Many people are living under conditions of disturbed circadian rhythm, and this affects their nutritional state and health. The purpose of this study was to clarify the types and levels of minerals that need to be consumed in order to maintain and promote good health under conditions of disturbed circadian rhythm. Mineral balance is affected by many nutritional factors, but the interactions involved are not clear. Therefore, in this experiment, the effects of dietary mineral levels on calcium (Ca) balance were examined by an orthogonal array method, one type of investigation design which is superior for factorial analysis and factor interaction analysis. Calcium (Ca), phosphorus (P), magnesium (Mg), sodium (Na) and zinc (Zn) were selected as the factors, and eight kinds of diet were prepared on the basis of the L₈ (2⁷)-type orthogonal array. The dietary level of each mineral was normal (AIN-76) or 1/3.5 of the normal content. Four-week-old rats (Fischer 344 strain) were kept for 4 weeks and fed one of these diets. Continuous darkness was used as a model of disturbed circadian rhythm. Retention of Ca was determined by a balance test conducted on the last 3 days of the 4-week feeding period. The highest Ca absorption (%) was observed in rats fed the normal Mg, low Ca and P diet or the normal Na, low Ca diet, whereas the lowest was observed in rats fed the normal Ca, P and Mg diet or the normal Ca and Na diet. Ca absorption was affected by interactions between P and Mg, and between Ca and Na. The highest Ca retention (mg/day) was observed in rats fed the normal Ca diet, whereas the lowest was observed in rats fed the low Ca diet. These findings differ from the results obtained for rats kept exposed to a normal light and dark cycle, suggesting that changes in mineral metabolism occur in rats kept under constant darkness.

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Effects of an aqueous extract from Salacia reticulata (SE), which has potent α-glucosidase inhibitory activity, on serum lipid levels in rats were investigated. Serum triglyceride (TG) in rats given a commercial diet containing 0.05 or 0.1% SE for 3 weeks was decreased. SE (0.1%) also suppressed the increase of serum and liver TG, but slightly increased the serum total and HDL-cholesterol (Cho) and liver Cho in rats given a high sucrose diet for 8 weeks. In rats fed a high-Cho diet for 1 week, SE (0.05, 0.1%) had no significant effects on the serum TG and Cho levels, but decreased the liver TG dose-dependently. Moreover, SE had no effect on the serum TG elevation in olive oil-loaded rats. These results confirmed that consecutive ingestion of SE lowered the serum TG level, and this activity appeared to be due to a decrease of absorbed sugars, which are the source of TG in vivo.

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We evaluated the effectiveness of consuming a spread containing plant stanol esters for reducing total cholesterol, low-density lipoprotein (LDL)-cholesterol and apolipoprotein B in Japanese adults with mildly elevated serum cholesterol levels. One hundred and five subjects were randomized to receive one of the following spreads containing plant stanol ester or placebo for 4 weeks: placebo spread; 1g plant stanol as stanol esters twice a day (3.4g plant stanol esters); or 1g plant stanol 3 times a day (5.1g plant stanol esters). The 4-week treatment period was followed by a 4-week follow-up period without treatment. Lipid levels were estimated at the baseline and at weeks 2, 4 and 8. Apoproteins were estimated at the baseline and at week 4. Levels of total cholesterol, LDL-cholesterol and apoprotein B were significantly reduced by 6.3%, 9.5% and 7.1%, respectively, after 4 weeks of daily treatment with 2g plant stanol as stanol esters. Levels of total cholesterol and LDL-cholesterol returned to the baseline after the 4-week follow-up period without treatment. No further reductions were observed in the group consuming 3g plant stanol as stanol esters per day. Levels of triglyceride (TG), high-density lipoprotein (HDL)-cholesterol and apoprotein Al were not changed by consumption of plant stanol esters. No clinically significant side effects were observed. Thus, plant stanol esters significantly reduced the levels of total cholesterol, LDL cholesterol and apoprotein B without any significant side effects in a mildly hypercholesterolemic Japanese population. These findings demonstrate that plant stanol esters are an effective dietary adjunct for reducing cholesterol levels.

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Though it is well known that aroma is one of the most important factors determining food selection, many recent studies have recognized that aroma key substances also play an important role in giving food some beneficial physiological functions for health. It is likely that these aroma compounds increase our appetite by acting as signals of active substances in food through their characteristic odor. This paper discusses the flavors and some functions of allicin and its related compounds in garlic, 4-hydroxy-2 (or 5)-ethyl-5 (or 2)-methyl-3 (2H)-furanone (HEMF) in soy sauce and miso, and citral in lemon grass and the rhizomes of ginger with reference to the literature.

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It is predicted that in the near future there will be a trend for the development of genetically-modified foods with enriched nutrients, better functionality, and medicinal ingredients, which will be of benefit to the consumer. One line of development will be aimed at the prevention of life-style-related diseases, for example high-oleic soybean oil and oil seeds enriched with n-3-type fatty acids. Another aim will be to overcome malnutrition in the developing countries, for instance by producing rice high in β-carotene, iron and protein. On the other hand, since genetically-modified foods are a matter of some concern among consumers, it will be necessary to establish methods for safety assessment. However, it is generally impossible to conduct safety assessments of genetically-modified foods in human subjects. Accordingly, we propose an evaluation method, in addition to the regular assessment supervised by the Ministry of Health and Welfare, which replaces common foods with genetically-modified foods and then simulates nutrient intake from genetically-modified foods according to the National Nutrition Survey in Japan and Standard Table of Food Composition in Japan.

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