Trends of Food Supply and Nutrient Intake in South Korea Over the Past 30 Years

Attributes of multiple concurrent functional gastrointestinal disorders in female university students in South Korea

Functional gastrointestinal disorders (FGIDs) are common in young adults, particularly women, who tend to develop multiple FGIDs over time. This study aimed to investigate the prevalence of multiple concurrent FGIDs among female university students and identify differences in dietary habits, academic stress, and quality of life (QOL) based on the number of concurrent FGIDs. This secondary analysis included data from 406 female participants, originally collected through an online survey from two universities in one city in Korea. The online survey was accessible only after participants were verified as students through their online community. Concurrent FGID was present in 25.8 percent (n = 16) of the participants with FGIDs (n = 62), with the most common being irritable bowel syndrome + functional dyspepsia overlap (43.8 percent, 7/16). Participants with multiple concurrent FGIDs consumed fewer grains and vegetables, while significantly more of them consumed instant food, fast food, milk, and tea/coffee. They experienced significantly higher academic stress and lower QOL than those without the disease. Female university students with concurrent FGIDs tend to have unhealthy dietary habits, and concurrent FGIDs negatively affect academic stress and QOL. Therefore, female university students should undergo early-stage screening for FGIDs, and a comprehensive program should address their dietary habits and stress-coping skills.

The association of diet-dependent acid load with colorectal cancer risk: a case-control study in Korea

Acid-base disequilibrium is a contributor to cancer development because it affects molecular activities such as insulin-like growth factor 1 levels and adiponectin production. However, evidence of an association of diet-induced acid-base imbalance with colorectal cancer (CRC) is limited. We examined whether colorectal carcinogenesis is attributable to a diet with a high acid load. We recruited a total of 923 CRC cases and 1846 controls at the National Cancer Center in Korea for inclusion in a case-control study. We collected information on nutrient intake and specific clinical parameters of CRC by using a semiquantitative FFQ and medical records, respectively. Potential renal acid load (PRAL) and net endogenous acid production (NEAP) were used to estimate diet-dependent acid load. We used an unconditional logistic regression model to analyse the association. Dietary acid load scores had a positive association with the odds of CRC (OR = 2·31 (95 % CI 1·79, 2·99) and OR = 2·14 (95 % CI 1·66, 2·76) for PRAL and NEAP, respectively, Pfor trend < 0·001). A stronger positive association was observed for females (OR = 3·09, 95 % CI 1·93, 4·94) than for males (OR = 1·71, 95 % CI 1·27, 2·31). Furthermore, acidogenic diets appeared to affect rectal cancer more strongly than colon cancer in females. Our study contributes to reinforcing epidemiological evidence regarding a detrimental effect of acidogenic diets on colorectal carcinogenesis. Thus, it is important to pay attention to the balance of acidogenic (e.g. poultry and red meat) and alkalinogenic foods (e.g. fruits and vegetables) in CRC prevention, especially for females.

Trends in intake and sources of dietary protein in Korean adults, 1998-2018

Although a decrease in carbohydrate intake and an increase in fat intake among Koreans have been reported, investigations of changes in protein intake have been limited. Thus, this study aimed to explore trends in the dietary intake of total, plant and animal proteins overall and by socio-demographic subgroups in Korea over the past two decades. A total of 78 716 Korean adults aged ≥ 19 years who participated in the seven survey cycles of the Korea National Health and Nutrition Examination Survey 1998-2018 were included. Dietary protein intake, overall and by source, was calculated using a single 24-h dietary recall data. Changes in dietary protein over 20 years were estimated using multiple linear regression analysis after adjusting for potential covariates. For total protein intake, a significant decrease was reported from 1998 to 2016-2018 (P for trend_linearity < 0·001), whereas an increasing trend was observed from 2007-2009 to 2016-2018 (P for trend_linearity < 0·001). In terms of protein intake by source, plant protein intake decreased while animal protein intake increased over the past two decades, indicating steeper trends during the recent decade (P for trend_linearity < 0·001). These trends were more pronounced among younger adults and those with higher household income and education levels. These findings suggest that continuous monitoring of dietary protein intake overall and by source (plant v. animal) across socio-demographic group is needed.

A review of recent evidence of dietary protein intake and health

The Korea National Health and Nutrition Examination Survey of 2013 to 2017 reported that the average protein consumption of the Korean population is above the current recommended nutrient intake of protein proposed by the Dietary Reference Intakes for Koreans. Some health professionals and the media often advise consuming diets high in protein for promoting metabolic regulation, weight control, and muscle synthesis. However, due to lack of scientific evidence, the validity and safety of high protein consumption are yet to be fully ascertained. The present review assesses recent evidence published in 2014-2020 from human studies, focusing on adequate protein intake and protein sources for the prevention of chronic diseases, particularly metabolic disorders and sarcopenia.

Association Between Dietary Fiber Intake and All-Cause and Cardiovascular Mortality in Middle Aged and Elderly Adults With Chronic Kidney Disease

Background and Aims

Despite accumulating evidence on the benefits of dietary fiber in the general population, there is a lack of representative data on mortality in patients with chronic kidney disease (CKD). This study examined the role of dietary fiber intake on all-cause and cardiovascular mortality in patients with CKD using representative Korean cohort data.

Methods

The study included 3,892 participants with estimated glomerular filtration rates &lt;60 mL/min/1.73 m2 from the Korean Genome and Epidemiology Study. Mortality status was followed by data linkage with national data sources. Nutritional status was assessed using a validated food frequency questionnaire. Dietary fiber was categorized into quintiles (Q). A multivariable Cox proportional hazards regression model was used to calculate hazard ratios (HRs) and 95% confidence intervals (CIs) for all-cause and cardiovascular mortality.

Results

The average daily fiber intake of patients with CKD was 5.1 g/day. During the 10.1-year follow-up period, 602 (149 cardiovascular) deaths were documented. The HR (95% CI) for all-cause mortality in the highest quintile compared with that in the lowest quintile was 0.63 (0.46–0.87) after adjusting for age, sex, BMI, smoking, alcohol intake, exercise, total calorie intake, hypertension, diabetes, and dyslipidemia (P = 0.005). The HR (95% CI) for cardiovascular mortality in the highest quintile compared with that in the lowest quintile was 0.56 (0.29–1.08) after adjusting for same confounders (P = 0.082).

Conclusion

In conclusion, we observed an inverse association between dietary fiber intake and all-cause mortality in CKD patients. Small increments in fiber intake reduced the risk of all-cause mortality by 37%. This finding highlights the need for inexpensive but important dietary modification strategies for encouraging fiber intake in the Korean CKD population.

TAS1R2 sweet taste receptor genetic variation and dietary intake in Korean females

Taste receptor type 1, member 2 (TAS1R2) controls the oral sensing of sweetness. Genetic variations in TAS1R2 have been shown to be associated with differential sweetness intensity and varying carbohydrate intake levels among individuals. This study examined whether rs7534618 A > C in TAS1R2 is associated with dietary behavior and energy nutrient intake in Korean females. A cross-sectional design utilizing data from the Multi-Rural Communities Cohort Study, which was a nationwide epidemiological research project in Korea, was applied in this study. In total, 2198 females were analyzed to evaluate the differences in macronutrient intake levels and intake of carbohydrate-rich and sweet-tasting foods between the rs7534618 genotypes. The findings suggest that individuals with the CC minor genotype tended to have lower carbohydrate but higher fat intake than subjects with the A* genotype (p = 0.035 and p = 0.042, respectively). Subjects with the CC genotype also exhibited less intake of total grains but greater intake of bread than those with the A* genotype (p = 0.017 and p = 0.006, respectively). However, these observed associations were statistically modest (false discovery rate adjusted p > 0.05). In conclusion, TAS1R2 rs7534618 is not a decisive genetic modifier of nutrition and dietary intake in Korean females. However, given the paucity of studies, these putative associations between the TAS1R variation and dietary intake may be referred for further sensory genetic studies in Koreans.

The DASH Diet and Cardiometabolic Health and Chronic Kidney Disease: A Narrative Review of the Evidence in East Asian Countries

The rising incidence of cardiometabolic diseases and chronic kidney disease (CKD) is a leading public health problem in East Asia. Diet is an important modifiable risk factor; thus, adopting a healthy diet such as the Dietary Approaches to Stop Hypertension (DASH) diet may help combat these chronic diseases. The DASH diet was originally developed in a U.S. population, and East Asia is demographically and culturally different from the U.S. Therefore, it is important to examine the evidence regarding the DASH diet and chronic disease in this unique population. This narrative review summarizes the evidence on the DASH diet and cardiometabolic health and CKD in East Asia. Culturally-modified DASH diets have been developed in some East Asian countries. Studies suggest the DASH diet is effective at lowering blood pressure in this population, though the long-term benefits remain unclear. Evidence also suggests the DASH diet may reduce the risk of type 2 diabetes and metabolic syndrome. Further research indicates the DASH diet and its components may reduce CKD risk. However, recommending the DASH diet in those who already have CKD is controversial, as it conflicts with current CKD dietary guidelines, especially in advanced CKD. Notably, current intakes in the general population differ from the DASH dietary pattern, suggesting public health efforts would be needed to encourage adoption of the DASH diet.