Effects of RAD50 SNP, sodium intake, and H. pylori infection on gastric cancer survival in Korea.

BACKGROUND: Double-strand break repair protein (RAD50) gene plays important roles in genomic integrity, DNA double-strand break repair, cell cycle checkpoint activation, telomere maintenance, and meiotic recombination. The risk allele of RAD50 may negatively affect cancer by reducing the DNA repair capacity. Additionally, Sodium intake and Helicobacter pylori (H. pylori) infection are major risk factors for gastric cancer (GC). Our study investigated the association between polymorphisms in RAD50 gene and the risk of GC case-fatality. We evaluated whether the association differed with sodium intake or H. pylori infection. METHODS: We enrolled 490 patients from two hospitals between 2002 and 2006. Their survival or death was prospectively followed up until December 31, 2016, through a review of medical records and telephone surveys. The GC survival was assessed using the Cox proportional hazards regression analysis. RESULTS: In 319 GC cases, the total person-years were 1928.3, and the median survival years was 5.4 years. A total of 137 GC deaths were recorded. Our fully adjusted model showed that the GG type of RAD50 rs17772583 polymorphism is significantly associated with an increased risk of GC case-fatality (hazard ratio [HR] = 2.20, 95% confidence interval [CI] = 1.28-3.77) compared to that associated with the homozygous AA type. In the high sodium intake group, patients with the GG type of RAD50 rs17772583 showed a significantly higher GC case-fatality (HR = 8.61, 95% CI = 2.58-26.68) than that of patients with homozygous AA type. In the positive-H. pylori infection group, patients with GG-type RAD50 rs17772583 showed a significantly higher GC case-fatality (HR = 10.11, 95% CI = 2.81-36.35) than that of with AA homozygotes. CONCLUSIONS: Patients with GG-type RAD50 rs17772583, high sodium intake, or a positive-H. pylori infection are at a significantly increased risk of GC case-fatality compared to that associated with the absence of these risk factors.

Glycemic Index, Glycemic Load, and FAS rs6586161 Polymorphism in Relation to Gastric Cancer Risk: A Case-Control Study in Korea.

Many dietary and genetic factors have been confirmed to be associated with gastric cancer risk. This research investigated gastric cancer risk with regard to the glycemic index, glycemic load, and FAS rs6586161 polymorphism. A total of 232 matched pairs were included in this case-control study. Data collection was conducted at two hospitals in Korea from 2002 to 2006. Dietary information was obtained from a food frequency questionnaire, and genotypes of FAS rs6586161 polymorphism were TT, TA, and AA type. Gastric cancer risk was increased for the highest tertile of glycemic index (vs. lowest tertile, OR = 1.84, 95% CI = 1.07-3.18), the highest tertile of glycemic load (vs. lowest tertile, OR = 2.14, 95% CI = 1.23-3.75), and the AA type of FAS rs6586161 polymorphism (vs. TT types, OR = 1.95, 95% CI = 1.13-3.39). Furthermore, gastric cancer risk was significantly elevated for the participants with the highest glycemic load and AA type of FAS rs6586161 polymorphism (vs. the lowest glycemic load and TT type, OR = 5.53, 95% CI = 2.01-15.21). Both the high glycemic load and AA type of FAS rs6586161 polymorphism increased gastric cancer risk; however, the interactions between these two elevated the risk of gastric cancer even more.

Alleviating air pollutant-associated hypertension by potassium intake in Korean adults: a cross-sectional study from the 2012-2016 Korea National Health and Nutrition Examination Survey.

Air pollution may increase the risk of hypertension (HTN) by increasing oxidative stress and inflammation, and reducing sodium excretion. Potassium intake may reduce the risk of HTN through sodium excretion and reduce inflammation and oxidative stress. This study is aimed at investigating the association between air pollutants and HTN and whether these associations differ based on the potassium intake data of Korean adults from the 2012-2016 Korean National Health and Nutrition Examination Survey (KNHANES). This cross-sectional study used data from KNHANES (2012-2016) combined with annual air pollutant data from the Ministry of Environment using administrative units. We included 15,373 adults who responded to the semi-food frequency questionnaire. Associations between ambient PM10, SO2, NO2, CO, and O3 with HTN according to potassium intake were assessed using the survey logistic regression model for complex samples analysis. After adjusting for potential covariates such as, age, sex, education level, smoking status, family income, alcohol consumption, body mass index (BMI), exercise status, and survey year, as the air pollutant score considering the five air pollutants increased (severe air pollution), the prevalence of HTN increased in a dose-dependent manner (p for trend < 0.001). Meanwhile, in the adults with higher potassium intake and who were exposed to lowest levels of air pollutants score (score = 0), the ORs of HTN were significantly lower (OR = 0.56, 95% CI: 0.32-0.97). In conclusion, our study suggests that exposure to air pollutants may increase the prevalence of HTN among Korean adults. However, high potassium intake may help prevent HTN caused by air pollutants.

Association between soy products, fruits, vegetables, and dairy products and gastric cancer risk in Helicobacter pylori-infected subjects: a case-control study in Korea.

BACKGROUND/OBJECTIVES: Consumption of certain protective foods may help inhibit Helicobacter pylori (H. pylori) associated gastric pathologies. However, studies conducted to assess the efficacy of protective foods in H. pylori-infected subjects are either limited or inconsistent. This study evaluated the association of individual or a combination of protective foods on the incidence of gastric cancer (GC) in H. pylori-positive subjects through a case-control study. MATERIALS/METHODS: Subjects aged 20-79 years were selected from 2 hospitals between December 2002 and September 2006. In total, 134 patients and 212 controls tested positive for H. pylori infection. Among these, we included 82 pairs of cases and controls matched by sex, age (± 5 years), enrollment period (± 1 years), and hospital. RESULTS: A higher intake of soy products was associated with a significantly lower risk of GC than a lower intake of soy products (odds ratio [OR] = 0.37, 95% confidence interval [CI] = 0.14-0.96). Additionally, a higher fruit intake resulted in a significantly lower risk of GC than a lower fruit intake (OR = 0.35, 95% CI = 0.13-0.94). A combination of food groups was evaluated, and a lower risk of GC was observed with a high intake of both soy products and fruits (OR = 0.20, 95% CI = 0.06-0.67), high intake of soy and dairy products (OR = 0.28, 95% CI = 0.10-0.78) and high intake of fruits and dairy products (OR = 0.28, 95% CI = 0.09-0.83). CONCLUSIONS: A high intake of soy products or fruits was associated with a lower risk of GC. A combination of soy products or fruits with dairy products was associated with a lower risk of GC. A balanced intake of soy products, fruits, and dairy products may help reduce GC risk.

The Association between Air Pollutants Exposure with Pre- and Hypertension by Vitamin C Intakes in Korean Adults: A Cross-Sectional Study from the 2013-2016 Korea National Health and Nutrition Examination.

OBJECTIVES: Oxidative stress and systemic inflammation are the main pathways by which air pollutants cause hypertension (HTN). Vitamin C intake may reduce the risk of HTN caused by air pollutants. This study aimed to investigate the association between air pollutants and pre-HTN and HTN in Korean adults and whether these associations were modified by vitamin C intake, using data from the 2013-2016 Korean National Health and Nutrition Examination Survey (KNHANES). DESIGN: Cross-sectional study. SETTING: This study used data from the KNHANES VI (2013-2015) and VII (2016) along with the data from the annual air pollution report of the Ministry of Environment. PARTICIPANTS: We included 11,866 adults who had responded to a semi-food frequency questionnaire. MEASUREMENTS: We used survey logistic regression models to evaluate the association of ambient PM10, SO2, NO2, CO, and O3 with pre-HTN and HTN according to vitamin C intake. RESULTS: After adjusting for potential covariates, exposure to ambient PM10, SO2, NO2, and CO was significantly associated with a high prevalence of pre-HTN and HTN, whereas exposure to O3 was significantly associated with a low prevalence of pre-HTN and HTN. In particular, as the air pollutant scores increased (severe air pollution), the prevalence of pre-HTN and HTN increased in a dose-dependent manner (highest score vs. lowest score, OR=1.85, 95% CI=1.39-2.46, p for trend <.0001). However, these associations were found to be pronounced in adults with low vitamin C intake (highest score vs. lowest score, OR=2.30, 95% CI=1.50-3.54, p for trend <.0001), whereas the statistical significance disappeared for adults with high vitamin C intake (highest score vs. lowest score, OR=1.40, 95% CI=0.93-2.12, p for trend=0.007). CONCLUSION: Exposure to air pollutants such as PM10, SO2, NO2, and CO may increase the prevalence of pre-HTN and HTN among Korean adults. In addition, a high intake of vitamin C may help prevent pre-HTN and HTN caused by air pollutants.

Association of Dietary Antioxidant Vitamin Intake and Gastric Cancer Risk According to Smoking Status and Histological Subtypes of Gastric Cancer: A Case-Control Study in Korea.

Smoking is a risk factor for gastric cancer (GC) and causes oxidative stress. Antioxidant vitamins may protect against oxidative stress. This study aimed to determine the association between dietary antioxidant vitamin intake and GC risk according to smoking status and the histological subtype. This case-control study included 286 pairs of patients with GC and controls aged 20-79 years enrolled at two hospitals from 2002 to 2006, matched by age (± 2 years), sex, hospital, and participation period (± 1 years). Dietary information was collected using a quantitative food frequency questionnaire (FFQ). When stratified by smoking status, increased intake of vitamin C (OR = 0.38; 95% CI = 0.17-0.84 for highest vs. lowest; P for trend = 0.033) and folate (OR = 0.28; 95% CI = 0.12-0.64 for highest vs. lowest; P for trend = 0.003) decreased GC risk in nonsmokers. Vitamin C (P for interaction = 0.043) and folate (P for interaction =0.015) levels were significantly associated with smoking status. Similar results were observed in nonsmokers with diffuse and mixed types of GC, but not in those with intestinal type of GC. Therefore, we found an inverse association between higher intake of dietary vitamin C and folate with the risk of GC among nonsmokers. These protective associations were strong in nonsmokers with diffuse and mixed types of GC.

Sex-dependent associations between MAP3K1 gene polymorphisms and soy products with the gastric cancer risk in Korea: a case-control study.

BACKGROUND/OBJECTIVES: The hormone-dependent effect of MAP3K1 gene polymorphisms may explain sex-specific differences in gastric cancer (GC) risk. Phytoestrogens have been shown to interact with this genetic factor. Here, we investigated the association between MAP3K1 gene polymorphisms and GC risk by sex and whether these associations differ depending on soy products intake. METHODS: Participants aged 20-79 years were recruited from two hospitals between December 2002 and September 2006. In all, 440 cases and 485 controls were recruited, among, 246 pairs of cases and controls, matched by sex, age (± 5 years), study admission period (± 1 years), and hospital, were included for the analysis. RESULTS: In dominant model, men with the A allele of rs252902 showed significantly increased GC risk (odd ratio; OR=2.19, 95% confidence interval; CI=1.31-3.64) compared to GG homozygotes. When stratified by intake of soy products, men with the A allele of rs252902 and low intake of soy products showed significantly higher GC risk (OR=3.29, 95% CI=1.55-6.78) than that in GG homozygotes. CONCLUSIONS: Men with the risk allele of MAP3K1 had a significantly increased GC risk compared to GG homozygotes; this trend was more pronounced in those with low intake of soy products.

Dietary zinc intake and mortality in patients with intestinal-type gastric cancer: A prospective cohort study in Korea.

Purpose: Current evidence regarding the association between zinc intake and gastric cancer (GC)-specific survival in patients with intestinal-type GC is lacking. Therefore, this cohort study investigated the association between zinc intake and GC mortality through follow-up on GC death among patients with intestinal-type GC and whether these effects differ according to the source of zinc intake. Methods: A total of 185 patients with intestinal-type GC were enrolled from two hospitals between 2002 and 2006. Their survival or death was prospectively followed up until December 31, 2016, through a review of medical records and telephone surveys. Results: A total of 178 patients were included and analyzed. The median follow-up period was 7.3 years. In the fully adjusted models, the highest tertile of total zinc intake showed a significantly lower GC mortality than the lowest tertile (hazard ratio, 0.22; 95% confidence interval: 0.08-0.64). In addition, the tertile of total zinc intake showed a dose-response association with GC mortality (p=0.015). Analysis of the source of zinc intake revealed that when zinc intake from staples (rice and noodles), animal, and plant food sources were combined, the results were similar to those of total zinc intake and GC mortality. Conclusion: Zinc intake through various foods may be effective in reducing GC mortality by achieving balance with other nutrients. Our results suggest that zinc improves the survival of patients with intestinal-type GC in Korea.

A high glycemic index and glycemic load increased the risk of gastric cancer: A case-control study in Korea.

Diet is a critical risk factor for gastric cancer, and Koreans consume significantly high amounts of carbohydrates. This study examined the association between carbohydrate intake, glycemic index, and glycemic load and the risk of gastric cancer and whether the association varied based on the general risk factors for gastric cancer. We hypothesized that carbohydrate intake, glycemic index, and glycemic load elevated gastric cancer risk and the relationship differed by the gastric cancer risk factors. This was a case-control study with a total of 307 matched pairs aged 20 to 79 years. Data collection was completed at two hospitals from December 2002 to September 2006. A food frequency questionnaire was applied for dietary assessment. Carbohydrate intake was not related to gastric cancer risk. However, a high glycemic index (odds ratio [OR], 1.88; 95% confidence interval (95% CI), 1.18-2.97) and glycemic load (OR, 2.51; 95% CI, 1.53-4.12) were significantly associated with the elevated risk of gastric cancer. When the relationship between glycemic load and gastric cancer risk was stratified by risk factors for gastric cancer, the gastric cancer risk especially increased among men, ≥65 years, smokers, drinkers, and people with Helicobacter pylori infection. Although there was no association between carbohydrate consumption and gastric cancer, high glycemic index and glycemic load were associated with the increased gastric cancer risk.

Gastric Cancer Risk Was Associated with Dietary Factors Irritating the Stomach Wall: A Case-Control Study in Korea.

The incidence of gastric cancer is high in Korea, and dietary factors are important risk factors for gastric cancer. This study examined whether gastric cancer risk was related to dietary factors that directly irritate the stomach wall. This case−control study consisted of 308 matched pairs of gastric cancer cases and controls recruited from 2002 to 2006 at two hospitals in Korea. Dietary assessments were completed using a food frequency questionnaire and a dietary habit questionnaire. Gastric cancer risk was increased for high meal frequency of >3 vs. low meal frequency of ≤3 times per day, overeating vs. not overeating, and preferred vs. not preferred spicy or salty foods. Furthermore, participants with dietary factors of high meal frequency, overeating, and preference for spicy or salty foods elevated the risk of gastric cancer compared to those with low meal frequency, not overeating, and not preferring spicy or salty foods, simultaneously. In conclusion, gastric cancer risk was significantly increased in people with dietary factors that irritate the stomach wall, such as high meal frequency, overeating, and preference for spicy or salty foods.

Dietary Reference Intakes of sodium for Koreans: focusing on a new DRI component for chronic disease risk reduction.

Sodium is a physiologically essential nutrient, but excessive intake is linked to the increased risk of various chronic diseases, particularly cardiovascular. It is, therefore, necessary to accomplish an evidence-based approach and establish the Korean Dietary Reference Intakes (KDRIs) index, to identify both the nutritional adequacy and health effects of sodium. This review presents the rationale for and the process of revising the KDRIs for sodium and, more importantly, establishing the sodium Chronic Disease Risk Reduction Intake (CDRR) level, which is a new specific set of values for chronic disease risk reduction. To establish the 2020 KDRIs for dietary sodium, the committee conducted a systematic literature review of the intake-response relationships between the selected indicators for sodium levels and human chronic diseases. In this review, 43 studies published from January 2014 to December 2018, using databases of PubMed and Web of Science, were finally included for evaluating the risk of bias and strength of evidence (SoE). We determined that SoE of the relationship between dietary sodium and cardiovascular diseases, cerebrovascular disease, and hypertension, was moderate to strong. However, due to insufficient scientific evidence, we were unable to establish the estimated average requirement and the recommended nutrient intake for dietary sodium. Therefore, the adequate intake of sodium for adults was established to be 1,500 mg/day, whereas the CDRR for dietary sodium was established at 2,300 mg/day for adults. Intake goal for dietary sodium established in the 2015 KDRIs instead of the tolerable upper intake level was not presented in the 2020 KDRIs. For the next revision of the KDRIs, there is a requirement to pursue further studies on nutritional adequacy and toxicity of dietary sodium, and their associations with chronic disease endpoint in the Korean population.

The Associations of Dietary Intake of High Sodium and Low Zinc with Gastric Cancer Mortality: A Prospective Cohort Study in Korea.

Sodium and zinc display opposite effects on immune cells, such as regulatory T cells (Tregs) and T helper 17 cells (Th17), resulting in an altered immune response. Immune cells have a pivotal role in regulating tumor progression, which may affect gastric cancer (GC) mortality. Thus, this cohort study investigated the associations between the combination of sodium and zinc intake and GC mortality and whether these associations differ by histological type by following up deaths of GC cases in Korea. A total of 490 patients with GC were enrolled between 2002 and 2006. Survival or death was prospectively followed up until December 31, 2016. Finally, 300 patients with the two main histological types of GC were included; 99 GC deaths occurred during a median follow-up period of 7.1 years. Patients with high sodium and low zinc intake had a significantly higher GC mortality than those with low sodium and high zinc intake (hazard ratio [HR], 2.07; 95% confidence interval [CI], 1.09-3.93). However, no significant association was found between the histological types of GC. In conclusion, we found that high sodium and low zinc intake may worsen the survival rate of patients with GC.

Erratum: Dietary Intake of Soy Products, Vegetables, and Dairy Products and Gastric Cancer Survival according to Histological Subtype: a Long-term Prospective Cohort Study.

[This corrects the article on p. 403 in vol. 21, PMID: 35079442.].

Alcohol consumption according to socioeconomic and hypertensive status among Korean adults.

This research investigated variations in alcohol consumption by socioeconomic factors and hypertensive status in South Korean adults, aged ≥19 years. This is a secondary data analysis using the Korea National Health and Nutrition Examination Survey (KNHANES). Alcohol intake by socioeconomic and hypertensive status was examined using data from the 2013 to 2016 KNHANES. Total participants were 19,641 adults, with 8,123 men and 11,518 women. Consumption of alcohol in the Korean population was estimated from a single 24-hour dietary recall. Alcohol intake differed, according to socioeconomic status, and, particularly, by occupation among Korean adults. Women with lower education consumed more alcohol daily than those with a higher education (p = 0.018). Furthermore, adult men with hypertension consumed a greater amount of alcohol daily, 30.9 g, than those with pre-hypertension, 23.7 g, followed by those without hypertension, 15.9 g (p < 0.001). In women, adults with pre-hypertension and hypertension consumed more alcohol daily, 9.4 g and 9.0 g, respectively, than those without, 6.6 g (p < 0.001). In addition, men with hypertension who were unaware of their disease and those who were cognizant consumed a higher amount of alcohol daily, 32.4 g and 28.6 g, respectively, than individuals without hypertension, 19.7 g (p < 0.001). Moreover, men with hypertension who had not been treated for hypertension and those in treatment consumed a greater amount of alcohol daily, 32.6 g and 28.0 g, respectively, than those without hypertension, 19.7 g (p < 0.001). In conclusion, Korean adults consume alcohol differently by socioeconomic status, and alcohol intake was more prevalent among people with hypertension.

Gastric Cancer and the Daily Intake of the Major Dish Groups Contributing to Sodium Intake: A Case-Control Study in Korea.

Studies on the association between gastric cancer (GC) and the intake of soup-based dish groups (noodles and dumplings, soups, and stews), which are sodium-contributing foods, in Korea are insufficient, and the results of studies on the intake of pickled vegetables such as kimchi are inconsistent. This study aimed to determine the association between the incidence of GC and the daily intake of high-sodium dish groups (noodles and dumplings, soups, stews, and pickled vegetables) and whether these associations differ depending on behavioral risk factors for GC. In this case-control study, subjects aged 20-79 years were recruited from two hospitals between December 2002 and September 2006. A total of 440 cases and 485 controls were recruited, of which 307 pairs were matched and included for the analysis. In our results, a higher intake of noodles and dumplings was associated with a significantly increased incidence of GC. In the participants who consumed past or current alcohol, a higher intake of noodles and dumplings was associated with a significantly increased incidence of GC. Our results suggest that efforts to reduce the daily sodium intake from noodles and dumplings are needed to prevent and reduce the incidence of GC.

Trends in Alcohol Consumption for Korean Adults from 1998 to 2018: Korea National Health and Nutritional Examination Survey.

Drinking culture has been well developed in Korea. This research assessed trends in daily pure alcohol consumption over time and examined its trends regarding socio-demographic variables and alcoholic beverage types. We used data from the 1998-2018 Korea National Health and Nutrition Examination Survey. A total of 87,623 adults aged ≥ 19 years were included. Alcohol intake was assessed via 24-h dietary recall, and pure alcohol content was calculated according to alcoholic beverage type. Daily alcohol consumption increased from 8.37 g in 1998 to 14.98 g in 2016-2018 (p for trend < 0.001). The degree of the increasing trend was higher for women (2.09 g to 5.79 g) than men (14.78 g to 23.94 g) from 1998 to 2016-2018. Alcohol intake was highest in men aged 30-49 years and women aged 19-29 years. Moreover, the change of the rising trend in alcohol consumption according to high socioeconomic factors was more pronounced than the other variables. Lastly, the alcohol intake from soju and beer was dominant in alcohol consumption and escalated over time. The total daily alcohol intake increased about two times during 21 years in Korea, and the trends varied according to socio-demographic status.

Dietary Intake of Soy Products, Vegetables, and Dairy Products and Gastric Cancer Survival according to Histological Subtype: a Long-term Prospective Cohort Study.

PURPOSE: Owing to differences in the general characteristics of gastric cancer (GC) according to histological type, the association of GC risk factors, such as diet, may also differ depending on the histological type. We investigated the associations between individual and combined intake of soy products, vegetables, and dairy products and GC mortality by following up cases of death among Korean GC cases and whether these associations differ according to the histological type. MATERIALS AND METHODS: A total of 508 GC cases were enrolled from two hospitals between 2002 and 2006. Their survival or death was prospectively followed up until December 31, 2016, through a review of medical records and telephonic surveys. Finally, 300 GC cases classified as intestinal- or diffuse-type GC cases were included. The median follow-up period was 7.1 years. RESULTS: In the fully adjusted model, a high intake of soy products (hazard ratio [HR], 0.43; 95% confidence interval [CI], 0.19-0.96) and the combination of soy products and vegetables (HR, 0.34; 95% CI, 0.12-0.96) or soy products and dairy products (HR, 0.37; 95% CI, 0.14-0.98) decreased the mortality from intestinal-type GC. In particular, patients consuming various potentially protective foods (HR, 0.23; 95% CI, 0.06-0.83) showed a highly significant association with a lower mortality from intestinal-type GC. However, no significant association was found with diffuse-type GC. CONCLUSIONS: High intake of potentially protective foods, including soy products, vegetables, and dairy products, may help increase survival in intestinal-type GC.

Twenty-year trends in vegetable consumption by preparation method and eating location for Korean population from 1998 to 2017.

Vegetables are an important source for the essential vitamins and minerals that are necessary for optimal health. This research investigated changes in vegetable intake over time in the Korean population from 1998 to 2017, focusing on preparation methods of vegetables and location of consumption. This cross-sectional study is based on the Korea National Health and Nutrition Examination Survey (KNHANES) that was established in 1998 to assess the health and nutritional status of the South Korean population. This research utilised information from 1998 to 2017 which is the extent of all available KNHANES data. Vegetable consumption was grouped, according to preparation methods and common eating locations. Both crude and age-standardised means of vegetable intake were derived via a 24-h dietary recall. All participants who completed a 24-h dietary recall survey were selected for the analyses. This included 109 220 individuals (49 069 men and 60 151 women) over the course of 20 years of the KNHANES. Total vegetable intake decreased over time (Pfor trends < 0·001), specifically, steamed and salted vegetables (Pfor trends < 0·001). In contrast, Koreans consumed noticeably more raw vegetables from 1998 to 2017 (Pfor trends < 0·001). Vegetable intake at home significantly declined (Pfor trends < 0·001), while that eaten at restaurants or outside the home increased greatly (Pfor trends < 0·001). Over 20 years, Koreans have ingested decreasing amounts of vegetables, but the intake of raw vegetables has escalated. However, the location of vegetable consumption has changed, with an increase at both restaurants and outside the home (approximately 70·0 %).

Do Where The Elderly Live Matter? Factors Associated with Diet Quality among Korean Elderly Population Living in Urban Versus Rural Areas.

This study aimed to examine whether there is an area difference on diet quality among the Korean elderly population. The effect of personal factors on diet quality is also estimated and compared between rural and urban areas. A cross-sectional data from the 2013-2015 Korea National Health and Nutrition Examination Survey (KNHANES) was used for this study. The participants were older adults aged ≥ 65 years (n = 3207) who participated in the KNHANES. Urban and rural areas classified the region and the Korean Healthy Eating Index (KHEI) assessed the diet quality. Personal factors that were related to diet quality included socio-demographic factors, health behaviors, and health conditions. This study found that the diet quality was different between urban and rural areas in the Korean elderly population, showing a higher mean of KHEI scores in urban areas than rural areas (67.3 for urban seniors, 63.6 for rural seniors, p < 0.001), and the regional difference was still significant, even after adjusting for the personal factors (p < 0.001). Different sets of personal factors were found to be significant that explain the diet quality of participants between areas, such as economic resources, walking exercise, and perceived oral health status in urban areas, and age and food insecurity in rural areas. In conclusions, this study found that there was a regional disparity in diet quality and some personal factors affecting diet quality were dependent on areas, which implied that regional environment with diverse contexts could influence diet quality. These findings emphasize the need to provide targeted intervention programs that take into account both the characteristics of individuals and local food environments in order to improve the overall diet quality in older adults.