Sex-specific effect of dietary cholesterol on plasma insulin and lipids of control and diabetic rats

The effect of dietary cholesterol on plasma glucose, insulin, total cholesterol, and triglycerides was determined in male and female rats with diabetes of neonatal orogin and in non-diabetic age-matched controls. A mild permanent diabetes was produced by streptozotocin injection of 2 day old neonatal rats. A 0.5% cholesterol diet was initiated at 8 weeks of age. Dietary cholesterol for 7 weeks did not affect plasma glucose in any group, but significantly increased plasma insulin in control (51%) and diabetic (32%) male rats, suggesting the presence of a dietary cholesterol-induced insulin-resistance. Plasma lipids were altered only in male rats with total cholesterol significantly increased by both diabetes and dietary cholesterol and triglycerides increased by dietary cholesterol. The finding of a dietary cholesterol-induced hyperinsulinemia in male rats, but not female rats may be significant in its relation to the pathogenesis of vascular disease.     

Effect of altered feeding patterns on serum lipids and lipoproteins in adult males

Effects of a three meal per day versus a six meal per day feeding pattern on selected serum lipids and lipoproteins in 17 males were examined. After a two week acclimatization period, subjects were randomly assigned to one of two groups. Each group followed a three meal per day pattern for six weeks and a six meal per day pattern for another six weeks. Serum total cholesterol and LDL-cholesterol levels were not significantly affected by the altered feeding patterns. There was a significant decrease in the triglyceride levels of one group, but not the other, during the six meal per day pattern. For both groups the HDL-cholesterol levels differed significantly (P≤0.05) between the two feeding patterns. However, the findings were dissimilar in that for one group the HDL-cholesterol was higher after the six meal per day pattern and, for the other group, the opposite was true. Only during Phase I, the acclimatization period when both groups were consuming three meals per day, were any significant differences in dietary intakes noticed. Specifically, subjects in Group I consumed significantly more total fat and saturated fat (P=0.01 and P=0.04, respectively). Throughout the study there were no significant differences between the two groups relative to polyunsaturated to saturated fat (P/S) ratios of the diets.     

Effects of saturated, monounsaturated, and omega-6 polyunsaturated fatty acids on plasma lipids, lipoproteins, and apoproteins in humans

The effects of dietary fats on plasma cholesterol, serum lipoproteins, and apoproteins (Apo), A-1, B, and CIII were studied. Twelve men consumed three different cholesterol-free formula diets in which polyunsaturated and saturated fats were partially substituted (20% of calories) for monoenoic fats with a constant of 40% of calories from fat. Total cholesterol and low-density lipoprotein cholesterol dropped from base-line values of 166 and 103 to 133 and 81 mg/dl (sat), 127 and 71 mg/dl (mono), and 123 and 65 mg/dl (poly), respectively. High-density lipoprotein cholesterol changed very little from base-line values of 46 to 40 mg/dl (sat), 45 mg/dl (poly), and 43 mg/dl (mono). The plasma concentrations of ApoB declined from base-line values of 80.3 mg/dl to 54.6 mg (mono), 51.8 mg (poly), and 59.6 mg (sat) while Apo CIII and Apo AI did not show any changes. This study demonstrates that: 1) changes in dietary fat affect serum lipids, lipoproteins, and apoproteins even when consumed on a cholesterol-free diet, and 2) omega-6 polyunsaturated fat lowers low-density lipoprotein cholesterol, total cholesterol, and ApoB to a greater extent than monounsaturated or saturated fat, 3) consumption of a cholesterol-free formula diet results in significant decreases in the concentrations of total and low-density lipoprotein cholesterol in plasma when compared to values obtained on a mixed food home diet containing approximately 300 mg cholesterol/day.     

Relationships of dietary zinc/copper ratios to plasma cholesterol and liver trace mineral deposition in young rats fed saturated and unsaturated fats

The effects of copper and zinc supplements on weight gains, plasma total and high density lipoprotein (HDL)-cholesterol levels and liver trace mineral levels were studied in young rats fed either coconut oil or corn oil. Dietary factors included 1.5 ppm and 6 ppm copper, 7.5 ppm and 30 ppm zinc, and the two fat sources. Weight gains and levels of total and HDL-cholesterol were higher in rats fed corn oil than in rats fed coconut oil. Increases in dietary zinc were associated with increases in total and HDL-cholesterol levels in rats fed corn oil, while increases in copper supplements were associated with decreases in total and HDL-cholesterol levels in rats fed either fat source. Supplements of 30 ppm zinc resulted in decreases in total cholesterol/HDL-cholesterol ratios in rats fed coconut oil but had no apparent effect on these ratios in rats fed corn oil. Thus, zinc may be a more important factor than copper in the reduction of this ratio, particularly if saturated fatty acids predominate in the diet. Increases in dietary copper were associated with increases in liver copper levels of rats fed either fat source. Increases in either dietary copper or zinc resulted in decreases in liver iron deposition in rats fed both fat sources. Results of this study indicate that a dietary zinc/copper ratio of 5 may be required for optimum growth of young rats.     

The cholesterolemic effect of skim milk in young men consuming controlled diets

A 34-day metabolic study was conducted with nine healthy adult men to test the hypocholesterolemic action of skim milk (2 qt/day). Intakes of kilocalories, carbohydrate, protein, fat, cholesterol, calcium and dietary fiber were controlled, as were the ratios of polysaturated to saturated fat and animal protein to total protein in the diet. The study was comprised of three experimental periods: a high calcium control period (2600 mg/day), a low calcium control period (800 mg/day), and a high calcium skim milk period (2600 mg/day). Consumption of skim milk was associated with increases in plasma cholesterol levels, low density lipoprotein (LDL)-cholesterol and LDL-total lipid levels, and ratio of plasma cholesterol to high density lipoprotein (HDL)-cholesterol; and a decrease in HDL-cholesterol. A high dietary calcium intake was associated with a decrease in the plasma cholesterol to HDL-cholesterol ratio and an increase in triglyceride content of very low density lipoproteins. In this study, no hypocholesterolemic effect of fresh skim milk was observed when it was consumed along with a diet representative of a typical American diet pattern.     

The effect of replacing dietary saturated fat with polyunsaturated or monounsaturated fat on plasma lipids in free-living young adults

OBJECTIVE: To examine, in free-living adults eating self-selected diets, the effects on plasma cholesterol of substituting saturated fat rich foods with either n-6 polyunsaturated or monounsaturated fat rich foods while at the same time adhering to a total fat intake of 30-33% of dietary energy. DESIGN: Two randomised crossover trials. SETTING: General community. SUBJECTS: Volunteer sample of healthy free-living nutrition students at the University of Otago. Trial I, n=29; and trial II, n=42. INTERVENTIONS: In trials I and II participants were asked to follow for 2(1/2) weeks a diet high in saturated fat yet with a total fat content that conformed to nutrition recommendations (30-33% energy). During the 2(1/2) week comparison diet, saturated fat rich foods were replaced with foods rich in n-6 polyunsaturated fats (trial I) whereas in trial II the replacement foods were rich in monounsaturated fats. Participants were asked to maintain a total fat intake of 30-33% of energy on all diets. MAIN OUTCOME MEASURES: Energy and nutrient intakes, plasma triglyceride fatty acids, and plasma cholesterol. RESULTS: When replacing saturated fat with either n-6 polyunsaturated fat or monounsaturated fat, total fat intakes decreased by 2.9% energy and 5.1% energy, respectively. Replacing saturated fat with n-6 polyunsaturated fat (trial I) lowered plasma total cholesterol by 19% [from 4.87 (0.88) to 3.94 (0.92) mmol/l, mean (s.d.)], low density lipoprotein cholesterol by 22% [from 2.87 (0.75) to 2.24 (0.67) mmol/l], and high density lipoprotein cholesterol by 14% [from 1.39 (0.36) to 1.19 (0.34) mmol/l], whereas replacing saturated fat with monounsaturated fat (trial II) decreased total cholesterol by 12%, low density lipoprotein cholesterol by 15%, and high density lipoprotein cholesterol by 4%, respectively. The change in the ratio of total to high density lipoprotein cholesterol was similar during trial I and trial II. CONCLUSIONS: Young adults are very responsive to dietary-induced changes in plasma cholesterol even when an isocaloric replacement of saturated fat with n-6 polyunsaturated or monounsaturated fat is not achieved. Replacing saturated fat with either n-6 polyunsaturated or monounsaturated fat is equally efficacious at reducing the total to high density lipoprotein cholesterol ratio. SPONSORSHIP: University of Otago, Meadow Lea Ltd.     

大豆异黄酮对糖尿病大鼠脂蛋白氧化的影响

目的 研究大豆异黄酮对糖尿病大鼠血浆脂蛋白脂质过氧化的影响。方法 给糖尿病大鼠饲喂添加大豆异黄酮的饲料8周，检测其血浆脂蛋白过氧化脂质程度以及氧化易感性的变化。结果 食用大豆异黄酮的糖尿病大鼠血浆总过氧化脂质低密度脂蛋白(LDL)和高密度脂蛋白(HDL)过氧化脂质含量明显减少，且在体外进行氧化修饰时，LDL氧化延滞时间明显延长，提示LDL氧化易感性下降。结论 大豆异黄酮显降低糖尿病大鼠LDL和HDL脂质过氧化程度，降低LDL氧化易感性，对糖尿病及其并发症的发生和发展能起到有效的防治作用。     

Effects of dietary saturated, monounsaturated, and n-3 fatty acids on blood pressure in healthy subjects

BACKGROUND: The quantity and quality of fats consumed in the diet influence the risk of cardiovascular disease (CVD). Although the effect of diet on plasma lipids and lipoproteins is well documented, less information exists on the role of fats on blood pressure (BP). OBJECTIVE: The objective was to evaluate the effects of different types of dietary fat on BP in healthy subjects. DESIGN: Healthy subjects (n = 162) were randomly assigned for 3 mo to follow 1 of 2 isoenergetic diets: 1 rich in monounsaturated fatty acids (MUFA diet) and the other rich in saturated fatty acids (SFA diet). Each group was further randomly assigned to receive supplementation with fish oil (3.6 g n-3 fatty acids/d) or placebo. RESULTS: Systolic BP (SBP) and diastolic BP (DBP) decreased with the MUFA diet [-2.2% (P = 0.009) and -3.8% (P = 0.0001), respectively] but did not change with the SFA diet [-1.0% (P = 0.2084) and -1.1% (P = 0.2116)]. The MUFA diet caused a significantly lower DBP than did the SFA diet (P = 0.0475). Interestingly, the favorable effects of MUFA on DBP disappeared at a total fat intake above the median (>37% of energy). The addition of n-3 fatty acids influenced neither SBP nor DBP. CONCLUSIONS: Changing the proportions of dietary fat by decreasing SFAs and increasing MUFAs decreased diastolic BP. Interestingly, the beneficial effect on BP induced by fat quality was negated by the consumption of a high total fat intake. The addition of n-3 fatty acids to the diet had no significant effect on BP.     

Effects of micronized okara dietary fiber on cecal microbiota,serum cholesterol and lipid levels in BALB/c mice

Abstract

Micronized by a dry grinding method (D-ODF) or a wet granulating method (W-ODF), okara dietary fiber (ODF), was fed to BALB/c mice for 28?d. The water holding capacity of D-ODF and W-ODF was significantly enhanced after micronization. W-ODF had a larger swell capacity and a higher content of soluble dietary fiber than crude ODF and D-ODF. After feeding for 28?d, the populations of Escherichia coli and Lactobacilli in the cecum were significantly lower and higher in the W-ODF group than other groups, respectively, while the population of Bifidobacterium increased in all groups. The effect of each diet on the population of E. coli. Lactobacilli and Bifidobacterium was all maintained for a short period of time except that the effectiveness of W-ODF diet on the Bifidobacterium population lasted slightly longer than other diets. At the end of the feeding period, serum total cholesterol (TC) and triglyceride in D-ODF and W-ODF diets were significantly lower and HDL-C/TC ratio was significantly higher than those in crude ODF.     

不同来源膳食蛋白质对大鼠体重及其血脂的影响

目的探讨不同膳食蛋白质摄入对大鼠体重及其血脂的长期动态影响。方法选用36只雄性成年Wistar大鼠,按体重随机分为酪蛋白组、大豆蛋白组和谷豆蛋白混合组,喂养12周,检测大鼠在体重及其血脂上的变化。结果大豆蛋白组体重、脂肪湿重、脂体比、TG和TC水平均显著低于酪蛋白组相应指标(P<0.05),HDL-C水平与酪蛋白组相比无统计学差异;谷豆蛋白混合组TC和TG水平均显著低于酪蛋白组和大豆蛋白组(P<0.05),HDL-C水平高于酪蛋白组,有统计学差异(P<0.05)。结论大豆蛋白可以降低大鼠TC和TG水平,谷豆蛋白混合后对TC和TG水平降低作用更明显,并有提高HDL-C的作用。     

Effects of taurine on plasma and liver lipids, erythrocyte ouabain sensitive Na efflux and platelet aggregation in Sprague Dawley rats

The effects of taurine on plasma and liver cholesterol, erythrocyte ouabain sensitive Na efflux and platelet aggregation were examined in Sprague Dawley rats fed control or 0.5% cholesterol with 0.2% cholate diet. Plasma and liver levels of total cholesterol were increased significantly (p<0.05) in rats fed cholesterol diet compared to the control, and taurine significantly decreased the elevated plasma level of cholesterol in rats fed cholesterol diet (p<0.05). HDL-cholesterol was decreased in groups fed the cholesterol diet regardless of taurine supplementation and the difference between groups with and without cholesterol was significant (p<0.01). Plasma triglyceride was decreased and liver triglyceride was increased both significantly (p<0.05) in rats fed cholesterol compared to the control. Plasma and liver triglyceride in rats fed taurine was decreased significantly compared to the control (p<0.05). Intracellular Na tended to be lower in rats fed cholesterol or taurine and higher in rats fed cholesterol plus taurine compared to the control. Na efflux through Na-K ATPase and the passive leak of Na was somewhat reduced in rats fed cholesterol or taurine and was augmented in rats fed cholesterol plus taurine compared to the control, which showed a similar trend to the intracellular Na. Taurine supplementation caused a suppression of Na efflux in groups fed control diet and restored the suppressed Na efflux in groups fed cholesterol. Platelet aggregation was significantly decreased in the group fed taurine compared to the control (p<0.05) and the group fed cholesterol plus taurine was also a little lower in aggregation than the group fed cholesterol. Microscopic examination showed that taurine prevented fatty liver in rats fed cholesterol diet. Taurine known for stimulating Na-K ATPase in some cell types rather decreased erythrocyte ouabain sensitive Na-K ATPase in the present study. Taurine had hypolipidemic and hypocholesterolemic effects and inhibited platelet aggregation which may be favorable for prevention of cardiovascular diseases.     

不同来源的蛋白质对大鼠血脂水平的影响

目的研究雄性大鼠在长期摄入不同来源和含量的蛋白质饲料后,其血脂水平及各血脂比值的变化。方法将断乳雄性大鼠按体重随机分为4组(n=15),分别给予牛奶粉(HM组和LM组)或大豆粉/蛋清粉(HS组和LS组)为蛋白质来源的饲料(每种饲料中总蛋白质含量分别为18%和9%),持续喂养20周后,检测各组大鼠血清中血脂水平,并计算各类血脂的比值。结果在各实验组中,HM组大鼠血清总胆固醇(TC)和高密度脂蛋白胆固醇(HDL-C)水平最高(P<0.05),TC/HDL-C比值最低(P<0.05);HS组大鼠甘油三酯(TG)水平最低(P<0.05)。HS与HM组的TG/HDL-C比值低于LS与LM组(P<0.05)。LS与HS组低密度脂蛋白胆固醇(LDL-C)水平和LDL-C/HDL-C比值均低于LM与HM组(P<0.05)。结论给予高剂量大豆粉来源蛋白质,可以显著降低大鼠的TG水平;若长期给予高剂量牛奶粉作为蛋白质来源,可明显升高大鼠血清胆固醇总体水平。     

The interrelated effects of n-6/n-3 and polyunsaturated/saturated ratios of dietary fats on the regulation of lipid metabolism in rats

The effects of various n-6/n-3 (0.45-9.31) and polyunsaturated/saturated (P/S; 0.25-6.08) ratios of dietary fatty acids on various lipid parameters were studied in rats using a combination of palm oil, safflower oil, soybean oil and perilla oil. When the n-6/n-3 ratio was changed while maintaining a constant P/S ratio (1.2), the concentration of serum cholesterol tended to increase linearly with the increasing n-6/n-3 ratio, whereas liver cholesterol tended to decrease. Serum triglyceride level increased linearly up to a n-6/n-3 ratio of approximately 5, whereas liver triglyceride was not influenced. When the n-6/n-3 ratio was kept relatively constant (5.6-6.4), serum and liver cholesterol levels decreased up to a P/S ratio of approximately 2, whereas serum triglyceride tended to be low below this value. The ratio of arachidonate to linoleate in tissue phosphatidylcholine (PC) was also influenced by the n-6/n-3 and P/S ratios; it increased up to a n-6/n-3 ratio of approximately 4, whereas it decreased up to a P/S ratio of approximately 2. The percentage of eicosapentaenoic and docosahexaenoic acid (n-3) in tissue phosphatidylcholine was positively related to dietary n-3 fatty acid levels. Prostacyclin (PGI2) production by thoracic aorta reached a plateau at a n-6/n-3 ratio approximately 5, whereas it tended to decrease with an increasing P/S ratio. Platelet production of thromboxane A2 exhibited a parabola-like pattern with a peak value at a n-6/n-3 ratio of approximately 2, whereas it was independent of the P/S ratio.(ABSTRACT TRUNCATED AT 250 WORDS)     

二硫化碳接触工人血脂和血清微量元素的变化

目的 探讨二硫化碳（CS2）作业工人血脂及血清微量元素含量的改变。方法 运用流行病学横断面调查和实验室检查。结果 接触组高密度脂蛋白（HDL－C）较干预组和对照组低,载脂蛋白B（ApoB)较干预组和对照组高;血清铜、锌、硒含量对照组最高、干预组次之、接触组最低。结论 接触CS2对作业工人血脂和血清微量元素有一定影响。     

The effects of polyunsaturated:saturated fatty acids ratios and peroxidisability index values of dietary fats on serum lipid profiles and hepatic enzyme activities in rats

Raising the dietary PUFA:saturated fatty acids (SFA) ratio has been recommended for the prevention of CVD. However, a high PUFA:SFA (P:S) ratio diet enhances oxidative stress because PUFA are highly susceptible to lipid peroxidation. Thus, we focused on the role of the dietary P:S ratio and peroxidisability index (PI) value on serum and liver tissue and investigated the effects of dietary P:S ratios (0.4, 1.0, and 4.8) with a fixed PI value (81) on serum lipid parameters and hepatic enzyme activities (experiment 1). To elucidate whether those phenomena were unique to the P:S ratio, we examined the effects of dietary PI values (36, 81, 126, and 217) with a constant P:S ratio (1.0) (experiment 2). Female Sprague-Dawley rats weighing 240-280 g were fed experimental diets for 4 weeks. When dietary PI value was maintained at 81, serum HDL-cholesterol (HDL-C) increased with increasing dietary P:S ratio. When the P:S ratio was fixed at 1.0, HDL-C was the lowest with mid-low PI (MLPI) (PI value of 81). In both experiments, serum LDL-cholesterol:HDL-C ratio kept in the range of 0-2. The hepatic superoxide dismutase, catalase, and glutathione peroxidase (GSH-Px) activities and thiobarbituric acid reactive substance (TBARS) concentrations were the highest in the lowest dietary P:S ratio group (experiment 1). GSH-Px, glutathione-S-transferase, and TBARS were the lowest in rats fed the MLPI diet (experiment 2). In conclusion, these results indicate that a P:S ratio of 1.0-1.5 and a PI value of 80-90 in the diet are within a favourable range to reduce the risk of CVD.     

Effects of soy isoflavone supplementation on plasma glucose,lipids, and antioxidant enzyme activities in streptozotocin-induced diabetic rats

This study was designed to examine the effects of feeding diets containing different levels of isoflavone on plasma glucose, insulin concentrations, and lipid profiles as well as tissue antioxidant enzyme activities in diabetic rats. Diabetes was induced in the rats with streptozotocin. Diabetic rats were further assigned to 1 control group and 3 experimental groups (ISO-1, ISO-2, and ISO-8). The control group received a casein-based diet without isoflavone, whereas the ISO-1, ISO-2, and ISO-8 groups received a similar diet but supplemented with 1, 2 and 8 times of isoflavone equivalent of normal human consumption as suggested by the manufacturer. All diets were adjusted to contain identical nutrients and were maintained for 24 days. Fasted and non-fasted blood was drawn after feeding for 21 and 24 days, respectively, and blood chemistry was analyzed. The liver, lung, and kidney were excised after sacrifice, and antioxdiant enzyme activities and lipid peroxidation products were measured. The results demonstrate that there were no differences in plasma glucose or insulin levels among groups, irregardless of whether rats had fasted or not. However, hemoglobin A_1c tended to be lower in the ISO-2 group than in the control and the ISO-1 groups. Plasma total cholesterol and low-density lipoprotein-cholesterol were significantly lower in the ISO-8 group than in the other groups. No differences in plasma triglyceride or high-density lipoprotein-cholesterol were observed among groups in the non-fasting state. There were no significant differences in superoxide dismutase, glutathione peroxidase activities, and malondialdehyde concentrations in liver, lung, and kidney homogenates among groups. These results suggest that 3 doses of isoflavone supplementation had no favorable effect on plasma glucose or insulin concentrations, nor had any influence on attenuating oxidative stress in diabetic rats. However, the ISO-2 group tended to have better chronic glycemic control than did the control and the ISO-1 group. In addition, a larger amount of isoflavone supplementation had beneficial effects on reducing plasma total cholesterol and low-density lipoprotein-cholesterol levels.     

Effects of dietary taurine supplementation on plasma and liver lipids in OVX rats fed calcium-deficient diet

Taurine supplementation has been shown to have an effect on lowering blood lipids in ovariectomized (OVX) rats. It therefore seemed desirable to find out whether the beneficial effect of taurine on OVX rats fed calcium-deficient diet could also be reproduced. Forty female Sprague-Dawley rats were divided into two groups. One group was OVX and the other group received a sham operation (Sham). Each rat group was further divided into the control diet and the taurine supplemented (2.0 g/100 g diet) diet group. All rats were fed on calcium-deficient diet and deionized water ad libitum for 6 weeks. Plasma and liver lipids were determined by using commercial kits. LDL-cholesterol concentrations were estimated with the equation of Friedewald et al. (1972). There were no significant differences in body weight gain and food intake between the control and taurine group within Sham and OVX groups, but body weight gain, food intake, and food efficiency ratio was higher in the OVX group. Concentrations of plasma total cholesterol, triglyceride, LDL-cholesterol were significantly lower in the taurine fed group of OVX rats fed Ca deficient diet, while HDL-cholesterol concentration was increased in the taurine fed group. Therefore, in this study, we examined whether taurine also prevented hypercholesterolemia induced by ovarian hormone deficiency in ovariectomized rats when they were fed a calcium-deficient diet. These results indicate that taurine may have some beneficial effects on hypercholesterolemia and hypertriglyceridemia in OVX rats fed calcium-deficient diet.     

Effects of various combinations of omega 3 and omega 6 polyunsaturated fats with saturated fat on serum lipid levels and eicosanoid production in rats

The effects of varying the ratio of polyunsaturated/saturated fatty acids (P/S) and omega 3/omega 6 polyunsaturated fatty acids (PUFA) of dietary fats on lipid metabolism were studied in rats using safflower oil (SFO), linseed oil (LSO), palm oil (PLO), and a 1:1 combination of these oils. The hypocholesterolemic and hypotriglyceridemic effects depended on the P/S ratio of dietary fats, LSO (omega 3 PUFA) being more effective than SFO (omega 6 PUFA). A similar pattern of the response was observed on liver cholesterol and triglyceride. The liver cholesterol-lowering effect of LSO, but not SFO, remained even when they were combined with PLO. The activity of liver delta 6-desaturase tended to be higher while that of liver phospholipase A2 was significantly lower in the LSO group than in the SFO or PLO groups. The aortic PGI2 production and the production by platelets of thromboxane A2 were significantly low in rats fed LSO accompanying a distinct reduction of arachidonate in tissue phospholipids. The depressing effect of LSO disappeared when it was combined with SFO but not with PLO. There were no significant differences in enzyme activities and eicosanoid production between SFO and PLO in spite of a large difference in their P/S ratio. Thus, lipid parameters examined were complicatedly regulated by the ratios of omega 3/omega 6 as well as P/S, suggesting an existence of an appropriate ratio for these variables.     

Effects of differing phenolic content in dietary olive oils on lipids and LDL oxidation

Summary.Background: Evidence from in vitro studies suggests that antioxidant olive oil phenolic compounds can prevent LDL oxidation. However, in vivo evidence in support of this hypothesis is sparse.Aim of the study: to establish the antioxidant effect of olive oils with differences in their phenolic compounds content in humansMethods: A controlled, double blind, cross-over, randomized, clinical trial using three similar olive oils with increasing phenolic concentration (from 0 to 150 mg/Kg) was conducted in 30 healthy volunteers. Olive oils were administered over three periods of 3 weeks preceded by two-week washout periods.Results: Urinary tyrosol and hydroxytyrosol increased (p < 0.020), in vivo plasma oxidized LDL decreased (p = 0.006), and ex vivo resistance of LDL to oxidation increased (p = 0.012) with the phenolic content of the olive oil administered. After virgin olive oil administration, an increase (p = 0.029) was observed in HDL cholesterol levels.Conclusions: Sustained consumption of virgin olive oil with the high phenolic content was more effective in protecting LDL from oxidation and in rising HDL cholesterol levels than that of other type of olive oils. Dose-dependent changes in oxidative stress markers, and phenolic compounds in urine, were observed with the phenolic content of the olive oil administered. Our results support the hypothesis that virgin olive oil consumption could provide benefits in the prevention of oxidative processes.* Participants of the SOLOS-Investigation are listed in the Appendix.     

Effects of fructo-oligosaccharides on blood glucose and serum lipids in diabetic subjects

Daily intake of 8.0 g per day of fructo-oligosaccharides for fourteen days significantly reduced mean fasting blood glucose levels by 15 mg/dl, mean serum total cholesterol levels by 19 mg/dl and LDL-cholesterol levels by 17 mg/dl in diabetic subjects (n=18), while the control diabetic subjects (n=10) who were given 5.0 g per day of sucrose showed no significant changes. The levels of serum HDL-cholesterol, triglycerides or free fatty acids were not significantly affected either by fructo-oligosaccharides or sucrose. These results indicate that the daily intake of fructo-oligosaccharides ameliorates the derangements of carbohydrate and lipid metabolism in diabetic subjects.