Use of Dietary Supplements among Japanese Female Nursing Professionals.

The use of dietary supplements has become a common way to maintain good health. This study evaluated the status of supplement use and supplement user characteristics among participants from the Japan Nurses' Health Study, which comprised a cohort of Japanese female nursing professionals. A questionnaire survey covering the use of vitamins and supplements was conducted. Supplements were classified according to their constituents and formulations. Logistic regression analyses were performed to determine the characteristics of supplement users. Results were as follows. There were 4,017 supplement users (34.4% of 11,665 valid answers). The supplement types used were: vitamins (n=2,655), minerals (n=1,121), amino acids and proteins (n=139), botanical products (n=714), animal by-products (n=849), herbal medicines (n=152), nutritional drinks (n=19), others (n=117), and unclassified supplements (n=320). Logistic regression analyses showed that supplement use was significantly associated with age and body mass index, and there were significantly higher proportions of supplement users among pregnant women, black tea drinkers, soy milk consumers, and lactobacillus beverage drinkers. In conclusion, the overall percentage of supplement users was 34.4%. A high prevalence of supplement use was observed among older, non-obese, and pregnant participants, and those who paid more attention to their health. The prevalence of supplement users was significantly higher among those who habitually drank black tea, soy milk, and lactobacillus beverages, suggesting participants used supplements to maintain their health or prevent diseases based on high health consciousness.

Optimal cut-off value for equol-producing status in women: The Japan Nurses' Health Study urinary isoflavone concentration survey.

Equol is one of the most active soy isoflavones. When the association between soy food intake in daily life and health outcomes is examined in epidemiological studies, it is important to define the equol-producing status of each individual. However, few studies have assessed equol-producing status without a soy challenge test. To determine a robust cutoff criterion for equol producer classification in observational studies, we conducted a urinary isoflavone concentration survey in daily life among women. Furthermore, we examined the association between eating habits regarding soy foods and equol-producing status. A total of 4,412 participants were included in the analyses. Urinary isoflavones were analyzed using a high-performance liquid chromatography method. We examined the distribution of the log10 equol/daidzein ratios, finding a mixture of two normal distributions, corresponding to equol producer and non-producer subpopulations. Applying a finite mixture model, we estimated the means, standard deviations, and mixing proportions of these two distributions. The estimation was carried out using the SAS NLIN procedure. The optimal cutoff point for the log10 equol/daidzein ratio in the study population was determined to be -1.42, according to the estimated parameters of the mixture distribution. Based on this criterion, 1,830 (41.5%) of the participants were identified as equol producers. Compared with non-consumers of soy foods, consumers of soy foods had significantly higher odds of being equol producers. Using log10-transformed equol/daidzein ratios ≥ -1.42 to define equol producers among Japanese women is reasonable and suitable for determining equol-producing status in epidemiological studies. We found that soy food eating habits were associated with equol-producing status. Further investigation is required to evaluate associations between equol-producing status in daily life and health outcomes. The results of this study suggest the best cutoff point to use in the definition of equol-producing status in daily life.

Herbal medicine, Hachimi-jio-gan, and its component cinnamomi cortex activate the peroxisome proliferator-activated receptor alpha in renal cells.

Hachimi-jio-gan is widely used to improve several disorders associated with diabetes, but its mechanism remains poorly understood. In an attempt to clarify the mechanism of Hachimi-jio-gan, we investigated the effects of this herbal medicine and its components in transfection studies of CV1 cells, especially nuclear receptor-mediated actions. One half (0.5) mg/ml of Hachimi-jio-gan activated peroxisome proliferator-activated receptor (PPARalpha), mediating the activation by 3.1-fold on DR1 response elements; however, it did not affect PPARgamma, thyroid hormone receptor, androgen receptor, estrogen receptor or RXR. In addition, this activation was observed in a dose-dependent manner. Next, to determine which components of Hachimi-jio-gan activate PPARalpha-mediated transcription, 8 of its components (rehmanniae radix, orni fructus, dioscoreae rhizoma, alismatis rhizoma, hoelen, moutan cortex, cinnamomi cortex, aconiti) were tested. Only cinnamomi cortex (1.0 mg/ml) increased PPARalpha-mediated transcription by 4.1-fold, and this activation was specific for PPAR alpha, and not for other nuclear receptors. Moreover, this PPARalpha-related activation by cinnamomi cortex is specifically observed in renal cells. Taken together, these findings indicate that Hachimi-jio-gan and cinnamomi cortex may have a pharmacological effect through the target site for PPARalpha.