Comparison of Various Foods Intakes and Their Relationships with Body Mass Index in Japanese Old Men and Women

Objective: Obesity is an important health problem, leading to many metabolic diseases such as type2 diabetes mellitus, cardiovascular diseases, cancer etc. There are many diet proposals to combat obesity. Since obesity is relatively rare in Japan, we wanted to know what kinds of foods influence body mass index (BMI) in old Japanese people. Methods: Healthy participants were given self-administered diet history questionnaires and described answers on each item by recollection of diets they took (7 days dietary recall). We used a brief-type self-administered diet history questionnaire (BDHQ) by using which the Japanese Ministry of Health, Labour and Welfare reports national Nutrition Surveys. From these questionnaires, we calculated the intakes of energy, carbohydrate, fat, protein or other foods. Results: Men take more alcohol, salt fruit, beans, and eggs than women. Intakes of major foods such as carbohydrate, lipid, and protein did not influence BMI in men and women. Conclusion: Within the range of foods intakes in Japan, no restriction of any food such as carbohydrate is not necessary for staying lean.

Foods Intakes and Their Influences on BMI (Body Mass Index) in Young and Middle Aged Women in Japan

Background: Japanese women’s body mass index (BMI) was known to be the lowest among people in OECD countries. We wanted to compare foods intakes and relationships between intakes of particular food species and BMI. Methods: We asked young and middle-aged women to participate and used a brief-type self-administered diet history questionnaire (BDHQ) to know the amounts of various food species they took. Results: Weights and BMI of young and middle-aged women were not different. Middle-aged women took almost all species of foods and energy more than young women. Except for cholesterol of soluble dietary fibers, there was no correlation between foods intakes and BMI. Conclusion: Both young and middle-aged Japanese women are lean (BMI;around 22). Middle-aged women took more energy, and proteins, carbohydrates, and lipids compared with young women. Middle-aged women spend more energy on house workings than young women in Japan.

Uniqueness of Tryptophan in the Transport System in the Brain and Peripheral Tissues

Amino acids are important substances that must be transported to tissues such as the brain and muscles. The process is considered insulin dependent. It is not known whether all the amino acids are almost equally dependent in their transportation to tissues. We want to know whether some important amino acids are transported differently from other amino acids. Especially tryptophan is important because it is converted to serotonin, melatonin or kynurenine. Results showed that Amino acids levels in the plasma were measured after the intakes of 50 grams of glucose or sucrose to young (18 - 22 years old) and old (≥50 years old) men. Total amino acids in the plasma decreased after the intakes of glucose. Total amino acids levels decreased more significantly in old men after the administration of sucrose. Total and non-essential amino acids in the plasma decreased significantly at 120 min after the intakes of glucose in young and old men, but only sucrose caused their decreases in both aged and young men. Both glucose and sucrose intakes decreased significantly the plasma levels of the total essential and branched amino acids in young and old men. Surprisingly, plasma levels of tryptophan did not decrease upon the administration of glucose but only slightly decreased upon the administration of sucrose in young men. In conclusion, not all the amino acids were transported well into tissues upon the administration of glucose or sucrose. Tryptophan seems to be relatively resistant for insulin to facilitate the transportation into tissues.

Measurement of Tryptophan Metabolites in Healthy Old Men and Patients of Type 2 Diabetes Mellitus (T2DM)

Background: Plasma levels of tryptophan (TRP) metabolites have not been measured extensively in patients of type 2 diabetes mellitus (T2DM). Methods: Metabolites analysis was performed by a liquid chromatograph tandem mass spectrometer, the LCMS-8060 quadrupole mass spectrometer combined with Nexera X2 liquid chromatograph system (Shimadzu Corporation, Kyoto, Japan). Body mass index (BMI) and TRP metabolites have been measured in healthy old men (n = 20) and patients of T2DM (n = 20). TRP metabolites were measured by using the ultrahigh speed liquid chromatography-mass spectros-copy (Shimadzu Corporation). Results: The plasma levels of 5-hydroxytryptophan (5-HTRP), 5-hydroxyindoleacetic acid (5-HIAA), kynurenic acid (KNA), 3-hydroxykynurenine (3-HKN), and 3-hydroxyanthranilic acid (3-HAA) were higher in patients of T2DM than healthy old men. Since 5HTRP and 5-HIAA belong to the serotonin pathway, and KNA, 3-HKN, and 3-HAA belong to the KN pathway of TRP metabolism, these pathways were activated more in the patients of T2DM. Since plasma levels of Indole-3-acetic acid were not elevated in T2DM, that pathway was not activated more in T2DM. Serotonin levels were not increased but 5-HIAA levels were increased in the plasma of T2DM patients, which may mean that serotonin was quickly metabolized to 5-HIAA in the patients of T2DM. Conclusion: Plasma levels of tryptophan metabolites in serotonin and kynurenine pathways increased in T2DM patients. Obesity expressed by BMI may not influence tryptophan metabolism in healthy old men and T2DM patients. These results indicate that our new method of the simultaneous measurements of all the tryptophan metabolites is the powerful measure to identify factor related to endogenous stresses seen in DM.

Effects of Dietary Citric Acid on Metabolic Indicators and Gene Expression in the Skeletal Muscles of Fasted Mice

Citric acid is recognized and utilized as a dietary supplement for its ability to eliminate fatigue. However, the molecular and cellular mechanism underlying this effect has not been elucidated. This study investigated the effect of intragastric citric acid administration on the energy metabolism and gene expression in the skeletal muscles of mice that had been fasted without exercise, using biochemical analyses of metabolic indicators and DNA microarrays. Expression of the genes involved in the glycolysis, tricarboxylic acid cycle and β-oxidation of fatty acids were not affected by citric acid administration. However, citric acid increased the level of blood glucose and expression of the phosphoenolpyruvate carboxykinase gene. These results indicate that citric acid ingestion may eliminate fatigue by promoting gluconeogenesis.

Effects of Dietary Green Rooibos on Physical Endurance in Swimming Mice

Green rooibos made from unfermented rooibos leaves contains high amounts of aspalathin. Dietary green rooibos is expected to increase physical endurance and decrease physical fatigue, because aspalathin has antioxidant activity and stimulates glucose uptake in muscle tissue. The aim of this study was to validate the effects of green rooibos and aspalathin by using a swimming mouse model. Dietary green rooibos and aspalathin tended to increase swimming time in mice. This beneficial effect might be induced by increased glycogen accumulation in the liver and skeletal muscles.

Plasma Levels of Amino Acids in Japanese Men and Their Changes after the Administration of Glucose and Sucrose

Background: It is not known whether plasma amino acids levels are different between young and old men in Japan. No research has been reported about changes in plasma levels of amino acids after the administration of glucose or sucrose to young and aged men. Objective: We want to know whether there are age differences in plasma levels of amino acids and if the administration of glucose or sucrose influences their levels. Results: Old people had lower plasma levels of most of amino acids, especially essential and branched-chain amino acids than young men. Plasma levels of amino acids were measured after the administration of 50 grams of glucose or sucrose to young (18 - 22 years old) and aged (≥50 years old) male adults. Plasma levels of total amino acids decreased after the administration of glucose. Decrease in the total amino acid levels was significant in aged men after the administration of sucrose. A significant decrease in plasma levels of total non-essential amino acids was observed at 120 min after the administration of glucose but not sucrose in both aged and young men. Both glucose and sucrose administrations resulted in a significant decrease in the plasma levels of the total essential amino acid levels and branched amino acids in young and aged men. Conclusion: These results suggest that there are age differences in plasma levels of amino acids. Upon the administration of glucose or sucrose amino acids, particularly essential amino acids, decreased in plasma. These amino acids may be transported from the blood soon after the administration of sugar (glucose or sucrose) to the tissues, such as muscles, possibly due to an increase in the insulin levels.

Expression of Genes Related to Glycolysis in the Liver and Skeletal Muscle of Rats after Citric Acid Administration

Citric acid is known to alleviate physical fatigue and improve athletic performance;however, the underlying mechanism is unknown. Therefore, we aimed to investigate the effect of citric acid administration on the expression of key glycolysis-related genes in the liver and skeletal muscle of rats. Eight-week-old male Sprague-Dawley rats were divided into two groups—control and citric acid groups. The rats were fasted overnight, after which distilled water or citric acid solution was administered intragastrically;after 150 min, the rats were sacrificed, and the liver and skeletal muscle were collected. In the skeletal muscle, namely soleus and gastrocnemius muscles, the phosphofructokinase and pyruvate kinase gene expression were significantly decreased by citric acid administration. In contrast, the glucokinase and pyruvate kinase gene expression in the liver was significantly increased. These results suggest that exogenous dietary citric acid suppresses glycolysis in the skeletal muscle at the transcription level.

Fatigue Alleviation Mechanism of Citric Acid Determined by Gene Expression Analysis in the Mouse Liver

Citric acid has been recognized for its ability to alleviate fatigue;however, the mechanism contributing to this effect has not yet been elucidated. Our previous study suggested that the alleviation of fatigue by citric acid intake might be induced by the acceleration of gluconeogenesis. In this study, we tested this hypothesis and evaluated whether the intake of citric acid accelerates gluconeogenesis in the mouse liver through microarray analysis. Because the microarray of focus includes 200 metabolic genes, it could be used to provide information on genes related to glucose metabolism as well as other pathways such as inflammation. Eight-week-old male C57/BL6J mice were divided into the distilled water and citric acid groups (n = 6), and were administered distilled water or a citric acid solution (20 mg/30g body weight) intragastrically with a probe, respectively. Forty minutes after administration, the mice were sacrificed by decapitation. The blood glucose level of the citric acid group was significantly higher (P = 0.001) than that of the distilled water group. The expression levels of genes related to glucose metabolism (Gck, Pfkl, Pklr, Pck1, G6pc) were not changed by the intake of citric acid. On the other hand, some transcriptional differences were observed in several other genes, including those related to inflammation, blood pressure, the electron transport system, uncoupling proteins, and anti-oxidation. The expression levels of genes related to inflammation were reduced in the citric acid group;e.g., the Il6 expression level was 0.78 times lower in the citric acid group than that in the distilled water group. In conclusion, the results of this study suggest that citric acid intake could accelerate gluconeogenesis and suppresses inflammation. Therefore, the fatigue-alleviation effects of citric acid might be induced by an additive effect between the maintenance of blood glucose levels and the suppression of inflammation.

Correlation of Various Foods Intakes and Plasma Levels of Omega Fatty Acids in Healthy Japanese Old Men

Background: Trans fatty acids are considered to impair health and some ω fatty acids are protective against atherosclerosis and diabetes mellitus. Trans fatty acids are said to be formed by the partial hydrogenation of vegetable oils. Some amounts are produced in digestive organs of ruminants and present in dairy products or meat. It is important how much these intaken fatty acids influence their plasma levels. Methods: Plasma levels of fatty acids including transforms of healthy old men are measured by gas chromatography and correlations between various foods intakes and plasma levels of trans fatty acids, and ω fatty acids are examined. Results: Intake of fish resulted in increase in plasma levels of docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) but intake of meat such as beef, cow and chicken meat did not increase plasma levels of arachidonic acid (AA). Intakes of oils increased plasma levels of dihomo-g-linolenic acid significantly and AA to some extent. Conclusion: Plasma levels of EPA and DHA increased upon intakes of fish in Japanese old men. Oil intake but not meat intake increased DGLA significantly. These results may explain low incidence of cardiovascular diseases in Japanese people compared with American people whose plasma levels of DHA and EPA are lower.

Effects of Various Foods Intakes on Plasma Levels of Trans Fatty Acids in Japanese Old Men

Background: Trans fatty acids are said to be formed by the partial hydrogenation of vegetable oils. Some amounts are produced in digestive organs of ruminants and present in dairy products or meat. In Japan, use of trans fatty acids in the foods is prohibited, thus trans fatty acids must come from foods or microbes in the digestive organs. Methods: Plasma levels of fatty acids including trans forms of healthy old men are measured by gas chromatography and correlations between various foods intakes and plasma levels of trans fatty acids such as palmitoelaidic, elaidic and linoelaidic acids are examined. Results: No correlations between various foods intakes and trans fatty acids were found except between intake of preference drinks such as tea or coffee and plasma levels of palmitoelaidic and linoelaidic acids. Conclusion: Since palmitoelaidic acid is cardioprotective, increase in plasma levels of palmitoelaidic acid may indicate that intakes of tea and coffee may be beneficial for heath by increasing palmitoelaidic acids.

Effects of Gender, Age, and Clot Formation on the Measurements of Tryptophan Metabolites in Blood

Background: Tryptophan metabolism plays important roles in health and diseases. Although simultaneous measurements of tryptophan metabolites are successfully measured, influences of age, gender, and clot formation on the measurements have not been reported. Methods: We took blood from young and old Japanese men and women and compared plasma levels of tryptophan metabolites. We also took plasma and serum from the blood of middle-aged men (n = 10). Metabolites analysis was performed by a liquid chromatograph tandem mass spectrometer, the LCMS-8060 quadrupole mass spectrometer combined with Nexera X2 liquid chromatograph system (Shimadzu Corporation, Kyoto, Japan). Body mass index (BMI) and TRP metabolites have been measured in healthy young men (n = 48), young women (n = 47), old men (n = 44), and old women (n = 39). TRP metabolites were measured by using the ultrahigh speed liquid chromatography-mass spectroscopy (Shimadzu Corporation). Results: Tryptophan and its metabolites such as serotonin, 5-hydroxyindole acetic acid, indole-3-acetic acid, kynurenine, anthranilic acid, were higher in young women and old men than young men and old women. Plasma levels of 3-hydroxykynurenine and xanthurenic acid were lower in young women and old men. Comparison of plasma and serum indicates that most of metabolites were higher in serum than plasma except for 3-hydroxy-kynurenine and quinolinic acid. Conclusion: Metabolites of the upper stream of degradation of tryptophan were higher in young women and old men than young men and old women, which suggests that the degradation of tryptophan was accelerated in young men and old women than young women and old men. Serum preparation may activate tryptophan degradation resulting in higher levels of metabolites in serum than in plasma.

Plasma Fatty Acid Composition in Men over 50 in the USA and Japan

Background: Coronary heart disease (CHD) rates differ markedly between the US and Japan. Fatty acid profiles have been linked to risk for CHD. Few studies have compared the plasma fatty acid composition, including trans fatty acids, in Japanese and US subjects. Methods: Fasting blood samples were taken from healthy older (>age 50) American (n = 76) and Japanese (n = 44) men, and plasma levels of 23 fatty acids were analyzed by gas chromatography and expressed as a percent of total fatty acids. Results: As expected, plasma levels of long-chain ω3 fatty acids (docosahexaenoic and eicosapentaenoic acids, DHA and EPA) were higher in Japanese men and ω6 fatty acids (e.g., arachidonic acid, AA) were lower compared with American men. Plasma levels of the major industrially-produced trans fatty acids (IP-TFAs;elaidic and linoelaidic acids) were far higher in American men, and levels of the potentially cardioprotective, primarily ruminant-derived trans fatty acid palmitoelaidic acid (POA) were higher in Japanese. Plasma levels of saturated or monounsaturated fatty acids were also higher in the American men. Conclusion: There are multiple differences in plasma fatty acid profiles between American and Japanese older men. The higher levels of DHA and EPA, along with the lower levels of the IP-TFAs, are consistent with the markedly lower risk for coronary heart disease in Japan vs. the US.