Diet high in monounsaturated fat does not have a different effect on arterial elasticity than a low-fat, high-carbohydrate diet

OBJECTIVE: To compare the effects of a modified-fat diet high in monounsaturated fat, and a low-fat/high-carbohydrate diet on arterial elasticity. DESIGN: Randomized crossover design; each diet period was 1 month and a 2-week wash out period occurred in between. SUBJECTS/SETTING: Thirty healthy, free-living, nonsmoking men and women were recruited from the Melbourne, Australia, metropolitan region of Australia. Men were aged 35 to 55 years and postmenopausal women were aged 50 to 60 years and were not taking hormone replacement therapy. Twenty-eight subjects completed the study. INTERVENTION: Two diets of equal energy value: a modified-fat diet and a low-fat/high-carbohydrate diet; the modified-fat diet had 3 times more energy from monounsaturated fat. MAIN OUTCOME MEASURES: Arterial elasticity and serum lipoprotein concentrations. STATISTICAL ANALYSIS: The general linear model was used to investigate overall effect and any carryover or order effects. Paired t test and the general linear model were used to compare the results from the 2 diet periods. RESULTS: High-density lipoprotein cholesterol concentration was significantly higher on the modified-fat diet than on the low-fat/low-carbohydrate diet. Arterial elasticity and concentrations of total cholesterol, low-density lipoprotein cholesterol, and triglycerides were not significantly different on the 2 diets. APPLICATIONS/CONCLUSIONS: There is no evidence to favor a diet high in monounsaturated fat over a low-fat/high-carbohydrate diet because of an effect on arterial elasticity. Other changes in diet may be needed to cause a beneficial effect on arterial elasticity.     

Balance of unsaturated fatty acids is important to a cholesterol-lowering diet: comparison of mid-oleic sunflower oil and olive oil on cardiovascular disease risk factors

OBJECTIVE: To evaluate the effects of a trans fat-free monounsaturated fatty acid-rich vegetable oil (NuSun sunflower oil, National Sunflower Association, Bismark, ND) that is a good source of polyunsaturated fatty acids (PUFA) and low in saturated fatty acids on lipid and lipoprotein levels and oxidative stress. DESIGN: A double-blinded, randomized, three period crossover, controlled feeding study. SUBJECTS/SETTING: Thirty-one men (n=12) and women (n=19) with moderate hypercholesterolemia who were 25 to 64 years of age. INTERVENTION: Experimental diets provided 30% fat (olive oil or NuSun sunflower oil contributed one half of the total fat), 8.3% vs 7.9% saturated fatty acid, 17.2% vs 14.2% monounsaturated fatty acid, and 4.3% vs. 7.7% PUFA (olive oil and NuSun sunflower oil, respectively), and 294 mg cholesterol. The control diet was an average American diet (34% fat, 11.2% saturated fatty acid, 14.9% monounsaturated fatty acid, 7.8% PUFA). Subjects consumed each diet for 4 weeks with a 2-week compliance break before crossing over to another diet. MAIN OUTCOME MEASURES: Lipid and lipoprotein levels were measured, and measures of oxidative stress, including lag time, rate of oxidation, total dienes, and lipid hydroperoxides, were assessed. STATISTICAL ANALYSIS: The mixed model procedure was used to test for main effects of diet, feeding period, and order of diets. Tukey-Kramer adjusted P values were used to determine diet effects. RESULTS: The NuSun sunflower oil diet decreased both total and low-density lipoprotein cholesterol levels compared with the average American diet and the olive oil diet. There was no effect of the olive oil diet compared with the average American diet. Total cholesterol decreased 4.7% and low-density lipoprotein cholesterol decreased 5.8% on the NuSun sunflower oil diet vs the average American diet. There was no effect of the experimental diets on triglyceride levels, rate of oxidation, total dienes, lipid hydroperoxides, or alpha-tocopherol. Lag time was the longest following the olive oil diet and shortest following the NuSun sunflower oil diet. CONCLUSIONS: The higher PUFA content appeared to account for the greater total and low-density lipoprotein cholesterol lowering and reduction in lag time of the NuSun sunflower oil diet. However, the fact that there were no differences in the resulting oxidation products suggests there were no adverse effects on low-density lipoprotein oxidation. Since PUFAs are important for cholesterol lowering, foods that replace saturated fatty acids should include a balance of unsaturated fatty acids.     

Effects of oleic-rich and omega-3-rich diets on serum lipid pattern and lipid oxidation in mildly hypercholesterolemic patients

AIMS: To evaluate which dietary fat elicits the best response in terms of plasma lipids, lipoproteins, and oxidative processes. METHODS: After a 4-week run-in period, 14 mildly hypercholesterolemic subjects were fed two balanced diets for 6-week periods. During the first intervention period, patients received a monounsaturated fatty acid (MUFA)-enriched diet (olive oil diet). During the second period this diet was supplemented by n-3 polyunsaturated fatty acids (PUFAs) (n-3 diet). RESULTS: After the olive oil diet, a significant decrease in total serum cholesterol (-8.54%, P<0.01), and in apolipoprotein B (Apo B) (-10.0%, P<0.01) was observed. With the addition of n-3 fatty acids no further significant changes in serum lipid concentrations were found. However, the n-3 diet was followed by an increase in lipoperoxides in isolated native low-density lipoprotein (LDL) (67.23%, P<0.01). CONCLUSIONS: A beneficial effect on the serum lipid pattern was observed with the olive oil-enriched diet. The lack of further beneficial modifications on blood lipids and lipoproteins and the increase in the oxidative susceptibility of LDL observed after the addition of n-3 PUFA to the olive oil diet does not favor the use of this diet in hypercholesterolemic patients if it is not associated with a high intake of antioxidants.     

Reduced serum cholesterol with dietary change using fat-modified and oat bran supplemented diets

A low-fat, low-cholesterol diet and oat bran supplementation for treatment of hypercholesterolemia were studied for their effectiveness in lowering blood lipids and their impact on dietary intake. Seventy-one free-living men and women with hypercholesterolemia (serum cholesterol greater than 75th percentile) were randomly assigned to one of the following four groups: low-fat, low-cholesterol diet (LFLC); low-fat, low-cholesterol diet plus 50 gm/day oat bran (LFLC + OB); 50 gm/day oat bran supplemented diet (OB); or 42.5 gm/day processed oat bran (ready-to-eat cereal containing beta-glucan concentrated from oat bran) (POB). Subjects assigned to regimens OB and POB were requested to add the oat supplement without making additional changes in their diet. Serum cholesterol and high-density lipoprotein cholesterol analyses were performed at 4-week intervals, and diet records were assigned and analyzed. All groups experienced significant decreases in cholesterol from original levels (p less than .05). The average decrease in total serum cholesterol varied from 10% to 17%, with no significant differences among the four groups. High-density lipoprotein cholesterol concentrations decreased in all groups except group 4, in which there was a slight increase; however, no differences were found between groups. Energy, fat, and cholesterol intakes decreased in all groups, suggesting that displacement of higher fat foods from the diet may be one of the many mechanisms whereby oat supplements lower serum cholesterol. In addition, all groups reduced their intakes of calcium, copper, folic acid, and potassium from marginal levels at the beginning of the study.(ABSTRACT TRUNCATED AT 250 WORDS)     

A high-fat diet supplemented with fish oil improves metabolic features associated with type 2 diabetes

ObjectiveThe goal of this study was to investigate the effects of a high-fat diet supplemented with fish oil or olive oil, fed to C57BL/6J mice for an extended period, on metabolic features associated with type 2 diabetes.MethodsMice were fed one of four diets for 30 wk: a low-fat diet, a high-fat diet supplemented with lard, a high-fat diet supplemented with fish oil, or a high-fat diet supplemented with olive oil. Phenotypic and metabolic analysis were determined at 15 and 25 to 30 wk, thereby providing comparative analysis for weight gain, energy consumption, fat distribution, glucose and insulin tolerance, and hepatic/plasma lipid analysis.ResultsMice fed a high-fat diet supplemented with fish oil had improved glucose tolerance after an extended period compared with mice fed a high-fat diet supplemented with lard. Moreover, mice fed a high-fat diet supplemented with fish oil had significantly decreased concentrations of liver cholesterol, cholesteryl ester, and triacylglycerol compared with mice fed a high-fat diet supplemented with either lard or olive oil.ConclusionMice fed a high-fat diet supplemented with fish oil improved metabolic features associated with type 2 diabetes such as impaired glucose tolerance and hepatic steatosis.     

Controlled evaluation of fat intake in the Mediterranean diet: comparative activities of olive oil and corn oil on plasma lipids and platelets in high-risk patients

Activities of low-fat diets with olive oil or corn oil on lipids and platelets were studied in 23 middle-aged patients with high atherosclerosis risk for 8 wk. The olive oil diet had a polyunsaturated-saturated ratio of 0.33 vs 1.28 for the corn oil diet. Plasma total cholesterol was reduced with corn oil, but high-density lipoprotein cholesterol levels were lower with corn oil and unchanged or raised by olive. Plasma apolipoprotein B levels were equally reduced by both diets; apolipoprotein AI and the apo AI:B ratio rose only with olive oil. Plasma-glucose levels were lowered significantly with olive oil. Changes in platelet function were characterized by a reduced sensitivity to arachidonic acid (particularly with corn oil) and to collagen (particularly with olive). An olive oil diet with a moderate fat intake (about 30% of total calories) leads to favorable plasma lipoprotein and platelet changes.     

Incorporation of Lean Red Meat into a National Cholesterol Education Program Step I Diet: A Long-Term,Randomized Clinical Trial in Free-Living Persons with Hypercholesterolemia

Objective: Clinicians often recommend that intake of all meat, particularly red meat, be reduced in conjunction with a low-fat, low-cholesterol diet to reduce low-density lipoprotein (LDL) cholesterol. This study was designed to determine the long-term effects of lean red meat (beef, veal and pork) compared to lean white meat (poultry and fish) consumption on lipoprotein concentrations in free-living hypercholesterolemic subjects consuming a National Cholesterol Education Program (NCEP) Step I diet.

Methods: A randomized, crossover design was utilized. Hypercholesterolemic men and women (LDL cholesterol between 3.37 and 4.92 mmol/L) (triglycerides <3.96 mmol/L) (n = 145) were counseled to consume ≥80% of their 170 g/d meat intake as either lean red meat or lean white meat for two 36-week phases, separated by a four-week washout period of free meat selection. Subjects were instructed to follow an NCEP Step I diet throughout the study.

Results: There were no significant differences in lipid concentrations between the lean red meat and lean white meat phases. LDL cholesterol was 4.02 ± 0.04 (SEM) and 4.01 ± 0.04 mmol/L in the white and red phases, respectively; this represented a decrease of ～2% from baseline concentrations (p < 0.01). Total cholesterol also declined by 1% from baseline (p < 0.05), and high-density lipoprotein (HDL) cholesterol rose over the study period by ～2% to ～3% from baseline to reach concentrations of 1.37 ± 0.03 mmol/L and 1.38 ± 0.03 mmol/L in the white and red phases, respectively (p < 0.001). Triglycerides were not altered by treatment.

Conclusions: Consumption of lean red meat or lean white meat, as part of an NCEP Step I diet, is similarly effective for reducing LDL cholesterol and elevating HDL cholesterol concentrations in free-living persons with hypercholesterolemia.     

Women and Men with Hypercholesterolemia Respond Similarly to an American Heart Association Step 1 Diet

Objective To compare serum lipid level responses of women and men with hypercholesterolemia to an American Heart Association (AHA) step 1 diet.Design Sixty-three women and 99 men with varying degrees of hypercholesterolemia were instructed on an AHA step 1 diet. Subjects were followed up on a biweekly basis with individual visits and group classes for 8 weeks.Setting Outpatient clinic facility of the Metabolic Research Group, University of Kentucky, Lexington.Subjects/samples Through community cholesterol screenings, we recruited 76 women and 108 men aged 30 to 70 years who were within 80% to 130% of their ideal body weight. Serum cholesterol levels were between 5.17 mmol/L and 8.99 mmol/L and serum triglyceride levels when subjects were fasting were less than 5.08 mmol/L. Sixty-three women and 99 men completed the study.Intervention Subjects followed an AHA step 1 diet (30% of energy from fat, 50 to 60% of energy from carbohydrate, 10 to 20% of energy from protein, and less than 300 mg cholesterol per day) for 8 weeks.Main outcome measures Serum lipid levels, nutrient intake, and body weight.Statistical analyses performed Subjects were divided into three groups according to initial serum cholesterol levels (mild=5.17 to 6.17 mmol/L; MODERATE=6.20 to 6.95 mmol/L; SEVERE = 6.98 mmol/L). Within-individual changes in nutrient intakes, body weights, and serum lipid levels were analyzed using dependent t tests. Between-group comparisons were made using analysis of variance (ANOVA). When significant differences were found using ANOVA, differences between groups were evaluated with the Tukey test.Results All subjects tolerated the diet well and average dietary adherence was good, as assessed by a food frequency questionnaire and analysis of 3-day diet records. Serum total cholesterol levels decreased 9.2% overall for women (P<.001) and 7.2% for men (P<.001); serum low-density lipoprotein cholesterol levels decreased 9.2% for women and 9.8% for men; and serum high-density lipoprotein cholesterol levels decreased 3.6% for women and 2.8% for men. Mean serum triglyceride levels decreased significantly for women but not for men. No significant differences were found in the responses of women and men in the corresponding groups. Women and men with higher initial serum cholesterol values showed significantly greater hypocholesterolemic responses to diet than those with lower initial serum cholesterol values.Applications/conclusions The findings of this study confirm the beneficial role of dietary intervention for reducing atherogenic serum lipid levels in women and men. J Am Diet Assoc. 1995; 95:436–441.     

Comparison of a low-fat/low-glycemic index diet to a low-fat only diet in the treatment of adults with hypercholesterolemia

The Low Glycemic Index and Cholesterol study was a 12-week randomized clinical trial comparing the effects on serum lipids of a novel low-fat/low-glycemic index (GI) diet with those of a low-fat only diet in adults with hypercholesterolemia. Sixty-two subjects (men and women) with elevated serum low-density lipoprotein cholesterol were randomized to one of the two dietary interventions. The low-GI intervention included substituting low-GI carbohydrates for high-GI carbohydrates. Dietary assessment and serum lipid measurements were performed at baseline (BL), 4 weeks (FV4), and 12 weeks (FV12). In the low-fat/low-GI group, dietary GI and glycemic load significantly decreased between the BL and FV4 and BL and FV12 time intervals; however, there were no significant differences in lipid values between the two groups at any time point. Importantly, whereas high-density lipoprotein cholesterol was unchanged in the low-fat/low-GI group over the 12 weeks, it decreased 5 mg/dL (11.4%) in the low-fat only group (P = .05).     

Fatty acid saturation of the diet and plasma lipid concentrations, lipoprotein particle concentrations, and cholesterol efflux capacity

BACKGROUND: The fatty acid content and saturation degree of the diet can modulate HDL composition and cholesterol efflux. OBJECTIVE: We studied the modifications in plasma lipoprotein particles and serum capacity to stimulate cholesterol efflux induced by different fatty acids. DESIGN: Seventeen women and 24 men followed in the same sequence 4 diets containing 35% of total energy as fat. The saturated fat diet contained 17% palm oil; the monounsaturated fat diet, 20.9% olive oil; the n-6 polyunsaturated fat diet, 12.5% sunflower oil; and the n-3 polyunsaturated fat diet, sunflower oil supplemented with 4-4.5 g fish oil/d. Each phase lasted 4-5 wk. RESULTS: In both sexes, apolipoprotein (apo) A-I concentrations were significantly lower with unsaturated fat diets than with the saturated fat diet, but concentrations of lipoproteins containing only apo A-I (Lp A-I) were lower only in the men. Concentrations of lipoproteins containing both apo A-I and apo A-II (Lp A-I:A-II) were lower with both polyunsaturated fat diets in the women but significantly higher in the men. Lp E concentrations were significantly higher with the 2 polyunsaturated fat diets. Lp E non-B particle concentrations were not modified in the men but were significantly higher in the women in both polyunsaturated fat phases. Lp C-III concentrations were higher with the saturated fat diet only in the men. The serum samples taken after the n-3 polyunsaturated fat phase were the most efficient for extracting cellular cholesterol in both sexes. CONCLUSIONS: The monounsaturated and polyunsaturated fat diets were healthier, producing a better lipid profile. The n-3 polyunsaturated fat diet increased the capacity of serum to promote the efflux of cholesterol from cells in culture.     

Effect of a diet high in monounsaturated fat from almonds on plasma cholesterol and lipoproteins.

The effect of almonds as part of a low saturated fat, low cholesterol, high-fiber diet was studied in 26 adults (13 men, 13 women). The baseline diet was modified in a similar way for all subjects by limiting meat, fatty fish, high-fat milk products, eggs, and saturated fat. Grains, beans, vegetables, fruit, and low-fat milk products were the foundation of the diet. During the almond diet period, raw almonds (100 mg/day) supplied 34 g/day of monounsaturated fatty acid (MUFA), 12 g/day of polyunsaturated fatty acid, and 6 g/day of saturated fatty acid. Almond oil was the only oil allowed for food preparation. There was a rapid and sustained reduction in low-density lipoprotein cholesterol without changes in high-density lipoprotein cholesterol. This was reflected in a total plasma cholesterol decrease from (means +/- SEM) 235 +/- 5.0 at baseline to 215 +/- 5.0 at 3 weeks, and to 214 +/- 5.0 mg/dl at 9 weeks (p less than 0.001). When the consumption of nuts high in MUFA increases the fat content of the diet, reduction rather than elevation of plasma cholesterol has to be expected, possibly due to the MUFA content of these nuts.     

Olive-oil-enriched diet: effect on serum lipoprotein levels and biliary cholesterol saturation

The effect of diet enriched with a monounsaturated fatty acid (olive oil) on serum lipoproteins, biliary cholesterol saturation index, and gallbladder motility compared with a standard low-fat diet was evaluated in 11 young volunteers admitted to a metabolic ward. A significant decrease of mean total cholesterol (-9.5%), total apo B (-7.4%), LDL cholesterol (-12.2%), and total triglycerides (-25.5%) was observed after the olive-oil-enriched diet. Total HDL- and HDL-subfractions-cholesterol levels as well as serum apo A-I mean levels remained unchanged. Cholesterol saturation index of the bile and fasting and after-meal gallbladder volumes were unaffected by the enriched diet as compared with the low-fat diet. Olive oil may be a natural fat that can be used for the control of plasma and LDL cholesterol as a valid alternative to polyunsaturated fatty acids.     

Baseline plasma C-reactive protein concentrations influence lipid and lipoprotein responses to low-fat and high monounsaturated fatty acid diets in healthy men

To date, no studies have compared the effects of consuming a low-fat diet and a high monounsaturated fatty acid (MUFA) diet, under unrestricted energy intake conditions, on plasma C-reactive protein (CRP) concentrations. Men [n = 61; 37.5 +/- 11.5 y old (mean +/- SD), mean BMI 29.0 +/- 5.0 kg/m2] were randomly assigned to consume ad libitum a moderately low-fat diet (25.8% of energy intake from fat) or a high-fat diet rich in MUFA (40.1% of energy intake from fat, 22.5% from MUFA) for 6-7 wk. Plasma CRP concentrations were measured using a highly sensitive assay. Neither diet affected the plasma CRP concentration. However, baseline CRP concentrations predicted lipoprotein/lipid responsiveness to the experimental diets. After intake of the low-fat diet, plasma total and VLDL-triglyceride (TG) concentrations were increased in the subgroup with high CRP concentrations (P < 0.05 and P < 0.01, respectively) whereas they were reduced in the subgroup with low CRP concentrations at baseline (P < 0.01 for both). The high-MUFA diet reduced plasma TG, VLDL-TG, and VLDL cholesterol only in the subgroup with low CRP at baseline (P < 0.0001). In conclusion, the low-fat diet and the high-MUFA diet did not affect plasma CRP concentrations. However, baseline plasma CRP concentrations may modulate the diet-induced changes in plasma lipid and lipoprotein concentrations.     

Effects of olive oil and tomato lycopene combination on serum lycopene, lipid profile, and lipid oxidation

OBJECTIVE: We compared the effect of two diets (a diet high in olive oil and a diet high in carbohydrate and low in olive oil) with high lycopene content and other controlled carotenoids on serum lycopene, lipids, and in vitro oxidation. METHODS: This was a randomized crossover dietary intervention study carried out in Launceston, Tasmania, Australia in healthy free-living individuals. Twenty-one healthy subjects who were 22 to 70 y old were recruited by advertisements in newspapers and a university newsletter. A randomized dietary intervention was done with two diets of 10 d each. One diet was high in olive oil and the other was high in carbohydrate and low in olive oil; the two diets contained the same basic foods and a controlled carotenoid content high in lycopene. RESULTS: Significant increases (P<0.001) in serum lycopene concentration on both diets were to similar final concentrations. Higher serum high-density lipoprotein cholesterol (P<0.01), lower ratio of total cholesterol to high-density lipoprotein (P<0.01), and lower triacylglycerols (P<0.05) occurred after the olive oil diet compared with the high-carbohydrate, low-fat diet. There was no difference in total antioxidant status and susceptibility of serum lipids to oxidation. CONCLUSIONS: Serum lycopene level changes with dietary lycopene intake irrespective of the amount of fat intake. However, a diet high in olive oil and rich in lycopene may decrease the risk of coronary heart disease by improving the serum lipid profile compared with a high-carbohydrate, low-fat, lycopene-rich diet.     

Sensory Responses to Fat are Not Affected by Varying Dietary Energy Intake From Fat and Saturated Fat Over Ranges Common in the American Diet

Objective To examine the effects of manipulating dietary fat in foods on sensitivity and hedonic response to fat in selected foods.Design Twenty subjects were randomly assigned to a sequence of three 8-week experimental diets (average American diet, step 1 diet, low-saturated-fat diet) that varied in energy from fat (37%, 30%, and 26%, respectively) and saturated fat (17%, 10%, and 6%, respectively). Subjects participated in sensory tests designed to assess their sensitivity to and liking for fat in several foods, before the study (baseline), after consumption of each diet, and after the study (washout).Subjects/setting Subjects were participants in the Dietary Effects on Lipoprotein and Thrombogenic Activity (DELTA) study.Results No significant differences were found among diets for difference thresholds (ie, just noticeable differences) for fat in milk and pudding, ad libitum mixing of low- and high-fat samples of milk and soup, and hedonic scaling of fat concentrations in milk and muffins and of cheese, mayonnaise, hot dog, and pastry samples.Applications/conclusions Within the dietary fat ranges and for the fat stimuli tested in this study, dietary fat as percentage of energy from fat and saturated fat was not a significant determinant of sensitivity to and/or liking for fat. Sensory factors should not be a barrier to the implementation of low-fat diets such as the step 1 and low-saturated-fat diets. J Am Diet Assoc. 1999;99:690–696.     

Impact of diets containing corn oil or olive/sunflower oil mixture on the human plasma and lipoprotein lipid metabolism

Summary Background The effects of monounsaturated fatty acids (MUFA) rich diets compared to those that are rich in polyunsaturated fatty acids (PUFA) as well as the effects of an intake of single oils compared to oil mixtures are controversially discussed and results are contradictory. Aim of this study To evaluate the effects of a plant oil-mixture (olive/sunflower oil; saturated/monounsaturated/polyunsaturated (S/M/P) = 14:69:17) high in oleic acid but also showing a moderate content of polyunsaturated fatty acids (PUFA) in comparison with a single, PUFA rich corn oil (S/M/P = 13:33:54) used in a normal, balanced diet on human plasma and lipoprotein metabolism. Methods The double-blind designed study comprised 28 healthy, non-smoking young men aged between 19 and 31 years. After two weeks of adjustment (mixed, balanced diet: 11.6 MJ average, average fat intake ∼105 g/d), the design included a two week test period in which a diet with 80 g corn oil/d vs a mixture of 68 g olive- and 12 g sunflower oil/d (total 80 g) as the main fat source was given, followed by a crossover after two weeks. Compliance and ingestion of diets were monitored by assessing the fatty acid pattern in LDL and by determination of α- and γ-tocopherol in plasma and LDL. Results Diets were well incorporated due to the significant changes in plasma- and LDL-tocopherol levels and the significant different average ratio of oleic acid to linoleic acid in LDL. The PUFA-rich corn oil diet was able to reduce low density lipoprotein (LDL) cholesterol from adjustment to T2 significantly (p < 0.01), which was also confirmed by a trend after cross over (p=0.15). Total cholesterol (only after cross over at T3), total triglycerides (TG) and very low density lipoprotein (VLDL)-TG were significantly lower at T2 after the corn oil diet than after the mixed oil diet. Total high density lipoproteins (HDL) and HDL cholesterol remained unchanged by both diets. Conclusions The results show that during the intervention of two weeks for each diet and the following cross over the corn oil diet had more influence on lipoprotein metabolism than the MUFA-rich diet. The hypocholesteremic effect of the PUFA-rich diet must also be connected with the high amount of unsaponifiable substances, mainly phytosterols in the corn oil. Received: 10 May 2001, Accepted: 17 September 2001     

Zinc Intake and Plasma Zinc Level are Maintained in Men Consuming Cholesterol-Lowering Diets

Objective Reduced zinc intake has been reported when cholesterol-lowering diets are adopted. This study examined whether such diets compromise the zinc status of men with hypercholesterolemia.Design Zinc intake on baseline 4-day food records and baseline plasma zinc levels were compared with intake and levels 12 and 24 months after subjects adopted a low-fat, increased-fiber diet. Dietary fiber intake, supplement use, alcohol intake, and exercise were evaluated as possible confounding variables.Subjects Subjects were free-living men (n=365) with baseline cholesterol level above the 75th percentile who were participants in a randomized trial comparing cholesterol-lowering diets with goals of 30%, 26%, 22%, and 18% of energy from fat and 300, 200, 100, and 100 mg cholesterol, respectively.Statistical analyses Data were analyzed using two sample t tests, multiple linear regression, and analysis of variance.Results For all subjects combined, mean fat and cholesterol intakes approached or met the guidelines of the National Cholesterol Education Program step 2 diet, with approximately 30 g fiber per day. Density (mg/1,000 kcal) of zinc intake was unchanged from the baseline value. We found a slightly positive relationship between fiber and zinc intakes; no relationship between fiber intake and plasma zinc level; no effect of supplement use (category included all types of supplements), alcohol use, or level of exercise on plasma zinc levels; and no difference by dietary assignment in zinc intake or plasma zinc levels.Application Zinc status does not appear to be at risk in adult men who adopt cholesterol-lowering diets. These results may not be generalized to higher-risk population groups or situations in which dietary counseling is less comprehensive. J Am Diet Assoc. 1995; 95:1274-1279.     

Plasma lipid effects of corn oil and extra-virgin olive oil in hypercholesterolaemic subjects: a randomised, controlled trial

The aim of our study was to directly compare the metabolic effect of monounsaturated fatty acid rich oils and polyunsaturated fatty acid rich oils on the plasma lipid pattern of moderately hypercholesterolaemic subjects under controlled isocaloric condition. After a 30-day run-in diet, 44 healthy Caucasian subjects with moderate hypercholesterolaemia were randomly assigned to one of four different isocaloric diets, differing only regarding the oil used (corn oil, corn oil supplemented with vitamin E, extra-virgin olive oil or different self-selected oils), for 45 days. At the end of the study, when compared to the baseline value, low-density lipoprotein (LDL)-cholesterolaemia was significantly lower only in patients taking corn oil (−13.9%; 95%CI −5.9 to −20.1; p = 0.02) or corn oil with added vitamin E (−19.1%; 95%CI −6.9 to −24.1; p = 0.03). Differences in plasma high-density lipoprotein (HDL)-cholesterol and triglyceride levels from baseline levels and between the four diets did not reach statistical significance.     

A changing role for dietary monounsaturated fatty acids

Evidence is accumulating that diets low in saturated fatty acids and high in monounsaturated fatty acids are effective in controlling blood lipid levels; a likely consequence could be a beneficial effect on the risk of coronary heart disease. Although as yet limited in number, studies have shown monounsaturated fatty acids to be the equivalent of polyunsaturated fatty acids or low-fat diets in lowering blood low-density-lipoprotein cholesterol. The monounsaturated acids apparently have the added advantage of not causing a decrease in high-density-lipoprotein cholesterol or an increase in blood triglycerides, which can be a consequence of other dietary modifications. In the past, olive oil was the only fat rich in monounsaturated acids that was generally available in the United States. Recently, canola oil, a fat also rich in monounsaturates, has appeared in retail food outlets. Other potential sources are high oleic sunflower and safflower oils. Because the culinary and organoleptic properties of the monounsaturated-rich oils can be identical to those of currently used oils, they should be readily accepted by the consumer. Whether the preferred healthful diet is one low in fat or one high in monoenes or polyenes, the primary dietary recommendation remains--decrease the intake of saturated fat and cholesterol.     

China: transformations of its cuisine,a prelude to understanding its people.

Objective:Familial hypercholesterolemia (FH) is a predominantly inherited disorder, which contributes to a defect of the LDL-cholesterol receptor. For adults with familial hypercholesterolemia (FH), it is known that a supplementary diet of monounsaturated fatty acids reduces elevated levels of total cholesterol and LDL-cholesterol and may further increase HDL-cholesterol. In particular the reduced intake of dietary fat reduces total serum cholesterol and LDL-cholesterol in the range of 10% to 15% and inhibits LDL-oxidation. Once the diagnosis of familial hypercholesterolemia is made in early childhood a supplementary diet with rapeseed oil should be started as early as possible to prevent development of atherosclerosis and subsequent complications. So far there are no reports of a lipid lowering diet enriched with rapeseed oil in children and adolescents.

Methods:Seventeen children and young adolescents (male = 6, female = 11, ages 4 to 19 years) diagnosed with FH were enrolled in this study. They received dietary training and a classical low fat/low cholesterol diet enriched with rapeseed oil over five months. In the first two months they received orally mean 15 g/day (8–23 g/day), for the remaining three months mean 22 g/day (15–30 g/day) rapeseed oil. The calculation of the three-days dietary protocols showed the following characteristics: 29.5% calories from fat, 14.3% calories from protein and 54.6% calories from carbohydrates. The subjects had six sessions of dietary counseling, and serum lipids levels and lipoprotein(a) were estimated; each month’s diet adherence was controlled by a dietitian and discussed with the patients and their families during this five-month study.

Result:During five months of rapeseed oil diet serum triglycerides decreased by 29% (119.2 ± 62.8 mg/dL vs. 84.9 mean ± 39.7 mg/dL), VLDL-cholesterol by 27% (23 ± 12 mg/dL vs. 17 ± 8 mg/dL), total cholesterol by 10% (233 ± 35 mg/dL vs. 213 ± 36 mg/dL), LDL-cholesterol by 7% (151 ± 31 mg/dL vs. 142 ± 31 mg/dL). HDL-cholesterol (59 ± 15 mg/dL vs. 57 ± 11 mg/dL) and Lp(a) (29.8 ± 36.3 mg/dL vs. 32.6 ± 40.7 mg/dL) were not changed significantly. The diet was well accepted; in most families a sustained change was reported.

Conclusions:Our results indicate that in children and adolescents with FH a lipid-lowering diet with rapeseed oil has a similar effect on total serum cholesterol and LDL-cholesterol compared to classical cholesterol reduction diets (step I). However, an additional pronounced effect on lowering of triglycerides and VLDL-cholesterol can be observed.