No abstract

Dietary supplementation with branched-chain amino acids (BCAAs), including leucine, isoleucine, and valine, has shown potential benefits for the metabolic profile. However, higher blood BCAA levels have been associated with insulin resistance. To our knowledge, there has been no study on dietary BCAAs and the risk of diabetes. We examined the association between BCAA intake and risk of diabetes in a population-based cohort study in Japan. A total of 13,525 residents of Takayama City, Japan, who enrolled in a cohort study in 1992 responded to a follow-up questionnaire seeking information about diabetes in 2002. Diet at baseline was assessed by means of a validated food frequency questionnaire. A high intake of BCAAs in terms of percentage of total protein was significantly associated with a decreased risk of diabetes in women after controlling for covariates; the hazard ratio for the highest tertile versus the lowest was 0.57 (95% confidence interval: 0.36, 0.90; P-trend = 0.02). In men, leucine intake was significantly marginally associated with the risk of diabetes; the hazard ratio for the highest tertile versus the lowest was 0.70 (95% confidence interval: 0.48, 1.02; P-trend = 0.06). Data suggest that a high intake of BCAAs may be associated with a decrease in the risk of diabetes.

Data suggest that natto intake may contribute to the reduction of CVD mortality.

This study examined oral cancer in a cohort of 78 140 women aged 30 -84 years in Karunagappally, Kerala, India, on whom baseline information was collected on lifestyle, including tobacco chewing, and sociodemographic factors during the period 1990 -1997. By the end of 2005, 92 oral cancer cases were identified by the Karunagappally Cancer Registry. Poisson regression analysis of grouped data, taking into account age and income, showed that oral cancer incidence was strongly related to daily frequency of tobacco chewing (Po0.001) and was increased 9.2-fold among women chewing tobacco 10 times or more a day. The risk increased with the duration of tobacco chewing during the first 20 years of tobacco chewing. Age at starting tobacco chewing was not significantly related to oral cancer risk. This is the first cohort study of oral cancer in relation to tobacco chewing among women.

The effects of soy or isoflavone intake on breast cancer need to be examined further in epidemiologic studies. We assessed the associations of soy and isoflavone intake with breast cancer incidence in a population-based prospective cohort study in Japan. Participants were members from the Takayama study, aged 35 years or older in 1992. The follow-up was conducted from the time of the baseline study (September 1, 1992) to the end of March 2008. Cancer incidence was mainly confirmed through regional population-based cancer registries. Breast cancer was defined as code C50 according to ICD-10. Soy and isoflavone intakes were assessed with a validated food frequency questionnaire. Using the Cox proportional hazard models, the association of soy and isoflavone intake with breast cancer was assessed after adjustments for age, body mass index, physical activity, smoking, alcohol consumption, education, age at menarche, age at first delivery, menopausal status, number of children and history of hormone replacement therapy. Among the 15,607 women analyzed, 172 had developed breast cancer. The relative risks of postmenopausal breast cancer were lower among women with higher intakes of soy (trend p 5 0.023) and isoflavone (trend p 5 0.046), although the relative risks of premenopausal breast cancer were not associated with intakes of soy and isoflavone. Decreased risks of breast cancer were found even among women with a moderate intake of soy and isoflavone. These results suggested that soy and isoflavone intakes have a protective effect on postmenopausal breast cancer.Soy foods, which are a rich source of isoflavone, a kind of phytoestrogen, are traditionally found in Asian diets and are consumed in a higher volume than that in the Western world.1 As the incidence of breast cancer within the Asian population is lower than that in the Western population, 2,3 it has been proposed that high intakes of soy or isoflavone might reduce the risk of breast cancer. Several experimental studies have also reported that soy has a property that suppresses mammary tumorigenesis. [4][5][6] In several epidemiologic studies, the association between soy or isoflavone intake and the risk of breast cancer has been examined. As far as we know, four meta-analyses were published between 2006 and 2011 and included different subset of studies.7-10 Among them, three meta-analyses showed that high soy intake was modestly associated with reduced breast cancer risk in Asian but not in Western populations. 7-9Only one study 10 reported that the protective effects of soy on breast cancer risk were not statistically significant among women in Asian countries. However, they considered Asian countries instead of Asian populations and the results from two studies conducted in Asian Americans were included as studies in Western countries, which might contribute to their nonsignificant findings in Asians. Besides, Trock et al. 10 and Qin et al. 9 reported that the protective effects were more apparent in premenopausal than postmenopausal women, although ...