primarily covering publications from 1990 to May 1, 2010), previously published guidelines, personal files, and expert opinion to summarize existing evidence, indicate gaps in current knowledge, and, when appropriate, formulate recommendations using standard American Heart Association criteria. All members of the writing group had the opportunity to comment on the recommendations and approved the final version of this document. After peer review by the American Heart Association, as well as review by the Stroke Council leadership, Council on Epidemiology and Prevention Council, and Scientific Statements Oversight Committee, the statement was approved by the American Heart Association Science Advisory and Coordinating Committee.

RESULTS

The construct of VCI has been introduced to capture the entire spectrum of cognitive disorders associated with all forms of cerebral vascular brain injury-not solely stroke-ranging from mild cognitive impairment through fully developed dementia. Dysfunction of the neurovascular unit and mechanisms regulating cerebral blood flow are likely to be important components of the pathophysiological processes underlying VCI. Cerebral amyloid angiopathy is emerging as an important marker of risk for Alzheimer disease, microinfarction, microhemorrhage and macrohemorrhage of the brain, and VCI. The neuropathology of cognitive impairment in later life is often a mixture of Alzheimer disease and microvascular brain damage, which may overlap and synergize to heighten the risk of cognitive impairment. In this regard, magnetic resonance imaging and other neuroimaging techniques play an important role in the definition and detection of VCI and provide evidence that subcortical forms of VCI with white matter hyperintensities and small deep infarcts are common. In many cases, risk markers for VCI are the same as traditional risk factors for stroke. These risks may include but are not limited to atrial fibrillation, hypertension, diabetes mellitus, and hypercholesterolemia. Furthermore, these same vascular risk factors may be risk markers for Alzheimer disease. Carotid intimal-medial thickness and arterial stiffness are emerging as markers of arterial aging and may serve as risk markers for VCI. Currently, no specific treatments for VCI have been approved by the US Food and Drug Administration. However, detection and control of the traditional risk factors for stroke and cardiovascular disease may be effective in the prevention of VCI, even in older people.

CONCLUSIONS

Vascular contributions to cognitive impairment and dementia are important. Understanding of VCI has evolved substantially in recent years, based on preclinical, neuropathologic, neuroimaging, physiological, and epidemiological studies. Transdisciplinary, translational, and transactional approaches are recommended to further our understanding of this entity and to better characterize its neuropsychological profile. There is a need for prospective, quantitative, clinical-pathological-neuroimaging studies to improve knowledge of the pathological basis of neuroimaging change and the complex interplay between vascular and Alzheimer disease pathologies in the evolution of clinical VCI and Alzheimer disease. Long-term vascular risk marker interventional studies beginning as early as midlife may be required to prevent or postpone the onset of VCI and Alzheimer disease. Studies of intensive reduction of vascular risk factors in high-risk groups are another important avenue of research.

Consumption of DHA + EPA by low-income women during pregnancy and lactation

BACKGROUND

The ω-3-fatty acid docosahexaenoic acid (DHA) is important in infant brain development and maturation. The advisable intake of the ω-3 fatty acids DHA and eicosapentaenoic acid (EPA) for pregnant and lactating women is 300 mg/d or 9 g/month. The objective of this cross-sectional study was to test the hypothesis that low-income pregnant/or lactating women do not consume advisable amounts of DHA+EPA and to determine whether any of the measured demographic factors were related to DHA and EPA consumption.

METHODS

This study was conducted September 2007 to March 2008 and used the N-3 Fatty Acid Food Frequency Questionnaire for dietary assessment in a convenience sample of women (N = 68) enrolled in a local maternal infant health program. Women who reported fish or seafood allergies were excluded. The monthly consumption of DHA+EPA from food sources was measured, and participant race, ethnicity, country of origin, primary language, level of education, marital status, intake of prenatal vitamins containing DHA+EPA, and warnings of fish toxicity were assessed. The data were analyzed using 1-way analysis of variance and t tests.

RESULTS

The average reported DHA+EPA intake was 1.18 g/month across all race/ethnicities. African Americans consumed significantly more DHA+EPA, 2.79 g/month, compared with Hispanics (1.64 g) and Caucasians (0.93 g). United States natives consumed significantly more DHA+EPA than immigrants (2.45 g vs 1.55 g).

CONCLUSIONS

Low-income pregnant/and lactating women in the study consumed less than the advisable amounts of DHA+EPA. Both ethnicity and country of origin are related to DHA+EPA intake.

Dietary intakes of arachidonic acid and alpha-linolenic acid are associated with reduced risk of hip fracture in older adults

PUFA are hypothesized to influence bone health, but longitudinal studies on hip fracture risk are lacking. We examined associations between intakes of PUFA and fish, and hip fracture risk among older adults (n = 904) in the Framingham Osteoporosis Study. Participants (mean age ~75 y at baseline) were followed for incident hip fracture from the time they completed the baseline exam (1988-1989) until December 31, 2005. HR and 95% CI were estimated for energy-adjusted dietary fatty acid exposure variables [(n-3) fatty acids: α-linolenic acid (ALA), EPA, DHA, EPA+DHA; (n-6) fatty acids: linoleic acid, arachidonic acid (AA); and the (n-6):(n-3) ratio] and fish intake categories, adjusting for potential confounders and covariates. Protective associations were observed between intakes of ALA (P-trend = 0.02) and hip fracture risk in a combined sample of women and men and between intakes of AA (P-trend = 0.05) and hip fracture risk in men only. Participants in the highest quartile of ALA intake had a 54% lower risk of hip fracture than those in the lowest quartile (Q4 vs. Q1: HR = 0.46; 95% CI = 0.26-0.83). Men in the highest quartile of AA intake had an 80% lower risk of hip fracture than those in the lowest quartile (Q4 vs. Q1: HR = 0.20; 95% CI = 0.04-0.96). No significant associations were observed among intakes of EPA, DHA, EPA+DHA, or fish. These findings suggest dietary ALA may reduce hip fracture risk in women and men and dietary AA may reduce hip fracture risk in men.

Protective effects of fish intake and interactive effects of long-chain polyunsaturated fatty acid intakes on hip bone mineral density in older adults: the Framingham Osteoporosis Study

BACKGROUND

Polyunsaturated fatty acids and fish may influence bone health.

OBJECTIVE

We aimed to examine associations between dietary polyunsaturated fatty acid and fish intakes and hip bone mineral density (BMD) at baseline (1988-1989; n = 854) and changes 4 y later in adults (n = 623) with a mean age of 75 y in the Framingham Osteoporosis Study.

DESIGN

BMD measures were regressed on energy-adjusted quartiles of fatty acid intakes [n-3 (omega-3): α-linolenic acid, eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), and EPA+ DHA; n-6 (omega-6): linoleic acid (LA) and arachidonic acid (AA); and n-6:n-3 ratio] and on categorized fish intakes, with adjustment for covariates. Effect modification by EPA+DHA intake was tested for n-6 exposures.

RESULTS

High intakes (≥3 servings/wk) of fish relative to lower intakes were associated with maintenance of femoral neck BMD (FN-BMD) in men (dark fish + tuna, dark fish, and tuna) and in women (dark fish) (P < 0.05). Significant interactions between AA and EPA+DHA intakes were observed cross-sectionally in women and longitudinally in men. In women with EPA+DHA intakes at or above the median, those with the highest AA intakes had a higher mean baseline FN-BMD than did those with the lowest intakes (quartile 4 compared with quartile 1: P = 0.03, P for trend = 0.02). In men with the lowest EPA+DHA intakes (quartile 1), those with the highest intakes of AA (quartile 4) lost more FN-BMD than did men with the lowest intakes of AA (quartile 1; P = 0.04). LA intake tended to be associated with FN-BMD loss in women (P for trend < 0.06).

CONCLUSIONS

Fish consumption may protect against bone loss. The protective effects of a high AA intake may be dependent on the amount of EPA+DHA intake.

Relation of Children's Dietary reporting accuracy to cognitive ability

A validation study of children's dietary reporting provided an opportunity to investigate whether cognitive ability is a source of systematic error in dietary recalls. From the fall of 2004 through the spring of 2007, fourth-grade children (n = 374) in Columbia, South Carolina, were observed eating school meals and interviewed to obtain 24-hour dietary recalls; subsequently, measures of dietary reporting error were calculated. The common factor extracted from 4 subject-area achievement tests (scores on which were provided by the school district for 362 children) was used as a measure of cognitive ability. For the 325 children who reported school meals that met the criteria to be reports about school meals, as cognitive ability increased, dietary reporting error decreased; the relation between cognitive ability and dietary reporting performance was stronger among girls than among boys. The mean cognitive ability for 37 children who reported no meals that satisfied the criteria for being reports about school meals was significantly lower than that for the 325 children who reported meals that satisfied these criteria. These findings indicate that cognitive ability is a source of systematic error in children's dietary recalls. More generally, the quality of epidemiologic survey data may depend systematically on the cognitive ability of respondents.

Are omega-3 fatty acids options for prevention and treatment of cognitive decline and dementia?

PURPOSE OF REVIEW

To report recent data on the potential role of omega-3 fatty acids (n-3 FA) found in oily fish, especially docosahexaenoic acid (DHA), to prevent and treat cognitive decline and Alzheimer's disease.

RECENT FINDINGS

Observational studies still provide conflicting results, in which the majority indicate beneficial effects on cognition, both when assessed as a continuous variable or as incident dementia, mainly Alzheimer's disease. Experimental studies have demonstrated potentially ameliorating effects of eicosapentaenoic acid (EPA) and DHA on amyloid fragment formation, signal transduction including upregulation of the apolipoprotein receptor SorLA, as well as on angiogenesis. The role of EPA and DHA metabolites on Alzheimer's disease pathology is under investigation. Recently, three randomized intervention studies, with duration up to 6 months have been reported. In contrast to a small study from Taiwan, no positive overall effects were reported from the Swedish OmegAD Study or from a Dutch study, although post hoc analyses indicate that selected individuals with mild forms of Alzheimer's disease or cognitive decline may respond to treatment.

SUMMARY

No firm conclusions can be drawn. Based on epidemiological data, fish including oily fish could be advised as part of a balanced diet for public health purpose, although the evidence for better cognition is only fairly consistent. It is unlikely that n-3 FA will emerge as a treatment option in general for improving cognitive function in patients with Alzheimer's disease. n-3 FA, especially DHA, may turn out as an adjuvant therapy in selected cases. Further long-term intervention studies on individuals with mild cognitive reductions are awaited.