The effects of polyunsaturated fat vs monounsaturated fat on plasma lipoproteins

The effect on plasma lipoproteins of exchanging fat type within currently recommended reduced-fat diets was studied in a free-living group of 19 men and 20 women who consumed both a polyunsaturated fat-enriched diet and a monounsaturated fat-enriched diet, each for a 12-week period, with saturated fat and cholesterol held constant. Mean plasma concentrations of low-density lipoprotein cholesterol and low-density lipoprotein total mass (analytic ultracentrifuge), and high-density lipoprotein (HDL) cholesterol and HDL total mass, did not change significantly on exchanging fat type. However, HDL2 cholesterol concentration was 50% higher and HDL3 cholesterol concentration was 7% lower for polyunsaturated compared with monounsaturated fat. Mean total mass of HDL2 was also 23.5% higher and concentration of apolipoprotein B was 5.4% lower on transfer to the polyunsaturated fat diet. Contrary to frequent assertions, we find no advantage with respect to plasma HDL concentrations in using predominantly monounsaturated rather than polyunsaturated fats in subjects who consumed reduced-fat, solid-food diets.     

Comparison of three cholesterol-lowering diets in normolipidemic men

Saturated fatty acids and cholesterol in the diet raise the plasma cholesterol concentration, and a reduction in these constituents is recommended widely. However, there is not general agreement as to which nutrients should replace saturated fatty acids. Several different substitute nutrients are possible. In this study, three cholesterol-lowering diets were compared in nine men living in a domiciliary. On a typical American diet at baseline, cholesterol levels were in the normal range. One replacement diet was high in polyunsaturated fatty acids (High Poly); another had 30% fat and corresponded to the American Heart Association's (AHA) recommended diet for the general public (AHA phase I); the third diet had 20% fat, equivalent to the AHA phase III diet for treatment of hypercholesterolemia. Compared with baseline levels, all diets caused similar reductions in total cholesterol and low-density lipoprotein cholesterol levels, but the High Poly and AHA phase III diets lowered the high-density lipoprotein cholesterol level more than the AHA phase I diet. Thus, for the limited number of patients in this study, the diet recommended for the general public appeared as effective for lowering of cholesterol levels as diets containing more polyunsaturates or more carbohydrates.     

Effective lipid lowering diets including lean meat

The plasma lipid and lipoprotein responses to two modified isoenergetic diets including meat were studied in 15 free living men with hyperlipidaemia (mean plasma cholesterol and triglyceride concentrations 8.1 and 3.4 mmol/l). A reference diet (diet A, 42% energy from fat, ratio of polyunsaturated to saturated fatty acids (P:S ratio) 0.2) was compared with a fat reduced diet (diet B, 35% energy from fat, P:S ratio 0.5) and with a further fat modified diet supplemented with fibre (diet C, 27% energy from fat, P:S ratio 1.0). Daily intake of meat and meat products (180 g/day) was the same in each dietary period; that in diet A had a fat content typical of the average British diet, whereas that in diets B and C was based on very lean meat and meat products. During consumption of diet B the plasma cholesterol concentration fell by 8.6% and low density lipoprotein cholesterol by 11%. During consumption of diet C plasma cholesterol fell by 18.5% and low density lipoprotein cholesterol by 23.8%. Triglyceride and high density lipoprotein cholesterol concentrations and body weight did not change appreciably during the study. A modified diet including a moderate amount of lean meat and meat products is compatible with a reduced lipoprotein mediated risk of atherosclerotic heart disease.     

Plasma lipoprotein levels in vegetarians. The effect of ingestion of fats from dairy products

The influence of dairy foods in the diet on plasma levels of total, low-density lipoprotein, and high-density lipoprotein cholesterol (TC, LDL-C, and HDL-C, respectively) was studied in 75 adult lactovegetarians living in the northeastern United States. Dairy products were the major sources of dietary saturated fat and cholesterol. The plasma TC level was positively correlated with dietary saturated fat and dietary cholesterol, and inversely correlated with the ratio of polyunsaturated to saturated fats in the diet. Correlations between the LDL-C level and the nutrients were similar to those of the TC level. The HDL-C level was not significantly related to any nutrients in the diet. The cholesterol levels of the lactovegetarians were compared with those of strict vegetarians. Lactovegetarians had 24% higher LDL-C levels and 7% higher HDL-C levels than strict vegetarians. Analysis within and among vegetarian populations suggests that ingestion of fatty dairy products raises the LDL-C level on a percentage basis about three times more than it raises the HDL-C level.     

The effect of filtered-coffee consumption on plasma lipid levels. Results of a randomized clinical trial.

OBJECTIVE.--To determine the effect of filtered-coffee consumption on plasma lipoprotein cholesterol levels in healthy men. DESIGN.--Randomized controlled trial with an 8-week washout period followed by an 8-week intervention period during which men were randomly assigned to drink 720 mL/d of caffeinated coffee, 360 mL/d of caffeinated coffee, 720 mL/d of decaffeinated coffee, or no coffee. SETTING.--Outpatient clinical research center in a university medical center. PARTICIPANTS.--One hundred healthy male volunteers. OUTCOME MEASURE.--Changes in plasma lipoprotein cholesterol levels during the intervention period. RESULTS.--Men who consumed 720 mL of caffeinated coffee daily had mean increases in plasma levels of total cholesterol (0.24 mmol/L, P = .001), low-density lipoprotein cholesterol (0.17 mmol/L, P = .04), and high-density lipoprotein cholesterol (0.08 mmol/L, P = .03). No significant changes in these plasma lipoprotein levels occurred in the other groups. Compared with the group who drank no coffee the group who drank 720 mL/d of caffeinated coffee had increases in plasma levels of total cholesterol (0.25 mmol/L, P = .02), low-density lipoprotein cholesterol (0.15 mmol/L, P = .17), and high-density lipoprotein cholesterol (0.09 mmol/L, P = .12) after adjustment for changes in diet. CONCLUSION.--Consumption of 720 mL/d of filtered, caffeinated coffee leads to a statistically significant increase in the plasma level of total cholesterol, which appears to be due to increases of both low-density lipoprotein and high-density lipoprotein cholesterol levels.     

不同脂肪酸饮食对大鼠肝脏xbp-1的影响

目的:探讨饱和脂肪酸、单不饱和脂肪酸、多不饱和脂肪酸饮食对大鼠肝脏X盒结合蛋白-1(XBP-1)的影响。方法:48只雄性Wistar大鼠随机分为4组:正常对照组(N组)、饱和脂肪酸饮食组(S组)、单不饱和脂肪酸饮食组(M组)、多不饱和脂肪酸饮食组(P组)。正常对照组给基础饲料(脂肪占10.3%);饱和脂肪酸饮食组的饲料是在基础饲料中添加15%猪油;单不饱和脂肪酸饮食组的饲料是在基础饲料中添加15%茶油;多不饱和脂肪酸饮食组的饲料是在基础饲料中添加15%豆油(脂肪占35.4%)。8周后4组各随机选8只大鼠行高胰岛素-正葡萄糖钳夹试验,同时留取空腹状态血清测定血脂、胰岛素等指标。肝脏XBP-1蛋白表达分别用Western blot法和免疫组化法测定。结果:①实验第8周末,与N组相比,P、M、S组大鼠进食量有所减少(P<0.05)。除外进食量的影响,与N组相比,S组血清总胆固醇(TC)、甘油三酯(TG)升高(P<0.05),M、P组差异无统计学意义(P>0.05);S、P组空腹胰岛素(FINS)、空腹血糖(FBG)升高,葡萄糖输注率(GIR)明显下降(P均<0.05),但S、P两组间无统计学意义(P>0.05);M...     

高脂饮食诱发大鼠营养性肥胖动物模型的研究

目的:通过高脂饮食诱发建立雄性SD营养性肥胖大鼠动物模型。方法:40只SD雄性青年大鼠采用D12492配方所制作的高脂肪、高热量食物进行限制饲喂,2周时剔除肥胖抵抗大鼠,其余大鼠随机分成两组,即正常对照组给予普通饲料饲喂,高脂饮食组给予高脂饲料喂养4周,观察体重、Lee's指数。高脂饲喂8周时禁食24 h后麻醉取血分离血清,取肝脏制备匀浆,取体脂称重并计算脂肪指数,用全自动生化分析仪检测血清和肝脂中总胆固醇(TC)、三酰甘油(TG)、高密度脂蛋白胆固醇(HDL-C)和低密度脂蛋白胆固醇(LDL-C)水平,并于正常组进行比较分析。结果:高脂饲喂4周后,高脂饮食组体重达到(299.3±17.74)g,而正常组大鼠体重仅为(202.8±9.14)g,高脂组的Lee's指数与正常组比较,差异有统计学意义(P<0.001);同时高脂饮食组大鼠的脂肪湿重、脂肪指数、血清TC、TG、LDL-C以及肝脂TC、TG水平均显著高于正常组大鼠,差异有统计学意义(P<0.05、P<0.01、P<0.001)。结论:选取SD雄性青年大鼠采用D12492配方所制高脂饲料运用限制喂养的方式成功建立营养性大鼠肥胖模型,节省造模成本,同时显著提高血清和肝脏中的TC、TG水平,造成动物的高脂血症和脂肪肝病变,与人类临床肥胖症及相关并发症颇为相似,为共同研究人类营养性肥胖伴发的高脂血症与脂肪肝提供较为理想的动物模型。     

茶多酚对家兔血脂影响的观察研究

目的探讨茶多酚对于高脂血症模型组家兔血脂的影响。方法采用随机数字表法将来自广东省食品药品职业技术学校实验动物中心80只家兔分为四组,即空白对照组、高血脂模型组、0.4%茶多酚治疗治疗组及0.8%茶多酚治疗组,每组各20只,分别给予基础饲料、高脂饲料、高脂饲料＋0.4%茶多酚及高脂饲料＋0.8%茶多酚,比较四组家兔体重、血清三酰甘油、总胆固醇、低密度脂蛋白胆固醇及高密度脂蛋白胆固醇等。结果空白对照组、高血脂模型组、0.4%茶多酚组及0.8%茶多酚组家兔实验前体重、血清三酰甘油、总胆固醇、低密度脂蛋白胆固醇及高密度脂蛋白胆固醇水平组间比较差异无统计学意义（P〈0.05）;与实验前比较,实验后高血脂模型组、0.4%茶多酚组及0.8%茶多酚组家兔体重、血清三酰甘油、总胆固醇、低密度脂蛋白胆固醇及高密度脂蛋白胆固醇水平均明显增高（均P〈0.05）,同时0.4%茶多酚组及0.8%茶多酚组体重、血清三酰甘油、总胆固醇、低密度脂蛋白胆固醇及高密度脂蛋白胆固醇水平均明显优于高血脂模型组,组间比较差异有统计学意义（P〈0.05）。结论茶多酚能够有效降低高脂血症模型组家兔血脂水平,具有一定血脂代谢调节作用。     

高脂诱导非酒精性脂肪性肝病小鼠肝脏Chemerin及其受体的表达

目的研究高脂饮食诱导非酒精性脂肪性肝病(NAFLD)小鼠肝脏Chemerin及Chemerin受体(CMKLR1)的表达情况。方法22只C57BL/6小鼠随机分为对照组(n=10)和高脂组(n=12),对照组给予基础饲料喂养,高脂组给予高脂饲料喂养,连续喂养18周后进行腹腔注射葡萄糖耐量试验(IPGTT)和胰岛素耐量试验(ITT),检测血清游离脂肪酸(FFA)、总胆固醇(TC)、甘油三酯(TG)、低密度脂蛋白(LDL)、高密度脂蛋白(HDL)、谷丙转氨酶(ALT);ITT结束后第3天处死小鼠,测肝脏TG含量,并做HE染色观察肝脏形态变化;采用实时荧光定量聚合酶链反应(RT-PCR)检测细胞因子Chemerin、CMKLR1及肿瘤坏死因子-α(TNF-α)mRNA水平的表达。结果高脂组与对照组相比,胰岛素的敏感性下降(P<0.05),肝脏HE染色存在明显的炎症及肝细胞脂肪变,肝脏的TG含量升高(P<0.05),血脂紊乱及肝功能损伤,肝脏Chemerin的mRNA水平下降(P<0.05),CMKLR1及TNF-α的mRNA水平表达上升(P<0.05)。结论经高脂喂养18周后小鼠NAFLD造模成功并伴有胰岛素抵抗,在这种模型中肝脏Chemerin及CMKLR1的表达改变可能与NAFLD的发病有关。     

扇贝裙边对高脂膳食健康人血脂水平的影响

①目的扇贝裙边为扇贝加工副产品，尚待充分开发利用。为观察该食物资源对高脂膳食诱导的健康人血脂水平的升高可能具有的抑制作用而进行本研究。②方法采用自身对照研究，选择３９名血脂正常青年男性，在给以高脂膳食的同时或一段时间后，按维持热能和主要营养素不变的原则，向其高脂膳食中添加一定量扇贝裙边（每日１５０ｇ）并取代部分低脂动物食品，观察受试者血脂水平的变化。③结果经过２１ｄ的高脂膳食期，受试者血清甘油三酯（ＴＧ）和总胆固醇（ＴＣ）水平均有一定升高，高密度脂蛋白胆固醇（ＨＤＬ－Ｃ）水平和ＨＤＬ－Ｃ／ＴＣ比值也有所下降；维持主要营养素摄取量和膳食营养构成比无明显变化，添加扇贝裙边后受试者血清ＴＧ和ＴＣ水平不再上升，且有所降低，ＨＤＬ－Ｃ水平及其在ＴＣ中所占比例回升。而受试者从正常膳食进入具有同样营养素量和比例的含扇贝裙边高脂膳食后，血清ＴＧ，ＴＣ水平却未见明显升高，ＨＤＬ－Ｃ含量和比例有一定增加。④结论扇贝裙边能很好地阻止和延缓高脂膳食所引起的健康人血脂水平的升高。     

中国汉族青年低脂高糖膳食6天后的血清高密度脂蛋白、胆固醇水平

目的探讨低脂高糖膳食对中国汉族青年血脂及载脂蛋白的影响。方法我室招募健康在校大学生自愿者56名[(22.89±1.80)岁],于7d平衡膳食后给予低脂高糖膳食6d,分别在第1d、8d、14d清晨收集受试者人类学指标并抽取空腹静脉血,测定血清甘油三酯(TG)、总胆固醇(TC)、高密度脂蛋白胆固醇(HDL-C)、低密度脂蛋白胆固醇(LDL-C)、血糖(GLU)、胰岛素(Insulin)、载脂蛋白A-Ⅰ(ApoA-Ⅰ)、载脂蛋白B-100(ApoB-100)浓度。结果经过6d低脂高糖膳食以后,健康男性青年血清HDL-C升高,而体质量(Weight)、体重指数(BMI)、TC及LDL-C降低;健康女性青年血清TG、胰岛素升高而TC及LDL-C降低。根据BMI分别将男女受试者分为高、中、低BMI3组分析发现,尽管某些变化不具有显著性,高、中、低BMI3组都出现TC及LDL-C降低;男性低BMI和高BMI组出现血清HDT-C及ApoA-Ⅰ显著升高,其它各组膳食前后变化差异无统计学意义。血清TG升高只在女性低BMI和中BMI组中出现。结论不同性别、BMI的健康青年低脂高糖膳食后的血脂及载脂蛋白改变不相同,但均没有发现HDL-C显著降低。     

有氧运动对高脂膳食金黄地鼠糖脂代谢及肝脏过氧化物酶增殖体受体的影响

目的探讨有氧运动对高脂膳食金黄地鼠糖脂代谢及过氧化物酶增殖体受体(PPARs)的影响。方法将健康雄性清洁级金黄地鼠20只随机分为对照组和运动组,每组10只。2组金黄地鼠均给予质量分数10%高脂膳食。运动组金黄地鼠做跑台运动10周,对照组未做跑台运动。10周后检测金黄地鼠生物化学指标及肝脏组织中PPARs的基因表达。结果有氧运动10周后,2组金黄地鼠血清三酰甘油、总胆固醇、低密度脂蛋白胆固醇、高密度脂蛋白胆固醇比较差异无统计学意义(P>0.05);运动组金黄地鼠空腹血糖、胰岛素水平明显低于对照组,差异有统计学意义(P<0.05,P<0.01);有氧运动可以金黄地鼠提高肝脏总胆固醇、肝脂酶、脂蛋白脂酶(LPL)水平(P<0.05);2组金黄地鼠血清、肝脏、肌肉及肾周脂肪中游离脂肪酸比较差异无统计学意义(P>0.05);有氧运动升高金黄地鼠肝脏PPARs不明显(P>0.05)。结论有氧运动对高脂膳食金黄地鼠肝脏PPARs影响不明显,但可以调节糖脂代谢,降低血糖及胰岛素水平,改善胰岛素抵抗。     

高脂饮食诱导的肥胖及肥胖抵抗大鼠血浆抵抗素水平的研究

目的探讨高脂饮食诱导的肥胖及肥胖抵抗大鼠血浆抵抗素水平的变化。方法将30只Wistar雄性大鼠随机分为正常对照组8只和高脂饮食组22只,分别给予普通饮食和高脂饮食。喂养8周,观察体重变化,按体重增量,高脂饮食组大鼠又分为高脂肥胖组12只及肥胖抵抗组10只,测定并比较各组大鼠血清三酰甘油、总胆固醇及抵抗素水平。结果高脂肥胖组大鼠血清三酰甘油水平显著高于正常对照组,有统计学意义(P<0.05);总胆固醇水平显著高于正常对照组和肥胖抵抗组,有统计学意义(P<0.05,P<0.01);高脂肥胖组血清抵抗素高于正常对照组和肥胖抵抗组(P<0.05),肥胖抵抗组血清抵抗素与正常对照组差异无统计学意义(P>0.05)。结论在高脂饮食诱导的肥胖大鼠中,血浆抵抗素水平升高,并存在着血脂紊乱,而肥胖抵抗大鼠血浆抵抗素水平没有明显的变化。提示血浆抵抗素水平可能参与肥胖抵抗的发生。     

中国人和日本人膳食组成、体力活动及血脂含量比较：成都－福研究

对中国成都３２６例成人，１１６例大学生以及日本福冈３００例成人，４５２９例大学生的膳食组成、体力活动及血脂含量进行了比较研究。结果表明：中国人摄取较多的碳水化合物，其谷物热量／总热量及多不饱和脂肪酸／饱和脂肪酸比值均较高，而且中国人体力活动指数也较高；但是中国人脂肪及蛋白质摄入量则较低，动物脂肪／总脂肪的比值也较低（Ｐ＜０．００１）．血脂分析表明，除女性甘油三酯含量外，中国成人血清总胆固醇、甘油三酯、高密度脂蛋白胆固醇及低密度脂蛋白胆固醇的水平显著低于相应的日本人（Ｐ＜０．００１）。     

Lovastatin efficacy in reducing low-density lipoprotein cholesterol levels on high- vs low-fat diets

The effectiveness of lovastatin was compared with both a high-fat vs low-fat diet. Hypercholesterolemic subjects were studied under metabolic ward conditions for diet periods of 3 weeks while receiving lovastatin (40 mg/d) or placebo. Multiple lipoprotein levels were measured during the final week of each diet period. Nineteen subjects completed the study on the high-fat (43% of kilojoules) diet and 16 on the low-fat (25% of kilojoules) diet. Lovastatin reduced total cholesterol by 23% and low-density lipoprotein cholesterol by 30%, compared with placebo on both diets, with no significant diet-drug interaction. High-density lipoprotein cholesterol was raised by 7% to 8% on the diet regimens. Addition of lovastatin to the low-fat diet permitted 80% of subjects on this diet, but less than 50% of those on the high-fat diet, to achieve current guidelines. Although lovastatin produces a comparable percentage reduction in lipoprotein profiles on either diet, the accompanying low-fat diet remains advisable for additional reduction of low-density lipoprotein cholesterol levels to specified goals.     

Effects of Red Palm Oil on Serum Lipids and Plasma Carotenoids Level in Chinese Male Adults

Objective Effects of red palm oil on major plasma carotenoids, tocopherol, retinol and serum lipids were evaluated when used in Chinese diet. Methods Red palm oil group (RPO) composedof 20 male subjects(aged 18-32) and soybean oil group (SBO) composed of 22 male subjects     

Superiority of traditional village diet and lifestyle in minimizing cardiovascular disease risk in Papua New Guineans

In the traditional society of Papua New Guinea (PNG) atherosclerotic cardiovascular diseases (CVD) are rare. However, among the urban population reports of cases of atheroma-related CVD are increasing. The purpose of this study was therefore to compare the CVD risk factors in a homogeneous population of the Southern Highlands Province living in both rural and urban areas differing only in their diet and lifestyle. A total of 221 Samberigi people over the age of 25 years were selected for the survey. These included 123 individuals from remote villages of Samberigi and 98 of their relatives who had lived in Port Moresby city continuously for a minimum of 5 years. The anthropometric measurements, blood lipid, blood glucose and glycosylated haemoglobin (HbA1c) levels were measured and compared. The rural diets were mainly of vegetarian type, limited in variety and low in fat and protein content. In the urban subjects, the typical meal comprised refined foods with high fat and protein content. The urban men and women had significantly (p < 0.05) greater body weight, body mass index (BMI), and waist and hip circumferences than their rural counterparts. In Port Moresby, 57% of the men and 67% of the women were overweight or obese compared to 28% of their rural counterparts. Similarly, the mean plasma total cholesterol, low-density lipoprotein cholesterol (LDLC), high-density lipoprotein cholesterol (HDLC), fasting blood glucose and HbA1c were significantly higher in the urban group. However, no significant differences were demonstrated for waist to hip ratio, LDLC/HDLC ratio and lipoprotein (a) levels between the two groups. The total cholesterol, LDLC and HbA1c were positively associated with age and BMI in both rural and urban locations. In conclusion, there were significant increases in CVD risk factors in the urban population compared to the rural residents. This was predominantly due to the adoption of a western lifestyle and diet as people moved from rural villages to the city of Port Moresby.     

低碳水化合物饮食对非酒精性脂肪性肝病治疗效果的Meta分析

目的系统评价低碳水化合物饮食干预对非酒精性脂肪性肝病(non-alcoholic fatty liver disease,NAFLD)的治疗效果。方法检索中国知网、万方、维普、PubMed、Embase和Cochrane Library数据库自建库到2019年3月低碳水化合物饮食干预治疗NAFLD相关文献,运用Cochrane偏倚风险评估工具进行文献质量评价,应用RevMan 5.3软件对提取的数据参数进行Meta分析,Stata15.0软件进行敏感性分析和发表偏倚检测。结果纳入的5篇随机对照研究符合标准,病例总数220例,Meta分析结果显示:低碳水化合物饮食与低脂饮食相比,可降低NAFLD患者低密度脂蛋白(LDL)和甘油三酯(TG)水平,但对体质指数(BMI)、高密度脂蛋白(HDL)、天门冬氨酸氨基转移酶(AST)、丙氨酸氨基转移酶(ALT)并未产生明显影响。敏感性分析和发表偏倚检测结果显示,单个研究对合并结果稳定性影响不显著且不存在明显发表偏倚。结论与低脂饮食相比,低碳水化合物饮食可显著改善患者部分血脂水平,但对BMI和肝酶改善作用有限。     

白芍总苷的降血脂、抗氧化作用及其对脂肪肝的防治研究

目的:研究白芍总苷的降血脂、抗氧化作用及其对脂肪肝的防治作用。方法:采用高脂高糖饮食建立脂肪肝大鼠模型,并预防性给予白芍总苷处理8周。8周后,处死大鼠,测定血浆中总胆固醇(TC)、甘油三酯(TG)、高密度脂蛋白胆固醇(HDL-C)、低密度脂蛋白胆固醇(LDL-C)、丙氨酸转氨酶(ALT)、天门冬氨酸转氨酶(AST)水平;取全肝称重,计算肝指数,同时测定肝组织中超氧化物歧化酶(SOD)、过氧化氢酶(CAT)和谷胱甘肽过氧化物酶(GSH-PX)活性以及丙二醛(MDA)的含量,取肝左叶,HE染色,光镜下观察肝脏组织学变化。结果:白芍总苷可明显降低脂肪肝大鼠血浆TC、TG、LDL-C水平,提高血浆HDL-C水平;降低肝指数,降低ALT和AST水平,明显提高肝脏组织中SOD、CAT和GSH-PX活性,降低MDA含量,改善肝脏组织学改变。结论:白芍总苷对高脂高糖饮食诱导的脂肪肝有防治作用,其作用机制可能与降血脂和提高肝脏抗氧化能力有关。