Plant stanol esters in low-fat milk products lower serum total and LDL cholesterol

Background Oil-based matrices enriched with plant stanol esters lower serum LDL cholesterol. The effects of low-fat milk products have been less thoroughly examined. Aim of the study To evaluate the effect of three less explored low-fat milk products enriched with plant stanol esters on serum lipid concentrations in subjects with mild or moderate hypercholesterolemia. Methods A meta-analysis of four unpublished sub-studies (yoghurt, yoghurt single-shot drink: Studies I and II, or milk). All the sub-studies were randomized, placebo-controlled, double-blind and had a parallel-group design. They were carried out in order to evaluate the effect of low-fat milk products enriched with plant stanol esters on serum lipid concentration. Each stanol-ester-enriched milk product provided 2 g of stanols per day, and in each study the intervention period was 5 weeks. A total of 199 hypercholesterolemic subjects completed the studies. Results The pooled treatment difference in total cholesterol was −3.8% (95% CI −6.0 to −1.7, p < 0.001) when stanol was compared to placebo. In LDL cholesterol, the pooled treatment difference was −4.9% (95% CI −7.8 to −1.8, p = 0.002). There were no significant differences between the groups in pooled HDL cholesterol or triacylglycerol concentrations. The results tended to be more pronounced when we were certain that the yoghurt single-shot drink was ingested with lunch, and when the baseline LDL-cholesterol concentration was ≥3.5 mmol/l. Conclusions These results imply that low-fat milk products enriched with plant stanol esters lower both total cholesterol and LDL cholesterol statistically significantly in subjects with mild or moderate hypercholesterolemia. The changes tended to relate to the baseline LDL-cholesterol concentration.     

Oat-bran cereal lowers serum total and LDL cholesterol in hypercholesterolemic men

Oat bran lowers serum lipid concentrations in healthy and hyperlipidemic subjects. To determine the effects of a ready-to-eat oat-bran cereal on lipid concentrations, we fed control (corn flakes) and oat-bran cereal diets for 2 wk to 12 men with undesirably high serum total-cholesterol concentrations. Subjects were randomly assigned to one of the two diets upon admission to the metabolic ward. After completing the first diet, subjects completed 2 wk on the alternate diet. Intakes of carbohydrate, protein, fat, and cholesterol were virtually identical on the two diets. The oat-bran cereal provided 25 g oat bran/d. The oat-bran cereal diet compared with the corn flakes diet lowered serum total-cholesterol and serum LDL-cholesterol concentrations significantly by 5.4% (p less than 0.05) and 8.5% (p less than 0.025), respectively. Final body weights on each of the diets were similar. Ready-to-eat oat-bran cereal provides a practical means to incorporate soluble fiber into the diet to lower serum cholesterol.     

Bakery products lower serum cholesterol concentrations in hypercholesterolemic men

Several foods rich in water-soluble fiber have documented hypocholesterolemic effects. To determine the cholesterol-lowering effects of high-soluble-fiber intake from refined, wheat-based bakery products, 10 hypercholesterolemic subjects ate a high-carbohydrate, high-fiber control diet in a metabolic ward for 7 d, followed by a diet rich in soluble fiber from bakery products for 21 d. Both control and bakery diets provided 25 g total dietary fiber/d; however, the bakery diet provided 6 g soluble fiber/d more than the control diet. Average serum total cholesterol concentrations stabilized during the control diet and then decreased 6.4% during the bakery diet. Serum low-density-lipoprotein cholesterol decreased 8.5% (P less than 0.05), apolipoprotein B-100 decreased 8.7% (P less than 0.05), and the ratio of apolipoprotein B-100 to apolipoprotein A-I decreased 9.5% (P less than 0.05) during the bakery diet. Results confirm previous reports that a small increase in soluble-fiber intake of approximately 6 g/d modestly decreases atherogenic serum cholesterol concentrations, regardless of fiber source.     

Black tea consumption reduces total and LDL cholesterol in mildly hypercholesterolemic adults

Despite epidemiological evidence that tea consumption is associated with the reduced risk of coronary heart disease, experimental studies designed to show that tea affects oxidative stress or blood cholesterol concentration have been unsuccessful. We assessed the effects of black tea consumption on lipid and lipoprotein concentrations in mildly hypercholesterolemic adults. Tea and other beverages were included in a carefully controlled weight-maintaining diet. Five servings/d of tea were compared with a placebo beverage in a blinded randomized crossover study (7 men and 8 women, consuming a controlled diet for 3 wk/treatment). The caffeine-free placebo was prepared to match the tea in color and taste. In a third period, caffeine was added to the placebo in an amount equal to that in the tea. Five servings/d of tea reduced total cholesterol 6.5%, LDL cholesterol 11.1%, apolipoprotein B 5% and lipoprotein(a) 16.4% compared with the placebo with added caffeine. Compared with the placebo without added caffeine, total cholesterol was reduced 3.8% and LDL cholesterol was reduced 7.5% whereas apolipoprotein B, Lp(a), HDL cholesterol, apolipoprotein A-I and triglycerides were unchanged. Plasma oxidized LDL, F2-isoprostanes, urinary 8-hydroxy-2'-deoxyguanosine, ex vivo ferric ion reducing capacity and thiobarbituric acid reactive substances in LDL were not affected by tea consumption compared with either placebo. Thus, inclusion of tea in a diet moderately low in fat reduces total and LDL cholesterol by significant amounts and may, therefore, reduce the risk of coronary heart disease. Tea consumption did not affect antioxidant status in this study.     

A single daily dose of soybean phytosterols in ground beef decreases serum total cholesterol and LDL cholesterol in young,mildly hypercholesterolemic men

BACKGROUND: Renal insufficiency is associated with altered vitamin B-6 metabolism. We have observed high concentrations of 4-pyridoxic acid, the major catabolite of vitamin B-6 metabolism, in plasma during renal insufficiency. OBJECTIVE: The objective was to evaluate the renal handling of 4-pyridoxic acid and the effects of renal dysfunction on vitamin B-6 metabolism. DESIGN: We measured the renal clearance of 4-pyridoxic acid and creatinine in 17 nonpregnant, 17 pregnant, and 16 lactating women. We then examined the influence of vitamin B-6 or alkaline phosphatase activity on the ratio of 4-pyridoxic acid to pyridoxal (PA:PL) in plasma in 10 men receiving a low (0.4 mg pyridoxine.HCl/d) or high (200 mg pyridoxine.HCl/d) vitamin B-6 intake for 6 wk, in 10 healthy subjects during a 21-d fast, in 1235 plasma samples from 799 people screened for hypophosphatasia, and in 67 subjects with a range of serum creatinine concentrations. RESULTS: Renal clearance of 4-pyridoxic acid was 232 +/- 94 mL/min in nonpregnant women, 337 +/- 140 mL/min in pregnant women, and 215 +/- 103 mL/min in lactating healthy women. These values were approximately twice the creatinine clearance, indicating that 4-pyridoxic acid is at least partially eliminated by tubular secretion. Elevated plasma creatinine concentrations were associated with marked elevations in 4-pyridoxic acid and PA:PL. PA:PL was not affected by wide variations in vitamin B-6 intake or by the wide range of pyridoxal-P concentrations encountered while screening for hypophosphatasia. CONCLUSIONS: Plasma 4-pyridoxic acid concentrations are markedly elevated in renal insufficiency. Plasma PA:PL can distinguish between increases in 4-pyridoxic acid concentrations due to increased dietary intake and those due to renal insufficiency.     

Cocoa flavanol-enriched snack bars containing phytosterols effectively lower total and low-density lipoprotein cholesterol levels

BACKGROUND: Dietary intervention studies incorporating phytosterol-enriched margarine spreads have reported significant decreases in total and low-density lipoprotein (LDL) cholesterol in populations with both normal lipid levels and those with hypercholesterolemia. There is emerging support for more diverse and lower-fat phytosterol-enriched matrixes. Controversy exists, however, over whether phytosterol-enriched foods affect serum fat-soluble vitamins. OBJECTIVE: We investigated whether a flavanol-rich cocoa snack food containing phytosterols would decrease total and LDL cholesterol levels in subjects with hypercholesterolemia and significantly affect serum fat-soluble vitamins and carotenoids. DESIGN: A randomized, double-blind parallel arm study design was used. Subjects were randomized to one of two dietary treatments: a cocoa flavanol-enriched snack bar containing 1.5 g phytosterol (n=32), or a control product containing no phytosterols (n=35). Subjects consumed two servings per day. RESULTS: Consumption of the phytosterol-enriched snack bars but not control bars for 6 weeks was associated with significant reductions in plasma total (4.7%; P<0.01) and LDL cholesterol (6%; P<0.01), and the ratio of total to high-density lipoprotein cholesterol (7.4%; P<0.001). There were no changes in high-density lipoprotein cholesterol, triglycerides, or lipid-adjusted lycopene, beta-cryptoxanthin, lutein/zeaxanthin, alpha-carotene levels, or levels of serum vitamins A or E. A significant reduction in lipid-adjusted serum beta-carotene was observed in the phytosterol but not the no-phytosterol-added group (P<0.05). CONCLUSIONS: This study supports the use of a novel phytosterol-enriched snack bar to effectively reduce plasma total and LDL cholesterol levels in a population with hypercholesterolemia. The data suggest that the incorporation of this snack food into a balanced diet represents a practical dietary strategy in the management of serum cholesterol levels.     

Macadamia nut consumption lowers plasma total and LDL cholesterol levels in hypercholesterolemic men

This study was conducted to assess the cholesterol-lowering potential of macadamia nuts. Seventeen hypercholesterolemic men (mean age 54 y) were given macadamia nuts (40-90 g/d), equivalent to 15% energy intake, for 4 wk. Plasma total cholesterol, LDL cholesterol, HDL cholesterol, triglycerides and homocysteine concentrations and the fatty acid composition of plasma lipids were determined before and after treatment. Plasma MUFA 16:1(n-7), 18:1(n-7) and 20:1(n-9) were elevated after intervention with macadamia nuts. Plasma (n-6) and (n-3) PUFA concentrations were unaffected by macadamia nut consumption. Plasma total cholesterol and LDL cholesterol concentrations decreased by 3.0 and 5.3%, respectively, and HDL cholesterol levels increased by 7.9% in hypercholesterolemic men after macadamia nut consumption. Plasma triglyceride and homocysteine concentrations were not affected by treatment. Macadamia nut consumption was associated with a significant increase in the relative intake of MUFA and a reduced relative intake of saturated fatty acids and PUFA. This study demonstrates that macadamia nut consumption as part of a healthy diet favorably modifies the plasma lipid profile in hypercholesterolemic men despite their diet being high in fat.     

Rye bread decreases serum total and LDL cholesterol in men with moderately elevated serum cholesterol

The objective of this study was to determine the hypocholesterolemic effects of whole meal rye and white wheat breads in healthy humans with elevated serum cholesterol concentrations, and the changes in plasma glucose and insulin concentrations during rye and wheat bread periods. The subjects were 18 men and 22 women with baseline serum cholesterol concentration of 6.4+/-0.2 mmol/L. The study design was a 2x4-wk crossover trial during which each subject randomly consumed rye and wheat breads (20% of daily energy) as part of their usual diet for 4 wk. The bread periods were separated by a 4-wk washout period. Blood samples (after fasting) were collected on two consecutive days at the beginning and end of the bread periods. Serum total cholesterol decreased by 8% (P = 0.002) in men but was not significantly altered in women during the rye bread period. The wheat bread period did not affect any of the variables studied. Analysis of the serum lipids in tertiles of rye bread consumption confirmed the reduction in total cholesterol (P = 0.048) in men and revealed the reduction in LDL cholesterol (P = 0.032); both were dependent on the amount of rye bread consumed (-2, -14 and -10% in total cholesterol and 0, -12 and -12% in LDL cholesterol). Neither rye nor wheat bread influenced the concentrations of glucose and insulin. In conclusion, rye bread is effective in reducing serum total and LDL cholesterol concentrations in men with elevated serum cholesterol. Good compliance with consuming a relatively large amount of rye bread in the usual diet indicates that rye bread offers a practical dietary means of reducing serum cholesterol in men.     

Carob pulp preparation rich in insoluble fibre lowers total and LDL cholesterol in hypercholesterolemic patients

Summary. Background: Recently, insoluble fibre from carob pulp has been found to affect blood lipids in animals in a similar manner as soluble dietary fibre. Aim of the study: To investigate whether a carob pulp preparation containing high amounts of insoluble fibre has a beneficial effect on serum cholesterol in humans. Methods: Volunteers (n = 58) with hypercholesterolemia were recruited to participate in a randomised, double- blind, placebo-controlled and parallel arm clinical study with a 6 week intervention phase. All participants consumed daily both, bread (two servings) and a fruitbar (one serving) either with (n = 29) or without (n = 29) a total amount of 15 g/d of a carob pulp preparation (carob fibre). Serum concentrations of total, LDL and HDL cholesterol and triglycerides were assessed at baseline and after week 4 and 6. Results: The consumption of carob fibre reduced LDL cholesterol by 10.5 ± 2.2% (p = 0.010). The LDL:HDL cholesterol ratio was marginally decreased by 7.9 ± 2.2 % in the carob fibre group compared to the placebo group (p = 0.058). Carob fibre consumption also lowered triglycerides in females by 11.3 ± 4.5% (p = 0.030). Lipid lowering effects were more pronounced in females than in males. Conclusion: Daily consumption of food products enriched with carob fibre shows beneficial effects on human blood lipid profile and may be effective in prevention and treatment of hypercholesterolemia.     

Soy isoflavones lower serum total and LDL cholesterol in humans: a meta-analysis of 11 randomized controlled trials

BACKGROUND: Clinical trials have reported the cholesterol-lowering effects of soy protein intake, but the components responsible are not known. OBJECTIVE: This meta-analysis was primarily conducted to evaluate the precise effects of soy isoflavones on lipid profiles. The effects of soy protein that contains enriched and depleted isoflavones were also examined. DESIGN: PUBMED was searched for English-language reports of randomized controlled trials published from 1990 to 2006 that described the effects of soy protein intake in humans. Eleven studies were selected for the meta-analysis. RESULTS: Soy isoflavones significantly decreased serum total cholesterol by 0.10 mmol/L (3.9 mg/dL or 1.77%; P = 0.02) and LDL cholesterol by 0.13 mmol/L (5.0 mg/dL or 3.58%; P < 0.0001); no significant changes in HDL cholesterol and triacylglycerol were found. Isoflavone-depleted soy protein significantly decreased LDL cholesterol by 0.10 mmol/L (3.9 mg/dL or 2.77%; P = 0.03). Soy protein that contained enriched isoflavones significantly decreased LDL cholesterol by 0.18 mmol/L (7.0 mg/dL or 4.98%; P < 0.0001) and significantly increased HDL cholesterol by 0.04 mmol/L (1.6 mg/dL or 3.00%; P = 0.05). The reductions in LDL cholesterol were larger in the hypercholesterolemic subcategory than in the normocholesterolemic subcategory, but no significant linear correlations were observed between reductions and the starting values. No significant linear correlations were found between reductions in LDL cholesterol and soy protein ingestion or isoflavone intakes. CONCLUSIONS: Soy isoflavones significantly reduced serum total and LDL cholesterol but did not change HDL cholesterol and triacylglycerol. Soy protein that contained enriched or depleted isoflavones also significantly improved lipid profiles. Reductions in LDL cholesterol were larger in hypercholesterolemic than in normocholesterolemic subjects.     

Cholesterol-lowering effect of beta-glucan from oat bran in mildly hypercholesterolemic subjects may decrease when beta-glucan is incorporated into bread and cookies

BACKGROUND: Findings about the effects of beta-glucan on serum lipoproteins are conflicting. OBJECTIVE: The study investigated the effects of beta-glucan from oat bran in bread and cookies (study 1) and in orange juice (study 2) on serum lipoproteins in mildly hypercholesterolemic subjects. DESIGN: In study 1, 48 subjects (21 men, 27 women) received for 3 wk control bread and cookies rich in wheat fiber. For the next 4 wk, by random assignment, 23 subjects continued to consume the control products, and 25 received bread and cookies rich in beta-glucan. Mean daily intake of beta-glucan was 5.9 g. Total dietary fiber intake did not differ significantly between the groups. In study 2, the same sources of control fiber and beta-glucan (5 g/d) as in study 1 were provided. For 2 wk, 25 of the original 48 subjects (10 men, 15 women) were randomly assigned to consume orange juice containing either wheat fiber (n = 13) or beta-glucan from oat bran (n = 12). After a washout period of 1 wk, dietary regimens were crossed over. RESULTS: In study 1, the change in LDL cholesterol did not differ significantly (-0.12 mmol/L; P = 0.173) between the 2 groups. In study 2, the drink rich in beta-glucan decreased LDL cholesterol by 0.26 +/- 0.07 mmol/L (6.7 +/- 1.8%; P = 0.001) and the ratio of total to HDL cholesterol by 0.26 +/- 0.11 (5.4 +/- 2.1%; P = 0.029) compared with the other drink. HDL-cholesterol and triacylglycerol concentrations did not change significantly. CONCLUSIONS: The food matrix or the food processing, or both, could have adverse effects on the hypocholesterolemic properties of oat beta-glucan.     

Fasting increases serum total cholesterol, LDL cholesterol and apolipoprotein B in healthy, nonobese humans.

Voluntary fasting is practiced by many humans in an attempt to lose body weight. Conflicting results have been published on the effects of food deprivation on serum lipids. To study the effect of acute starvation on serum lipids, 10 nonobese (93-124% of ideal body weight), healthy adults (6 men, 4 women, 21-38 y old) fasted (no energy) for 7 d. Fasting increased total serum cholesterol from 4.90 +/- 0.23 to 6.73 +/- 0.41 mmol/L (37.3 +/- 5.0%; P < 0.0001) and LDL cholesterol from 2.95 +/- 0.21 to 4.90 +/- 0.36 mmol/L (66.1 +/- 6. 6%; P < 0.0001). Serum apolipoprotein B (apo B) increased from 0.84 +/- 0.06 to 1.37 +/- 0.11 g/L (65.0 +/- 9.2%; P < 0.0001). The increases in serum cholesterol, LDL and apo B were associated with weight loss. Fasting did not affect serum concentrations of triacylglycerol and HDL cholesterol. Serum concentrations of insulin-like growth factor-I (IGF-I) decreased from 246 +/- 29 (prefast) to 87 +/- 10 microg/L after 1 wk of fasting (P < 0.0001). We conclude that, in nonobese subjects, fasting is accompanied by increases in serum cholesterol, LDL and apo B concentrations, whereas IGF-I levels are decreased.     

A study of the correlation between serum total cholesterol and low-density lipoproteins (LDL) in Chinese

Serum total cholesterol and lipoprotein analysis was performed on the same blood samples of 139 asymptomatic Chinese subjects aged 40-60 years. There was a highly significant correlation between serum total cholesterol and low density lipoproteins (correlation coefficient = 0.8376, p less than 0.001) in Chinese, which means that total cholesterol can be used as the initial screening to identify individuals who may need lipoprotein analysis. The American National Cholesterol Education Programme (ANCEP) recommended threshold total cholesterol levels that indicate lipoprotein analysis for the high risk and low risk groups were found to have high sensitivities and negative predictive values but relatively low specificities and positive predictive values. Thirty to forty per cent of the lipoprotein analyses recommended by the ANCEP guidelines were not necessary. There was no significant age or sex influence on the degree of correlation between serum total cholesterol and LDL.     

Walking and serum cholesterol in adults.

We measured the association between walking for exercise and the ratio of total cholesterol/HDL cholesterol in 3,621 adults. After controlling for age, gender, income, body fat, alcohol use, exercise other than walking, and cigarette smoking, adults in the high, moderate, and low duration walking categories were compared to those in the no walking-no exercise category. The relative risk for total/HDL ratios of 5.0 or more were .46 (95% CI = .27, .80), .48 (95% total/HDL ratios of 5.0 or more were .46 (95% CI = .27, .80), .48 (95% CI = .30, .76), and 1.11 (95% CI = .81, 1.53) respectively.     

Effect of fermented milk (yogurt) containing Lactobacillus acidophilus L1 on serum cholesterol in hypercholesterolemic humans

OBJECTIVE: Two controlled clinical studies were performed to examine effects of consumption of one daily serving of fermented milk (FM) (yogurt) on serum lipids. METHODS: In the first study, subjects were randomly allocated to FM containing Lactobacillus acidophilus L1 of human origin or to FM containing L. acidophilus ATCC 43211 of swine origin. In this single-blind study, subjects consumed one 200 ml serving of FM daily for 3 weeks. The second study was a double-blind, placebo-controlled, cross-over study. Subjects completed a 4-week first treatment, had a 2-week washout, and completed a second 4-week treatment. In the second study subjects consumed FM containing L. acidophilus L1 or placebo FM over 4 weeks. RESULTS: In the first study, FM containing L. acidophilus L1 was accompanied by a 2.4% (p<0.05) reduction of serum cholesterol concentration. In the second study, strain L1 reduced serum cholesterol concentration by 3.2% (p<0.05) in the first treatment period. In the second treatment period there were no significant changes in serum cholesterol concentration. Combined analysis of the two L1 treatment studies demonstrated a 2.9% (p<0.01) reduction in serum cholesterol concentration. CONCLUSION: Since every 1% reduction in serum cholesterol concentration is associated with an estimated 2% to 3% reduction in risk for coronary heart disease, regular intake of FM containing an appropriate strain of L. acidophilus has the potential of reducing risk for coronary heart disease by 6 to 10%.     

Consumption of tall oil-derived phytosterols in a chocolate matrix significantly decreases plasma total and low-density lipoprotein-cholesterol levels

In a randomized, double-blind, placebo-controlled trial we evaluated the effect of dietary chocolates enriched with a wood-based phytosterol-phytostanol mixture, containing 18 % (w/w) sitostanol, compared with placebo dietary chocolates in seventy subjects with primary hypercholesterolaemia (total cholesterol levels below 8 mmol/l). For 4 weeks, participants consumed three servings of the phytosterol-enriched chocolate/d that provided 1.8 g unesterified phytosterols/d or a placebo chocolate in conjunction with a low-fat, low-cholesterol diet. Plasma total and LDL-cholesterol levels were statistically significantly reduced by 6.4 % (-0.44 mmol/l) and 10.3 % (-0.49 mmol/l), respectively, after 4 weeks of phytosterol-enriched-chocolate treatment. Plasma HDL-cholesterol and triacylglycerol levels were not affected. Consumption of phytosterol-enriched chocolates significantly increased plasma lathosterol concentration (+20.7 %), reflecting an increased endogenous cholesterol synthesis in response to phytosterol-induced decreased intestinal cholesterol absorption. Furthermore, the chocolates enriched with phytosterols significantly increased both plasma sitosterol (+95.8 %) and campesterol (+64.1 %) levels, compared with the placebo chocolate group. However, the absolute values of plasma sitosterol and campesterol remained within the normal range, that is, below 10 mg/l. The chocolates with phytosterols were palatable and induced no clinical or biochemical side effects. These findings indicate that dietary chocolate enriched with tall oil-derived phytosterols (1.8 g/d) is effective in lowering blood total and LDL-cholesterol levels in subjects with mild hypercholesterolaemia and thus may be helpful in reducing the risk of CHD in these individuals.     

大豆异黄酮对高胆固醇模型大鼠血清胆固醇浓度和肝脏胆固醇代谢的影响

目的观察大豆异黄酮对高脂模型大鼠血清胆固醇浓度及其肝脏胆固醇代谢关键酶基因表达的影响。方法 9周龄SD雄性大鼠8只喂饲AIN93M饲料（阴性对照组）,18只喂饲高脂饲料建立高胆固醇模型。14 d后将高胆固醇大鼠随机分为异黄酮组（每天灌胃360 mg/kg BW大豆异黄酮）和高脂对照组,喂饲高脂饲料至实验结束。30 d后测血脂,实时定量聚合酶链式反应（polymerase chain reaction,PCR）测定肝脏羟甲戊二酰辅酶A还原酶（3-hydroxy-3-methylglutaryl-Coenzyme A reductase,Hmgcr）、胆固醇7α-羟化酶（cytochrome P450,family 7,subfamily a,polypeptide 1,Cyp7a1）、低密度脂蛋白受体（low density lipoprotein receptor,Ldlr）mRNA表达量。结果异黄酮组大鼠血清总胆固醇（total cholesterol,TC）和低密度脂蛋白胆固醇（low density lipoprotein cholesterol,LDLC）浓度分别比高脂对照组降低了23.7%（q=2.79,P=0.010）和23.2%（q=2.63,P=0.015）;动物肝脏的Hmgcr和Cyp7a1 mRNA表达量均出现下降,但差异无统计学意义（均有P〉0.05）。结论大豆异黄酮可明显降低高胆固醇大鼠血清TC和LDLC浓度,有可能影响肝脏胆固醇代谢。