Carbohydrate and lipid metabolism in patients with non-insulin-dependent diabetes mellitus: effects of a low-fat, high-carbohydrate diet vs a diet high in monounsaturated fatty acids

Nineteen patients affected by non-insulin dependent diabetes mellitus (NIDDM), in good glycemic control (fasting plasma glucose 7.2 +/- 0.3 mmol/L, glycosylated hemoglobin 6.3 +/- 0.2%), underwent three isocaloric dietary phases. In phases 1 and 3 the diet was rich in complex carbohydrates (Carbo) whereas in phase 2 it was rich in monounsaturated fatty acids (Mono). Plasma glucose concentrations were 7.1 +/- 0.3 and 7.2 +/- 0.3 mmol/L for the two Carbo phases and 7.5 +/- 0.4 mmol/L for the Mono phase (NS). Plasma total cholesterol values for the Carbo phases were 6.2 +/- 0.2 and 6.4 +/- 0.2 mmol/L, respectively, and 6.5 +/- 0.2 mmol/L on the Mono phase (NS). Similarly, no significant changes were noticed for plasma triglycerides and high-density-lipoprotein (HDL) cholesterol. Thus, both diets were well-tolerated and did not alter glucose homeostasis or worsen plasma lipid concentrations. Consequently, these results suggest that a wider dietary choice can be made available to NIDDM patients without producing unwanted side effects.     

Effects of diets rich in monounsaturated fatty acids on plasma lipoproteins--the Jerusalem Nutrition Study. II. Monounsaturated fatty acids vs carbohydrates.

Seventeen male Yeshiva students were randomly allocated to a crossover study with two 12-wk dietary periods of monounsaturated fatty acids (MUFAs) vs a carbohydrate (CHO)-rich diet while concentrations of saturated (SFAs) and polyunsaturated (PUFAs) fatty acids were kept similar. Total plasma cholesterol (TC) decreased significantly by approximately 7.7% and low-density-lipoprotein cholesterol (LDL-C) by 14.4% on the MUFA diet, whereas on the CHO diet no significant change in cholesterol concentrations occurred, in contrast to that predicted by the equations of Keys and Hegsted. Concentrations of high-density-lipoprotein cholesterol (HDL-C) did not change significantly on either diet. On the MUFA diet there was a significantly lower proneness to peroxidation of plasma and LDL lipids and less extensive metabolism of conditioned LDL by peritoneal macrophages. We conclude that dietary MUFAs lower TC and LDL-C concentrations, independently of other dietary fatty acids and in addition may reduce the susceptibility of LDL to oxidative stress.     

Dynamic study of the changes in the composition of fatty acids in serum lipid fractions under a diet rich in polyunsaturated fatty acids

Appropriate adjustment of diet and specially reduction of the saturated fatty acids content is the cornerstone of correcting many hyperlipidemias. What we have tried in our study was first to show the evolution of the changes in the serum's fatty acids composition under a rich polyunsaturated fatty acids diet, second to find an index proving that the diet had correctly been taken. Chromatographic analysis were performed after ultracentrifugal separation of the lipoprotein fractions. Seven volunteers, non fat, and normolipemics were selected. Samples were collected every three or five days before and during the diet. The whole test lasted twenty days. What had been shown is that the linoleic acid content increased but the one of the oleic acid decreased in all lipoprotein fractions. Those changes are bestly illustrated by using the (formula: see text) ratio as a kinetic index. The triglycerid fraction modifications are faster than the phospholipid's one. Concerning the other fatty acids, the modifications are less spectacular : the palmitic acid decrease in every lipids fractions and the palmitoleic acid has a significant decrease only in the esterified cholesterol. And the stearic acid has no variation at least significatively.     

A monounsaturated fatty acid-rich pecan-enriched diet favorably alters the serum lipid profile of healthy men and women

Frequent consumption of nuts is associated with decreased risk of cardiovascular disease. We investigated the effect of pecans rich in monounsaturated fat as an alternative to the Step 1 diet in modifying serum lipids and lipoproteins in men and women with normal to moderately high serum cholesterol. In a single-blind, randomized, controlled, crossover feeding study, we assigned 23 subjects (mean age: 38 y; 9 women, 14 men) to follow two diets, each for 4 wk: a Step I diet and a pecan-enriched diet (accomplished by proportionately reducing all food items in a Step I diet by one fifth for a 20% isoenergetic replacement with pecans). The percentage of energy from fat in the two diets was 28.3 and 39.6%, respectively. Both diets improved the lipid profile; however, the pecan-enriched diet decreased both serum total and LDL cholesterol by 0.32 mmol/L (6.7 and 10.4%, respectively) and triglyceride by 0.14 mmol/L (11.1%) beyond the Step I diet, while increasing HDL cholesterol by 0.06 mmol/L (2.5 mg/dL). Serum apolipoprotein B and lipoprotein(a) decreased by 11.6 and 11.1%, respectively, and apolipoprotein A1 increased by 2.2% when subjects consumed the pecan compared with the Step I diet. These differences were all significant (P < 0.05). A 20% isoenergetic replacement of a Step I diet with pecans favorably altered the serum lipid profile beyond the Step I diet, without increasing body weight. Nuts such as pecans that are rich in monounsaturated fat may therefore be recommended as part of prescribed cholesterol-lowering diet of patients or habitual diet of healthy individuals.     

Differential effects of saturated and monounsaturated fatty acids on postprandial lipemia and incretin responses in healthy subjects.

BACKGROUND: Elevations of postprandial triacylglycerol-rich plasma lipoproteins and suppressions of HDL-cholesterol concentrations are considered potentially atherogenic. Long-term studies have shown beneficial effects of monounsaturated fatty acids (eg, oleic acid) on fasting lipid and lipoprotein concentrations in humans. A direct stimulatory effect of oleic acid on the secretion of glucagon-like peptide 1 (GLP-1) was shown in animal studies. OBJECTIVE: We compared the postprandial responses of glucose, insulin, fatty acids, triacylglycerol, gastric inhibitory polypeptide (GIP), and GLP-1 to test meals rich in saturated and monounsaturated fatty acids. DESIGN: Ten young, lean, healthy persons ingested 3 meals: an energy-free soup consumed with 50 g carbohydrate (control meal), the control meal plus 100 g butter, and the control meal plus 80 g olive oil. Triacylglycerol and retinyl palmitate responses were measured in total plasma, in a chylomicron-rich fraction, and in a chylomicron-poor fraction. RESULTS: No significant differences in glucose, insulin, or fatty acid responses to the 2 fat-rich meals were seen. Plasma triacylglycerol responses were highest after the butter meal, with chylomicron triacylglycerol rising 2.5-5-fold. Retinyl palmitate responses were higher and more prolonged after the butter meal than after the control and olive oil meals, whereas both postprandial HDL-cholesterol concentrations and GLP-1 and GIP responses were higher after the olive oil meal than after the butter meal. CONCLUSIONS: Olive oil induced lower triacylglycerol concentrations and higher HDL-cholesterol concentrations than butter, without eliciting differences in concentrations of glucose, insulin, or fatty acids. Furthermore, olive oil induced higher concentrations of GLP-1 and GIP than did butter, which may point to a relation between fatty acid composition, incretin responses, and triacylglycerol metabolism in the postprandial phase.     

Effects of diets rich in monounsaturated fatty acids on plasma lipoproteins--the Jerusalem Nutrition Study: high MUFAs vs high PUFAs

Twenty-six Yeshiva students were randomly assigned to a 24-wk crossover study of monounsaturated fatty acid (MUFA) vs polyunsaturated fatty acid (PUFA) diets (50% carbohydrate, 32% fat, 18% protein) fed alternately during two 12-wk periods. Total plasma cholesterol (TC) decreased significantly by approximately 10% and approximately 16% on the MUFA and PUFA diets, respectively. Plasma triglyceride response was variable. Low-density-lipoprotein cholesterol (LDL-C) decreased in both groups with an additional significant effect between periods. Concentrations of high-density-lipoprotein cholesterol did not change significantly. LDL-receptor status in fresh monocytes, affinity of LDL towards the LDL receptor in cultured fibroblasts, zonal-centrifugation profiles, and lipoprotein composition were not significantly different between the diets. There was a significantly higher tendency toward lipid peroxidation on the PUFA diet, as ascertained by more thiobarbituric acid-reactive-substances formation on that diet. Dietary PUFA results in somewhat lower TC and LDL-C concentrations whereas with MUFA the susceptibility of LDL to oxidative stress is lower.     

A monounsaturated fatty acid-rich diet reduces macrophage uptake of plasma oxidised low-density lipoprotein in healthy young men

During atherogenesis, a pathological accumulation of lipids occurs within aortic intimal macrophages through uptake of plasma oxidised LDL (oxLDL). The aim of the present study was to determine whether macrophage uptake of plasma oxLDL and LDL susceptibility to oxidation may be determined by quantity and quality of dietary fat. Twenty healthy young men were subjected to three dietary periods, each lasting 4 weeks. The first was an SFA-enriched diet (38 % fat, 20 % SFA), which was followed by a carbohydrate (CHO)-rich diet (30 % fat, < 10 % SFA, 55 % CHO) or a MUFA olive oil-rich diet (38 % fat, 22 % MUFA) following a randomised cross-over design. After each diet period, LDL particles were oxidised with Cu ions to determine LDL susceptibility to oxidation and subsequently incubated with the U937-macrophage cell line to determine the percentage of uptake of plasma oxLDL. The shift from the MUFA diet to the SFA- or CHO-rich diets reduced the resistance of LDL particles to oxidation, decreasing lag time (P = 0.038) and increasing the propagation rate (P = 0.001). Furthermore, the MUFA-rich diet demonstrated reduced macrophage uptake of plasma oxLDL (P = 0.031) as compared with the SFA-rich diet. Finally, macrophage uptake of plasma oxLDL was correlated (r 0.45; P = 0.040) with total amount of conjugated dienes after LDL oxidation. Our data suggest that a MUFA-rich diet may have favourable effects on cardiovascular risk since it prevents the oxidative modifications of LDL and reduces macrophage uptake of plasma oxLDL.     

Comparison of the effects on lipoproteins and apolipoproteins of a diet high in monounsaturated fatty acids, enriched with avocado, and a high-carbohydrate diet.

A randomized trial was conducted to compare effects of a diet high in monounsaturated fatty acids, enriched with avocado (AE), and a high-complex-carbohydrate diet (AHA-III) on blood lipid concentrations. Fifteen females between 37 and 58 y of age were allocated either to AE followed by AHA-III, or vice versa. Each dietary phase lasted 3 wk. Both diets were found to lower total cholesterol compared with baseline values. AE was more effective, with an 8.2% decrease (P less than 0.05) whereas AHA-III was associated with a 4.9% decrease (NS). Low-density-lipoprotein cholesterol and apolipoprotein B decreased significantly on AE but not on AHA-III (P less than 0.05). The high-density-lipoprotein (HDL) concentration did not change on AE but decreased 13.9% on AHA-III (P less than 0.01). It is concluded that AE is more effective than is AHA-III in decreasing total cholesterol, and, unlike AHA-III, it does not decrease HDL concentrations.     

Ingestion of a single serving of saury alters postprandial levels of plasma n-3 polyunsaturated fatty acids and long-chain monounsaturated fatty acids in healthy human adults

ABSTRACT: BACKGROUND: Saury oil contains considerable amounts of n-3 polyunsaturated fatty acids (PUFA) and monounsaturated fatty acids (MUFA) with long aliphatic tails (>18C atoms). Ingestion of saury oil reduces the risk of developing metabolic syndrome concomitant with increases in n-3 PUFA and long-chain MUFA in plasma and organs of mice. We therefore evaluated changes in postprandial plasma fatty acid levels and plasma parameters in healthy human subjects after ingestion of a single meal of saury. FINDINGS: Five healthy human adults ingested 150 g of grilled saury. Blood was collected before the meal and at 2, 6, and 24 hr after the meal, and plasma was prepared. Plasma levels of eicosapentaenoic acid, docosahexaenoic acid, and long-chain MUFA (C20:1 and C22:1 isomers combined) increased significantly throughout the postprandial period compared with the pre-meal baseline. Postprandial plasma insulin concentration increased notably, and plasma levels of glucose and free fatty acids decreased significantly and subsequently returned to the pre-meal levels. CONCLUSIONS: Our study suggests that a single saury meal may alter the postprandial plasma levels of n-3 PUFA and long-chain MUFA in healthy human subjects.     

Effects of high-fat and low-fat diets rich in monounsaturated fatty acids on serum lipids,LDL size and indices of lipid peroxidation in healthy non-obese men and women when consumed under controlled conditions

Objective  

To study the effects of the dietary fat content on cardiovascular disease risk factors in humans when the fatty acid composition and types of carbohydrates are kept constant.     

Physiological effects of diet enriched in essential fatty acids in young men

The investigations were carried out on healthy young males aged 20-21 years. Those young men, whose previously different diets were determined by the dietary habits of their families, were selected and grouped under uniform conditions (feeding, housing, physical activity). After 4 months staying under these uniform conditions their diet was changed adding E.F.A. to their previous food rations. Food rations enriched with E.F.A. were given to these young males for 3 months. Then E.F.A. additions to the diet was stopped and the observed subjects received food rations, identical as during the initial 4-month period prior to E.F.A. enrichment, these rations were given during 5 months. Immediately after grouping these men were subjected to biochemical investigation of the serum and to anthropometric and general medical examinations (examination I). The subsequent examinations (II, III, IV) were carried out while the subjects were living under uniform conditions: II) after 4 months on the diet without E.F.A. enrichment, III) after 3 months on the diet enriched with E.F.A., and IV) after 5 months of diet without E.F.A. enrichment (after withdrawal of additional E.F.A.). The investigations were begun on 97 young males (examination I). The consecutive examinations (II, III, IV) were carried out on smaller groups of subjects for reasons on with the authors had no influence. During the experiment, 2-3 times in a month, sample of daily food rations given to the studied subjects and residual food on the plates were taken for analysis. This was done for determination of actual food intake. Through the whole period of the experiment the observed subjects were inquired about additional food consumed. The biochemical investigations of the nutritional state of these young subjects included hematological indices, serum proteins, selected biochemical components in the serum, activity of certain enzymes in the serum, serum lipid components and serum level of certain vitamins. The results of these investigations show the enrichment of diets during 3 months with vegetable fats (sunflower oil, margarine containing 40% of E.F.A.) for increasing the amount of E.F.A. in the whole daily food (together with additional food calculated on the basis of inquiry information) from 14.7 g to 27.7 g (3,2% kcal and 5,8% kcal respectively) has a favorable effect on selected serum lipids. The following changes appeared: decrease of total lipid level, total cholesterol level, cholesterol content of beta and prebeta-lipoproteins levels, free fatty acid level and the favorable changes in the composition of fatty acid in total lipid and selected lipid fractions in the serum. Food enrichment with E.F.A. led to rise the level of linoleic acid and total E.F.A. level and to fall the level of saturated fatty acids. The ratio of polyunsaturated to saturated fatty acids changes favorably both in total serum lipids and in different lipid fraction...     

Dietary intake of n-3 polyunsaturated fatty acids in healthy adults in relation to current recommended intake

The health benefits of n-3 PUFA and especially long-chain n-3 PUFA are well recognized and recommendation of their dietary intake for general population are elaborated However, there is still a need for assessment of LCn-3 PUFA intake in different population groups. The aim of this study was to assess intake of n-3 PUFA, particularly long-chain n-3PUFA (LCn-3 PUFA) and to identify their major sources in diets of healthy subjects. The studied group consisted of 182 adults, both men and women. Assessment of n-3 PUFA dietary intake was based on individual 3-day records. Data were analyzed using updated polish food composition tables and "Dieta 2" and "Dieta 4" Software. It was found, that more than 40% of studied subjects consumed daily less than 1 g ALA, about 50%--less than 100 mg LCn-3 PUFA and about 60% less than 10 mg DHA.     

A diet containing rapeseed oil-based fats does not increase lipid peroxidation in humans when compared to a diet rich in saturated fatty acids

OBJECTIVE: To compare the effects of a rapeseed oil-based diet containing an increased proportion of easily oxidised polyunsaturated fatty acids such as alpha-linolenic acid with a diet rich in saturated fatty acids on the degree of lipid peroxidation in the human body. DESIGN: A randomised cross-over study. SUBJECTS AND INTERVENTIONS: Nineteen healthy moderately hyperlipidemic subjects (six women and 13 men, age 50+/-8 y and body mass index (BMI) 24.5+/-2.6 kg/m(2)) were given a rapeseed oil-based diet (RO) and a control diet (SAT) rich in saturated fatty acids during two consecutive 4 week periods separated by a 4 week wash-out period. Biomarkers of lipid peroxidation and antioxidants were analysed in plasma and urine. RESULTS: No significant differences in plasma or urinary levels of free 8-iso-prostaglandin F(2alpha), plasma total 8-iso-prostaglandin F(2alpha) plasma hydroperoxides or plasma malondialdehyde were observed between the RO and SAT diets (P=0.14-0.95). A higher concentration of serum gamma-tocopherol was detected after the RO diet compared to the SAT diet (P<0.001), whereas the serum alpha-tocopherol concentration and plasma antioxidative capacity did not differ between the two test diets. The total cholesterol, LDL cholesterol and LDL/HDL ratio were lower after the RO diet compared to the SAT diet (P<0.001), while HDL cholesterol and total triglyceride levels were similar after the two diets. CONCLUSION: These results suggest that a rapeseed oil-based diet rich in alpha-linolenic acid does not seem to increase the degree of lipid peroxidation in plasma and urine compared to a diet rich in saturated fats. This is possibly due to a sufficient content of antioxidants in the rapeseed oil diet to increase circulating concentrations of antioxidants that may protect unsaturated fatty acids from oxidation. SPONSORSHIP: Swedish Council for Forestry and Agricultural Research and Foundation for Geriatric Research.     

Dietary regulation of serum lipids in healthy, young adults.

When healthy medical students and their wives were fed a diet providing 2,375 kcal per day, 33 per cent of which was derived from fat, and received a cholesterol intake of less than 250 mg. per day, their serum cholesterol levels were significantly reduced. Differences in the change in the phospholipids of the students and their wives suggest a different response of the sexes to the diet. Since increasing the P:S ratio from 0.3 to 1.2 produced comparable lowering of serum lipids, data suggest that cholesterol intake and caloric balance are of prime importance in maintaining the level of serum cholesterol.     

Effects of butter high in ruminant trans and monounsaturated fatty acids on lipoproteins, incorporation of fatty acids into lipid classes, plasma C-reactive protein, oxidative stress, hemostatic variables, and insulin in healthy young men

BACKGROUND: Evidence suggests that ruminant trans fatty acids (FAs), such as vaccenic acid, do not increase the risk of ischemic heart disease (IHD). However, the effects of ruminant trans FAs on risk markers of IHD have been poorly investigated. OBJECTIVE: The objective was to investigate the effect of butter with a naturally high content of vaccenic acid and a concomitantly higher content of monounsaturated FAs on classic and novel risk markers of IHD. DESIGN: In a double-blind, randomized, 5-wk, parallel intervention study, 42 healthy young men were given 115 g fat/d from test butter that was high in vaccenic acid (3.6 g vaccenic acid/d) or a control butter with a low content of vaccenic acid. Blood and urine samples were collected before and after the intervention. RESULTS: The intake of the vaccenic acid-rich diet resulted in 6% and 9% lower total cholesterol and plasma HDL-cholesterol concentrations, respectively, than did the intake of the control diet (P = 0.05 and 0.002, respectively), whereas the ratio of total to HDL cholesterol did not differ significantly between the groups. The FA composition of lipid classes reflected the FAs' proportion of the test butter. No other differences were observed. CONCLUSIONS: Butter high in ruminant trans and monounsaturated FAs resulted in significantly lower total and HDL cholesterol than did the control butter with higher amounts of saturated FAs. It may be that the differences were due to the greater content of monounsaturated FAs and the lesser content of saturated FAs in the butter rich in ruminant trans FAs, rather than to the content of vaccenic acid per se.     

Effects of arachidonate-enriched triacylglycerol supplementation on serum fatty acids and platelet aggregation in healthy male subjects with a fish diet

The changes in fatty acid composition of serum and in platelet aggregation induced by supplementation of arachidonate-enriched TAG were investigated in twenty-four healthy Japanese men in a double-blind, placebo-controlled study. The arachidonate-enriched TAG ingested was an edible oil, extracted and purified from a biomass of submerged fermented Mortierella alpina. Mean daily intake of fish and shellfish by subjects was 87.2 (se5.3) g/d, while dietary intakes of arachidonic acid (ARA) by the ARA group and placebo group were 175 (se12) and 179 (se13) mg/d, respectively. In the ARA group, after 2-week supplementation of 838 mg ARA/d, ARA concentration in serum phospholipids was increased from 9.6 (se0.4) to 13.7 (se0.4) g/100 g total fatty acids, and was significantly different from that in the placebo group (P < 0.001). This level was maintained for 4 weeks but returned to baseline level after a 4-week washout period. Linoleic acid concentration in serum phospholipids decreased from 19.2 (se0.8) to 16.3 (se0.6) g/100 g total fatty acids in the ARA group. Similarly, ARA content of serum TAG increased after ARA supplementation. Neither the EPA nor DHA content of serum phospholipids or TAG was altered by ARA supplementation. The platelet aggregation induced in platelet-rich plasma by adding adenosine diphosphate, collagen and ARA, physical characteristics of subjects, and biochemical parameters were unchanged throughout the test period. These findings suggest that ARA concentration in serum phospholipids and TAG can be safely increased by supplementation of arachidonate-enriched TAG oil.     

Kupffer cells ameliorate hepatic insulin resistance induced by high-fat diet rich in monounsaturated fatty acids: the evidence for the involvement of alternatively activated macrophages

Background

Resident macrophages (Kupffer cells, KCs) in the liver can undergo both pro- or anti-inflammatory activation pathway and exert either beneficiary or detrimental effects on liver metabolism. Until now, their role in the metabolically dysfunctional state of steatosis remains enigmatic. Aim of our study was to characterize the role of KCs in relation to the onset of hepatic insulin resistance induced by a high-fat (HF) diet rich in monounsaturated fatty acids.

Methods

Male Wistar rats were fed either standard (SD) or high-fat (HF) diet for 4 weeks. Half of the animals were subjected to the acute GdCl₃ treatment 24 and 72 hrs prior to the end of the experiment in order to induce the reduction of KCs population. We determined the effect of HF diet on activation status of liver macrophages and on the changes in hepatic insulin sensitivity and triacylglycerol metabolism imposed by acute KCs depletion by GdCl₃.

Results

We found that a HF diet rich in MUFA itself triggers an alternative but not the classical activation program in KCs. In a steatotic, but not in normal liver, a reduction of the KCs population was associated with a decrease of alternative activation and with a shift towards the expression of pro-inflammatory activation markers, with the increased autophagy, elevated lysosomal lipolysis, increased formation of DAG, PKCε activation and marked exacerbation of HF diet-induced hepatic insulin resistance.

Conclusions

We propose that in the presence of a high MUFA content the population of alternatively activated resident liver macrophages may mediate beneficial effects on liver insulin sensitivity and alleviate the metabolic disturbances imposed by HF diet feeding and steatosis. Our data indicate that macrophage polarization towards an alternative state might be a useful strategy for treating type 2 diabetes.

     

Substitution of dietary monounsaturated fatty acids for saturated fatty acids in a free-living population: a feasibility study

The fatty acid composition of the diet of seven free-living subjects (five men and two women) aged 41–56 years was altered for 1 month. The aim was to increase the intake of monounsaturated fatty acids (MUFAs) from subjects current habitual levels of 12% dietary energy to a target intake of 18% dietary energy, and to decrease saturated fatty acid (SFA) from habitual levels of 16% dietary energy to target levels of 10% dietary energy. The change in fatty acid intake was achieved by supplying volunteers with foods prepared using MUFA-containing spreads or olive oil (ready meals, sweet biscuits and cakes) and also by supplying spreads, cooking oil and MUFA-enriched milk for domestic use. Body weight and plasma total cholesterol measurements were made at baseline and at 2 and 4 weeks on the diet as an aid to maintaining subject compliance. MUFA consumption was significantly increased from 12% dietary energy to 16% dietary energy ( P <0.01), and SFA intake was reduced from 16% dietary energy to 6% dietary energy ( P <0.01) during the 4-week intervention. The diet failed to achieve the target increase in MUFA but exceeded the target reduction in SFA. This was due to the fact that subjects reduced their total fat intake from a mean habitual level of 38% dietary energy to a mean level of 30% dietary energy. During the dietary period, mean plasma cholesterol levels were lower at 2 weeks ( P <0.01) and at 4 weeks ( P <0.01) than the baseline, with a mean reduction of 20% over the dietary period. This study demonstrates the difficulty of achieving increased MUFA intakes (by SFA substitution) in free-living populations when only a limited range of fatty-acid modified food products are provided to volunteers.     

不同膳食脂肪酸构成比对大鼠血脂影响

目的 观察不同脂肪酸比值对大鼠血脂水平的影响.方法 将72只Wistar大鼠按体重随机分为基础组和5个实验组(A-E).实验组分别设饱和脂肪酸.单不饱和脂肪酸.多不饱和脂肪酸比值(S.M.P)为1:1.7:1.2,1:1:1,2:1:1,1:2:1和1:1:2的饲料喂养12周,在第0,4,8,12周取血测定血脂水平.结果 S.M.P为1:1:2时甘油三酯(TG)水平显著低于其余各组(P＜0.05),1:1:1组TG水平显著低于1:1.7:1.2组,2:1:1组和1:2:1组(P＜0.05).S.M.P为2:1:1时总胆固醇(TG)水平和低密度脂蛋白胆固醇(LDL)水平显著高于其余各组(P＜0.05).1:1:1组和1:1:2组的高密度脂蛋白胆固醇(HDL)水平显著高于其余各组(P＜0.05),12周末分别为(0.59±0.12)和(0.61±0.15)mmol.L.结论 膳食脂肪酸比值1:1:2和1:1:1比现状值1:1.7:1.2有利于健康,适当的增加膳食多不饱和脂肪酸的摄入更有利于维持血脂在较低水平.对心血管疾病有预防作用.