Keiko Baba

Misreporting of dietary energy, protein, potassium and sodium in relation to body mass index in young Japanese women

Objective:Although under-reporting of dietary intake is more common in persons with a high body mass index (BMI), it is not well known whether or not misreporting is selective for different foods (and hence energy and nutrients), particularly in non-Western populations. We examined misreporting of dietary intake against biomarkers and its relation with BMI in young Japanese women.Design:Cross-sectional study.Subjects:A total of 353 female Japanese dietetic students aged 18–22 years (mean BMI: 21.4 kg/m2, mean fat intake: 29.8% of energy).Methods:Misreporting of dietary energy, protein, potassium and sodium (assessed by a self-administered diet history questionnaire) was examined against respective biomarkers (estimated energy expenditure and 24-h urinary excretion). Reporting accuracy was calculated as the ratio of reported intake to that estimated from corresponding biomarkers (complete accuracy: 1.00).Results:Mean reporting accuracy of absolute intake (amount per day) varied considerably (0.86–1.14). Reporting accuracy of absolute intake decreased with increasing BMI (P for trend <0.001). However, no association was observed between reporting accuracy of energy-adjusted values and BMI (P for trend >0.15), indicating that BMI-dependent misreporting was canceled by energy adjustment. This was owing to positive correlation between the reporting accuracy of energy intake and that of absolute intake of the three nutrients (Pearson correlation coefficient: 0.49–0.67, P<0.0001).Conclusions:Although differential misreporting of absolute intake was associated with BMI, differential misreporting of energy-adjusted value was not. These findings support the use of energy-adjusted values in the investigation of diet–disease relationships among lean populations with a low-fat intake.

Total n-3 polyunsaturated fatty acid intake is inversely associated with serum C-reactive protein in young Japanese women.

Little is known about the relation of dietary factors to circulating C-reactive protein (CRP) concentrations in young adults and non-Western populations. We cross-sectionally examined associations between dietary intake and serum CRP concentrations in young Japanese women. The subjects were 443 female Japanese dietetic students aged 18 to 22 years. Dietary intake was assessed with a validated, self-administered, comprehensive, diet history questionnaire. Serum CRP concentrations were measured by highly sensitive nephelometry. The prevalence of elevated CRP (> or = 1 mg/L) was 5.6%. After adjustment for possible confounding factors including body mass index, a significant inverse association was seen between total n-3 polyunsaturated fatty acid intake and elevated CRP. The multivariate adjusted odds ratios of elevated CRP for women with intake below and above the median (1.1% of energy) were 1.00 and 0.33 (95% confidence interval, 0.13-0.82; P = .02), respectively. Intake of eicosapentaenoic acid + docosahexaenoic acid and alpha-linolenic acid was not associated with elevated CRP concentrations (P = .62 and P = .27, respectively). Vitamin C intake was independently inversely associated with elevated CRP, although the association was nonsignificant (P = .10). No clear associations were observed for other dietary factors examined including total fat, saturated fatty acids, monounsaturated fatty acids, polyunsaturated fatty acids, total dietary fiber, soluble dietary fiber, insoluble dietary fiber, and magnesium; fruits, vegetables, and fish and shellfish; and dietary glycemic load (P = .27 to P = .99). In conclusion, total n-3 polyunsaturated fatty acid intake showed an independent inverse association with elevated serum CRP concentration in a group of young Japanese women.

Lower estimates of δ-5 desaturase and elongase activity are related to adverse profiles for several metabolic risk factors in young Japanese women

Little is known about the relation between the activities of certain enzymes involved in endogenous fatty acid synthesis and metabolic risk factors, particularly in young adults and non-Western populations. In this cross-sectional study, we examined the associations between estimated desaturase and elongase activities and metabolic risk factors in young Japanese women. The subjects were 640 female Japanese dietetic students aged 18 to 22 years. Body height and weight, from which body mass index (BMI) was derived, waist circumference, and blood pressure were measured. Fasting blood samples were collected for biochemical and fatty acid measurements. Desaturase and elongase enzyme activities were estimated as the ratio of product to precursor of individual fatty acids in serum lipids. delta-9 desaturase activity was positively associated with BMI, diastolic blood pressure, total and low-density lipoprotein cholesterol, and triacylglycerol and was negatively associated with high-density lipoprotein cholesterol (P <or= .019). delta-6 desaturase activity showed positive associations with BMI, systolic blood pressure, triacylglycerol, and the homeostasis model assessment of insulin resistance (P <or= .045). delta-5 desaturase activity showed independent negative associations with BMI, systolic blood pressure, triacylglycerol, insulin, and the homeostasis model assessment of insulin resistance (P <or= .007). Elongase activity was associated negatively with BMI, systolic and diastolic blood pressures, and triacylglycerol and was positively associated with high-density lipoprotein cholesterol (P <or= .026). In conclusion, increased estimates of delta-9 and delta-6 desaturase activity and decreased estimates of delta-5 desaturase and elongase activity were associated with adverse profiles for several metabolic risk factors in young Japanese women.

Dietary total antioxidant capacity from different assays in relation to serum C-reactive protein among young Japanese women.

BackgroundThe association between dietary total antioxidant capacity (TAC) from different assays and serum C-reactive protein (CRP) has not been assessed in non-Western populations. We examined the association between dietary TAC and serum CRP concentration in young Japanese women using different four TAC assays.MethodsThe subjects were 443 young Japanese women aged 18–22 years. Dietary TAC was assessed with a self-administered diet history questionnaire and the TAC value of each food using the following four assays: ferric reducing ability of plasma (FRAP); oxygen radical absorbance capacity (ORAC); Trolox equivalent antioxidant capacity (TEAC); and total radical-trapping antioxidant parameter (TRAP). Serum CRP concentrations were measured by highly sensitive nephelometry.ResultsThe major contributor to dietary TAC was green, barley, and oolong tea (FRAP: 53%, ORAC: 45%, TEAC: 36%, and TRAP: 44%). The prevalence of elevated CRP concentrations (≥ 1 mg/L) was 5.6%. TAC from FRAP was inversely associated with serum CRP concentrations (adjusted odds ratio [OR] for elevated CRP concentration in high [compared with low] dietary TAC group: 0.39 [95% confidence interval (CI): 0.16-0.98]; P = 0.04). TAC from ORAC was inversely associated with CRP, although the association was not significant (OR: 0.48 [95% CI: 0.20-1.14]; P = 0.10). TAC from TEAC was inversely associated with CRP (OR: 0.32 [95% CI: 0.12-0.82]; P = 0.02), as was TAC from TRAP (OR: 0.31 [95% CI: 0.12-0.81]; P = 0.02).ConclusionsDietary TAC was inversely associated with serum CRP concentration in young Japanese women regardless of assay. Further studies are needed in other populations to confirm these results.

Dietary glycemic index is associated with decreased premenstrual symptoms in young Japanese women

OBJECTIVES High glycemic index (GI) carbohydrates may increase brain serotonin, which in turn acts to alleviate premenstrual symptoms, because, although the main determinant of brain serotonin concentration is a high plasma ratio of tryptophan to other large neutral amino acids, a high-GI diet has been shown to increase this ratio. In this observational cross-sectional study, we investigated associations between dietary GI and other dietary carbohydrates and premenstrual symptoms. METHODS Subjects were 640 female Japanese dietetic students 18-22 y of age. Dietary carbohydrates were assessed using a validated, self-administered, comprehensive diet history questionnaire. Menstrual cycle symptoms were assessed using the retrospective version of the Moos Menstrual Distress Questionnaire (MDQ). Independent associations of dietary GI and glycemic load and intake of available carbohydrate and dietary fiber with the MDQ total score and subscale scores (pain, concentration, behavioral change, autonomic reactions, water retention, and negative affect) in the premenstrual phase (expressed as percentages relative to those in the intermenstrual phase) were examined. RESULTS Dietary GI was independently inversely associated with total MDQ score in the premenstrual phase (P for trend = 0.02). Dietary GI also showed independent and inverse associations with several MDQ subscale scores in the premenstrual phase, including concentration, autonomic reactions, and water retention (P for trend < 0.05). Conversely, dietary glycemic load and intake of available carbohydrate and dietary fiber were not associated with any of the MDQ scores in the premenstrual phase. CONCLUSION Dietary GI was independently associated with decreased premenstrual symptoms in a group of young Japanese women.

Association between Hardness (Difficulty of Chewing) of the Habitual Diet and Premenstrual Symptoms in Young Japanese Women

Recent evidence suggests that voluntary rhythmic movements such as chewing may increase blood serotonin and subsequently brain serotonin, which in turn acts to alleviate premenstrual symptoms. In this observational cross-sectional study, we tested the hypothesis that hardness (difficulty of chewing) of the habitual diet (i.e. dietary hardness) is associated with decreased premenstrual symptoms. Subjects were 640 female Japanese dietetic students aged 18-22 years. Dietary hardness was assessed as an estimate of masticatory muscle activity for the habitual diet (i.e. the difficulty of chewing the food). The consumption of a total of 107 foods was estimated by means of a self-administered, comprehensive diet history questionnaire, and masticatory muscle activity during the ingestion of these foods was estimated according to published equations. Menstrual cycle symptoms were assessed using the retrospective version of the Moos Menstrual Distress Questionnaire, from which total score and subscale scores (i.e. pain, concentration, behavioral change, autonomic reactions, water retention, and negative affect) in the premenstrual phase were calculated and expressed as percentages relative to those in the intermenstrual phase. Dietary hardness was not associated with total score in the premenstrual phase (P for trend = 0.48). Further, no association was seen for any subscale score in the premenstrual phase (P for trend = 0.18-0.91). In conclusion, this preliminary study failed to substantiate a hypothesized inverse relationship between hardness of the habitual diet and premenstrual symptoms. Considering the plausibility of the putative mechanism, however, further investigation using more relevant measures of chewing and premenstrual symptoms is warranted.

Neighborhood Socioeconomic Status and Premenstrual Symptoms: A Cross-sectional Study of Young Japanese Women

Recent evidence suggests reduced levels of serotonin, which may be associated with premenstrual symptoms, among populations in socioeconomically disadvantaged areas. In this cross-sectional study, we examined the association between neighborhood socioeconomic status (SES) and premenstrual symptoms. Participants were 640 female Japanese dietetic students aged 18–22 years, residing in 210 municipalities in Japan. Neighborhood SES index was defined by seven municipal-level variables (unemployment, household overcrowding, poverty, education, income, home ownership, and vulnerable groups), with an increasing index signifying increasing neighborhood socioeconomic disadvantage. Menstrual cycle symptoms were assessed using the Moos Menstrual Distress Questionnaire, from which subscale (pain, concentration, behavioral change, autonomic reactions, water retention, and negative affect) and total scores in the premenstrual phase were calculated and expressed as percentages relative to those in the intermenstrual phase. Neighborhood SES index was positively associated with pain score in the premenstrual phase (P = 0.02). This association remained after adjustment for potential confounding factors (P = 0.008). Neighborhood SES index also showed a positive relation with water retention score in the premenstrual phase (P = 0.03), although not independently of potential confounding factors (P = 0.14). However, no association was seen between neighborhood SES index and other subscale scores or total score in the premenstrual phase (P > 0.05). In conclusion, neighborhood socioeconomic disadvantage was independently associated with higher pain in the premenstrual phase, although a clear relationship with premenstrual symptoms was not found. Considering the plausibility of the proposed mechanism, however, further investigation using more relevant neighborhood SES indicators is warranted.