Validation and reproducibility of food frequency questionnaire for Korean genome epidemiologic study

The Longitudinal Effect of Sugar-Sweetened Beverage Consumption and Risk of All-Cause and Cause-Specific Mortality in Korean Adults: Results From the Health Examinees Study

OBJECTIVE

High consumption of sugar-sweetened beverages (SSBs) is associated with an increased risk of all-cause and cardiovascular disease (CVD) mortality; however, the data and results for Asian populations, particularly in Korea, are limited and unclear. Therefore, this research aimed to investigate the association between types of SSB consumption and risk of all-cause and cause-specific mortality in South Korean adults.

METHODS

This prospective study included Korean adults aged 40 to 79 who participated in the Health Examinees Study. The baseline survey was conducted from 2004 to 2013, and death data were obtained until December 2022. A food frequency questionnaire was used to assess SSB intake, and all-cause, CVD, and cancer mortality were estimated. The SSB included total SSB, soda, and other drinks (Korean traditional SSB).

RESULTS

A total of 126,856 participants were included (mean [standard deviation]: age, 53.1 [8.3] years; 82,311 [64.9%] women). During a mean follow-up of 11.0 years, 5741 all-cause, 936 CVD, and 2662 cancer deaths were recorded. Increased soda consumption was associated with higher all-cause mortality (1-3 servings/wk: hazard ratio [HR], 1.125; 95% confidence interval [CI], 1.003-2.263; ≥3 servings/wk: HR, 1.190, 95% CI, 1.011-1.401), compared with low soda intake (never-<1 serving/wk). However, there was no association between total SSB consumption and other drinks with all-cause and cause-specific mortality. In the dose-response analysis, a trend in which a higher risk of all-cause and CVD cancers was observed with increasing soda intake.

CONCLUSION

In this large prospective study, soda intake of >1 serving/wk was associated with an increased risk of all-cause mortality among Korean adults. However, there was no association between total SSB or other drinks and mortality. As the consumption of SSBs increases in the Korean population, appropriate control strategies are needed to reduce SSB consumption and the disease burden.

Long-term alcohol consumption and incident health risk conditions related to cardiometabolic risk markers: A 20-year prospective cohort study

BACKGROUND AND AIMS

Amid questions about a perceived association between low-to-moderate alcohol consumption and reduced cardiovascular risk from recent studies, research examining the impact of alcohol consumption on cardiometabolic risk markers has reported inconsistent results. We measured the association between long-term alcohol consumption and incident health risk conditions related to cardiometabolic risk markers.

DESIGN, SETTING AND PARTICIPANTS

A prospective cohort analysis was conducted using data from a population-based cohort (2001-2020) of 4708 Koreans aged 40-69 years who were free of chronic diseases, including metabolic syndrome, at baseline.

MEASUREMENTS

Alcohol consumption and incident cases related to cardiometabolic risk markers were assessed biennially using interviewer-administered questionnaires or health examinations. The average alcohol intake was calculated to reflect long-term consumption. Alcohol consumption was categorized as none or rarely (0-2 g/day), light (2 < -16 g/day, within guideline limits), medium (16 < -32 g/day) and heavy (>32 g/day).

FINDINGS

After full adjustment for covariates, light, medium or heavy alcohol consumption was positively associated with metabolic syndrome [hazard ratio (HR) = 1.55, 95% confidence interval (CI) = 1.32-1.83], abdominal obesity (HR = 1.41, 95% CI = 1.17-1.70), hyperglycemia (HR = 1.91, 95% CI = 1.62-2.26), high blood pressure (HR = 2.04, 95% CI = 1.72-2.41) and hypertriglyceridemia (HR = 1.59, 95% CI = 1.30-1.93), with the results presented for heavy alcohol consumption only (p-values for trend <0.001 for all cases). By sex, positive associations between light alcohol intake and hyperglycemia and high blood pressure were observed only in women (p-values for interaction and p-values for trend <0.05 for all cases).

CONCLUSIONS

Long-term light (within guideline limits), medium or heavy alcohol consumption appears to be positively and linearly associated with incident health risk conditions related to cardiometabolic risk markers. The threshold dose of alcohol for developing hyperglycemia and high blood pressure appears to be lower in women.

The association of diet-dependent acid load with gastrointestinal cancer risk in the Cancer Screenee Cohort in Korea

BACKGROUND/OBJECTIVES

Diet-induced acidosis is a determinant of gastrointestinal (GI) cancer susceptibility. However, the current evidence remains insufficient to establish a link between an acidogenic diet and cancer because the majority of previous studies were restricted to a case‒control design. We investigated whether the dietary acid load is involved in GI carcinogenicity.

SUBJECTS/METHODS

We conducted a prospective cohort study of 10,741 participants who attended check-ups from October 2007 to December 2020 at the National Cancer Center, Korea. The participants were followed up until December 2020 to determine incident GI cancer cases. A Cox proportional hazards regression model was used to examine the dietary acid load, as reflected by the potential renal acid load (PRAL), the net endogenous acid production (NEAP), and net acid excretion (NAE), in relation to GI cancer risk.

RESULTS

A total of 208 incident GI cancer cases were identified during the follow-up period. We observed a significantly increased GI cancer risk among male participants with high PRAL, NEAP, and NAE scores (hazard ratios (HRs) = 1.53 (95% confidence interval (CI): 1.05-2.22), 1.51 (1.04-2.19), and 1.73 (1.18-2.53), respectively). Importantly, acidogenic foods seem to have detrimental effects even in individuals who are not obese.

CONCLUSIONS

Our findings add substantial evidence to the argument that diet-dependent acid load plays certain roles in GI carcinogenesis, especially in males. Thus, attention should be given to the dietary acid‒base load for the prevention of GI cancer.

Network Approach to Evaluate the Effect of Diet on Stroke or Myocardial Infarction Using Gaussian Graphical Model

Background/Objectives/Methods: Current research on the link between diet and stroke or myocardial infarction primarily focuses on individual food items. However, people's eating habits involve complex combinations of various foods. By employing an innovative approach known as the Gaussian graphical model to identify dietary patterns along with the Cox proportional model, the study aimed to identify dietary networks and explore their relationship with the incidence of stroke and/or myocardial infarction in the Korean population. The research utilized data from 84,729 participants in the Korean Genome and Epidemiological Study (KoGES), including the HEXA cohort (61,140 participants), CAVAS cohort (15,419 participants), and Ansan-Ansung cohort (8170 participants). Results: The network identified five dietary patterns or communities consisting of different food groups, while nine food groups did not belong to any community. The High-Protein and Green Tea Community consistently reduced the risk of stroke and myocardial infarction (MI), particularly among females. In most communities, no significant associations with stroke risk were noted in males, and the Rice and High-Calorie Beverages Community was linked to an increased risk of MI in both the total population and females. Conclusions: Dietary patterns derived from network analysis revealed distinct dietary habits in the Korean population, offering new insights into the relationship between diet and the risk of stroke and MI.

FTO rs9939609 polymorphism is associated with dietary quality in Korean females

PURPOSE

Variation in fat mass and obesity-associated gene (FTO) is a critical risk factor in the etiology of obesity. FTO is associated with preference and sensory perception of nutrients and dietary intake. However, the effect of genetic variation on overall dietary quality has not yet been fully elucidated. This study examined whether FTO rs9939609 (T > A) was associated with dietary quality in Koreans.

METHODS

Data of 46,928 individuals from the Korean Genome and Epidemiology Study were analyzed according to FTO rs9939609 genotype, general characteristics, and diet quality based on the Korean Healthy Eating Index (KHEI), employing sex- and age-stratified approaches.

RESULTS

The FTO genotype did not significantly influence overall diet quality; however, female carriers of the obesity risk allele A (TA + AA) showed significantly higher KHEI scores for balance of energy nutrient consumption, especially for carbohydrate ratio (2.00 ± 1.99 versus 1.90 ± 1.98, Padjusted <0.001) and fat ratio (2.87 ± 2.15 versus 2.76 ± 2.17, Padjusted <0.001) than A-allele non-carriers (TT). Furthermore, when the females were grouped based on their median age (51 years), such an association between the FTO genotype and energy nutrient ratio was only evident in the younger group. However, such an effect of the genetic variant on diet quality and energy nutrient consumption was not evident in males, and the interactive effect of FTO and sex and age was not statistically significant.

CONCLUSION

The FTO rs9939609 (T > A) polymorphism is associated with dietary quality, particularly influencing the balance of energy nutrient intake in Korean females.

Association between cumulative pack-year smoking exposure and sarcopenia: a KoGES cohort study

BACKGROUND

Sarcopenia is the age-related involuntary loss of skeletal muscle mass and strength. Many factors, such as ageing and behaviour, may affect the risk of sarcopenia. However, no study had confirmed the association between cumulative exposure to smoking and the risk of developing sarcopenia. Therefore, in this study we investigated the association between cumulative smoking exposure and the risk of sarcopenia.

METHODS

After excluding some invalid data, 8818 participants aged 40-69 years were included in the Korean Genomics and Epidemiology Study (KoGES) cohort, spanning 16 years (2001-2016). Sarcopenia was diagnosed based on biennial measurements of the appendicular lean mass index using bioelectrical impedance analysis following the Asian Working Group for Sarcopenia (AWGS) criteria. Smoking status and cumulative smoking exposure were self-reported at baseline. Cox proportional hazards regression analysis was conducted to assess sarcopenia occurrence based on smoking status and cumulative smoking amount after adjusting for age, sex, medical history, marital status, alcohol consumption and smoking habits, protein intake, and physical activity.

RESULTS

The study induced 8818 participants with an average age of 51.9 years; 44.5% were men, and the mean follow-up duration was 8.4 years. After adjusting for covariates, smokers exhibited a higher risk of sarcopenia than non-smokers, with a hazard ratio of 1.279 (95% confidence interval: 1.064-1.657). Moreover, there was a dose-response relationship between cumulative smoking exposure and sarcopenia risk, with hazard ratios increasing with higher pack-year values relative to non-smokers.

CONCLUSION

Cumulative smoking exposure, measured in pack-years, was associated with increased sarcopenia incidence in a Korean cohort.

Iron Consumption and Colorectal Cancer in Korean Adults: A Prospective Cohort Study

Background/Objectives: Colorectal cancer (CRC) is a major health concern in Korea, with its increasing incidence emphasizing the urgent need to identify risk factors. Recent studies suggest that heme iron elevates CRC risk, but evidence remains conflicting. This study examined the associations between total, heme, and non-heme iron intake and the incidence of colorectal, colon, and rectal cancer in Koreans. Methods: Using the Korean Genome and Epidemiology Study Health Examinee (KoGES HEXA) cohort, a large community-based cohort of healthy Koreans, we constructed a database of iron content for foods listed in a validated food frequency questionnaire (FFQ) and assessed dietary iron intake for each participant. Colorectal, colon, and rectal cancer cases were identified via the national cancer registry up to 2018. The association between iron consumption and cancers was evaluated with hazard ratios (HRs) and 95% confidence intervals (95%CIs) using multivariable-adjusted Cox regression. Results: During the 9.1-year median follow-up of 109,908 participants (37,697 men and 71,401 women, median age: 53.8 years), 608 new CRC cases were identified. Moderate total iron consumption in the second quintile (5.00-6.27 mg/day) decreased CRC (HR: 0.75; 95%CI: 0.58-0.97) and colon cancer (HR: 0.71; 95%CI: 0.51-1.00) risk compared to the lowest consumption quintile (1.09-4.99 mg/day), as did non-heme iron intake in the second quintile (4.98-6.24 mg/day) compared to its lowest quintile (1.09-4.97 mg/day) (CRC HR: 0.75; 95%CI: 0.58-0.98; colon cancer HR: 0.70; 95%CI: 0.49-0.98). Conclusions: Moderate total and non-heme iron intake reduced colorectal and colon cancer risk in Koreans, possibly via the displacement of carcinogens and the increased intake of protective micronutrients from plant-based foods. Larger-scale studies may be instrumental in substantiating these results.

Body-Weight Fluctuations and the Association Between the Consumption of Protein-Rich Foods and the Incidence of Metabolic Syndrome Among Middle-Aged Women in Korea

BACKGROUND/OBJECTIVES

Metabolic syndrome (MetS) is a growing global health concern, driven in part by increasing rates of overweight and obesity. In Korea, MetS incidence escalates particularly among middle-aged women, eventually surpassing that of men. While protein-rich diets have been associated with improved metabolic health, the impact of protein intake on body weight fluctuations (BWFs) and MetS risk has received limited attention, especially in Korean populations.

METHODS

Using data from the Korean Genome and Epidemiology Study (KoGES), this study examined whether a higher intake of protein-rich foods is linked to smaller BWF and lower MetS incidence in middle-aged Korean women. Dietary intake was assessed through validated questionnaires, and BWF was calculated based on repeated anthropometric measurements over a long-term follow-up. MetS was defined according to established clinical criteria.

RESULTS

Preliminary findings indicated that participants who consumed higher amounts of protein-rich foods, particularly animal-based proteins (e.g., fish, low-fat dairy), tended to exhibit smaller BWFs. Additionally, lower BWF was associated with a reduced risk of MetS, suggesting that stable weight regulation may play a protective role against metabolic dysfunction. Potential mechanisms include the preservation of lean mass, enhanced energy expenditure, and reduced carbohydrate intake when protein consumption is increased. These findings highlight the importance of dietary strategies that optimize protein intake to help minimize BWF and potentially lower MetS risk in middle-aged Korean women. Future research should investigate the specific sources and quality of protein and their long-term effects on metabolic health outcomes in diverse populations.

Identification of Novel Genetic Variants and Food Intake Factors Associated with Type 2 Diabetes in South Korean Adults, Using an Illness-Death Model

Type 2 diabetes (T2D) is a prevalent chronic disease in the Korean population, influenced by lifestyle, dietary habits, and genetics. This study aimed to identify the effects of food intake and genetic factors on T2D progression in Korean adults using a multi-state illness-death model. We analyzed three transition models: normal glucose tolerance (NGT) to prediabetes (PD), NGT to T2D, and PD to T2D. We first identified dietary patterns significantly associated with each transition, using multivariate Cox proportional hazards models. Then, we assessed the impact of single-nucleotide polymorphisms (SNPs) on each transition, incorporating these dietary patterns as covariates. Our analysis revealed significant associations between the identified dietary patterns and the risk of PD and T2D incidence among individuals with NGT. We also identified novel genetic variants associated with disease progression: two SNPs (rs4607517 in Glucokinase [GCK] and rs758982 in Calcium/Calmodulin-Dependent Protein Kinase II Beta [CAMK2B]) in the NGT to PD model, and eight SNPs in the NGT to T2D model, including variants in the Zinc Finger Protein 106 (ZNF106), PTOV1 Extended AT-Hook Containing Adaptor Protein (PTOV1), Proprotein Convertase Subtilisin/Kexin Type 2 (PCSK2), Forkhead Box D2 (FOXD2), Solute Carrier Family 38 Member 7 (SLC38A7), and Neuronal Growth Regulator 1 (NEGR1) genes. Functional annotation analysis using ANNOVAR revealed that rs4607517 (GCK) and rs59595912 (PTOV1) exhibited high Combined Annotation-Dependent Depletion (CADD) and Deleterious Annotation of Genetic Variants using Neural Networks (DANN) scores, suggesting potential pathogenicity and providing a functional basis for their association with T2D progression. Integrating dietary and genetic factors with a multi-state model, this comprehensive approach offers valuable insights into T2D development and highlights potential targets for prevention and personalized interventions.

Gene-Lifestyle Interactions in Renal Dysfunction: Polygenic Risk Modulation via Plant-Based Diets, Coffee Intake, and Bioactive Compound Interactions

Background: This study aimed to investigate genetic variants associated with the estimated glomerular filtration rate (eGFR) and their interactions with lifestyle factors and bioactive compounds in large hospital-based cohorts, assessing their impact on renal dysfunction risk. Methods: Participants were categorized into two groups based on eGFR: High-GFR (control; n = 51,084) and Low-GFR (renal dysfunction; n = 7617), using an eGFR threshold of 60 mL/min/1.73 m2. Genetic variants were identified through a genome-wide association analysis, and their interactions with lifestyle factors were assessed a using generalized multifactor dimensionality reduction (GMDR) analysis. Additionally, interactions between polygenic risk scores (PRS) and nutrient intake were examined. Results: Low eGFR was associated with higher urinary protein levels (4.67-fold) and correlated with a Western-style diet and with saturated fat, arginine, and isoleucine intakes but not sodium intake. The genetic model for low eGFR included variants linked to energy production and amino acid metabolism, such as rs1047891_CPS1, rs3770636_LRP2, rs5020545_SHROOM3, rs3812036_SLC34A1, and rs4715517_HCRTR2. A high PRS was associated with a 1.78-fold increased risk of low eGFR after adjusting for sociodemographic and lifestyle factors. The PRS from the 6-SNP model interacted with plant-based diets (PBDs) and coffee intake, where individuals with higher PBD and coffee consumption had a lower risk of renal dysfunction. Additionally, CPS1 rs1047891 interacted with vitamin D intake (p = 0.0436), where the risk allele was linked to lower eGFR with low vitamin D intake but not with high intake. Molecular docking showed that vitamin D3 had a lower binding energy to the CPS1 mutant type (-9.9 kcal/mol) than the wild type (-7.5 kcal/mol), supporting a potential gene-nutrient interaction influencing renal function. Conclusions: Middle-aged and elderly individuals with a high genetic risk for renal dysfunction may benefit from a plant-based diet, moderate coffee consumption, and sufficient vitamin D intake.

Relationship between HECTD4 gene variants, obesity, and coffee consumption

BACKGROUND

In genome-wide association studies, the HECT domain E3 ubiquitin-protein ligase 4 (HECTD4) gene was suggested to be associated with obesity-related traits and coffee consumption. However, the association of genetic variants between coffee consumption and obesity has not been tested in Koreans. Therefore, we investigated whether HECTD4 gene variants act as effect modifiers on the relationship between obesity and coffee.

METHODS

This study analyzed the correlation between coffee consumption and obesity among 58,698 individuals representing the Health Examinees. Participants were categorized into obese (BMI ≥ 25.0 kg/m2) and nonobese (18.5 ≤ BMI < 23.0 kg/m2). Food consumption was assessed by a food frequency questionnaire.

RESULTS

We identified four HECTD4 gene variants associated with obesity-related traits and coffee consumption based on Bonferroni-corrected significance level (p < 0.00014). Furthermore, multivariate logistic regression analysis confirmed that the impact of coffee consumption on obesity differed based on the HECTD4 rs2074356 genotypes. A positive correlation between obesity and coffee consumption was observed, with a more pronounced effect in individuals with the G allele (OR = 1.61 for 1 to <2 cups/day, p = 1.89 × 10-37; OR = 1.82 for ≥2 cups/day, p = 1.73 × 10-42) than in those with the A allele (OR = 1.47 for 1 to <2 cups/day, p = 7.41 × 10-17; OR = 1.45 for ≥2 cups/day, p = 7.24 × 10-11).

CONCLUSION

Our findings suggest that the influence of coffee consumption on obesity may vary in Koreans depending on the HECTD4 gene variant.

Cluster analysis of diet and lifestyle factors associated with metabolic dysfunction-associated steatotic liver disease: findings from Korean Genome and Epidemiology Study

PURPOSE

As the global prevalence of metabolic dysfunction-associated steatotic liver disease (MASLD) continues to increase, its early detection is crucial. We investigated the combined effects of various factors on MASLD development to enhance the understanding of individuals at high risk of MASLD.

METHODS

A total of 4670 participants from the Korean Genome and Epidemiology Study were included. Cluster analysis and Cox proportional hazards regression were conducted to identify distinct risk factor clusters and evaluate their association with MASLD incidence.

RESULTS

Four clusters were identified based on lifestyle characteristics: Cluster 1 (LA)-low activity, Cluster 2 (HPF)-lowest carbohydrate intake with high protein and fat intake, Cluster 3 (HC)-highest carbohydrate intake with low protein and fat intake, and Cluster 4 (ASC)-highest alcohol consumption and smoking levels. Cluster 4 (ASC) exhibited the highest cumulative incidence of MASLD, followed by Cluster 3 (HC). Compared to Clusters 1, 2, and 3, Cluster 4 (ASC) had significantly higher hazard ratios (HRs) for MASLD incidence (HR: 1.35 [95% confidence interval {CI}: 1.19-1.53]; p < 0.001, HR: 1.31 [95% CI: 1.14-1.50]; p < 0.001, and HR: 1.22 [95% CI: 1.07-1.38]; p = 0.002, respectively).

CONCLUSION

Clusters exhibiting various risk factor phenotypes were identified, and smoking, alcohol consumption, and carbohydrate intake were significantly associated with a higher risk of MASLD. Our findings support the importance of early screening and personalized approaches for individuals at high risk of MASLD.

Impact of Meal Frequency on Insulin Resistance in Middle-Aged and Older Adults: A Prospective Cohort Study

BACKGRUOUND

Insulin resistance (IR) is central to metabolic disorders and significantly influenced by diet. Studies on meal frequency (MF) and metabolic indicators have shown mixed results. This study explores the link between MF and IR in middle-aged and older adults.

METHODS

This prospective cohort study included 4,570 adults aged 40 to 69 years from the Korean Genome and Epidemiologic Study. MF were divided into two groups based on whether they consumed three or more, or fewer than three, meals daily. IR was evaluated using the homeostasis model assessment of insulin resistance (HOMA-IR); participants were classified as IR if their HOMA-IR value was ≥2.5. Multiple Cox proportional hazard regression analyses were conducted to examine the association between MF and the incidence of IR.

RESULTS

After adjusting for all variables, individuals in the MF ≥3 group showed a reduced incidence of IR compared to those in the MF <3 group (hazard ratio, 0.880; 95% confidence interval, 0.782 to 0.990). Additionally, subgroup analyses by sex, diabetes mellitus (DM), and body mass index (BMI) showed that this association persisted only in men, individuals without DM, and those with a BMI <25.

CONCLUSION

Our findings indicate that a higher MF among middle-aged and older adults is associated with a reduced incidence of IR. However, this association was maintained only in men, individuals without DM, and those without obesity.

Gene-Diet Interactions in High-Density Lipoprotein Cholesterol-Related Polymorphisms and Cardiovascular Disease Risk: Insights from the Korean Genome and Epidemiology Study

Background: Understanding gene-diet interactions is crucial for establishing dietary guidelines for cardiovascular diseases (CVD). This study analyzed the interaction between dietary intake and six genome-wide association study (GWAS)-identified single nucleotide polymorphisms (SNP) associated with high-density lipoprotein (HDL) cholesterol levels and their impact on CVD risk. Methods: A total of 68,806 participants in the Korean Genome and Epidemiology Study (KoGES) were analyzed. Six target SNPs (LPL: rs17482753; ABCA1: rs1883025; APOA5: rs651821; LIPC: rs1077835; CETP: rs17231506; and LIPG: rs9953437) were extracted from genome-wide SNP genotype data. Dietary intake was assessed using a food frequency questionnaire. SNP genotyping was conducted using the Korea Biobank Array (Korean Chip), a specialized genotyping platform designed for GWAS of blood biochemical traits in the Korean population. SNP-diet interactions on CVD risk were analyzed using generalized linear models (GLM). Results: Among the six SNPs, ABCA1: rs1883025 and APOA5: rs651821 showed significant gene-diet interactions. For rs1883025 (ABCA1), carriers of the T allele exhibited reduced HDL cholesterol levels. However, in the high-protein intake group, individuals with the T/T genotype had a significantly lower risk of ischemic stroke compared to those in the low-protein intake group (interaction p-value = 0.044). For rs651821 (APOA5), carriers of the T allele also had lower HDL cholesterol levels, but individuals with the C/C genotype (wild-type homozygotes) in the low-fat intake group showed a significantly reduced risk of coronary artery disease (interaction p-value = 0.0155). Conclusions: This study suggests potential interactions between polymorphisms associated with low HDL cholesterol and dietary patterns, particularly high-protein and low-fat diets, in relation to CVD risk. These findings highlight the importance of personalized dietary recommendations based on genetic profiles to reduce CVD risk. They provide a basis for future research aimed at developing precision nutrition guidelines and targeted interventions to manage hypo-HDL cholesterolemia and nutrition-related CVD risks.

Intake of sodium and potassium, sodium-potassium intake ratio, and their relation to the risk of diabetes mellitus

We aimed to examine the effects of sodium and potassium intake on the risk of diabetes mellitus (DM). In a cohort of 99,552 working-age Korean adults (60,591 men; mean age 39.7 ± 6.9 and 38,961 women; mean age 38.4 ± 6.5), we longitudinally evaluated the risk of DM in relation to quartile levels of sodium intake, potassium intake, and the sodium-potassium ratio. A Cox proportional hazards model was used to assess the risk of DM by calculating adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) for incident DM (adjusted HR [95% CI]). In men, sodium intake was not associated with the risk of DM (first quartile: reference, second quartile: 0.96 [0.87-1.07], third quartile: 0.94 [0.84-1.05], and fourth quartile: 1.02 [0.89-1.18]). Women did not show a significant association between sodium intake and the risk of DM (first quartile: reference, second quartile: 0.87 [0.69-1.09], third quartile: 1.02 [0.81-1.29], and fourth quartile: 1.01 [0.76-1.33]). Additionally, potassium intake and the sodium-potassium ratio were not significantly associated with the risk of DM in either men or women. In conclusion, no significant association was observed between sodium or potassium intake and the risk of DM among working-age Korean adults.

Metagenomic Analysis Identifies Sex-Related Gut Microbial Functions and Bacterial Taxa Associated With Skeletal Muscle Mass

BACKGROUND

This study aimed to explore the association between gut microbiota functional profiles and skeletal muscle mass, focusing on sex-specific differences in a population under 65 years of age.

METHODS

Stool samples from participants were analysed using metagenomic shotgun sequencing. Skeletal muscle mass and skeletal muscle mass index (SMI) were quantified (SMI [%] = total appendage muscle mass [kg]/body weight [kg] × 100) using bioelectrical impedance analysis. Participants were categorized into SMI quartiles, and associations between gut microbiota, functional profiling and SMI were assessed by sex, adjusting for age, BMI and physical activity.

RESULTS

The cohort included 1027 participants (651 men, 376 women). In men, Escherichia coli (log2 fold change 3.08, q = 0.001), Ruminococcus_B gnavus (log2 fold change 2.89, q = 0.014) and Enterocloster sp001517625 (log2 fold change 2.47, q = 0.026) were more abundant in the lowest SMI compared to the highest SMI group. In contrast, Bifidobacterium bifidum (log2 fold change 3.13, q = 0.025) showed higher levels in the second lowest SMI group in women. Microbial pathways associated with amino acid synthesis (MET-SAM-PWY: log2 fold change 0.42; METSYN-PWY: log2 fold change 0.44; SER-GLYSYN-PWY: log2 fold change 0.20; PWY-5347: log2 fold change 0.41; P4-PWY: log2 fold change 0.53), N-acetylneuraminate degradation (log2 fold change 0.43), isoprene biosynthesis (log2 fold change 0.20) and purine nucleotide degradation and salvage (PWY-6353: log2 fold change 0.42; PWY-6608: log2 fold change 0.38; PWY66-409: log2 fold change 0.52; SALVADEHYPOX-PWY: log2 fold change 0.43) were enriched in the lowest SMI in men (q < 0.10). In women, the second lowest SMI group showed enrichment in energy-related pathways, including lactic acid fermentation (ANAEROFRUCAT-PWY: log2 fold change 0.19), pentose phosphate pathway (PENTOSE-P-PWY: log2 fold change 0.30) and carbohydrate degradation (PWY-5484: log2 fold change 0.31; GLYCOLYSIS: log2 fold change 0.29; PWY-6901: log2 fold change 0.27) (q < 0.05).

CONCLUSIONS

This study highlights sex-specific differences in gut microbiota and functional pathways associated with SMI. These findings suggest that gut microbiota may play a role in muscle health and point toward microbiota-targeted strategies for maintaining muscle mass.

Impact of Mediterranean Diet Adherence on the Incidence of New-Onset Hypertension in Adults With Obesity in Korea: A Nationwide Cohort Study

This study investigated the association between adherence to the Mediterranean diet (MD) and new-onset hypertension (HTN) in a cohort of community-dwelling, middle-aged, older Korean individuals with obesity. We used data from the Korean Genome and Epidemiology Study, a population-based prospective cohort study. The Korean version of the MD Adherence Screener was used to evaluate compliance with the MD. The primary endpoint was the incidence of new-onset HTN. Cox proportional hazard models were used to estimate the hazard ratio (HR) and 95% confidence interval for HTN incidence with increasing MD adherence. Data from 1995 participants with obesity without HTN at baseline were analyzed. After adjusting for confounders, participants with moderate (Group 2) and high adherence (Group 3) to the MD had HRs for new-onset HTN of 0.72 (0.57-0.90) and 0.73 (0.56-0.95), respectively, compared with those with low adherence (Group 1). Sex and age differences were associated with MD adherence and HTN incidence. The association between MD adherence and HTN incidence was only significant in males and in participants aged 40-64 years. There was no significant association between MD adherence and new-onset HTN in females or those aged ≥ 65 years. In conclusion, this study found a significant association between adherence to the MD and a reduction in new-onset HTN in Korean adults with obesity. Considering its value and sustainability, the adoption of the MD may contribute to the prevention of new-onset HTN in populations with obesity.

The possible association of dietary fiber intake with the incidence of depressive symptoms in the Korean population

OBJECTIVES

This study investigates the effect of dietary fiber on the prevention of depressive symptoms.

METHODS

In a cohort of 88,826 Korean adults (57,284 men and 31,542 women), we longitudinally evaluated the risk of depressive symptoms according to quartiles of dietary fiber intake for 5.8 years of follow-up. A food frequency questionnaire was used in evaluating dietary fiber intake. Depressive symptoms were assessed by the Center for Epidemiological Studies-Depression (CES-D) scale, in which CES-D ≥ 16 was defined as depressive symptoms. The Cox proportional hazards model was used to calculate the adjusted hazard ratio (HR) and 95% confidence intervals (CI) for depressive symptoms (adjusted HR [95% CI]). Subgroup analysis was performed for gender and BMI (≥25 or <25).

RESULT

In men, the risk of depressive symptoms significantly decreased with the increase of dietary fiber (quartile 1: reference, quartile 2: 0.93 [0.87-0.99], quartile 3: 0.91 [0.85-0.98] and quartile 4: 0.84 [0.77-0.92]). This association was more prominently observed in men with BMI ≥ 25 (quartile 1: reference, quartile 2: 0.95 [0.86-1.06], quartile 3: 0.88 [0.79-0.99] and quartile 4: 0.84 [0.73-0.97]). Women did not show a significant association between quartile groups of dietary fiber intake and the risk of depressive symptoms across subgroup analysis for BMI.

CONCLUSION

High intake of dietary fiber is potentially effective in reducing depressive symptoms in Korean men. The protective effect of dietary fiber on depressive symptoms may vary by gender and obesity.

Association Between Consumption of Foods Containing Vitamin D and All-Cause Mortality in Korea

Sufficient vitamin D levels are reported to be a factor in reducing various chronic diseases and resulting mortality rates. Well-dried mushrooms and blue-backed fish are known to be rich in vitamin D. In this study, the association between mortality rates and the intake of vitamin D-rich foods was confirmed using data from the Korean Genome and Epidemiological Study (KoGES). Among the KoGES database, we followed up a total of 6844 adults who participated in the Ansung-Ansan cohort study recruited from 2001 to 2002 and continued for an average of 16.7 years until 2018. The main findings were analyzed using Cox regression analysis. During follow-up, 439 cases of all-cause mortality, 149 cases of cancer-related mortality, and 91 cases of cardiovascular mortality were confirmed. In the fully adjusted model, the hazard ratio (HR) for all-cause mortality in quartile 3 of mushroom consumption was 0.709 (95% confidence interval [CI], 0.525-0.958) compared with quartile 1. In addition, the HRs for cardiovascular mortality in quartile 3 of mushroom consumption were 0.348 (95% CI, 0.154-0.787) compared with those in quartile 1. The HRs of cardiovascular mortality for quartiles 3 and 4 of fish consumption were 0.442 (95% CI, 0.226-0.865) and 0.533 (95% CI, 0.285-0.998), respectively, compared with quartile 1. In conclusion, moderate consumption of mushrooms was related to decreased risk of all-cause and cardiovascular mortality, while heightened fish consumption was inversely related to cardiovascular mortality.

Association of dietary manganese intake and the IL1R1 rs3917225 polymorphism with thyroid cancer risk: a prospective cohort study in Korea

Dietary Mn intake may have a beneficial effect in reducing cancer risk; however, its association with thyroid cancer (TC) risk remains inadequately understood. Additionally, Mn was associated with inflammation markers. Thus, we examined whether dietary Mn intake emerges a protective role against TC and whether this preventative effect has an interaction with IL1 receptor type 1 (IL1R1) rs3917225. The prospective study was designed at National Cancer Center in Korea between October 2007 and December 2020 including 17 754 participants. We identified TC cases by following participants until December 2020. Mn intake was collected using a semiquantitative food frequency questionnaire (SQFFQ). Genotyping was performed to determine IL1R1 rs3917225. The hazard ratios (HR) and 95 % confidence interval (CI) were calculated with a Cox proportional hazards model. We ascertained 108 incident TC cases throughout follow-up duration. Dietary Mn intake was found to be inversely associated with TC risk (HR (95 % CI)=0·64 (0·44, 0·95)). However, IL1R1 rs3917225 seemed to modify this association; the protective effect was limited to G-allele carriers (HR = 0·30 (0·11, 0·86), P interaction=0·028). A higher dietary Mn was suggested to be a protective factor against TC. Additionally, we drew a potential biological interaction between Mn intake and IL1R1 rs3917225 with a greater effect among individuals with a minor allele. This implies that when considering the cancer-preventive role of Mn, it is important to account for the influence of inflammatory gene participation.

Association of Metabolic Diseases and Moderate Fat Intake with Myocardial Infarction Risk

BACKGROUND

Myocardial infarction (MI) can range from mild to severe cardiovascular events and typically develops through complex interactions between genetic and lifestyle factors.

OBJECTIVES

We aimed to understand the genetic predisposition associated with MI through genetic correlation, colocalization analysis, and cells' gene expression values to develop more effective prevention and treatment strategies to reduce its burden.

METHODS

A polygenic risk score (PRS) was employed to estimate the genetic risk for MI and to analyze the dietary interactions with PRS that affect MI risk in adults over 45 years (n = 58,701). Genetic correlation (rg) between MI and metabolic syndrome-related traits was estimated with linkage disequilibrium score regression. Single-cell RNA sequencing (scRNA-seq) analysis was performed to investigate cellular heterogeneity in MI-associated genes.

RESULTS

Ten significant genetic variants associated with MI risk were related to cardiac, immune, and brain functions. A high PRS was associated with a threefold increase in MI risk (OR: 3.074, 95% CI: 2.354-4.014, p < 0.001). This increased the risk of MI plus obesity, hyperglycemia, dyslipidemia, and hypertension by about twofold after adjusting for MI-related covariates (p < 0.001). The PRS interacted with moderate fat intake (>15 energy percent), alcohol consumption (<30 g/day), and non-smoking, reducing MI risk in participants with a high PRS. MI was negatively correlated with the consumption of olive oil, sesame oil, and perilla oil used for cooking (rg = -0.364). MI risk was associated with storkhead box 1 (STOX1) and vacuolar protein sorting-associated protein 26A (VPS26A) in atrial and ventricular cardiomyocytes and fibroblasts.

CONCLUSIONS

This study identified novel genetic variants and gene expression patterns associated with MI risk, influenced by their interaction with fat and alcohol intake, and smoking status. Our findings provide insights for developing personalized prevention and treatment strategies targeting this complex clinical presentation of MI.

A comprehensive analysis of fruit, vegetable, and legume consumption and the risk of hypertension: results from the KoGES_CAVAS cohort

PURPOSE

This study aimed to investigate the association between total consumption of fruits (F), vegetables (V), and legumes (L) and their subgroups and hypertension risk in adults aged ≥ 40 years in the Cardiovascular Disease Association Study (CAVAS).

METHODS

We analyzed data from 10,325 normotensive participants using cumulative average dietary consumption from repeated food frequency questionnaires during the follow-up. Incidence rate ratios (IRRs) were estimated with a modified Poisson regression model and a robust error estimator to evaluate the association between hypertension risk and total consumption of fruits, vegetables, and legumes, as well as their 17 subgroups.

RESULTS

During an average follow-up of 5.20 years, 2159 cases of hypertension were recorded. Total consumption of FVL, FV, fruits, vegetables, and legumes showed overall inverse trends with hypertension risk. Considering multiplicity, fruit consumption was inversely associated with hypertension risk in both men (IRR 0.64; 95% CI 0.52-0.79) and women (IRR 0.76; 95% CI 0.64-0.91). Vegetables were inversely associated with hypertension in women (IRR 0.67; 95% CI 0.53-0.86). Most subgroups showed inverse associations, especially in men with overweight/obesity. However, frequent pickled green leafy vegetable consumption was positively associated with hypertension risk in postmenopausal women but not in premenopausal women (Pinteraction = 0.0004).

CONCLUSION

Consumption of FVL, including their subgroups, generally shows inverse associations with hypertension risk. However, caution is advised for recommending pickled vegetables, particularly for postmenopausal women, due to the potential adverse effects of sodium. The benefits of these foods in preventing hypertension are especially pronounced in men with overweight/obesity.

Association between plant-based diets and risk of metabolic dysfunction-associated steatotic liver disease in Korean adults: A prospective cohort study

OBJECTIVES

Few studies have investigated the correlation between plant-based diet indices (PDIs) and the risk of metabolic dysfunction-associated steatotic liver disease (MASLD) in the Korean population. Therefore, this study aimed to investigate the association between PDIs and the risk of MASLD in Korean adults.

METHODS

This cohort study utilized data from the Health Examinees Study conducted in the South Korean population. Dietary and nutrient intake were assessed at baseline and follow-up using a food frequency questionnaire and the Korean Food Consumption Table. Food items were categorized into overall PDI, healthy PDI (hPDI), and unhealthy PDI (uPDI), with MASLD defined using the fatty liver index. Baseline characteristics and food intake groups were evaluated based on PDI quintiles and stratified by sex. Further analyses involved stratification by age, body mass index, alcohol intake, and physical activity in men and women.

RESULTS

Over a median follow-up period of 4.2 y, MASLD occurred in 1532 participants. Both men and women in the highest hPDI quintile had a reduced risk of MASLD (men: HR: 0.71, 95% CI: 0.55-0.91, p = 0.0031; women: HR: 0.61, 95% CI: 0.48-0.78, p < 0.0001). Conversely, the highest uPDI quintile was associated with a higher risk of MASLD.

CONCLUSIONS

This cohort study revealed an association of the overall PDI and hPDI with a lower risk of MASLD, highlighting the importance of adhering to these types of plant-based diets to prevent MASLD among Korean adults.

Protein source associated with risk of metabolic syndrome in adults with low and adequate protein intake: A prospective cohort study of middle-aged and older adults

OBJECTIVES

Metabolic syndrome is associated with an increased risk of diabetes, cardiovascular disease, and all-cause mortality. Some evidence suggests that the cardiometabolic health benefits of protein intake may vary by the source (animal or plant); however, the evidence is inconsistent. This study aimed to assess the risk of developing metabolic syndrome according to the protein source.

PARTICIPANTS

Among a total of 3,310 participants aged 40 years or older in the Ansan and Ansung population based prospective cohort, 1,543 incident cases of metabolic syndrome were identified between 2007 and 2018.

MEASUREMENTS

Dietary intake was assessed using a validated food frequency questionnaire. Cox proportional hazards models were used to estimate the hazard ratios (HRs) and 95% confidence intervals (CIs) by quintile (Q), adjusting for demographics and health-related lifestyle factors.

RESULTS

Higher intake of animal protein (HRquintile5 (Q5) vs quintile1 (Q1) [95% CIs]: 0.76 [0.59-0.96], P-trend ≤ 0.0307) and a higher relative intake of animal protein (HRQ5 vs.Q1: 0.78 [0.64-0.95], P-trend ≤ 0.0017) were associated with a significantly decreased risk of developing metabolic syndrome. In subgroup analyses, associations between the risk of metabolic syndrome and the relative intake of animal and plant protein differed according to whether the total protein intake was within the recommended nutrient intake (RNI). Specifically, significant associations were observed only among those with a total protein consumption below the RNI (HRQ5vs Q1 [95% CIs]: 0.72 [0.56-0.93] for the relative intake of animal protein), but not among those consuming above the RNI. This association was more significant in women than in men.

CONCLUSION

A higher absolute and relative intake of animal protein were associated with a significantly decreased risk of metabolic syndrome, particularly among those who consumed less than the RNI of protein.

Genome-Wide Approach of Gene-Nutrient Intake Interaction Study for Essential Hypertension in a Large Korean Cohort (KoGES)

Background/Objectives: There is limited evidence on gene-nutrient interaction associated with hypertension (HTN). We examined interactions between genotypes and various nutrients that influenced high blood pressure (BP). Methods: Data were obtained from a total of 50,808 participants from the Korean Genome and Epidemiology Study (KoGES). Dietary intake was assessed by a food frequency questionnaire, and dietary reference intakes (DRIs) were set. We performed genome-wide association analyses (GWAS) and subsequent interaction analyses with genome-wide significant SNPs to identify genomic loci that interact with specific nutrients associated with HTN. Results: We identified one locus near the CUB and Sushi Multiple Domains 1 (CSMD1) gene that showed interaction with dietary iron and vitamin B6 (Vit.B6) intake and significantly influenced HTN risk. Among the individuals consuming iron above DRI (9.5 mg/day for men, 9.25 mg/day for women), carriers of the rs13282715 minor allele (A) at 8p23.2 showed a lower risk of HTN than those who did not (odds ratio [OR] 0.723, 95% confidence interval [CI] (0.644-0.813), p-value 4.858 × 10-8; interaction p-value 1.336 × 10-3). Among the individuals consuming Vit.B6 above DRI (1.5 mg/day for men, 1.4 mg/day for women), carriers of the same variant rs13282715 minor allele (A) also showed a lower risk of HTN (OR 0.733, 95% CI 0.733 (0.656-0.819), p-value 4.121 × 10-8; interaction p-value 7.183 × 10-4). Conclusions: We identified a novel gene-nutrient interaction regarding dietary iron and Vit.B6 intake affecting the risk of HTN in Korean adults. This suggests individuals with the variant may benefit from lower HTN risk from dietary intervention of iron and Vit.B6 intake. Further studies with larger diverse populations are warranted to validate our findings.

Adherence to the Cancer Prevention Recommendations from World Cancer Research Fund/American Institute for Cancer Research After Cancer Diagnosis on Mortality in South Korea

BACKGROUND/OBJECTIVES

The World Cancer Research Fund/American Institute for Cancer Research recommends following the recommendations for cancer prevention even after cancer diagnosis. To provide evidence on the potential benefits of adherence on improved survival, we investigated the effects of post-diagnostic adherence to the recommendations regarding diet, physical activity, and body weight on all-cause mortality among Korean cancer survivors.

METHODS

Among the total number of cancer survivors (n = 173,195) recruited from 2004 to 2013 for the Health Examinees study, 5485 were selected for the analyses and classified by tertiles according to the adherence score. The Cox proportional hazards model was used to estimate the adjusted hazard ratios (HR) and their 95% confidence intervals (CI) of the adherence groups on all-cause mortality.

RESULTS

Although no clear association was observed overall during a mean follow-up of 10.1 (standard deviation = 3.0) years, reduced mortality was observed for the middle (HR = 0.74 [95% CI = 0.51-1.08]) and highest adherent group (0.66 [0.43-0.99]) in comparison to the lowest adherent group among long-term survivors (>5 years after cancer diagnosis).

CONCLUSIONS

Among the cancer prevention recommendation items, "be physically active" and "limit consumption of fast foods" were inversely associated with mortality. Adhering to the WCRF/AICR cancer prevention recommendations may help improve the prognosis of long-term cancer survivors.

N-3 Fatty Acids in Seafood Influence the Association Between the Composite Dietary Antioxidant Index and Depression: A Community-Based Prospective Cohort Study

Accumulating evidence suggests that seafood and its components, such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), are associated with mental health. However, little is known regarding whether the status of n-3 polyunsaturated fatty acids (PUFAs) modify the effect of dietary antioxidants on depression. The main purpose of study is to investigate longitudinal associations between seafood consumption and depression among 2564 participants aged 40-69 years using data from the Korean Genome and Epidemiology Study. The composite dietary antioxidant index (CDAI) and dietary intake were measured by a validated 106-item food frequency questionnaire and depression was assessed using the Beck Depression Inventory (BDI). The Cox's proportional hazard model was used to examine the risk of depression according to seafood consumption. During an 8-year follow-up period, 165 (11.9%) men and 224 (18.9%) women experienced depression. After adjustment for confounders, the risk of depression was inversely associated with seafood consumption, with a 42% lower risk (HR T5 vs. T1 = 0.58, 95% CI: 0.35-0.98, p = 0.040) only being found among women. In a group with a high n-3 PUFA intake, CDAI scores were negatively correlated with BDI scores (r = -0.146, p < 0.001) among women. Seafood consumption might lead to more favorable outcomes against depression if accompanied by an increased intake of foods that are rich in antioxidants.

Diet-Wide Association Study for the Incidence of Type 2 Diabetes in Three Population-Based Cohorts

BACKGROUND

Dietary factors are well-known modifiable risk factors for type 2 diabetes (T2D), but many studies overlook the interrelationships between these factors, even though foods are often consumed together and contain a variety of nutrients.

OBJECTIVES

In this study, we employed a diet-wide association study approach to investigate the links between various dietary factors and T2D onset, taking into account complex dietary patterns.

METHODS

We analyzed 16,666 participants without T2D from three Korean population-based cohorts: the Multi-Rural Communities Cohort (n = 8302), the Atherosclerosis Risk of a Rural Area Korean General Population cohort (n = 4990), and the Kanghwa cohort (n = 3374). A two-step approach was employed. In the first step, robust Poisson regression analysis was used for the initial screening (false discovery rate-adjusted p-values < 0.05). In the second step, a hierarchical cluster analysis was conducted of all dietary factors, followed by mutual adjustment of the screened factors within each cluster to account for interrelationships.

RESULTS

The 11 food clusters screened were cooked rice with beans, rice cakes, breads/spreads, bread products, cheese and pizza/hamburger, grain powder, snack/confections, nuts and roasted beans, soy milk, traditional beverages, and non-native fruit. These factors were similarly distributed across three of the seven clusters in each cohort. After mutual adjustment, cooked rice with beans (p-value ≤ 2.00 × 10-7 in all three cohorts) and non-native fruits (p-value ≤ 5.91 × 10-3 in two cohorts) remained significantly associated with lower T2D risk in more than one cohort.

CONCLUSIONS

The inverse association of cooked rice with beans, not observed with other types of cooked rice, and that of non-native fruits, suggest that incorporating beans into rice and eating various fruits may be an effective strategy for preventing diabetes.

Serum bilirubin levels and risk of colorectal cancer in Korean adults: results from the Korean Genome and Epidemiology Study-Health Examinee (KoGES-HEXA) Cohort Study

BACKGROUND

Current evidence on associations between circulating bilirubin and colorectal cancer (CRC) risk is inconsistent.

METHODS

In this prospective study, we investigated associations of pre-diagnostic circulating levels of total and indirect bilirubin with CRC risk in 78,467 Korean adults aged 40-78 years at recruitment, considering potential non-linearity and sex differences. Hazard ratios (HR) and 95% confidence intervals (CI) for associations with CRC risk were estimated with Cox proportional hazard regression.

RESULTS

During a median 7.9-year follow-up, 539 incident CRC cases were recorded. In multivariable-adjusted models, higher levels of total bilirubin were associated with a 26% (CI: 42% to 7%) lower risk of CRC among men and women combined, comparing the highest with the lowest tertile (P-linear trend = 0.003). A U-shaped association was observed in men, with the lowest risk at approximately 0.8 mg/dL (=13.7 μmol/L) of total bilirubin (P for non-linearity = 0.01). Although the association was largely null in women, there was no evidence for effect modification by sex (P-interaction = 0.73). Associations between indirect bilirubin and CRC risk were similar.

CONCLUSIONS

Higher circulating levels of total and indirect bilirubin were inversely associated with the risk of CRC among Korean adults. The associations were strongly inverse and U-shaped among men.

A higher dietary alpha-linolenic acid intake is associated with lower colorectal cancer risk based on MUC4 rs2246901 variant among Korean adults

Alpha-linolenic acid (C18:3n-3 [ALA]) intake may have a beneficial effect in reducing cancer risk; however, its association with colorectal cancer (CRC) risk remains conflicted. Additionally, ALA was emphasized as being associated with mucins, an important glycoproteins family within the intestine. Thus, we hypothesized that a higher dietary ALA intake may reduce the risk of CRC and this preventive effect has an interaction with mucin 4 (MUC4) rs2246901. We conducted a case-control study at the National Cancer Center in Korea, involving 1039 cases and 1982 controls, aiming to determine the interaction of the MUC4 rs2246901 polymorphism and ALA intake in CRC risk. Dietary ALA intake was collected via semiquantitative food frequency questionnaire (SQFFQ), categorizing by 4 quartiles. We evaluated the odds ratios (ORs) and 95% confidence intervals (CIs) through unconditional logistic regression models. Higher dietary ALA intake was found to be inversely associated with CRC risk (adjusted OR = 0.58; 95% CI, 0.45-0.75, P for trend < .001). No significant association between MUC4 rs2246901 polymorphism and CRC risk was found. In a recessive model, MUC4 rs2246901 seemed to modify this association; participants with at least 1 major allele and higher ALA intake had a significantly lower CRC risk than those who had a lower intake (adjusted OR = 0.56; 95% CI, 0.43-0.72; P interaction = .047). A higher dietary ALA was proposed as a potential protective nutrient against CRC. Moreover, this association might be influenced by presence of the MUC4 rs2246901 polymorphism.

Sex-specific associations between dietary legume subtypes and type 2 diabetes in a prospective cohort study

OBJECTIVES

Dietary soy, known for its high phytoestrogen content, has been suggested to exhibit a sex-specific association with type 2 diabetes. However, evidence regarding the sex-specific associations of different legume subtypes with type 2 diabetes remains scarce. We aimed to evaluate whether habitual consumption of soy and non-soy legumes (beans and peanuts) was prospectively and sex-specifically associated with the risk of type 2 diabetes incidence, taking into considering significant sex-specific genetic factors beyond legume consumption.

METHODS

A total of 16,666 participants (96,945 person-years) were followed and 945 incident cases were observed. Cumulative intake of legume subtypes was calculated using a food frequency questionnaire administered at baseline and during the revisit surveys.

RESULTS

Non-soy legumes are inversely associated with type 2 diabetes in both men and women. Dietary soy intake, however, demonstrated a unilaterally interacting sex-specific association with type 2 diabetes risk (pinteraction for sex=0.017). Specifically, there was a significant inverse association with type 2 diabetes risk in women (incidence rate ratio, 0.66; 95% confidence interval, 0.48 to 0.80; ptrend=0.007), but no such association was observed in men. This sex-specific association persisted and even appeared antagonistic in minor allele carriers of 2 novel single nucleotide polymorphisms, rs10196939 (LRRTM4) and rs11750158 (near GFPT2) (pinteraction for sex=0.001 and 0.011, respectively).

CONCLUSIONS

Habitual consumption of legumes shows protective impacts against type 2 diabetes, although these benefits vary by sex. Non-soy legumes provide health advantages for both men and women, whereas soy consumption seems to be beneficial exclusively for women.

Gene-diet interactions in carbonated sugar-sweetened beverage consumption and metabolic syndrome risk: A machine learning analysis in a large hospital-based cohort

BACKGROUND AND AIM

Carbonated sugar-sweetened beverages (CSSB) intake has been increasingly linked to metabolic diseases. To investigate the association between CSSB intake and metabolic syndrome (MetS) risk, and the interaction between genetic predisposition to CSSB intake and dietary patterns.

METHODS

We examined a hospital-based cohort of 57,940 participants, categorized into low-CSSB (n = 52,848) and high-CSSB (n = 5092) groups based on a 50 ml daily consumption cutoff. A genome-wide association study (GWAS) identified single-nucleotide polymorphisms (SNPs) associated with CSSB intake, and SNP-SNP/SNP-environment interactions were explored. Using XGBoost and deep neural network (DNN) approaches, we developed prediction models for CSSB intake.

RESULTS

The low- and high-CSSB groups daily consumed an average of 0.56 and 8.91 g sugar from the soda, respectively. The high-CSSB group had unhealthy dietary habits and a lower intake of carotenoids, folate, vitamins C and D, calcium, flavonoids, and phenols than the low-CSSB group, consistent with the results of the prediction models. A polygenic risk score (PRS) based on 6 selected SNPs, linked to genes involved in obesity, diabetes, and nervous system disorders, showed the strongest association with CSSB intake and insulin resistance. Notably, carbohydrate, fat, and Western-style diet (WSD) intake interacted with the PRS, with lower carbohydrate and higher fat and WSD intakes associated with a stronger PRS-sugar intake relationship. The prediction models by XGboost and DNN mainly included dietary factors to explain CSSB intake.

CONCLUSIONS

A significant interplay between genetic predisposition and poor dietary habits, particularly increased CSSB intake associated with WSD, contributed to MetS risk. It suggested that personalized dietary interventions based on genetic profiles could mitigate MetS risk, especially in populations transitioning to Westernized diets.

A higher dietary inflammatory index score is associated with an increased risk of developing dyslipidemia and its components only in women

The dietary inflammatory index (DII) is a tool to evaluate the inflammatory potential of diets. Our research hypothesized that a higher DII score would be associated with an increased risk of dyslipidemia and that this outcome may differ by sex. Data from the Korean Genome and Epidemiology Study were used. The analysis included participants aged 40 to 69 years from the HEXA study (n = 40,500) and the Ansan-Ansung study (n = 4701). The mean follow-up was 5.03 years for the HEXA study and 8.14 years for the Ansan-Ansung study. The DII scores were calculated based on dietary data. Cox proportional hazards regression analysis was used to calculate hazard ratio (HR) and 95% confidence interval (CI). In pooled analyses, a high DII score was associated with a higher risk of dyslipidemia and its components. Sex-specific analyses revealed associations only in women. A pro-inflammatory diet, as indicated by a higher DII score, was associated with an increased risk of hypercholesterolemia, hyper-low-density lipoprotein cholesterolemia, hypertriglyceridemia, and dyslipidemia, with HR of 1.17 (95% CI: 1.06, 1.29), 1.16 (95% CI: 1.03, 1.29), 1.32 (95% CI: 1.12, 1.52), and 1.17 (95% CI: 1.08, 1.26), respectively. However, among men, there was no association between DII and dyslipidemia. These findings emphasize the inflammation feature of existing dietary patterns in influencing the development of dyslipidemia and related health issues. Further research will be needed to identify the mechanisms of how DII scores affect the risk of dyslipidemia.

A combination of red and processed meat intake and polygenic risk score influences the incidence of hyperuricemia in middle-aged Korean adults

BACKGROUND/OBJECTIVES

The high consumption of purine-rich meat is associated with hyperuricemia. However, there is limited evidence linking the consumption of red and processed meat to the genetic risk of hyperuricemia. We investigated the relationship between various combinations of red and processed meat consumption and the polygenic risk scores (PRSs) and the incidence of hyperuricemia in middle-aged Koreans.

SUBJECTS/METHODS

We analyzed the data from 44,053 participants aged ≥40 years sourced from the Health Examinees (HEXA) cohort of the Korean Genome and Epidemiology Study (KoGES). Information regarding red and processed meat intake was obtained using a semiquantitative food frequency questionnaire (SQ-FFQ). We identified 69 independent single-nucleotide polymorphisms (SNPs) at uric acid-related loci using genome-wide association studies (GWASs) and clumping analyses. The individual PRS, which is the weighted sum of the effect size of each allele at the SNP, was calculated. We used multivariable Cox proportional hazards models adjusted for covariates to determine the relationship between red and processed meat intake and the PRS in the incidence of hyperuricemia.

RESULTS

During an average follow-up period of 5 years, 2,556 patients with hyperuricemia were identified. For both men and women, the group with the highest red and processed meat intake and the highest PRS was positively associated with the development of hyperuricemia when compared with the group with the lowest red and processed meat intake and the lowest PRS (hazard ratio [HR], 2.72; 95% confidence interval [CI], 2.10-3.53; P < 0.0001; HR, 3.28; 95% CI, 2.45-4.40; P < 0.0001).

CONCLUSION

Individuals at a high genetic risk for uric acid levels should moderate their consumption of red and processed meat to prevent hyperuricemia.

Association between carbohydrate to protein or fat ratio and mortality: A prospective cohort study

BACKGROUND & AIMS

The effect of dietary macronutrient balance on longevity and metabolic health remains a subject of considerable interest. We aimed to investigate the association of carbohydrate-to-protein and carbohydrate-to-fat ratios with all-cause and cardiovascular mortalities.

METHODS

In this population-based study, data from the Korean Genome and Epidemiology Study were integrated with those from national data sources, including mortality records from the Korea National Statistical Office. The primary outcomes were all-cause and cardiovascular mortalities. Carbohydrate-to-protein and carbohydrate-to-fat ratios were evaluated based on dietary habits assessed through a food frequency questionnaire. Harrell's C-index was employed to determine optimal cut-off points for carbohydrate-to-protein and carbohydrate-to-fat ratios. Cox proportional hazards regression models were used to assess associations.

RESULTS

A total of 143,050 participants aged ≥40 years were included in the analyses. Compared with individuals with non-elevated carbohydrate-to-protein ratios (<5.2), those with elevated carbohydrate-to-protein ratios (>9.9) exhibited a higher all-cause mortality (hazard ratio 1.09, 95% confidence interval 1.01-1.17); however, no correlation between carbohydrate-to-protein ratio and cardiovascular mortality (hazard ratio 1.13, 95% confidence interval 0.96-1.32) was observed. Compared with those with non-elevated carbohydrate-to-fat ratios (<5.1), those with higher carbohydrate-to-fat ratios (>7.1) exhibited increased all-cause (hazard ratio 1.08, 95% confidence interval 1.00-1.16) and cardiovascular (hazard ratio 1.27, 95% confidence interval 1.06-1.52) mortalities.

CONCLUSIONS

Our findings regarding macronutrient ratios and their association with mortality suggest that reducing excessive carbohydrate intake and increasing the consumption of protein and fats may have beneficial effects on longevity and cardiovascular health. Further studies are needed to understand the underlying mechanisms of these effects.

Association between nut consumption and mortality risk: a 20-year cohort study in Korea with a stratified analysis by health-related variables

BACKGROUND

Although nuts are a well-known healthy food group, the relationship between nut consumption and mortality remains unclear, particularly among Asians. This prospective cohort study examined the association between nut consumption and the risk of all-cause, cardiovascular disease (CVD), and cancer mortality in Korean adults.

METHODS

Data from two cohorts (the Ansan-Ansung and Health-Examinees) from the Korean Genome and Epidemiology Study were used. A total of 114,140 individuals aged 40-79 years were included in the data analyses. Nut consumption was assessed using a validated semi-quantitative food frequency questionnaire and categorized into four groups: non-consumers, less than 1 serving/week, 1-2 servings/week, and 2 or more servings/week (one serving was 15 g of nuts). Mortality outcomes were determined based on the 2001-2021 death records from Statistics Korea. Cox proportional hazard regression analysis was used to calculate hazard ratios (HRs) and 95% confidence intervals (CIs) for mortality across nut consumption categories. A stratified subgroup analysis by health-related variables was also performed.

RESULTS

During a mean follow-up of 12.3 years, 4,559 deaths were recorded. After adjusting for covariates, the HR for all-cause mortality was 0.877 (95% CI = 0.772-0.996, p for trend = 0.006) in individuals with a nut consumption of 2 or more servings/week compared with that in non-consumers. Multivariable HRs for CVD mortality were 0.800 (95% CI = 0.681-0.939) in individuals consuming less than 1 serving/week, 0.656 (95% CI = 0.469-0.918) in those consuming 1-2 servings/week, and 1.009 (95% CI = 0.756-1.347) in those consuming 2 or more servings/week compared with that in non-consumers (p for trend = 0.080). No association was observed between nut consumption and cancer mortality. Stratified analysis identified significant interactions in the association between nut consumption and all-cause mortality by age, body mass index, and physical activity.

CONCLUSIONS

Nut consumption was linearly associated with the reduced risk of all-cause mortality and showed a non-linear dose-response relationship with CVD mortality in Koreans, but had no association with cancer mortality. The effects of nut consumption, which have been inadequately investigated in this population, varied across different subgroups. These findings suggest that incorporating nuts into the diet should be encouraged for long-term health of Korean adults.

High Polygenic Risk Scores Positively Associated with Gastric Cancer Risk Interact with Coffee and Polyphenol Intake and Smoking Status in Korean Adults

BACKGROUND/OBJECTIVES

This study investigated the relationship between single nucleotide polymorphisms (SNPs) and gastric cancer (GC) risk, while also examining the interaction of genetic factors with lifestyle variables including the nutrient and bioactive compound intake in Korean adults of a large hospital-based cohort.

METHODS

We conducted a genome-wide association study (GWAS) comparing GC patients (n = 312) with healthy controls without cancers (n = 47,994) to identify relevant genetic variants. Generalized multifactor dimensionality reduction (GMDR) was employed to detect SNP interactions between diets and lifestyles. We utilized polygenic risk scores (PRSs) to assess individuals' GC risk based on multiple SNP loci. Among the selected SNPs, since SEMA3C_rs1527482 was a missense mutation, bioactive compounds which decrease the binding energy were found with its wild and mutated proteins by molecular docking analysis.

RESULTS

Individuals with high PRSs exhibited a 4.12-fold increased risk of GC compared to those with low PRSs. Additional factors associated with elevated GC risk included a low white blood cell count (OR = 5.13), smoking (OR = 3.83), and low coffee consumption (OR = 6.30). The SEMA3C_rs1527482 variant showed a positive correlation with GC risk. Molecular docking analyses suggested that certain polyphenols, including theaflavate, rugosin E, vitisifuran B, and plantacyanin, reduced the binding free energy in both wild-type and mutated SEMA3C_rs1527482. However, some polyphenols exhibited differential binding energies between its wild and mutated forms, suggesting they might modulate wild and mutated proteins differently.

CONCLUSION

High PRSs and SEMA3C_rs1527482 interact with immune function, coffee intake, polyphenol consumption, and smoking status to influence GC risk. These findings could contribute to developing personalized nutrition and lifestyle interventions to reduce GC risk.

Influence of dietary cholesterol on metabolic syndrome risk in middle-aged Korean adults: using the Korean Genome and Epidemiology Study (KoGES)

BACKGROUND

The association between dietary cholesterol and metabolic diseases remains controversial. However, the majority of studies focus on egg intake, and there is a limitation in the availability of prospective cohort studies. Our study examined the association between dietary cholesterol and the incidence risk of metabolic syndrome (MetS) in middle aged adults using large prospective cohort study in Republic of Korea.

METHODS

The Health Examinees cohort from the Korean Genome and Epidemiology Study was used from baseline to follow-up. Dietary cholesterol intake was assessed by the validated semi-quantitative food frequency questionnaire. Participants were classified as quintile groups according to adjusted dietary cholesterol for total energy intake. MetS was defined as more than 3 of the 5 components of MetS. Hazard ratio (HR) and 95% confidence intervals (CI) for MetS were evaluated by multivariable cox regression analyses.

RESULTS

Of the total 40,578 participants, metabolic syndrome developed in 4,172 (10.28%) individuals during an average follow-up period of approximately 4.76 years. Dietary cholesterol did not exhibit a significant association with the risk of MetS after adjusting for potential confounding factors, but a trend was observed indicating an increased risk with higher intake (p for trend = 0.044). Among the components of MetS, the incidence risk of high waist circumference (HR: 1.164, 95% CI: 1.049-1.290), high blood pressure (HR: 1.188, 95% CI: 1.075-1.313), high serum triglyceride (HR: 1.132, 95% CI: 1.044-1.227) and high fasting blood glucose (HR: 1.217, 95% CI: 1.132-1.308) in the group that consumed the highest dietary cholesterol intake was increased compared with the group that consumed the lowest dietary cholesterol intake. Dose-response relationship suggested a positive linear association between dietary cholesterol intake and the risk of high waist circumference (p-linearity = 0.004), blood pressure (p-linearity = 0.012), and triglycerides (p-linearity = 0.005).

CONCLUSION

This study suggests a positive association between dietary cholesterol intake and the risk of MetS and its components (abdominal obesity, hypertension, hypertriglyceridemia, and hyperglycemia) in middle-aged Korean adults.

Fish and meat intake in relation to colorectal adenoma in asymptomatic Korean adults

Introduction

Colorectal adenomas are recognized as precursors to colorectal cancer through the adenoma-carcinoma sequence. Identifying modifiable dietary factors that may inhibit cancer progression is critical, but epidemiologic studies in Asian populations are scarce.

Methods

This study explored the impact of fish and meat intake on colorectal adenoma risk among Koreans. The study enrolled asymptomatic adults who visited Seoul National University Hospital Healthcare System Gangnam Center for health check-ups from May to December 2011. All participants underwent screening colonoscopy and completed a validated food frequency questionnaire. The study included 536 adenoma patients, 135 high-risk adenoma patients and 1,122 adenoma-free controls. Using multivariate logistic regression, we calculated odds ratios (ORs) and 95% confidence intervals (CIs) for fish and meat intake related to colorectal adenoma status, significant at p < 0.05.

Results

The intake of total fish, meat, red meat, chicken or processed meat showed no clear association with the prevalence of colorectal adenoma after adjusting for age, education, smoking status, alcohol intake, physical activity, body mass index, metabolic syndrome, colorectal cancer family history, total energy intake, and total fruit and vegetable intake. However, higher fish intake was associated with lower odds of high-risk colorectal adenoma, with a significant trend observed across quartiles (P for trend = 0.04). This trend was more pronounced among men than women (P for trend = 0.01).

Conclusion

In conclusion, we observed a significant inverse association between high fish intake and the prevalence of high-risk adenoma, but there were no clear associations between red and processed meat or chicken in the Korean population.

Association between traditional Korean fermented vegetables (kimchi) intake and serum lipid profile: using the Korean Genome and Epidemiology Study (KoGES) cohort

PURPOSE

Dyslipidemia is a major health issue worldwide. There is growing interest in understanding the potential role of kimchi consumption on serum lipid profiles. However, there are limited epidemiological studies available on this topic. Therefore, this study aims to investigate the association between kimchi intake and serum lipid profiles.

METHODS

We conducted an epidemiological study on participants (aged 40-69 years old) selected from the Health Examinees (HEXA) cohort study (n = 61,761). Four types of kimchi, including Baechu kimchi (cabbage kimchi), Kkakdugi (radish kimchi), Nabak kimchi/Dongchimi (a type of water kimchi made with fermented vegetables), and other kimchi, were assessed by a 106-food item semi-quantitative validated food frequency questionnaire (FFQ). Each kimchi intake is the average value calculated from the FFQ of the baseline and follow-up surveys. Fasting blood data were obtained at baseline and follow-up visits. Linear regression was used to examine the relationship between the intake of kimchi and the change in serum lipid profiles.

RESULTS

The mean years between the baseline survey and a follow-up survey was 4.97 years. In this study, compared to the lowest category (< 1 serving/day), Baechu kimchi intake (2- < 3 servings/day) had more negative correlations with the change in values of total cholesterol (β: -1.600, 95% confidence interval [CI, -2.744, -0.456]), triglycerides (β: -3.372, 95% CI [-5.414, -1.330]), and low-density lipoprotein cholesterol (β: -1.155, 95% CI [-2.214, -0.095]) in women. In men, Baechu kimchi intake (2- < 3 servings/day) had a more positive correlation associated with the changes in values of high-density lipoprotein cholesterol (β: 0.049, 95% CI [0.031, 0.907]) compared to the lowest intake category (< 1 serving/day).

CONCLUSIONS

Among Korean adults, consumption of kimchi, particularly Baechu kimchi, was found to be associated with improvements in serum lipid profiles. Further studies are required to conduct additional interventions to confirm the association between kimchi and serum lipid profiles.

Association between dairy-rich dietary pattern and metabolic dysfunction-associated steatotic liver disease: Findings from the Korean Genome and Epidemiology Study

BACKGROUNDS

Dietary components and the development of metabolic dysfunction-associated liver disease (MASLD) are closely linked, but large-scale studies on dietary patterns and MASLD are scarce, most previous studies having focused on individual nutrients or foods rather than overall dietary patterns. Therefore, we aimed to investigate the association between dietary patterns and MASLD in Koreans.

METHODS

A total of 6,052 participants from the Korean Genome and Epidemiology Study. Dietary intake was assessed using a validated Korean semiquantitative food frequency questionnaire comprising 106 food items. Principal component analysis was used to determine the major dietary patterns. Cox proportional hazard regression analysis was performed to assess the association between the incidence of MASLD and dietary patterns.

RESULTS

Four major dietary patterns, namely carnivore, plant-based, dairy-rich, and starch-rich diet patterns, were identified. The carnivore, plant-based, and starch-rich diet patterns showed no significant association with incident MASLD, while the dairy-rich diet pattern was associated with a lower risk of MASLD, also showing significantly lower cumulative incidence of MASLD in the higher adherence to dairy-rich diet pattern.

CONCLUSION

The dairy-rich diet pattern was significantly associated with a lower risk of MASLD in Koreans. Appropriate dietary guidance based on dietary patterns is crucial for preventing MASLD.

TAS2R38 bitterness receptor genetic variation is associated with diet quality in Koreans

Genetic variation in the bitter taste receptor gene taste receptor type 2, member 38 (TAS2R38) is associated with an individual's bitter taste sensitivity, food preference and consumption, which may also influence overall diet quality. This study aims to determine whether the TAS2R38 bitter taste receptor genetic variation is associated with overall diet quality using the Korean Healthy Eating Index (KHEI). A total of 41,839 individuals from the Korean Genome and Epidemiology Study were analyzed for their TAS2R38 diplotypes (rs713598, rs1726866, and rs10246939), general characteristics, and KHEI scores by obesity status. Results revealed that in the non-obese group, individuals with the AVI/AVI diplotype had a significantly higher score of 'ratio of white meat to red meat' than individuals with the PAV/* diplotype (3.89 ± 3.23 vs. 3.79 ± 3.18, adjusted p = 0.029). However, obese individuals with the PAV/* diplotype showed a significantly higher level of the mean score of 'moderation' (19.32 ± 5.82 vs. 18.92 ± 5.80, adjusted p = 0.026) and total KHEI score (61.07 ± 12.19 vs. 60.52 ± 12.29, adjusted p = 0.008) than those with the AVI/AVI diplotype. Finally, an interactive effect between bitterness genetic variation and obesity level was observed in those scores of 'ratio of white meat to red meat' (adjusted p = 0.007), 'moderation' (adjusted p = 0.013), and total KEHI (adjusted p = 0.007). In conclusion, TAS2R38 genetic variation is associated with overall diet quality in Koreans, which is more evident in the obese group.

Association between Processed Meat Protein Consumption and Incident Osteoporosis in Adults Aged 50 Years and Older: A Prospective Cohort Study Based on Korean Genome and Epidemiology Study Data (2005-2020)

BACKGROUND

Osteoporosis is one of the inevitable diseases affecting an aging society, substantially impacting the quality of life of its population. Protein intake has been shown to be beneficial in reducing the incidence of osteoporosis, and the effects of both animal and vegetable proteins have been studied. However, the relationship between processed meat consumption and osteoporosis has not been studied in Korea. Therefore, we aimed to analyze the correlation between processed meat consumption and incident osteoporosis in adults.

METHODS

Our analysis included 1,260 adults aged 50 years and older from the Korean Genome and Epidemiology Study (KoGES), recruited between 2005 and 2020. Participants were categorized into two groups according to their processed meat intake, assessed using a semi-quantitative 103-food item food frequency questionnaire. Diagnosis of osteoporosis was based on questionnaire answers. Multiple Cox hazard regression analyses were conducted to examine the association between processed meat intake and incident osteoporosis.

RESULTS

During an average follow-up period of 8.8 years, 230 participants developed osteoporosis. According to the Cox proportional regression models, the hazard ratio (95% confidence interval) of incident osteoporosis in the high intake group was 0.62 (0.41-0.94), compared to the low intake group after adjusting for confounding variables.

CONCLUSION

These findings reveal that processed meat protein intake is inversely related to the incidence of osteoporosis in adults aged 50 years and older. This in turn suggests that processed meat intake can be proposed as an additional strategy to prevent osteoporosis.

Association between dietary patterns and obesity: a longitudinal prospective cohort study

OBJECTIVES

The obesity prevalence in South Korea in 2021 stood at 38.4%. South Korea faces unique challenges in providing essential and emergency guidelines for weight management because of stepping into an aging society. We aimed to determine the daily diet patterns among the general Korean population and to investigate the association between such patterns and different obesity.

STUDY DESIGN

Longitudinal prospective cohort study.

METHODS

A total of 6539 adult participants (mean age 50.8 years, 52.9% male) with normal-weight adults were included from the Ansan-Ansung cohort of 10,030 Korean adults aged 40 or older and followed for an average of 11 years. Obesity was defined according to the criteria from the Korean Society for The Study of Obesity. Baseline dietary intake was assessed using a validated 103-item food frequency questionnaire. Dietary patterns were derived from k-means cluster analysis.

RESULTS

In the multivariate analysis, referring to white rice + baechu kimchi, participants from multigrain rice + baechu kimchi showed lower HR for obesity development (waist circumference defined-obesity; HR: 0.87, 95% CI: 0.79, 0.95; body fat percentage defined-obesity; HR: 0.89, 95% CI: 0.80, 0.98). Further analysis documented that except for body fat percentage defined-obesity, consuming milk or dairy products was linked to a reduced incidence of the other three obesity (body mass index defined-obesity; HR: 0.84, 95% CI: 0.72, 0.99; waist circumference defined-obesity; HR: 0.82, 95% CI: 0.71, 0.94; waist-to-hip ratio defined-obesity; HR: 0.75, 95% CI: 0.61, 0.91).

CONCLUSIONS

Following a diet that includes multigrain rice, fermented baechu kimchi, and dairy products is linked to a decreased risk of obesity in Korean adults. Public health programs and policies could incorporate these dietary recommendations, targeting specific population groups such as schoolchildren, adults, and the elderly. Additionally, further research is needed to explore the synergistic effects of various foods and their interactions within dietary patterns on obesity outcomes.

A higher consumption of green and white-colored vegetables and fruits is associated with lowered breast cancer risk among Korean women

Breast cancer (BrCa) remains a significant health concern globally, influenced by both nonmodifiable and modifiable risk factors. Limited studies have explored the role of color-specific vegetables and fruits, which are rich in specific phytonutrients, on BrCa risk. We hypothesized that consuming color-specific vegetables and fruits may decrease BrCa risk in Korean women. This case-control study examined the relationship between the intake of different-colored vegetables and fruits and the risk of BrCa, considering menopausal, hormone receptor status, tumor subtypes. We matched 395 patients and 395 controls by age and recruited from the National Cancer Center in Korea. Dietary data was collected via food frequency questionnaire, categorizing by colors: green, orange/yellow, red/purple, and white. Odds ratio (OR) and 95% confidence intervals (CIs) were calculated by logistic regression models, with subgroup analyses for menopausal, hormone receptor status, and tumor subtypes. Results shown BrCa patients consumed less vegetables and fruits than control group. Higher consumption of green, other orange/yellow, and white vegetables and fruits was negatively associated with BrCa risk [OR (95% CIs) of Q4 vs Q1 = 0.59 (0.36-0.94); 0.55 (0.33-0.89); and 0.60 (0.37-0.96), respectively]. Particularly, a greater intake of dark green leafy vegetables was significantly associated with reduced BrCa risk (OR of Q4 vs Q1 = 0.55, 95% CI = 0.34-0.89). Subgroup analysis consistently demonstrated inverse associations between higher intake of green-color vegetables and fruits and BrCa risk. Our findings suggest that a diet rich in green and white-color vegetables and fruits may lower BrCa risk among Korean women.

Serum 25-hydroxyvitamin D levels and risk of all-cause and cause-specific mortality: A 14-year prospective cohort study

BACKGROUND & AIMS

The circulating vitamin D level that is optimal for health is unknown. This study aimed to examine the association between circulating vitamin D level and risk of all-cause and cause-specific mortality.

METHODS

This prospective cohort study included 18,797 Korean adults aged 40 years or older, living in rural areas, with no history of cancer or cardiovascular disease (CVD) at baseline. Serum 25-hydroxyvitamin D (25(OH)D) levels were measured at baseline. Participants were followed-up from the survey date (2005-2012) until December 31, 2021. Cox proportional hazards regression was used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for mortality by baseline vitamin D level. Restricted cubic splines were used to explore the nonlinearity.

RESULTS

The median (interquartile range) of 25(OH)D level was 55.8 (40.8-71.8) nmol/L. During a median follow-up of 14.3 years, 2250 deaths were recorded. Compared with participants with a 25(OH)D level <30 nmol/L, higher vitamin D levels (30 to < 50, 50 to < 75, and ≥75 nmol/L) were associated with a lower risk of all-cause mortality: HR (95% CI) of 0.82 (0.69-0.98), 0.74 (0.62-0.88), and 0.69 (0.57-0.84), respectively. A nonlinear relationship between vitamin D level and all-cause mortality was observed, with the risk plateauing between 50 and 60 nmol/L (p for nonlinearity = 0.009). The association was more pronounced for cancer-related mortality. HR 0.55 (95% CI: 0.39-0.77) for a 25(OH)D level ≥75 nmol/L compared with <30.0 nmol/L. Low vitamin D levels were associated with increased CVD mortality in men.

CONCLUSIONS

Vitamin D level was inversely associated with all-cause and cause-specific mortality in middle-aged and older adults. Maintaining a serum 25(OH)D level of approximately 50-60 nmol/L may contribute to longevity and warrants further investigation.

Dietary Intake of Antioxidant Vitamins and Its Relation to the Progression of Chronic Kidney Disease in Adults With Preserved Renal Function

OBJECTIVE

It is expected that antioxidants contribute to slow the progression of chronic kidney disease (CKD). However, there are no data on the protective effect of dietary antioxidant vitamins on CKD. The purpose of study was to evaluate the renoprotective effect of dietary antioxidant vitamins in the general population.

DESIGN AND METHODS

The study participants were 127,081 Korean adults with preserved renal function with estimated glomerular filtration rate ≥60 mL/min/1.73 m2. They were categorized into 3 groups by tertile levels of dietary antioxidant vitamins intake including vitamins C, E, and A. Cox proportional hazard assumption was used to calculate multivariable hazard ratios and 95% confidence interval for the incident moderate to severe CKD (adjusted hazard ratio [95% confidence interval]) according to tertile levels of dietary intake of antioxidant vitamins. Subgroup analysis was conducted to evaluate the risk of progression from normal to mildly decreased renal function, and from mildly decreased renal function to moderate to severe CKD.

RESULTS

The risk of moderate to severe CKD was not significantly associated with the third tertile of dietary antioxidant vitamin intake including vitamin C (1.02 [0.78-1.34]), E (0.96 [0.73-1.27]), and A (0.98 [0.74-1.29]). Additionally, any tertile groups didn't show the significant association with the risk of moderate to severe CKD. Subgroup analysis also didn't show the decreased risk of progression from normal to mildly decreased renal function, and from mildly decreased renal function to moderate to severe CKD in any tertile groups.

CONCLUSION

Dietary intake of vitamins C, E, and A was not significantly associated with the risk of CKD progression.

Multipartite network analysis to identify environmental and genetic associations of metabolic syndrome in the Korean population

Network analysis has become a crucial tool in genetic research, enabling the exploration of associations between genes and diseases. Its utility extends beyond genetics to include the assessment of environmental factors. Unipartite network analysis is commonly used in genomics to visualize initial insights and relationships among variables. Syndromic diseases, such as metabolic syndrome, are characterized by the simultaneous occurrence of various signs, symptoms, and clinicopathological features. Metabolic syndrome encompasses hypertension, diabetes, obesity, and dyslipidemia, and both genetic and environmental factors contribute to its development. Given that relevant data often consist of distinct sets of variables, a more intuitive visualization method is needed. This study applied multipartite network analysis as an effective method to understand the associations among genetic, environmental, and disease components in syndromic diseases. We considered three distinct variable sets: genetic factors, environmental factors, and disease components. The process involved projecting a tripartite network onto a two-mode bipartite network and then simplifying it into a one-mode network. This approach facilitated the visualization of relationships among factors across different sets and within individual sets. To transition from multipartite to unipartite networks, we suggest both sequential and concurrent projection methods. Data from the Korean Association Resource (KARE) project were utilized, including 352,228 SNPs from 8840 individuals, alongside information on environmental factors such as lifestyle, dietary, and socioeconomic factors. The single-SNP analysis step filtered SNPs, supplemented by reference SNPs reported in a genome-wide association study catalog. The resulting network patterns differed significantly by sex: demographic factors and fat intake were crucial for women, while alcohol consumption was central for men. Indirect relationships were identified through projected bipartite networks, revealing that SNPs such as rs4244457, rs2156552, and rs10899345 had lifestyle interactions on metabolic components. Our approach offers several advantages: it simplifies the visualization of complex relationships among different datasets, identifies environmental interactions, and provides insights into SNP clusters sharing common environmental factors and metabolic components. This framework provides a comprehensive approach to elucidate the mechanisms underlying complex diseases like metabolic syndrome.

Identification of interactions between genetic risk scores and dietary patterns for personalized prevention of kidney dysfunction in a population-based cohort

BACKGROUND & AIM

Chronic kidney disease (CKD) is a heterogeneous disorder that affects the kidney structure and function. This study investigated the effect of the interaction between genetic factors and dietary pattern on kidney dysfunction in Korean adults.

METHODS

Baseline data were obtained from the Ansan and Ansung Study of the Korean Genome and Epidemiology Study involving 8230 participants aged 40-69 years. Kidney dysfunction was defined as an estimated glomerular filtration rate < 90 mL/minute/1.73 m2. Genomic DNAs genotyped on the Affymetrix® Genome-Wide Human SNP array 5.0 were isolated from peripheral blood. A genome-wide association study using a generalized linear model was performed on 1,590,162 single-nucleotide polymorphisms (SNPs). To select significant SNPs, the threshold criterion was set at P-value < 5 × 10-8. Linkage disequilibrium clumping was performed based on the R2 value, and 94 SNPs had a significant effect. Participants were divided into two groups based on their generic risk score (GRS): the low-GR group had GRS > 0, while the high-GR group had GRS ≤ 0.

RESULTS

Three distinct dietary patterns were extracted, namely, the "prudent pattern," "flour-based and animal food pattern," and "white rice pattern," to analyze the effect of dietary pattern on kidney function. In the "flour-based and animal food pattern," higher pattern scores were associated with a higher prevalence of kidney dysfunction in both the low and high GR groups (P for trend < 0.0001 in the low-, high-GR groups of model 1; 0.0050 and 0.0065 in the low-, high-GR groups of model 2, respectively).

CONCLUSIONS

The results highlight a significant association between the 'flour-based and animal food pattern' and higher kidney dysfunction prevalence in individuals with both low and high GR. These findings suggest that personalized nutritional interventions based on GR profiles may become the basis for presenting GR-based individual dietary patterns for kidney dysfunction.

Association between dietary carotenoid intake and breast cancer risk: a case-control study among Korean women

The association between dietary carotenoids and breast cancer (BC) risks were inconsistent. Therefore, this study investigated the association between dietary carotenoid and BC risks among Korean women. We recruited participants from the National Cancer Centre of Korea. Odds ratios and 95% confidence intervals were calculated with a logistic regression model. There was an inverse association between dietary carotenoid subclasses and BC risks; in particular, a higher intake of β-carotene and lutein/zeaxanthin was associated with reduced BC risks. After subgroup analysis with estrogen receptor (ER)/progesterone receptor (PR) status, there was similar trend among ER-/PR- women. We further investigated which foods contribute to the carotenoid intake. A higher intake of radish leaves, kale, and bracken was associated with lowered BC risks. Accordingly, dietary carotenoid, particularly β-carotene and lutein/zeaxanthin, appears to be associated with a lower risk of BC among Korean women.