Circulating Plasma Metabolites and Cognitive Function in a Puerto Rican Cohort.

BACKGROUND: Minorities, including mainland Puerto Ricans, are impacted disproportionally by Alzheimer's disease (AD), dementia, and cognitive decline. Studying blood metabolomics in this population has the potential to probe the biological underpinnings of this health disparity. OBJECTIVE: We performed a comprehensive analysis of circulating plasma metabolites in relation to cognitive function in 736 participants from the Boston Puerto Rican Health Study (BPRHS) who underwent untargeted mass-spectrometry based metabolomics analysis and had undergone a battery of in-person cognitive testing at baseline. METHODS: After relevant exclusions, 621 metabolites were examined. We used multivariable regression, adjusted for age, sex, education, apolipoprotein E genotype, smoking, and Mediterranean dietary pattern, to identify metabolites related to global cognitive function in our cohort. LASSO machine learning was used in a complementary analysis to identify metabolites that could discriminate good from poor extremes of cognition. We also conducted sensitivity analyses: restricted to participants without diabetes, and to participants with good adherence to Mediterranean diet. RESULTS: Of 621 metabolites, FDR corrected (p < 0.05) multivariable linear regression identified 3 metabolites positively, and 10 negatively, associated with cognitive function in the BPRHS. In a combination of FDR-corrected linear regression, logistic regression regularized via LASSO, and sensitivity analyses restricted to participants without diabetes, and with good adherence to the Mediterranean diet, ß-cryptoxanthin plasma concentration was consistently associated with better cognitive function and N-acetylisoleucine and tyramine O-sulfate concentrations were consistently associated with worse cognitive function. CONCLUSION: This untargeted metabolomics study identified potential biomarkers for cognitive function in a cohort of Puerto Rican older adults.

Dietary Intake and Its Determinants Among Adults Living in the Metropolitan Area of Puerto Rico.

There is scarce information regarding the dietary intake of adults living in Puerto Rico (PR). We aimed to assess intake of nutrients and foods, adherence to recommended intake of nutrients and diet quality, and sociodemographic and lifestyle factors correlated with diet quality among adults in the San Juan metropolitan area of PR. Data were obtained from participants of the cross-sectional convenience-sample Puerto Rico Assessment of Diet, Lifestyle, and Diseases (n = 248; ages 30-75 years). Diet quality was defined using the Alternate Healthy Eating Index 2010 (AHEI; range 0-110 indicating lower-higher quality). Linear regression models were used to relate AHEI to sociodemographic and lifestyle factors. Most participants met the Estimated Average Requirement (EAR) for iron, folate, and vitamins B12 and B6; 61% met the EAR for magnesium and 56% for calcium. Only 4% met the EAR for vitamin D, and 7% met the adequate intake for potassium. The main contributors to total energy intake were sugary beverages (11.8%), sweets/desserts (10.2%), dairy (8.5%), mixed dishes (7.6%), starches (6.3%), fast foods (5.5%), and rice (4.9%). The mean (SD) AHEI score was 59.8 (11.0). The lowest AHEI components for which recommended servings were met were red/processed meats, fruit, sodium, sugary beverages, and polyunsaturated fats, and the highest were nuts/legumes, omega-3 fats, and whole grains. Significantly higher AHEI scores were noted for older adults, other ethnicities (vs. Puerto Rican), being single, having some college or higher education, and never/formerly smoking. Adults living in PR report healthy and unhealthy dietary intakes, providing an opportunity to improve diet at the population level.

The Mediterranean Diet and 2-Year Change in Cognitive Function by Status of Type 2 Diabetes and Glycemic Control.

OBJECTIVE: To determine associations of a Mediterranean diet score (MeDS) with 2-year change in cognitive function by type 2 diabetes and glycemic control status and contrast it against other diet quality scores. RESEARCH DESIGN AND METHODS: We used data from the longitudinal Boston Puerto Rican Health Study (n = 913; 42.6% with type 2 diabetes at 2 years). Glycemic control at baseline was categorized as uncontrolled (hemoglobin A1c ≥7% [53 mmol/mol]) versus controlled. Two-year change in glycemic control was defined as stable/improved versus poor/declined. We defined MeDS, Healthy Eating Index, Alternate Healthy Eating Index, and Dietary Approaches to Stop Hypertension scores. Adjusted mixed linear models assessed 2-year change in global cognitive function z score, executive and memory function, and nine individual cognitive tests. RESULTS: Higher MeDS, but no other diet quality score, was associated with higher 2-year change in global cognitive function in adults with type 2 diabetes (ß ± SE = 0.027 ± 0.011; P = 0.016) but not in those without (P = 0.80). Similar results were noted for Mini-Mental State Examination, word recognition, digit span, and clock drawing tests. Results remained consistent for individuals under glycemic control at baseline (0.062 ± 0.020; P = 0.004) and stable/improved over 2 years (0.053 ± 0.019; P = 0.007), but not for individuals with uncontrolled or poor/declined glycemic control. All diet quality scores were associated with higher 2-year memory function in adults without type 2 diabetes. CONCLUSIONS: Both adhering to a Mediterranean diet and effectively managing type 2 diabetes may support optimal cognitive function. Healthy diets, in general, can help improve memory function among adults without type 2 diabetes.

Prospective Associations of Erythrocyte Composition and Dietary Intake of n-3 and n-6 PUFA with Measures of Cognitive Function.

Polyunsaturated fatty acid (PUFA) consumption is recommended as part of a healthy diet, but evidence of the impact of individual species and biological concentrations on cognitive function is limited. We examined prospective associations of PUFA erythrocyte composition and dietary intake with measures of cognitive function among participants of the Boston Puerto Rican Health Study (aged 57 years). Erythrocyte and dietary PUFA composition were ascertained at baseline and associated with 2-year scores on the Mini-Mental State Exam (MMSE) (n = 1032) and cognitive domain patterns derived from a battery of tests (n = 865), as well as with incidence of cognitive impairment. Erythrocyte and dietary n-3 PUFA were not significantly associated with MMSE score. However, total erythrocyte and dietary n-3 very-long-chain fatty acids (VLCFA), and intake of individual species, were associated with better executive function (P-trend < 0.05, for all). There was evidence that greater erythrocyte n-6 eicosadienoic acid concentration was associated with lower MMSE and executive function scores (P-trend = 0.02). Only erythrocyte arachidonic acid (ARA) concentration predicted cognitive impairment (Odds Ratio = 1.26; P = 0.01). Among Puerto Rican adults, we found that n-3 VLCFA consumption may beneficially impact executive function. Further, these findings provide some evidence that n-6 metabolism favoring greater ARA tissue incorporation, but not necessarily dietary intake, could increase the risk of cognitive impairment.

The Omega-3 Index Is Inversely Associated with Depressive Symptoms among Individuals with Elevated Oxidative Stress Biomarkers.

BACKGROUND: Omega-3 (n-3) fatty acid (FA) consumption is thought to improve depressive symptoms. However, current evidence is limited, and whether this association exists among Puerto Ricans, a population burdened by depression, remains uncertain. OBJECTIVES: We examined the association between ω-3 FA biomarkers and depressive symptoms as well as the potential influence of oxidative stress. METHODS: Baseline and longitudinal analyses were conducted in the Boston Puerto Rican Health Study (n= 787; participants aged 57 ± 0.52 y, 73% women). Urinary 8-hydroxy-2'-deoxyguanosine (8-OHdG) concentration, a measure of oxidative stress, and erythrocyte FA composition were collected at baseline. We calculated the omega-3 index as the sum of eicosapentaenoic and docosahexaenoic acids, expressed as a percentage of total FAs. Baseline and 2-y depressive symptoms were characterized by using the Center for Epidemiological Studies-Depression Scale (CES-D). Statistical analyses included linear and logistic regression. RESULTS: Urinary 8-OHdG concentration tended to modify the relation between the erythrocyte omega-3 index and baseline CES-D score (P-interaction = 0.10). In stratified analyses, the omega-3 index was inversely associated with CES-D score (ß = -1.74, SE = 0.88;P= 0.02) among those in the top quartile of 8-OHdG concentration but not among those in the lower quartiles. The relation between the omega-3 index and CES-D at 2 y was more clearly modified by 8-OHdG concentration (P-interaction = 0.04), where the omega-3 index was inversely associated with CES-D at 2 y, adjusted for baseline (ß = -1.66, SE = 0.66;P= 0.02), only among those with elevated 8-OHdG concentrations. Among individuals not taking antidepressant medications and in the top tertile of urinary 8-OHdG concentration, the omega-3 index was associated with significantly lower odds of a CES-D score ≥16 at baseline (OR: 0.72; 95% CI: 0.53, 0.96) but not at 2 y (OR: 0.83; 95% CI: 0.60, 1.15). CONCLUSIONS: An inverse association between the omega-3 index and depressive symptoms was observed among participants with elevated oxidative stress biomarkers. These data suggest that oxidative stress status may identify those who might benefit from ω-3 FA consumption to improve depressive symptoms.

Associations of erythrocyte fatty acid patterns with insulin resistance.

BACKGROUND: Synergistic or additive effects or both on cardiometabolic risk may be missed by examining individual fatty acids (FAs). A pattern analysis may be a more useful approach. In addition, it remains unclear whether erythrocyte FA composition relates to insulin resistance among Hispanics/Latinos. OBJECTIVE: We derived erythrocyte FA patterns for a Puerto Rican cohort and examined their association with diet and insulin resistance in cross-sectional and prospective analyses. DESIGN: At baseline, principal components analysis was used to derive factor patterns with the use of 24 erythrocyte FAs from 1157 participants of the Boston Puerto Rican Health Study (aged 45-75 y). Dietary intake was assessed with a validated semiquantitative food-frequency questionnaire. The homeostasis model assessment of insulin resistance (HOMA-IR) was calculated at baseline and at the 2-y follow-up. Relations between FA patterns and HOMA-IR were analyzed in a sample of 922 participants with available data. RESULTS: Five FA patterns were derived, differentiated by 1) relatively high de novo lipogenesis (DNL) FAs and low n-6 (ω-6) FAs, 2) high very-long-chain saturated FAs, 3) high n-3 (ω-3) FAs, 4) high linoleic acid and low arachidonic acid, and 5) high trans FAs. The DNL pattern was positively correlated with sugar and inversely with n-6 and monounsaturated FA intakes. Only the DNL pattern was positively related to baseline HOMA-IR [adjusted geometric means (95% CIs) for quartiles 1 and 4: 1.72 (1.58, 1.87) and 2.20 (2.02, 2.39); P-trend < 0.0001]. Similar associations were observed at 2 y, after adjustment for baseline status [quartiles 1 and 4 means (95% CIs): 1.61 (1.48, 1.76) and 1.84 (1.69, 2.00); P-trend = 0.02]. These results remained consistent after the exclusion of participants with diabetes (n = 485). CONCLUSION: Our findings suggest that upregulated DNL associated with a diet high in sugar and relatively low in unsaturated FAs may adversely affect insulin sensitivity in a Hispanic/Latino cohort.