Epigenome-Wide Association Study of Dietary Fiber Intake in African American Adolescents

Diet Quality and Epigenetic Aging in the Women's Health Initiative

BACKGROUND

Higher diet quality scores are associated with a lower risk for many chronic diseases and all-cause mortality; however, it is unclear if diet quality is associated with aging biology.

OBJECTIVE

This study aimed to examine the association between diet quality and a measure of biological aging known as epigenetic aging.

DESIGN

A cross-sectional data analysis was used to examine the association between three diet quality scores based on self-reported food frequency questionnaire data and five measures of epigenetic aging based on DNA methylation (DNAm) data from peripheral blood.

PARTICIPANTS/SETTING

This study included 4,500 postmenopausal women recruited from multiple sites across the United States (1993-98), aged 50 to 79 years, with food frequency questionnaire and DNAm data available from the Women's Health Initiative baseline visit.

MAIN OUTCOME MEASURES

Five established epigenetic aging measures were generated from HumanMethylation450 Beadchip DNAm data, including AgeAccelHannum, AgeAccelHorvath, AgeAccelPheno, AgeAccelGrim, and DunedinPACE.

STATISTICAL ANALYSES PERFORMED

Linear mixed models were used to test for associations between three diet quality scores (Healthy Eating Index, Dietary Approaches to Stop Hypertension, and alternate Mediterranean diet scores) and epigenetic aging measures, adjusted for age, race and ethnicity, education, tobacco smoking, physical activity, Women's Health Initiative substudy from which DNAm data were obtained, and DNAm-based estimates of leukocyte proportions.

RESULTS

Healthy Eating Index, Dietary Approaches to Stop Hypertension, and alternate Mediterranean diet scores were all inversely associated with AgeAccelPheno, AgeAccelGrim, and DunedinPACE (P < 0.05), with the largest effects with DunedinPACE. A one standard deviation increment in diet quality scores was associated with a decrement (β ± SE) in DunedinPACE z score of -0.097 ± 0.014 (P = 9.70 x 10-13) for Healthy Eating Index, -0.107 ± 0.014 (P = 1.53 x 10-14) for Dietary Approaches to Stop Hypertension, and -0.068 ± 0.013 (P = 2.31 x 10-07) for the alternate Mediterranean diet.

CONCLUSIONS

In postmenopausal women, diet quality scores were inversely associated with DNAm-based measures of biological aging, particularly DunedinPACE.

Epigenome-wide association study of diet quality in the Women's Health Initiative and TwinsUK cohort

BACKGROUND

Diet quality is a risk factor for chronic disease and mortality. Differential DNA methylation across the epigenome has been associated with chronic disease risk. Whether diet quality is associated with differential methylation is unknown. This study assessed whether diet quality was associated with differential DNA methylation measured across 445 548 loci in the Women's Health Initiative (WHI) and the TwinsUK cohort.

DESIGN

The discovery cohort consisted of 4355 women from the WHI. The replication cohort consisted of 571 mono- and dizygotic twins from the TwinsUK cohort. DNA methylation was measured in whole blood using the Illumina Infinium HumanMethylation450 Beadchip. Diet quality was assessed using the Alternative Healthy Eating Index 2010 (AHEI-2010). A meta-analysis, stratified by study cohort, was performed using generalized linear models that regressed methylation on AHEI-2010, adjusting for cell composition, chip number and location, study characteristics, principal components of genetic relatedness, age, smoking status, race/ethnicity and body mass index (BMI). Statistical significance was defined as a false discovery rate < 0.05. Significant sites were tested for replication in the TwinsUK cohort, with significant replication defined by P < 0.05 and a consistent direction.

RESULTS

Diet quality was significantly associated with differential DNA methylation at 428 cytosine-phosphate-guanine (CpG) sites in the discovery cohort. A total of 24 CpG sites were consistent with replication in the TwinsUK cohort, more than would be expected by chance (P = 2.7x10-4), with one site replicated in both the blood and adipose tissue (cg16379999 located in the body of SEL1L).

CONCLUSIONS

Diet quality was associated with methylation at 24 CpG sites, several of which have been associated with adiposity, inflammation and dysglycaemia. These findings may provide insight into pathways through which diet influences chronic disease.

Epigenetic signatures underlying inflammation: an interplay of nutrition, physical activity, metabolic diseases, and environmental factors for personalized nutrition

AIM AND OBJECTIVE

Emerging translational evidence suggests that epigenetic alterations (DNA methylation, miRNA expression, and histone modifications) occur after external stimuli and may contribute to exacerbated inflammation and the risk of suffering several diseases including diabetes, cardiovascular diseases, cancer, and neurological disorders. This review summarizes the current knowledge about the harmful effects of high-fat/high-sugar diets, micronutrient deficiencies (folate, manganese, and carotenoids), obesity and associated complications, bacterial/viral infections, smoking, excessive alcohol consumption, sleep deprivation, chronic stress, air pollution, and chemical exposure on inflammation through epigenetic mechanisms. Additionally, the epigenetic phenomena underlying the anti-inflammatory potential of caloric restriction, n-3 PUFA, Mediterranean diet, vitamin D, zinc, polyphenols (i.e., resveratrol, gallic acid, epicatechin, luteolin, curcumin), and the role of systematic exercise are discussed.

METHODS

Original and review articles encompassing epigenetics and inflammation were screened from major databases (including PubMed, Medline, Science Direct, Scopus, etc.) and analyzed for the writing of the review paper.

CONCLUSION

Although caution should be exercised, research on epigenetic mechanisms is contributing to understand pathological processes involving inflammatory responses, the prediction of disease risk based on the epigenotype, as well as the putative design of therapeutic interventions targeting the epigenome.

Higher chocolate intake is associated with longer telomere length among adolescents

BACKGROUND

Chocolate intake has shown cardiometabolic health benefits. Whether chocolate has any effect on cellular aging remains unknown. We aimed to test the hypothesis that higher chocolate intake is associated with longer leukocyte telomere length (LTL) in adolescents.

METHODS

A total of 660 adolescents (aged 14-18 years) were included in the analysis. The chocolate intake was assessed by 7-day, 24-h dietary recalls and split into three groups, which were none, <2 servings/week, and 2 servings/week or more. LTL (T/S ratio) was determined by a modified quantitative polymerase chain reaction-based assay.

RESULTS

Among the 660 adolescents, 58% did not take any chocolate, 25% consumed <2 servings/week, and 17% consumed ≥2 servings/week. Compared to non-consumers, adolescents who consumed chocolate of ≥2 servings/week had 0.27 standard deviation (SD) longer LTL (p = 0.014). Higher chocolate consumption was associated with increased apolipoprotein A1 (ApoA1) (p = 0.038) and ApoA1/high-density lipoprotein (HDL) (p = 0.046). Moreover, higher ApoA1/HDL levels were correlated with longer LTL (p = 0.026).

CONCLUSION

Adolescents who consume 2 servings/week or more of chocolate candy have longer LTL compared with non-consumers, and ApoA1/HDL pathway may be involved in this relationship.

Race, Gender, Family Structure, Socioeconomic Status, Dietary Patterns, and Cardiovascular Health in Adolescents

BACKGROUND

Dietary patterns represent a broad picture of food and nutrient consumption and may be more predictive of health outcomes than individual foods and nutrients.

OBJECTIVE

We investigated the relations among race, gender, family structure, parental socioeconomic status (SES), dietary patterns, and cardiovascular disease (CVD) profiles among adolescents in the southeastern region of the United States.

METHODS

A total of 743 adolescents from a cross-sectional study were divided into 4 dietary pattern groups by K-means cluster analysis. Multinomial logistic regression was performed to determine the relations among the parental SES, family structures, and dietary patterns of the adolescents. Associations between dietary patterns and CVD profiles were analyzed by multiple linear regression.

RESULTS

Four dietary patterns were derived: "healthy" (17%), "snacks and sweets" (26%), "processed meat" (20%), and "sugar-sweetened beverage (SSB) and fried food" (37%). Whites and females were more likely to have a "healthy" dietary pattern (Ps < 0.001). There were significant race/ethnicity differences in family structures, SES, and dietary patterns (Ps < 0.05). In whites, higher mother's education and father's education and occupation were associated with greater likelihood of a "healthy" dietary pattern (Ps < 0.05). Stay-at-home mother was associated with less likelihood of an "SSB and fried food" pattern (P = 0.023). In blacks, higher mother's occupation, father's education, and living with both parents were associated with more likelihood of a "healthy" dietary pattern (Ps < 0.05). Stay-at-home father was associated with less likelihood of the "snacks and sweets" (P = 0.025) and "SSB and fried food" dietary patterns (P = 0.044). Overall, adolescents with poor dietary patterns exhibited higher percentage body fat, waist circumference, systolic blood pressure, fasting insulin, homeostasis model assessment of insulin resistance, C-reactive protein, and total triglyceride (Ps < 0.05).

CONCLUSIONS

Our data suggest that family structure, parental working status, and SES are associated with the diet quality in adolescents. Moreover, "snacks and sweets," "processed meat," and "SSB and fried food" dietary patterns are all associated with worse CVD risk profiles.