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

Higher dietary intake of live microbes is inversely associated with accelerated biological aging

Objective: It remains unclear whether dietary live microbe intake is associated with biological aging. Therefore, the present study aimed to investigate the associations between dietary live microbe intake and biological aging. Methods: Our study included 7719 participants aged 20 years and older from the 2007-2010 cycles of the National Health and Nutrition Examination Survey (NHANES). Participants were categorized into groups using two distinct methods. The first method grouped participants based on the live microbial level of the consumed foods, dividing them into three dietary live microbe intake groups: low, medium, and high. The second method classified participants according to the quantity of live microbe-containing foods they consumed (referred to as MedHi), with three groups: G1 (no MedHi intake), G2 (MedHi intake below the median), and G3 (MedHi intake above the median). Biological age was evaluated using the Klemera-Doubal method biological age (KDM-BA) and phenotypic age (PA). KDM-BA acceleration and PA acceleration was determined if participants' KDM-BA or PA exceeded their chronological age, respectively. Multivariable logistic regression models were conducted to explore the associations of dietary live microbe intake groups and dietary MedHi intake groups with the acceleration of KDM-BA and PA. Results: Compared with participants in the low dietary live microbe intake group, those in the high dietary live microbe intake group had a 20% (95% CI: 2% to 35%) reduced risk of KDM-BA acceleration and a 25% (95% CI: 4% to 42%) reduced risk of PA acceleration. Similarly, participants in the G3 group with higher dietary MedHi intake had a 24% (95% CI: 10% to 35%) lower risk of KDM-BA acceleration and a 29% (95% CI: 17% to 39%) lower risk of PA acceleration compared with those in the G1 group. The stratified analyses showed that the associations of dietary MedHi intake with accelerated KDM-BA and PA were not influenced by age, gender, race, smoking, alcohol consumption, physical activity, race, and history of hypertension, diabetes, and cardiovascular disease. Conclusion: Higher dietary intake of live microbes was inversely associated with accelerated biological aging. A diet rich in live microbes may help slow down the aging process.

Slower Pace of Epigenetic Aging and Lower Inflammatory Indicators in Females Following a Nutrient-Dense, Plant-Rich Diet Than Those in Females Following the Standard American Diet

Background

Plant-based diets are associated with lower inflammatory biomarkers and reduced risk of age-related chronic diseases. Epigenetic biomarkers of aging are DNA methylation-based tools that estimate biological age and rate of aging, providing insights into age-related health risks. Healthy diet and lifestyle indicators correlate with slower epigenetic aging.

Objectives

Neither inflammatory biomarkers nor epigenetic aging has yet been studied in the nutrient-dense, plant-rich (Nutritarian) diet, a plant-based diet that emphasizes specific plant foods, such as cruciferous vegetables, beans and other legumes, onions and garlic, mushrooms, berries, nuts, and seeds. We aimed to compare inflammatory status and epigenetic age acceleration in females following a Nutritarian diet with those of females following a standard American diet (SAD).

Methods

We investigated dietary inflammatory potential, epigenetic age acceleration using first, second, and third-generation clocks, and additional health-related epigenetic biomarkers in this retrospective cohort study of 48 females who habitually (≥5 y) follow a Nutritarian diet and 49 females without obesity who habitually (≥5 y) follow a SAD. Participants completed a series of online questionnaires and provided a blood sample.

Results

Epigenetic age acceleration, indicated by the third-generation clock DunedinPACE, was significantly slower in the Nutritarian group than that in the SAD group (P = 4.26 × 10-6). The Nutritarian diet group showed lower dietary inflammatory potential, as indicated by Empirical Dietary Inflammatory Pattern and Dietary Inflammatory Index. We observed differences in methylation-predicted immune cell subsets (lower neutrophils and higher T regulatory cells) and a lower epigenetic biomarker proxy for C-reactive protein, both of which suggested a lower inflammatory status in the Nutritarian group. Epigenetic biomarker proxies for LDL cholesterol, body mass index (BMI), insulin-like growth factor binding protein 5, and blood glucose were also lower in the Nutritarian group.

Conclusions

Our findings suggest the Nutritarian diet could help reduce chronic inflammation and slow epigenetic aging.

Evaluating the connection between diet quality, EpiNutrient intake and epigenetic age: an observational study

BACKGROUND

DNA methylation (DNAm) has unique properties which makes it a potential biomarker for lifestyle-related exposures. Epigenetic clocks, particularly DNAm-based biological age predictors [epigenetic age (EA)], represent an exciting new area of clinical research and deviations of EA from chronological age [epigenetic age acceleration (EAA)] have been linked to overall health, age-related diseases, and environmental exposures.

OBJECTIVES

This observational study investigates the relationships between biological aging and various dietary factors within the LifeLines-DEEP Cohort. These factors include diet quality, processed food consumption, dietary glycemic load, and intake of vitamins involved in maintaining the epigenetic homeostasis (vitamins B-9, B-12, B-6, B-2, and C).

METHODS

Dietary records collected using food-frequency questionnaires were used to estimate diet quality [LifeLines Diet Score (LLDS)], measure the intake of unprocessed/ultraprocessed food according to the NOVA food classification system, and the adequacy of the dietary intake of vitamins B-9, B-12, B-2, B-6, and C. EA using Horvath, Hannum, Levine, and Horvath2 epigenetic clock models and DNAm-predicted telomere length (DNAm-TL) were calculated from DNAm data in 760 subjects. Associations between dietary factors and EAA were tested, adjusting for sex, energy intake, and body composition.

RESULTS

LLDS was associated with EAA (EAA_Horvath: β: -0.148; P = 1 × 10-4; EAA_Hannum: β: -0.148; P = 9 × 10-5; EAA_Levine: β: -0.174; P = 1 × 10-5; and EAA_Horvath2: β: -0.176; P = 4 × 10-6) and DNAm-TL (β: 0.116; P = 0.003). Particularly, EAA was associated with dietary glycemic load (EAA_Horvath: β: 0.476; P = 9 × 10-10; EAA_Hannum: β: 0.565; P = 1 × 10-13; EAA_Levine: β: 0.469; P = 5 × 10-9; EAA_Horvath2: β: 0.569; P = 1 × 10-13; and DNAmTL adjusted for age: β: -0.340; P = 2 × 10-5) and different measures of food processing (NOVA classes 1 and 4). Positive EAA was also associated with inadequate intake of vitamin B-12 (EAA_Horvath: β: -0.167; P = 0.002; EAA_Hannum: β: -0.144; P = 0.007; and EAA_Horvath2: β: -0.126; P = 0.019) and C (EAA_Hannum: β: -0.136; P = 0.010 and EAA_Horvath2: β: -0.151; P = 0.005).

CONCLUSIONS

Our findings corroborate the hypothesis that nutrition plays a pivotal role in influencing epigenetic homeostasis, especially DNAm, thereby contributing to individual health trajectories and the pace of aging.

Diet, Pace of Biological Aging, and Risk of Dementia in the Framingham Heart Study

OBJECTIVE

People who eat healthier diets are less likely to develop dementia, but the biological mechanism of this protection is not well understood. We tested the hypothesis that healthy diet protects against dementia because it slows the pace of biological aging.

METHODS

We analyzed Framingham Offspring Cohort data. We included participants ≥60 years-old, free of dementia and having dietary, epigenetic, and follow-up data. We assessed healthy diet as long-term adherence to the Mediterranean-Dash Intervention for Neurodegenerative Delay diet (MIND, over 4 visits spanning 1991-2008). We measured the pace of aging from blood DNA methylation data collected in 2005-2008 using the DunedinPACE epigenetic clock. Incident dementia and mortality were defined using study records compiled from 2005 to 2008 visit through 2018.

RESULTS

Of n = 1,644 included participants (mean age 69.6, 54% female), n = 140 developed dementia and n = 471 died over 14 years of follow-up. Greater MIND score was associated with slower DunedinPACE and reduced risks for dementia and mortality. Slower DunedinPACE was associated with reduced risks for dementia and mortality. In mediation analysis, slower DunedinPACE accounted for 27% of the diet-dementia association and 57% of the diet-mortality association.

INTERPRETATION

Findings suggest that slower pace of aging mediates part of the relationship of healthy diet with reduced dementia risk. Monitoring pace of aging may inform dementia prevention. However, a large fraction of the diet-dementia association remains unexplained and may reflect direct connections between diet and brain aging that do not overlap other organ systems. Investigation of brain-specific mechanisms in well-designed mediation studies is warranted. ANN NEUROL 2024;95:1069-1079.