Appropriate protein intake is one strategy in the management of metabolic syndrome in Korean elderly to mitigate changes in body composition.

Higher protein intake could reduce metabolic syndrome (MetS) by managing body composition among Korean elderly although the research is scant. Herein, we examined the hypothesis that the optimal protein intake of Korean elderly is associated with both improvements in MetS risk as well as favorable changes in body composition. The present study employs a national data source, the Korea National Health and Nutrition Examination Survey (KNHANES, 2009), and a total 1,567 elderly (651 men and 916 women) were included in the final data analyses. The incidence of sarcopenia was significantly greater in MetS group than normal group. We observed significantly differences in the amount of protein in the participants' diet that related to sex, income, and education level. The highest protein consumption group had significantly reduced abdominal obesity (44%; 0.293-0.652, P < .001), lower HDL-cholesterol (47%, 0.316-0.683, P < .001), elevated TG (45%, 0.298-0.679, P < .001), and MetS (42%, 0.293-0.598, P < .001) compared to the other groups, after adjustment for sex, income, education level. Total muscle mass were correlated positively with protein consumption, but there was a negative correlation between protein consumption and total fat mass. The present study suggests that at least 0.8 g/kg per day of protein may reduce MetS and help manage body composition changes to mitigate MetS in Korean elderly.

The most effective factors to offset sarcopenia and obesity in the older Korean: Physical activity, vitamin D, and protein intake.

OBJECTIVE: The aim of this study was to evaluate the effects of the types and levels of physical activity in conjunction with protein intake and vitamin D on sarcopenia and obesity status in an elderly population. METHODS: Study participants (N = 4452) were ages ≥60 y and included 1929 men and 2523 women who completed a body composition analysis with a dual energy x-ray absorptiometry and provided health and dietary data. RESULTS: Higher appendicular skeletal muscle mass/weight was observed in the non-obese group, although obese participants had greater weights. The non-obese sarcopenia subgroup showed health problems related to insulin resistance and metabolic-related factors compared with the nonsarcopenic group. The total metabolic equivalent was significantly different in both obese categories, regardless of sarcopenic status. The prevalence of obesity, sarcopenia, and sarcopenic obesity relatively increased with a diet deficient of protein intake and vitamin D. CONCLUSION: These data suggest that sarcopenia had a significant association with metabolic-related factors; physical activity, especially vigorous activity; and protein intake and vitamin D levels in a non-obese elderly population. Therefore, maintaining healthy body weight by means of resistance exercise and enhanced protein intake and vitamin D may help offset sarcopenia in this age group.

Can nutrition label recognition or usage affect nutrition intake according to age?

OBJECTIVES: The aim of this study was to investigate the effect of the use of nutrition labeling on nutritional intake according to age groups, focusing on Korean elderly. METHODS: Study participants (N = 5223) were adults at least 20 y of age and had participated in the Korean National Health Examination and Nutrition Survey in 2012. Data for recognition/use of nutrition labels were obtained by self-report. Nutrition intake also was estimated by 24-h dietary recall. Participants were categorized into three age groups: 20 to 39 y, 40 to 59 y, and ≥60 y. Generalized linear model was conducted to test mean differences between nutrition label recognition (NLR) and nutrition label use (NLU) groups for nutrient intake, according to the age groups. RESULTS: Results from this study indicated that younger individuals (age groups of 20-39 and 40-59 y) in the NLU group showed a significant association with nutrient intake compared to those in the NLR group. Additionally, nutrition intake status in the NLU group improved positively. Whereas older participants (≥60 y) in the NLR group showed a significant association with most nutrient intake compared with the NLU group. The study also found that protein intake was reduced in the NLU group compared with the non-NLU group across the age groups, except for older participants (age group 20-39 y: 79.16 versus 86.30 g, P = 0.050; age group 40-59 y: 69.97 versus 75.58 g, P = 0.040; age group of ≥60 y: 64.72 versus 64.89 g, P = 0.967). CONCLUSIONS: The present study revealed that nutrition labeling cannot be effective for the elderly, and there were several areas of misunderstanding. Therefore, more systematic education on the topic of nutrition labeling is required to help the elderly make healthier food decisions.

Impact of dining out on nutritional intake and metabolic syndrome risk factors: data from the 2011 Korean National Health and Nutrition Examination Survey.

The frequency of dining out has rapidly increased; however, the independent associations between dining out, metabolic syndrome risk factors and nutritional status have not been well characterised. The aim of the present study was to investigate the associations between dining out, nutritional intakes and metabolic syndrome risk factors among Korean adults, using data from the 2011 Korean National Health and Nutrition Examination Survey. Frequency of dining out was significantly associated with intake of nutrients such as energy, water, protein, fat, carbohydrate, Ca, Na, vitamin A and carotene. Especially, the result revealed that Korean adults had insufficient Ca intake compared with the Korean reference intake (700 mg). As the frequency of dining out increased, so did energy intake. In addition, individuals who dined out seven or more times per week experienced a 64% higher likelihood of blood pressure abnormalities, an 88% higher likelihood of waist circumference abnormalities, and a 32% higher likelihood of low HDL-cholesterol levels than those who dined out less than once per week. BMI was not associated with the frequency of dining out. Our findings suggest that strategies to modify dining-out behaviour could reduce metabolic syndrome risk factors via improved nutrition.

Body composition changes were related to nutrient intakes in elderly men but elderly women had a higher prevalence of sarcopenic obesity in a population of Korean adults.

In this study, we examined the relationship between sarcopenic obesity (SO) and nutrition status, according to sex in Korean adults who were 60 years or older. Body composition was categorized as SO, sarcopenic nonobesity, nonsarcopenic obesity, and nonsarcopenic nonobesity. Obesity was defined by body mass index. Sarcopenia was defined as an appendicular skeletal muscle mass divided by weight (Wt) of less than 1 SD below the sex-specific mean for young adults. Subjects included 1433 subjects (658 men and 775 women) who were 60 years or older and who participated in the fifth Korea National Health and Nutritional Examination Survey 2010. Sarcopenic obesity was more prevalent in women (31.3%) than in men (19.6%). Individuals with SO had significantly higher fasting insulin, homeostasis model assessment of insulin resistance (male: 3.2 ± 1.4, female: 3.4 ± 2.1), and triglycerides (male: 167.3 ± 90.6 mg/dL, female: 160.7 ± 85.0 mg/dL). High-density lipoprotein was under the normal criteria (50 mg/dL) in women. Intake of nutrients associated with muscle loss (protein, vitamin D, calcium, and vitamin C) was significantly different among the male but not the female groups. Although protein intake was normal, calcium and vitamin D intakes were insufficient in all groups. In conclusion, body composition changes were related to nutrient intakes in elderly (60 years or older) men but not elderly women. Women had a higher prevalence of SO than did men, suggesting that early nutritional intervention in elderly women may help them address age-associated body composition changes.

Dietary pattern classifications with nutrient intake and body composition changes in Korean elderly.

BACKGROUND/OBJECTIVES: The body composition changes in aging increased the risk of metabolic disorder. Recent dietary studies have increasingly focused on the correlations between dietary patterns and chronic diseases to overcome the limitations of traditional single-nutrient studies because nutrients in food have complex relations that interact. SUBJECTS/METHODS: This study was conducted to classify a dietary pattern among Korean elderly using cluster analysis and to explore the relationships between dietary patterns and body composition changes in Korean elderly aged 65 years or older. The study subjects (n = 1,435) were individuals who participated in the Korean National Health Examination and Nutrition Survey (KNHANES) in 2011. RESULTS: THERE WERE THREE DIETARY PATTERNS DERIVED BY CLUSTER ANALYSIS IN THIS STUDY: 'Traditional Korean' (37.49% of total population), 'Meat and Alcohol' (19.65%) and 'Westernized Korean' (42.86%). The (1) 'Traditional Korean' pattern was characterized by high consumptions of white rice and low protein, low fat, and low milk products, while (2) 'Westernized Korean' pattern ate a Korean-style diet base with various foods such as noodles, bread, eggs and milk, (3) 'Meat and Alcohol' pattern had high consumptions of meat and alcohol. In body composition changes, compared with the 'Traditional Korean' pattern, the 'Meat & alcohol' pattern was associated with a 50% increased risk of having elevated BMI (kg/m(2)), 'Westernized Korean' pattern was associated with a 74% increased abnormality of ASM/Wt (kg) by logistics analysis. Most of the Korean adult population continues to follow ether a traditional Korean having beneficial effects for successful aging. However, the 'Traditional Korean' pattern showed low protein intake (0.7 g/kg), calcium intake, and vitamin D intake as well as low of appendicular skeletal muscle mass (ASM (kg)) among 3 groups. CONCLUSIONS: Considering the low ASM, consumption of protein, calcium and vitamin D should be increased for Korean elderly health body composition.

Applying the Health Belief Model to college students' health behavior.

The purpose of this research was to investigate how university students' nutrition beliefs influence their health behavioral intention. This study used an online survey engine (Qulatrics.com) to collect data from college students. Out of 253 questionnaires collected, 251 questionnaires (99.2%) were used for the statistical analysis. Confirmatory Factor Analysis (CFA) revealed that six dimensions, "Nutrition Confidence," "Susceptibility," "Severity," "Barrier," "Benefit," "Behavioral Intention to Eat Healthy Food," and "Behavioral Intention to do Physical Activity," had construct validity; Cronbach's alpha coefficient and composite reliabilities were tested for item reliability. The results validate that objective nutrition knowledge was a good predictor of college students' nutrition confidence. The results also clearly showed that two direct measures were significant predictors of behavioral intentions as hypothesized. Perceived benefit of eating healthy food and perceived barrier for eat healthy food to had significant effects on Behavioral Intentions and was a valid measurement to use to determine Behavioral Intentions. These findings can enhance the extant literature on the universal applicability of the model and serve as useful references for further investigations of the validity of the model within other health care or foodservice settings and for other health behavioral categories.

A newly synthesized, potent tyrosinase inhibitor: 5-(6-hydroxy-2-naphthyl)-1,2,3-benzenetriol.

In searching for new agents with a depigmenting effect, we synthesized a derivative of resveratrol, 5-(6-hydroxy-2-naphthyl)-1,2,3-benzenetriol (5HNB) with a potent tyrosinase inhibitory activity. 5HNB inhibited mushroom tyrosinase with an IC(50) value of 2.95 microM, which is more potent than the well-known anti-tyrosinase activity of kojic acid (IC(50)=38.24). The results of the enzymatic inhibition kinetics by Lineweaver-Burk analysis indicated 5HNB inhibits tyrosinase non-competitively when L-tyrosine was used as the substrate. Based on the strong inhibitory action of 5HNB, it is expected that 5HNB can suppress melanin production in which tyrosinase plays the essential role. Our expectation was confirmed by the experimentations with B16 melanoma cells in which 5HNB inhibited melanin production. We propose that 5HNB might have skin-whitening effects as well as therapeutic potential for treating skin pigmentation disorders.

5-Hydroxytrytophan inhibits tert-butylhydroperoxide (t-BHP)-induced oxidative damage via the suppression of reactive species (RS) and nuclear factor-kappaB (NF-kappaB) activation on human fibroblast.

5-Hydroxytryptophan (5HTP), an analogue of tryptophan, is a precursor of serotonin that also has effective antioxidative and anti-apoptotic properties (1) . However, the cellular mechanisms underlying these properties of 5HTP have not been explored. In this study, we tested the hypothesis that 5HTP exerts its antioxidative action against oxidative stress and inflammation by suppressing the activation of the key pro-inflammatory transcriptional pathways, p38 mitogen-activated protein kinase (p38MAPK) and nuclear factor-kappaB (NF-kappaB). The study was carried out using human fibroblast cells that were challenged by tert-butylhydroperoxide (t-BHP)-induced oxidative damage. Results show that 5HTP significantly reduced t-BHP-induced oxidative damage in human fibroblast cells, as determined by cell cytotoxicity, intracellular reactive species (RS) and peroxynitrite (ONOO(-)) generation, and inducible nitric oxide synthase expression. Moreover, 5HTP protected human fibroblast cells against t-BHP-induced oxidative DNA damage, as determined by 4,6-diamidino-2-phenlylindole (DAPI) staining. Pretreatment of human fibroblast cells with 5HTP also dose-dependently inhibited glutathione (GSH) depletion, indicating that it protects cells against t-BHP-induced oxidative damage. Western blot analysis revealed that 5HTP also markedly increased Bcl-2 expression and suppressed both p38MAPK and NF-kappaB activation in the t-BHP-treated human fibroblast cells. When these results are taken together, they strongly indicate that 5HTP has beneficial and protective effects against t-BHP-induced cell death in vitro, as demonstrated by its antioxidative and anti-inflammatory actions. Data further showed that the protective mechanisms underlying the actions of 5HTP against oxidative stress-induced damage are associated with RS/ONOO(-) scavenging and the inhibition of lipid peroxidation and GSH depletion.

Modulation of age-related NF-kappaB activation by dietary zingerone via MAPK pathway.

Zingerone, a major component found in ginger root, has been known as anti-mutagenic and anti-carcinogenic activities that are often associated with its anti-oxidative and anti-inflammatory activities. In recent studies, we examined molecular mechanism of zingerone treatment on pro-inflammatory NF-kappaB activation via the redox-related NIK/IKK and MAPK pathways. Action mechanism of zingerone on NF-kappaB signaling was investigated in aged rat kidney and endothelial cells. The results showed that zingerone had not only the antioxidant effect by constitutive suppression of ROS, but also anti-inflammatory effects by suppression of nuclear factor (NF)-kappaB activation in aged rat. In addition, zingerone treatment suppressed gene activation of pro-inflammatory enzymes, COX-2 and iNOS, which were upregulated with aging through NF-kappaB activation and IKK/MAPK signaling pathway. These experiments strongly indicate that zingerone treatment exerts a beneficial efficacy by suppressing both oxidative stress and age-related inflammation through the modulation of several key pro-inflammatory genes and transcription factors. Thus, the significance of our findings is that the zingerone treatment may provide some preventive measure against chronic inflammatory conditions that underlie many age-related inflammatory diseases, such as metabolic syndrome, cardiovascular disease, dementia, arthritis, diabetes, osteoprosis, and cancers.

Antimelanogenic activity of 3,4-dihydroxyacetophenone: inhibition of tyrosinase and MITF.

3,4-Dihydroxyacetophenone (3,4-DHAP) was evaluated for antimelanogenic activity. The tyrosinase inhibitory action by 3,4-DHAP using mushroom tyrosinase revealed a strong inhibitory effect. To further explore this matter, inhibition of tyrosinase and melanin content was measured in B16 melanoma cells (B16 cells). Further, tyrosinase and microphthalmia transcription factor (MITF) protein levels were determined by the Western blot method. Additionally, tyrosinase and MITF protein levels were reduced by 3,4-DHAP. Our data indicate that the antimelanogenic activity of 3,4-DHAP was probably due to its inhibition of tyrosinase activity and the suppression of tyrosinase and MITF protein levels.

Inhibition of melanogenic activity by 4,4'-dihydroxybiphenyl in melanoma cells.

In our previous study, we showed that 4,4'-dihydroxybiphenyl (44'-BP) reduced melanin content via the inhibition of tyrosinase. In the current study, we utilized 44'-BP treated B16 melanoma cells (B16 cells) to measure several key cellular parameters known to be involved in melanogenic activity. Included in these measurements were tyrosinase and microphthalmia transcription factor (MITF) protein levels, cyclic AMP levels, protein kinase A (PKA) activation, and reduced glutathione (GSH) and oxidized glutathione (GSSG) levels. Results showed that 44'-BP effectively suppressed the amounts of tyrosinase and MITF proteins, cAMP levels, and PKA activation. In addition, 44'-BP enhanced the GSH/GSSG ratio. In conclusion, our data provide an evidence that 44'-BP suppressed several cellular key parameters in the melanogenic pathway by downregulating the cAMP-dependent PKA signaling pathway and decreasing MITF gene expression (implied from the reduced protein levels), which in turn suppressed tyrosinase. We propose that the antimelanogenic action of 44'-BP is likely carried out by a combined effect of its anti-oxidant property and its ability to enhance intracellular GSH levels.

Anti-inflammatory action of dietary fish oil and calorie restriction.

Inflammation, inflammatory mediators, cyclooxygenase (COX)-2, and inducible nitric oxide (iNOS) are all influenced by age-related oxidative status. To investigate the effect of dietary fish oil (FO) and calorie restriction (CR) on oxidative stress-related inflammatory status with age, (NZB/NZW) F1 (B/W) mice were fed for 4 and 9 months either ad libitum or calorie-restricted (60% of ad libitum intake) diets containing 5% corn oil or 5% FO. We measured several key oxidative and inflammatory markers: TBARS, xanthine oxidase (XOD)-derived superoxide generation, and PGE2 and LTB4 production. Expressions of renal COX-1, COX-2, and iNOS mRNA were analyzed by RT-PCR; additionally, COX-2 protein was estimated by Western-blot method. Results show that FO intake and CR individually and together suppressed age-related increases in lipid peroxidation and superoxide generation. The inhibitory effects of dietary FO and CR were also found for iNOS expression, COX-2 expression, which subsequently led to the suppression of PGE2 and LTB4. We conclude that the beneficial effects of FO feeding and CR are synergistic in ameliorating the age-related nephritis of B/W mice by suppressing COX-2 and iNOS, reactive species generation, and pro-inflammatory mediators.

4,4'-Dihydroxybiphenyl as a new potent tyrosinase inhibitor.

The color of mammalian skin is determined by many factors, for which visible ones are the degree and distribution of melanin pigmentation. Because tyrosinase, (polyphenol oxidase) is the key enzyme for melanin biosynthesis, the use of various tyrosinase inhibitors is a common practice for whitening purpose in cosmetics. In the present study, the inhibition of tyrosinase by 4,4'-dihydroxybiphenyl (44'-BP) was investigated. In addition to tyrosinase inhibiting activity, melanin biosynthesis was assessed in B16F10 melanoma cells (B16 cells). The results showed that 44'-BP exhibits a strong anti-tyrosinase activity with IC50=1.91 microM. The kinetic analysis of tyrosinase inhibition revealed that 44'-BP acts a competitive inhibitor (Ki=4.0 x 10(-4) M at 2.5 microM and Ki =21 x 10(-5) M at 5 microM). Furthermore, data on melanin biosynthesis indicated that the amount of melanin was clearly suppressed by 44'-BP.

Peroxynitrite scavenging activity of indole derivatives: interaction of indoles with peroxynitrite.

One of the products of nitrogen-derived free radicals, peroxynitrite (ONOO(-)), is formed by the reaction of superoxide anion (O(2)(*-)) with nitric oxide (NO). ONOO(-) can cause damage to proteins and DNA through nitration. In particular, proteins and their constituent amino acids have been proven to be extremely sensitive to ONOO(-). However, the lack of specific endogenous defense enzymes to protect against ONOO(-) has prompted many researchers to search for endogenous scavengers. We previously found 5-hydroxytryptamine (HT), which is an indole derivative (ID), to be an efficient ONOO(-) scavenger. In the present study, the interaction of several other indoles was further investigated: tryptophan (TRP), 5-hydroxyL-tryptophan (HLT), HT, N-acetyl-5-hydroxytryptamine (AHT), 5-methoxyindole-3-acetate (MIA), 5-methoxytryptamine (MT), and melatonin. The ONOO(-) scavenging activity of ID was assayed by measuring the formation of oxidized dihydrorhodamine-123 (DHR-123). The scavenging efficacy was expressed as the IC(50), denoting the concentration of each indole required to cause 50% inhibition of DHR-123 formation. In a separate in vitro study, the protective effect of IDs against ONOO(-)-induced nitration of bovine serum albumin was investigated. Nitration was quantified using an immunoassay with a monoclonal anti-nitrotyrosine antibody, and a horseradish peroxidase-conjugated anti-mouse secondary antibody from sheep. The results revealed that the inhibitory activities of indoles were as follows: HLT, IC(50) = 0.73 microM; HT, IC(50) = 1.03 microM; and AHT, IC(50) = 0.98 microM), showing relatively strong activities against ONOO(-). Interestingly, TRP, MIA, MT, and melatonin were less effective. Regarding the protection of albumin by IDs, the data showed that the formation of ONOO(-) was inhibited in a dose-dependent manner. Further probing of the mode of the interaction of indoles revealed that the hydroxyl groups in IDs are required for the enhanced scavenging action. It was concluded that several indole derivatives with hydroxyl groups are effective scavengers against ONOO(-), and that the scavenging efficacy depends on the presence of hydroxyl groups located within the indole ring structure.

Inhibition of tyrosinase by protocatechuic aldehyde.

The purpose of this study was to determine the inhibitory action of protocatechuic aldehyde (PCA) on tyrosinase activity. PCA is one of the compounds found in the root of Salvia miltiorrhiza. Our study documented that PCA has a potent inhibitory effect on tyrosinase, which catalyzes the rate-limiting step of melanin biosynthesis. Although melanin biosynthesis has an essential function normally in human skin for defense against ultraviolet light of the sun, its abnormal activity as seen in pigmentation disorder could lead to serious medical problems. Our data showed that PCA, with concentrations ranging from 1 x 10(-5) M to 8 x 10(-5) M, exhibited dose-dependent inhibition of the enzyme activity with 50% of inhibition at 19.92 x 10(-6) M. A further kinetic analysis on PCA inactivation of tyrosinase activity revealed a competitive inhibition of the enzyme at the L-tyrosine binding site. The findings of our present study merit further research on the applicability of PCA as a potential agent for treatment of pigmentation disorder.

The structure-activity relationship of flavonoids as scavengers of peroxynitrite.

Peroxynitrite is a cytotoxic intermediate produced by the reaction between a superoxide anion radical and nitric oxide. The scavenging activities of flavonoids on peroxynitrite were investigated to illustrate the structure-activity relationship. Peroxynitrite was scavenged by the presence of various flavonoids, whose structures seem to be closely related to the degree of scavenging. Of 31 compounds tested, the most active was quercetin, with an IC50 value of 0.93 microM. Others had IC50 values ranging from 0.96 to more than 10 microM. The scavenging activity was postulated to be governed by the position of the hydroxyl group. Ortho-hydroxyl structures increased the scavenging activity on peroxynitrite.

Age-related changes in redox status of rat serum.

Aging and age-related diseases are known to be associated with increased oxidative stress. To protect against the deleterious effects of oxidative stress, a well-co-ordinated network of enzymatic and nonenzymatic anti-oxidant defense systems is essential. In the present study, we investigated the age-related redox status of serum by analyzing hydrogen peroxide, hydroxyl radical, superoxide-scavenging abilities, and other redox markers. Results showed the anti-oxidative capacity to be significantly decreased in serum of aged rats, which was accompanied by a marked increase in peroxide levels. Our analyses also revealed that levels of nitrated proteins, induced by peroxynitrite treatment, were higher in old rats than in young rats. Our results clearly indicated that the serum redox balance shifted toward oxidation during aging. To further confirm this age-related redox shift, we quantified the changes in thiol content. The total thiol level was found to be significantly decreased in the aged group. We also noticed an age-related reduction in serum albumin, which may be partially responsible for the decreased serum thiol levels. A similar pattern can be explained by low levels of serum GSH in old rats compared to young rats. The significance of the present study is the data showing increased oxidative stress in serum during aging, attributed to a decrease in major antioxidant components in serum.