Kijoon Kim

Greater Total Antioxidant Capacity from Diet and Supplements Is Associated with a Less Atherogenic Blood Profile in U.S. Adults

Evidence from epidemiologic studies has shown that total antioxidant capacity (TAC) in the diet might be inversely associated with stroke, heart failure, and inflammatory biomarkers. However, studies on the association of TAC from both diet and supplements with cardiovascular disease (CVD) risk factors in the U.S. population are lacking. This cross-sectional population-based study aimed to investigate the association of TAC with both diet and supplements with CVD risk factors among 4039 U.S. adults in National Health and Nutrition Examination Survey (NHANES) 2007–2012. TAC from both food sources and dietary supplements was estimated from two 24-h dietary recalls using the NHANES supplement ingredient database, United States Department of Agriculture (USDA) proanthocyanidin, flavonoid, and isoflavone databases. Top contributors to TAC were tea, antioxidant supplements, vegetable mixture, orange juice, berries, and wine. Antioxidant supplement users had 1.6 times higher TAC than non-users. Greater TAC was associated with reduced triglycerides (TG) (−1.39% change; 95% CI = −2.56 to −0.21), TG to high-density lipoprotein cholesterol (HDL-C) ratio (−2.03% change; 95% CI = −3.45 to −0.60), HDL-C (0.65% change; 95% CI = 0.07 to 1.23), insulin (−1.37% change; 95% CI = −2.64 to −0.09), homeostasis model assessment of insulin resistance (HOMA-IR) (−1.57% change; 95% CI = −3.02 to −0.09) and C-reactive protein (CRP) (−0.83% change; 95% CI = −1.29 to −0.38) after adjusting for potential confounders. There was no significant association between TAC and waist circumference, BMI, blood pressure, low-density lipoprotein cholesterol (LDL-C), total cholesterol (TC), and fasting glucose. The findings of this study support the hypothesis that an antioxidant-rich diet and intake of supplements are beneficial to reduce CVD risk.

Greater flavonoid intake is associated with improved CVD risk factors in US adults.

Epidemiological studies have reported that diets high in flavonoids are associated with a reduced risk of CVD. However, evidence on the association of dietary flavonoid intake with CVD risk factors is still scarce. The present study aimed to investigate the association of dietary flavonoid intake with CVD risk factors among US adults in the National Health and Nutrition Examination Survey (NHANES) 2007-2012. A total of 4042 US adults aged 19 years and older from the NHANES 2007-2012 participated in this cross-sectional, population-based study. Intakes of total and individual flavonoids were estimated from 2-d 24-h diet recall data by matching with the expanded US Department of Agriculture flavonoid, isoflavone and proanthocyanidin databases. After adjusting for covariates, increased HDL-cholesterol was associated with higher total flavonoid intake (0·54 % change). TAG and TAG:HDL-cholesterol ratio were inversely associated with anthocyanidin (-1·25 % change for TAG; -1·60 % change for TAG:HDL-cholesterol ratio) and total flavonoid intakes (-1·31 % change for TAG; -1·83 % change for TAG:HDL-cholesterol ratio), respectively. Insulin and homoeostasis model assessment for insulin resistance (HOMA-IR) were inversely associated with flavone (for insulin, -3·18 % change; 95 % CI -5·85, -0·44; for HOMA-IR, -3·10 % change; 95 % CI -5·93, -0·19) and isoflavone intakes (for insulin, -3·11 % change; 95 % CI -5·46, -0·70; for HOMA-IR, -4·01 % change; 95 % CI -6·67, -1·27). BMI was negatively associated with anthocyanidin intake (-0·60 % change). This study showed that higher flavonoid intake was associated with improved CVD risk factors. Further research is warranted to confirm the findings from this study as these associations were moderate in strength.

Development of a comprehensive analytical method for furanocoumarins in grapefruit and their metabolites in plasma and urine using UPLC-MS/MS: a preliminary study

Abstract To develop a comprehensive analytical method for photoactive furanocoumarins, grapefruit (whole, flesh, peel and juice) was extracted using QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe) method. Seven furanocoumarins: bergaptol, psoralen, 8-methoxypsoralen, bergapten, 6′,7′-dihydroxybergamottin (6′,7′-DHB), epoxybergamottin and bergamottin were determined in grapefruit using UPLC-MS/MS. The concentrations of furanocoumarins in the plasma and urine of six healthy young adults before and after ingestion of grapefruit or grapefruit juice were also determined. Recovery rates of furanocoumarins by QuEChERS method from matrix spike sample and laboratory calibrate sample were 125.7 ± 25.4% and 105.7 ± 6.3%, respectively. Bergamottin and 6′,7′-DHB were predominant compounds in grapefruit flesh, juice and plasma, while bergaptol and 6′,7′-DHB were major compounds detected in the urine. The results demonstrated that bergamottin and 6′,7′-DHB were metabolized to bergaptol. Overall, the analytical methods developed in the present study can be applied to the analysis of various furanocoumarins in plant sources and biological samples.

Differential association of dietary carbohydrate intake with metabolic syndrome in the US and Korean adults: data from the 2007–2012 NHANES and KNHANES

Background/objectivesThe risk factors for metabolic syndrome may differ between Western and Asian countries due to their distinct dietary cultures. However, few studies have directly compared macronutrient intake and its association with the risk of metabolic syndrome in the US and Korean adults using national survey data.Subject/methodsBased on the data from the US and Korean versions of the 2007–2012 National Health and Nutrition Examination Survey (NHANES, KNHANES), a total of 3,324 American and 20,515 Korean adults were included. In both countries, dietary intake was measured using a 24-h dietary recall method and metabolic syndrome was defined using the National Cholesterol Education Program Adult Treatment Panel III criteria.ResultsThe percentages of energy intake from carbohydrate, protein, and fat were 50:16:33 in the US adults and 66:15:19 in the Korean adults. Regarding metabolic abnormalities, Korean adults in the highest quintile of carbohydrate intake showed an increased risk of metabolic syndrome in men and women, with abnormalities of reduced HDL cholesterol and elevated triglyceride levels. In contrast, the US men showed no significant association with metabolic syndrome and its abnormalities, while the US women showed an increased risk of reduced HDL cholesterol and elevated triglycerides.ConclusionsA high carbohydrate intake is associated with metabolic abnormalities. As Korean adults consume more carbohydrate than American adults, stronger associations of dietary carbohydrate with metabolic syndrome were observed. Thus, further studies are necessary to elucidate the underlying mechanisms of different contributors to developing metabolic disease in Western and Asian populations.