It is known that elevation of total cholesterol (TC) or LDL-cholesterol (LDL-C) causes various diseases. However, it has also been shown that intake of polyphenol improves lipid metabolism and lowers vascular disease risk. A feature of pine bark extract is its high content of polyphenol, and this extract is expected to have therapeutic application for reducing TC and LDL-C levels in the blood and liver. Therefore we examined the effect of pine bark extract on TC level in rats that were fed high-cholesterol diets. Five groups of rats were fed a control diet, a high-cholesterol diet, or diets containing pine bark extract (0.02%, 0.2%, 2% added) during the test period. Plasma TC, HDL-cholesterol (HDL-C), triglyceride (TG) and phospholipid (PL) were measured at intervals during the feeding period. In addition, TC and TG in the liver, and cholesterol and total bile acids (TBA) in the feces were also measured. It was found that the plasma TC level decreased, the plasma HDL-C level increased, and the liver TC level decreased in the group fed the pine-bark-extract-containing diet. Cholesterol and TBA levels in the feces increased in the pine-bark-extract-fed rats, suggesting that pine bark extract promoted excretion of cholesterol and bile acids. These results indicate that pine bark extract lowers cholesterol levels in both the blood and liver.

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Emerging risk factors such as obesity, dyslipidemia, high blood pressure, and insulin resistance constitute a condition known as metabolic syndrome. As indicated in our earlier papers, reduced whole blood fluidity, as estimated by micro-channel array flow analysis, is closely interrelated to hyperglycemia and hyperlipidemia in this syndrome. However, the possible detrimental effects of obesity on hemorheologic behavior have been less well acknowledged. In the present study, 150 non-cigarette-smoking patients with metabolic syndrome were enrolled, and body mass index, hemorheological profiles and laboratory parameters were evaluated. The data obtained were statistically compared with those derived from 48 healthy, agematched, non-smoking individuals. Statistical analyses revealed that the findings in non-smoking patients with metabolic syndrome were intimately associated with hyperglycemia, lipid and lipoprotein serum levels, elevation of C-reactive protein, and an increased leukocyte count, accounting for the presence of underlying proinflammatory events in the vascular system. These data indicate that hemorheological characteristics in the presence of metabolic syndrome are strongly related to blood glucose level rather than body mass index. The benefits and limits of using a micro-channel array flow analyzer to elucidate the effects of supplementary food and medicines on hemorheology are also briefly discussed.

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To clarify the role of L-carnitine in energy expenditure, we examined the effects of single and continuous L-carnitine supplementation on oxygen consumption (VO₂) and respiratory quotient (RQ) in rats fed high-carbohydrate and high-fat (lard) diets. The cumulative VO₂ during the 12-h dark (feeding) period was increased significantly (7.7% and 7.5%, respectively) by continuous administration of 1% L-carnitine to rats fed the high-carbohydrate and high-fat diets. The increases in cumulative VO₂ were sustained during the 12-h light (non-feeding) period. The RQ values decreased slightly in both diet groups after continuous carnitine supplementation. However, the single supplementation of carnitine did not increase the VO₂, or decrease the RQ. We next examined the continuous effects of carnitine on visceral fat accumulation and lipid metabolism in liver and plasma. When rats were fed the high-fat diet for 4 weeks, the retroperitoneal and epididymal adipose tissue weight and body weight increased significantly, as compared with those of rats fed the high-carbohydrate diet. These increases in fat mass were suppressed by adding 1% L-carnitine. The pronounced increases in triglyceride (TG) and cholesterol (TC) contents in the livers of rats fed the high-fat diet were also suppressed by adding carnitine. The plasma concentration of TG was lowered significantly by continuous administration of carnitine to rats fed the high-fat diet as well as the high-carbohydrate diet, but the plasma TC levels were not affected. These results indicate that continuous L-carnitine supplementation stimulates energy expenditure, inhibits visceral fat accumulation, and increases the levels of liver and plasma TG in rats fed a high-fat diet.

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This study investigated the incorporation of unusual fatty acids into cellular lipids of breast cancer cells and its relevance to cell cytotoxicity. Fatty acids added to the culture medium were preferentially incorporated into triacylglycerols rather than into phospholipids. The length of the main carbon chain appeared to be the critical factor for incorporation into cellular lipids. Incorporation of branched-chain fatty acids was higher than that of cycloalkyl fatty acids, and similar to that of hydroxy fatty acids. The cytotoxicities of branched-chain fatty acids were stronger than those of cycloalkyl or hydroxy fatty acids. Thus, of the fatty acids studied, only branched-chain fatty acids exhibited cytotoxicity against breast cancer cells. These observations suggest that the branched carbon chain structure has some relevance to its cytotoxicity.

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D-Psicose is one of the rare sugars present in small quantities in commercial carbohydrates and agricultural products. We studied the effects of D-psicose and psico-rare sugar (a mixture of 75% D-fructose and 25% D-psicose) on glycemic responses after oral carbohydrate tolerance tests in rats. Male Wistar rats (6 months old) were administrated 2g/kg sucrose, maltose or soluble starch together with 0.2g/kg D-psicose or psico-rare sugar. D-Psicose or psico-rare sugar significantly inhibited the increment of plasma glucose concentration induced by sucrose or maltose. The starch-induced glycemic response tended to be suppressed by D-psicose or psico-rare sugar, although not to a significant degree. These results suggest that D-psicose and psico-rare sugar are functional monosaccharides that suppress the glycemic response after carbohydrate ingestion.

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Basic principles of Japanese dietary reference intakes (DRIs) published in 2005 for n-3 polyunsaturated fatty acids (n-3 fatty acids) are described in detail, and the evidence tables used for their establishment are presented. Since n-3 fatty acids are essential fatty acids and their deficiency leads to dermatitis and growth retardation, their minimal requirement (=lower limit) should be established. However, since only a few case reports of n-3 fatty acid deficiency have been published, it is difficult to establish their minimal requirement. Therefore, the concept of adequate intake (AI), representing the median intake of the Japanese population, was adopted. As most contemporary Japanese do not suffer from dermatitis and growth retardation, the median intake of n-3 fatty acids by age and sex was used as the AI of n-3 fatty acids. As AI is a rather expedient procedure, it is likely that the actual minimal requirement is lower than the AI level. Reports published to date have demonstrated that sufficient intake of n-3 fatty acids can prevent ischemic heart disease. The median intake of n-3 fatty acids by Japanese is much higher than that in the group showing highest intake of n-3 fatty acids among Americans. Thus, intake of n-3 fatty acids equivalent to the median for the Japanese population is considered to adequately decrease the incidence of ischemic heart disease. For Japanese individuals over 18 years of age, the median intake of n-3 fatty acids was set as the lower limit of the tentative dietary goal (DG) for preventing lifestyle-related diseases. The lower limit of DG for individuals over 18 years of age thus became 2.0-2.9g/day. Adverse effects of a higher intake of n-3 fatty acids are also described. Although there have been many reports of increased bleeding time and elevated LDL-cholesterol concentrations, there have been no reports of increased occurrence of clinically adverse bleeding or ischemic heart disease. Therefore, we did not set an upper limit for n-3 fatty acid intake. In the DRIs for 2005, the effects of heavy metals such as mercury and cadmium and chemical environmental pollutants such as dioxins and PCBs present in fish in very small amounts were not considered. However, in this article, evidence tables related to consumption of mercury from fish are presented and the safety of fish intake by pregnant women is discussed.

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