Choline intake and its dietary reference values in Korea and other countries: a review

Choline is a water-soluble organic compound that is important for the normal functioning of the body. It is an essential dietary component as de novo synthesis by the human body is insufficient. Since the United States set the Adequate Intakes (AIs) for total choline as dietary reference values in 1998, Australia, China, and the European Union have also established the choline AIs. Although choline is clearly essential to life, the 2020 Dietary Reference Intakes for Koreans (KDRIs) has not established the values because very few studies have been done on choline intake in Koreans. Since choline intake levels differ by race and country, human studies on Koreans are essential to set KDRIs. Therefore, the present study was undertaken to provide basic data for developing choline KDRIs in the future by analyzing data on choline intake in Koreans to date and reference values of choline intake and dietary choline intake status by country and race.

Literature review and future tasks necessary to establish of Korean Dietary Reference Intake for choline / 한국영양학회지

Choline, an essential nutrient for humans, is required for the structural integrity of the cell membranes, methyl-group metabolism, synthesis of the neurotransmitter acetylcholine, synthesis of the membrane phospholipid components of the cell membranes, and the transport of lipids and cholesterol. Choline can be synthesized in the body, but it is insufficient to meet the daily requirements and hence it must be obtained through the diet. In the United States/Canada, Australia/New Zealand, Europe, China, and Taiwan, the adequate intake (AI) and tolerable upper intake level (UL) of choline have been established, while the establishment of the 2020 Dietary Reference Intakes for Koreans (KDRI) for choline was postponed due to the lack of a choline database for Korean foods and studies on the choline intake of Koreans. However, as part of the preparation work for the 2020 DRI revision and finalization, choline intake and the possibility of disease occurrence were verified through analysis of published data. The groundwork for the subsequent establishment of a choline DRI was laid through a literature search, evaluation, and review of the literature reported from 1949 up to 2019. This can be regarded as the culmination of this project. According to the results of randomized controlled trials (RCTs), cohort studies, case-control studies, and cross-sectional observational studies in humans, approximately 400-500 mg/day of choline intake was effective in preventing liver function damage (fatty liver), neural tube damage, cardiovascular disease, breast cancer, and cognitive function improvement. The same amount of choline intake, however, also correlated with the risk of prostate and colorectal cancer. At present, there is limited information available on choline intake and health outcomes, particularly for the Korean population. More human studies, including clinical trials on the requirements and the physiological benefits associated with dietary intake, are needed to establish the KDRI for choline.

The Effects of Diet Alone or in Combination with Exercise in Patients with Prehypertension and Hypertension: a Randomized Controlled Trial

BACKGROUND AND OBJECTIVES: Supervised lifestyle interventions, including dietary and exercise programs, may be infeasible to implement in real-world settings. Therefore, this study aimed to evaluate the effectiveness of a home-based lifestyle modification intervention on blood pressure (BP) management. METHODS: Eighty-five patients aged over 20 years and diagnosed with prehypertension or mild hypertension were randomly assigned to an advice-only comparison group (C group, n=28), a Dietary Approaches to Stop Hypertension (DASH) diet education group (D group, n=30), or a DASH and home-based exercise group (D+Ex group, n=27). The intervention lasted for 8 weeks. The primary outcome was the difference in office systolic blood pressure (SBP) before and after the study period (Trial registry at ClinicalTrials.gov, NCT01637909). RESULTS: Seventy-two participants (87.8%) completed the trial. The degree of change in office SBP did not significantly differ among the intervention groups; however, the D+Ex group demonstrated a tendency toward decreased SBP. Upon analysis of 24-hour ambulatory BP measurements, daytime ambulatory SBP was significantly lower in the D+Ex group (134 mmHg; 95% confidence interval [CI], 131 to 137; p=0.011) than in the C group (139.5 mmHg; 95% CI, 130.9 to 137), and daytime ambulatory SBP was significantly decreased in the D+Ex group (−5.2 mmHg; 95% CI, −8.3 to −2.1; p=0.011) compared to the C group (0.4 mmHg, 95% CI, −2.5 to 3.3). CONCLUSIONS: In conclusion, lifestyle modification emphasizing both diet and exercise was effective for lowering BP and should be favored over diet-only modifications.

The Effects of Diet Alone or in Combination with Exercise in Patients with Prehypertension and Hypertension: a Randomized Controlled Trial

BACKGROUND AND OBJECTIVES@#Supervised lifestyle interventions, including dietary and exercise programs, may be infeasible to implement in real-world settings. Therefore, this study aimed to evaluate the effectiveness of a home-based lifestyle modification intervention on blood pressure (BP) management.@*METHODS@#Eighty-five patients aged over 20 years and diagnosed with prehypertension or mild hypertension were randomly assigned to an advice-only comparison group (C group, n=28), a Dietary Approaches to Stop Hypertension (DASH) diet education group (D group, n=30), or a DASH and home-based exercise group (D+Ex group, n=27). The intervention lasted for 8 weeks. The primary outcome was the difference in office systolic blood pressure (SBP) before and after the study period (Trial registry at ClinicalTrials.gov, NCT01637909).@*RESULTS@#Seventy-two participants (87.8%) completed the trial. The degree of change in office SBP did not significantly differ among the intervention groups; however, the D+Ex group demonstrated a tendency toward decreased SBP. Upon analysis of 24-hour ambulatory BP measurements, daytime ambulatory SBP was significantly lower in the D+Ex group (134 mmHg; 95% confidence interval [CI], 131 to 137; p=0.011) than in the C group (139.5 mmHg; 95% CI, 130.9 to 137), and daytime ambulatory SBP was significantly decreased in the D+Ex group (−5.2 mmHg; 95% CI, −8.3 to −2.1; p=0.011) compared to the C group (0.4 mmHg, 95% CI, −2.5 to 3.3).@*CONCLUSIONS@#In conclusion, lifestyle modification emphasizing both diet and exercise was effective for lowering BP and should be favored over diet-only modifications.

Association of serum carotenoid, retinol, and tocopherol concentrations with the progression of Parkinson's Disease

BACKGROUND/OBJECTIVES: A pivotal role of oxidative stress has been emphasized in the pathogenesis as well as in the disease progression of Parkinson's disease (PD). We aimed at investigating serum levels of antioxidant vitamins and elucidating whether they could be associated with the pathogenesis and progression of PD. MATERIALS/METHODS: Serum levels of retinol, α- and γ-tocopherols, α- and β-carotenes, lutein, lycopene, zeaxanthin and β-cryptoxanthin were measured and compared between 104 patients with idiopathic PD and 52 healthy controls matched for age and gender. In order to examine the relationship between antioxidant vitamins and the disease progression, multiple group comparisons were performed among the early PD (Hoehn and Yahr stage I and II, N = 47), advanced PD (stage III and IV, N = 57) and control groups. Separate correlation analyses were performed between the measured antioxidant vitamins and clinical variables, such as Hoehn and Yahr stage and Unified Parkinson's Disease Rating Scale (UPDRS) motor score. RESULTS: Compared to controls, PD patients had lower levels of α- and β-carotenes and lycopene. α-carotene, β-carotene and lycopene levels were significantly reduced in advanced PD patients relative to early PD patients and were negatively correlated with Hoehn and Yahr stage and UPDRS motor score in PD patients. No significant differences were found in serum levels of retinol, α- and γ-tocopherols, and other carotenoids between PD patients and controls. No significant correlations were found between these vitamin levels and clinical variables in PD patients. CONCLUSIONS: We found that serum levels of some carotenoids, α-carotene, β-carotene and lycopene, were lower in PD patients, and that these carotenoids inversely correlated with clinical variables representing disease progression. Our findings suggest that decreases in serum α-carotene, β-carotene and lycopene may be associated with the pathogenesis as well as progression of PD.

Inhibitory effect of Gastrodia elata Blume extract on alpha-melanocyte stimulating hormone-induced melanogenesis in murine B16F10 melanoma

BACKGROUND/OBJECTIVES: Gastrodia elata Blume (GEB), a traditional herbal medicine, has been used to treat a wide range of neurological disorders (e.g., paralysis and stroke) and skin problems (e.g., atopic dermatitis and eczema) in oriental medicine. This study was designed to investigate whether GEB extract inhibits melanogenesis activity in murine B16F10 melanoma. MATERIALS/METHOD: Murine B16F10 cells were treated with 0-5 mg/mL of GEB extract or 400 µg/mL arbutin (a positive control) for 72 h after treatment with/without 200 nM alpha-melanocyte stimulating hormone (α-MSH) for 24 h. Melanin concentration, tyrosinase activity, mRNA levels, and protein expression of microphthalmia-associated transcription factor (MITF), tyrosinase, tyrosinase-related protein (Trp)1, and Trp2 were analyzed in α-MSH-untreated and α-MSH-treated B16F10 cells. RESULTS: Treatment with 200 nM α-MSH induced almost 2-fold melanin synthesis and tyrosinase activity along with increased mRNA levels and protein expression of MITF, tyrosinase, Trp1 and Trp2. Irrespective of α-MSH stimulation, GEB extract at doses of 0.5-5 mg/mL inhibited all these markers for skin whitening in a dose-dependent manner. While lower doses (0.5-1 mg/mL) of GEB extract generally had a tendency to decrease melanogenesis, tyrosinase activity, and mRNA levels and protein expression of MITF, tyrosinase, Trp1, and Trp2, higher doses (2-5 mg/mL) significantly inhibited all these markers in α-MSH-treated B16F10 cells in a dose-dependent manner. These inhibitory effects of the GEB extract at higher concentrations were similar to those of 400 µg/mL arbutin, a well-known depigmenting agent. CONCLUSIONS: These results suggest that GEB displays dose-dependent inhibition of melanin synthesis through the suppression of tyrosinase activity as well as molecular levels of MITF, tyrosinase, Trp1, and Trp2 in murine B16F10 melanoma. Therefore, GEB may be an effective and natural skin-whitening agent for application in the cosmetic industry.

Bioconverted Jeju Hallabong tangor (Citrus kiyomi × ponkan) peel extracts by cytolase enhance antioxidant and anti-inflammatory capacity in RAW 264.7 cells

BACKGROUND/OBJECTIVES: Citrus and its peels have been used in Asian folk medicine due to abundant flavonoids and usage of citrus peels, which are byproducts from juice and/or jam processing, may be a good strategy. Therefore, the aim of this study was to examine antioxidant and anti-inflammatory effects of bioconversion of Jeju Hallabong tangor (Citrus kiyomi × ponkan; CKP) peels with cytolase (CKP-C) in RAW 264.7 cells. MATERIALS/METHODS: Glycosides of CKP were converted into aglycosides with cytolase treatment. RAW 264.7 cells were pre-treated with 0, 100, or 200 µg/ml of citrus peel extracts for 4 h, followed by stimulation with 1 µg/ml lipopolysaccharide (LPS) for 8 h. Cell viability, DPPH radical scavenging activity, nitric oxide (NO), and prostagladin E2 (PGE2) production were examined. Real time-PCR and western immunoblotting assay were performed for detection of mRNA and/or protein expression of pro-inflammatory mediators and cytokines, respectively. RESULTS: HPLC analysis showed that treatment of CKP with cytolase resulted in decreased flavanone rutinoside forms (narirutin and hesperidin) and increased flavanone aglycoside forms (naringenin and hesperetin). DPPH scavenging activities were observed in a dose-dependent manner for all of the citrus peel extracts and CKP-C was more potent than intact CKP. All of the citrus peel extracts decreased NO production by inducible nitric oxide synthase (iNOS) activity and PGE2 production by COX-2. Higher dose of CKP and all CKP-C groups significantly decreased mRNA and protein expression of LPS-stimulated iNOS. Only 200 µg/ml of CKP-C markedly decreased mRNA and protein expression of cyclooxygenase-2 in LPS-stimulated RAW 264.7 cells. Both 100 and 200 µg/ml of CKP-C notably inhibited mRNA levels of interleukin-1β (IL-1β) and IL-6, whereas 200 µg/ml CKP-C significantly inhibited mRNA levels of TNF-α. CONCLUSIONS: This result suggests that bioconversion of citrus peels with cytolase may enrich aglycoside flavanones of citrus peels and provide more potent functional food materials for prevention of chronic diseases attributable to oxidation and inflammation by increasing radical scavenging activity and suppressing pro-inflammatory mediators and cytokines.

Relationship between thresholds and self-assessed preference for saltiness and sodium intake in young women / 한국영양학회지

PURPOSE: We recruited 118 women in their early 20's to examine the relationship between sodium intake and salty taste thresholds and preference. We also examined the association of salty taste preference with sodium-related dietary behaviors and major dishes contributing to sodium intake. METHODS: Daily sodium intake was estimated using a 127-item dish-frequency questionnaire. Salty taste thresholds and preference were measured using rating scales using water solution of NaCl and a self-administered questionnaire based on a Likert scale, respectively. RESULTS: Salty taste preference showed positive correlation with daily sodium intake and sodium intake-increasing behaviors, and inverse association with sodium intake-decreasing behaviors, including salt and soy sauce use at the table, the frequency of eating out and home delivery of foods, broth consumption of soup, stew or noodle soup, the use of ready-to-serve or processed foods, fresh vegetable intake, and the accommodating attitude toward bland food. Intake of sodium-contributing dishes, including ramen, spicy soft-tofu stew, radish kimchi, and dishes containing kimchi, also showed positive association with salty taste preference. Unexpectedly, detection and recognition thresholds of salty taste showed no association with salty taste preference, sodium intake, and sodium-related dietary behaviors. CONCLUSION: These findings suggest that salty taste preference could reflect sodium intake of individuals rather than thresholds of saltiness, and may be used as a simple and effective proxy for usual sodium intake.

4th-grade elementary-school children's body image and dietary habits according to body mass index / 한국영양학회지

PURPOSE: The goal of this study was to examine body image satisfaction and perception according to weight status, and to investigate those associations with dietary habits and nutritional status among preadolescent children. METHODS: Body image and dietary habits and intake were assessed in 134 elementary school students in grade 4. Children were categorized according to normal and overweight or obese groups. Figure rating scales were used to assess body image perception (identification of perceived current body size) and dissatisfaction (difference between perceived current body size and ideal body image). RESULTS: There were sex differences in body image perceptions. Normal-weight girls, overweight or obese girls and boys were more likely to desire a leaner body size than their perceived body size compared with normal-weight boys. Body image satisfaction and perception showed an association with weight status. More overweight or obese children indicated dissatisfaction or underestimation of body image than normal-weight children. Children with body image dissatisfaction due to heavier perceived body size than ideal body image showed lower frequencies of consumption of meals and vegetables, compared to those who were satisfied with their body image. Children who underestimated their body image were more likely to have a lower frequency of breakfast and meal regularity and a higher frequency of eating out of home or food deliveries than those with accurate body image perception. In addition, body image underestimation showed an association with lower intakes of protein, dietary fiber and calcium, and the higher percentage of calories derived from fat. CONCLUSION: Body image dissatisfaction as well as underestimation in children before puberty showed an association with overweight or obesity, and was also related to unhealthy dietary habits. These findings highlight the importance of accurate perception and satisfaction with body image in preadolescent children in order to prevent development of obesity in adolescents and adults.

Dietary sodium intake in young Korean adults and its relationship with eating frequency and taste preference

Dietary sodium intake is considered one of the major causal factors for hypertension. Thus, to control the increase of blood pressure and reduce the risk of hypertension-related clinical complications, a reduction in sodium intake is recommended. The present study aimed at determining the association of dietary sodium intake with meal and snack frequency, snacking time, and taste preference in Korean young adults aged 20-26 years, using a 125-item dish-frequency questionnaire. The mean dietary sodium intakes of men and women were 270.6 mmol/day and 213.1 mmol/day, which were approximately 310% and 245% of the daily sodium intake goal for Korean men and women, respectively. Dietary sodium intake was positively correlated with systolic blood pressure in the total group, and BMI in the total and men-only groups. In the total and men-only groups, those who consumed meals more times per day consumed more dietary sodium, but the number of times they consumed snacks was negatively correlated with dietary sodium intake in the total, men-only, and women-only groups. In addition, those who consumed snacks in the evening consumed more sodium than those who did so in the morning in the men-only group. The sodium intake was also positively associated with preference for salty and sweet taste in the total and women-only groups. Such a high intake of sodium in these young subjects shows that a reduction in sodium intake is important for the prevention of hypertension and related diseases in the future.

Interaction Effects of Lipoprotein Lipase Polymorphisms with Lifestyle on Lipid Levels in a Korean Population: A Cross-sectional Study

Lipoprotein lipase (LPL) plays an essential role in the regulation of high-density lipoprotein cholesterol (HDLC) and triglyceride levels, which have been closely associated with cardiovascular diseases. Genetic studies in European have shown that LPL single-nucleotide polymorphisms (SNPs) are strongly associated with lipid levels. However, studies about the influence of interactions between LPL SNPs and lifestyle factors have not been sufficiently performed. Here, we examine if LPL polymorphisms, as well as their interaction with lifestyle factors, influence lipid concentrations in a Korean population. A two-stage association study was performed using genotype data for SNPs on the LPL gene, including the 3' flanking region from 7,536 (stage 1) and 3,703 (stage 2) individuals. The association study showed that 15 SNPs and 4 haplotypes were strongly associated with HDLC (lowest p = 2.86 x 10(-22)) and triglyceride levels (lowest p = 3.0 x 10(-15)). Interactions between LPL polymorphisms and lifestyle factors (lowest p = 9.6 x 10(-4)) were also observed on lipid concentrations. These findings suggest that there are interaction effects of LPL polymorphisms with lifestyle variables, including energy intake, fat intake, smoking, and alcohol consumption, as well as effects of LPL polymorphisms themselves, on lipid concentrations in a Korean population.

Interaction Effects of Lipoprotein Lipase Polymorphisms with Lifestyle on Lipid Levels in a Korean Population: A Cross-sectional Study

Lipoprotein lipase (LPL) plays an essential role in the regulation of high-density lipoprotein cholesterol (HDLC) and triglyceride levels, which have been closely associated with cardiovascular diseases. Genetic studies in European have shown that LPL single-nucleotide polymorphisms (SNPs) are strongly associated with lipid levels. However, studies about the influence of interactions between LPL SNPs and lifestyle factors have not been sufficiently performed. Here, we examine if LPL polymorphisms, as well as their interaction with lifestyle factors, influence lipid concentrations in a Korean population. A two-stage association study was performed using genotype data for SNPs on the LPL gene, including the 3' flanking region from 7,536 (stage 1) and 3,703 (stage 2) individuals. The association study showed that 15 SNPs and 4 haplotypes were strongly associated with HDLC (lowest p = 2.86 x 10(-22)) and triglyceride levels (lowest p = 3.0 x 10(-15)). Interactions between LPL polymorphisms and lifestyle factors (lowest p = 9.6 x 10(-4)) were also observed on lipid concentrations. These findings suggest that there are interaction effects of LPL polymorphisms with lifestyle variables, including energy intake, fat intake, smoking, and alcohol consumption, as well as effects of LPL polymorphisms themselves, on lipid concentrations in a Korean population.

The Effects of a Nutrition and Body Shape Education Program as Part of Health Promoting Projects in an Elementary School

The purpose of this study was to evaluate the effects of a nutrition education program as part of health promoting projects in an elementary school. A total of 168 students in the 4th grade were enrolled in the program for 6 months. A self-administered questionnaire was developed to assess nutrition knowledge and dietary habit. Nutrient intakes and body shape perceptions were measured using 24-hour recall method and self-ratings of body shape figures, respectively. The education program was conducted in various ways, focused on healthy dietary behavior, nutrients' roles and sources, and proper body shape perceptions, etc. After the education program, nutrition knowledge and dietary habit were significantly improved. Dietary habit scores were significantly and positively related to nutrition knowledge levels. Body shape perceptions were significantly and properly changed after the program. Dissatisfaction with perceived current body shape and discrepancy between shapes desired and considered healthy were significantly decreased. But girls still indicated a desire to be leaner than shapes which were perceived current and considered healthy. Nutrient intakes were partly improved by the program, but some nutrients, such as calcium, folate, zinc, sodium and niacin, were still remained deficient or excessive. These findings indicate that enhancement of nutrition knowledge is extended to the improvement of dietary habit. In addition, establishment of proper body shape perception is closely related to healthy dietary habits and is required to good nutrition and health.

Serum Phospholipid Fatty Acids in Benign Breast Tumor and Breast Cancer

Studies on the relationship between blood fatty acids and the risk of breast cancer have not yielded definite conclusions. The role of fatty acids in the development and progression of breast cancer is unclear. We conducted a case-control study to determine serum phospholipid fatty acid composition in benign breast tumor and breast cancer. Subjects consisted of 27 benign breast tumor and 68 breast cancer patients, and 28 matched controls. The levels of fatty acids were measured by gas chromatography. Higher arachidonic and palmitic acids were observed in breast cancer patients as compared with control and benign breast tumor patients. The percentage of total saturated fatty acids in breast cancer was higher than in control and benign breast tumor patients. The level of stearic acid was lower in benign breast tumor and breast cancer patients. Saturation index, the ratio of stearic to oleic acid, was lower in benign breast tumor and breast cancer patients compared to the control. Moreover, stearic acid was negatively and arachidonic acid was positively correlated with the cancer stage. In conclusion, our results support that serum phospholipid compositions of specific fatty acids are associated with the risk of benign breast tumor as well as breast cancer. Further studies are necessary to investigate mechanisms linked to the breast cancer etiology.

Increased Inflammation, Reduced Plasma Phospholipid Eicosapentaenoic Acid and Reduced Antioxidant Potential of Treated Hypertensive Patients with Metabolic Syndrome

PURPOSE: In the present study, we tested whether the presence of metabolic syndrome (MetS) would worsen the features of inflammation, plasma omega 3 fatty acid levels and antioxidant potential in treated hypertensive patients. MATERIALS AND METHODS: Two groups were classified by the components of MetS: a reference group of treated hypertensive subjects: hypertension (HTN) group (n = 39) and with more than two additional MetS components: HTN with Mets group (n = 40). We further compared the parameters between HTN group and HTN with MetS group. RESULTS: The results showed that age (p < 0.001) and body mass index (BMI) (p < 0.001) were significantly different between HTN group and HTN with MetS group. Age- and BMI-adjusted total radical trapping antioxidant potential (TRAP) (p < 0.01) was significantly lower, whereas age- and BMI-adjusted CD (p < 0.05) and interleukin (IL) 6 (p < 0.05) were significantly higher in HTN with MetS group than in HTN group. Moreover, HTN with MetS group had significantly lower levels of age- and BMI-adjusted plasma phospholipid eicosapentaenoic acid (EPA) than HTN group (p < 0.05). On the other hand, the levels of age- and BMI-adjusted intracellular cell adhesion molecule-1 (ICAM-1), adiponectin and high molecular weight (HMW)-adiponectin were not significantly different between the groups. CONCLUSION: In conclusion, our results showed increased inflammatory marker, reduced antioxidant potential and EPA levels in treated hypertensive patients in the presence of MetS, suggesting the importance of changes of therapeutic lifestyle to modify the features of MetS.

Levels of Serum Antioxidant Minerals and Enzyme Capacities of Korean Male Patients with Coronary Artery Disease / 대한지역사회영양학회지

Increased oxidative stress contributes to the progression of atherosclerosis. We measured serum antioxidant mineral concentrations, capacities of serum antioxidant enzymes and fasting lipid profile in 97 male patients with coronary artery disease (CAD) and 21 male controls. Nutrient intake was assessed by the semi-quantitative food frequency method. CAD patients were divided into single-vessel disease (SVD, n = 66) and multi-vessel disease (MVD, n = 31) groups on the coronary angiography. The ratio of serum LDL- to HDL-cholesterol elevated with an increasing number of diseased vessels compared to the control (control < SVD