Various health plans have been proposed in Japan in order to extend healthy life expectancy. We have accumulated scientific evidence related to lifestyle factors that are beneficial for preservation of bone health. First, we have screened nutrients and food components that affect bone metabolism using osteoblast and osteoclast formation assay systems. Vitamin A and vitamin K derivatives as well as soybean isoflavones appeared to be likely candidates. Since isoflavones have been a focus of attention because of their weak estrogenic activity as phytoestrogens, we have assessed the safety and efficacy of isoflavones, and their cooperative effects with exercise on bone metabolism in postmenopausal healthy Japanese women as well as an animal model of osteoporosis. On the other hand, we have demonstrated that undigestible carbohydrates stimulate the production of equol, which seems to be an active form of isoflavone, from isoflavone daidzein by gut microbiota. Finally, a dietary pattern for preservation of healthy bone has been proposed. These results are considered to be helpful for devising measures for the elderly in health plans.

The health-promoting functions of the probiotic Lactobacillus gasseri strain SBT2055 (LG2055) were studied, focusing on its effectiveness via the gastrointestinal tract after dietary intake. With regard to suppression of abdominal fat accumulation, we first found that enlargement of mesenteric fat adipocytes was suppressed in rats fed a high-fat diet containing LG2055. Then, a series of intervention trials in human volunteers, which included an exploratory trial, one for dose-setting, and one for corroboration of effectiveness using the final products, were conducted. All revealed suppression of abdominal fat accumulation after consumption of LG2055. With regard to immunomodulatory function, we observed enhancement of immunoglobulin A production in the small intestine and a protective effect against influenza virus infection in mice fed LG2055. In an intervention trial in humans, consumption of LG2055 resulted in upregulation of the influenza virus vaccine-specific antibody titer and natural killer cell activity. Of the findings described above, those for suppression of abdominal fat accumulation were employed as data for Food for Specified Health Use and Foods with Function Claims approved in Japan, allowing relevant products to be labeled with such health claims.

High-amylose rice elicits a reduced postprandial glucose response, as well as a lower glycemic index, in comparison with low-amylose white rice. The Ehime Research Institute of Agriculture has been growing the high-amylose rice variety “Hoshinishiki” because its yield and taste may be rated more highly than other high-amylose rice varieties grown in a similar climate. The objective of this study was to assess the glycemic index of “Hoshinishiki”. The protocol employed conformed to that of the Japanese Association for Glycemic Index Studies. The subjects were eight healthy men aged 21‐48 years. The glycemic index of “Hoshinishiki” was calculated from the incremental area under the curve (IAUC) of the blood glucose level two hours after consumption of standard white rice (twice) and “Hoshinishiki” (once). The mean IAUC was 4872.5 min・mg/dL and 4015.31 min・mg/dL for standard white rice and “Hoshinishiki”, respectively. The glycemic index of “Hoshinishiki” based on these values was 86.2. In conclusion, the glycemic index for the high-amylose rice variety “Hoshinishiki” grown in Ehime prefecture is 86.2, compared with that of standard white rice.