The effect on serum lipids and oxidized low-density lipoprotein of supplementing self-selected low-fat diets with soluble-fiber, soy, and vegetable protein foods

An increased intake of soluble fiber and soy protein may improve the blood lipid profile. To assess any additional benefit on serum lipids of providing soy protein and soluble-fiber foods to hyperlipidemic subjects already consuming low-fat, low-cholesterol therapeutic diets, 20 hyperlipidemic men and postmenopausal women completed 8-week test and control dietary treatments in a randomized crossover design as part of an ad libitum National Cholesterol Education Program (NCEP) step 2 therapeutic diet (<7% saturated fat and <200 mg/d cholesterol). During the test phase, foods high in soy, other vegetable proteins, and soluble fiber were provided. During the control phase, low-fat dairy and low-soluble-fiber foods were provided. Fasting blood lipid and apolipoprotein levels were measured at 4 and 8 weeks of each phase. On the test diet, 12 +/- 2 g/d soy protein was selected from the foods chosen. Direct comparison of test and control treatments indicated an elevated high-density lipoprotein (HDL) cholesterol concentration on the test diet (6.4% +/- 2.4%, P = .013) and a significantly reduced total to HDL cholesterol ratio (-5.9% +/- 2.3%, P = .020). The proportion of conjugated dienes in the low-density lipoprotein (LDL) cholesterol fraction was significantly reduced (8.5% +/- 3.3%, P = .020) as a marker of oxidized LDL. A combination of acceptable amounts of soy, vegetable protein, and soluble-fiber foods as part of a conventional low-fat, low-cholesterol therapeutic diet is effective in further reducing serum lipid risk factors for cardiovascular disease.     

Effects of phytosterol ester-enriched margarine on plasma lipoproteins in mild to moderate hypercholesterolemia are related to basal cholesterol and fat intake

Dietary phytosterols have been reported to lower total and low-density lipoprotein (LDL) cholesterol. However, less is known about the influence of cholesterol and fat intake on the cholesterol-lowering effect of esterified phytosterols in mild to moderate hypercholesterolemia. Sixty-three healthy subjects (38 women, 25 men, 42 +/- 11 years, LDL cholesterol > 130 mg/dL) were investigated in a randomized, double-blind, placebo-controlled, cross-over study. A total of 20 g/d of a phytosterol ester-enriched margarine (1.82 g/d of phytosterols) was compared with a control margarine (0.06 g/d of phytosterols). After 3 weeks of intake, participants crossed over to the other margarine. A 3-day dietary recall was performed at the beginning and at the end of the study to assess cholesterol, fat, and energy intake. Phytosterol ester-enriched margarine significantly changed total cholesterol (-3.4%, P <.005), LDL cholesterol (-5.4%, P <.001, 144 +/- 28 v 154 +/- 26 mg/dL), high-density lipoprotein (HDL) cholesterol (+3.4%, P <.05), apolipoprotein B (-4.0%, P <.005), and LDL/HDL cholesterol ratio (-7.8%, P <.001) compared with the control margarine. In the tertiles with the highest dietary intake of cholesterol, energy, total fat, and saturated fatty acids, and with the highest baseline proportion of campesterol to cholesterol, LDL cholesterol reduction was 11.6% (P <.001), 9.5% (P =.001), 9.4% (P =.001), 8.4% (P =.005), and 6.2% (P =.014), respectively. Triglycerides, plasma viscosity, and fibrinogen concentration did not change significantly. The improvements of LDL, HDL, total cholesterol, apolipoprotein B concentrations, and LDL/HDL cholesterol ratio during the daily consumption of a phytosterol ester-enriched margarine were most marked in those subjects with a high dietary intake of cholesterol, energy, total fat, and saturated fatty acids and with high baseline cholesterol absorption.     

Effect of short-term low- and high-fat diets on low-density lipoprotein particle size in normolipidemic subjects

High-fat, low-carbohydrate diets have been shown to raise plasma cholesterol levels, an effect associated with the formation of large low-density lipoprotein (LDL) particles. However, the impact of dietary intervention on time-course changes in LDL particle size has not been investigated. To test whether a short-term dietary intervention affects LDL particle size, we conducted a randomized, double-blind, crossover study using an intensive dietary modification in 12 nonobese healthy men with normal plasma lipid profile. Participants were subjected to 2 isocaloric 3-day diets: high-fat diet (37% energy from fat and 50% from carbohydrates) and low-fat diet (25% energy from fat and 62% from carbohydrates). Plasma lipid levels and LDL particle size were assessed on fasting blood samples after 3 days of feeding on each diet. The LDL particles were characterized by polyacrylamide gradient gel electrophoresis. Compared with the low-fat diet, plasma cholesterol, LDL cholesterol, and high-density lipoprotein cholesterol were significantly increased (4.45 vs 4.78 mmol/L, P = .04; 2.48 vs 2.90 mmol/L, P = .005; and 1.29 vs 1.41 mmol/L, P = .005, respectively) following the 3-day high-fat diet. Plasma triglycerides and fasting apolipoprotein B-48 levels were significantly decreased after the high-fat diet compared with the low-fat diet (1.48 vs 1.01 mmol/L, P = .0003 and 9.6 vs 5.5 mg/L, P = .008, respectively). The high-fat diet was also associated with a significant increase in LDL particle size (255.0 vs 255.9 Å; P = .01) and a significant decrease in the proportion of small LDL particle (<255.0 Å) (50.7% vs 44.6%, P = .01). As compared with a low-fat diet, the cholesterol-raising effect of a high-fat diet is associated with the formation of large LDL particles after only 3 days of feeding.     

Characterization of high-density lipoprotein binding to guinea pig hepatic membranes: effects of dietary fat quality and cholesterol feeding

The effects of dietary fat quality and cholesterol intake on expression of guinea pig hepatic membrane high-density lipoprotein (HDL) binding sites were studied. Animals were fed semisynthetic diets containing 7.5% (wt/wt) of either corn oil (CO), olive oil (OL), or lard. The cholesterol diet was prepared by incorporating 0.25% recrystallized cholesterol into standard guinea pig chow. Plasma cholesterol levels of guinea pigs on the CO diet were significantly lower (P less than .02) than animals on the OL or lard diets. HDL cholesterol levels did not differ between the polyunsaturated, monounsaturated, and saturated dietary fat groups. Guinea pigs on the high cholesterol diet had increased total and HDL cholesterol levels compared with animals on the chow diet (P less than .01). Initial studies demonstrated that HDL binding to hepatic membranes was temperature-dependent. A threefold increase in binding was observed when assays were performed at 37 degrees C, as compared with 4 degrees C, for all membrane preparations. Dietary fat quality and dietary cholesterol intake significantly altered HDL binding to hepatic membranes with increased HDL binding to membranes of animals fed polyunsaturated fat and the high cholesterol diet. At 37 degrees C, HDL binding to hepatic membranes of CO-fed animals was 26% and 46% higher than for membranes of OL- and lard-fed guinea pigs, respectively. A high cholesterol intake increased HDL binding by 24% at both 4 degrees C and 37 degrees C. Scatchard analysis demonstrated that while membrane affinity for HDL (Kd) was not affected by diet, changes did occur in the total number of HDL binding sites.(ABSTRACT TRUNCATED AT 250 WORDS)     

Effects of exercise, dietary cholesterol, and dietary fat on blood lipids

Exercise, a low fat diet, or a diet low in saturated fat content can each lower plasma total cholesterol and low-density lipoprotein (LDL) cholesterol. We investigated whether these factors together could prevent the lipid-raising effects of dietary cholesterol. Ten healthy, athletic, normolipidemic male volunteers were studied. Two diets of 4 weeks duration each were compared in a randomized, blind crossover design. Diets were identical except for cholesterol content: one contained 600 mg/d; the other 200 mg/d. Both diets contained 15% of calories as protein, 55% as carbohydrate, 30% as fat, and the polyunsaturated fat to saturated fat ratio was 1.5. Exercise level and body weight were kept constant in each subject. As compared with plasma values obtained following the 200-mg/d cholesterol diet, mean values following the 600-mg/d cholesterol diet significantly increased for LDL cholesterol and apolipoprotein B by 10% and 13%, respectively. Mean plasma triglycerides, high-density lipoprotein 2 and 3, and apolipoprotein A-1 levels did not change significantly. Individual responses, however, were highly variable. Three subjects increased LDL cholesterol by more than 25%; 2 subjects increased LDL cholesterol by 10% to 25%; and 5 subjects had 5% or less change in LDL cholesterol. A dietary cholesterol increase can significantly elevate plasma LDL cholesterol and apolipoprotein B in certain normolipidemic, healthy men even when they are exercising regularly and consuming a moderately fat restricted, low saturated fat diet. Dietary cholesterol restriction may therefore be justifiable even when other life-style and dietary measures to minimize blood cholesterol are undertaken.     

Effects of pistachio nuts consumption on plasma lipid profile and oxidative status in healthy volunteers

BACKGROUND AND AIM: Effects of pistachio nuts consumption on plasma lipid profile and oxidative status were investigated in healthy volunteers with normal lipid levels. METHODS AND RESULTS: The study was conducted in 24 healthy men and 20 healthy women. All subjects consumed their regular diets during a 1-week period. After this period, half of the subjects (12 men and 10 women, mean age 32.8 +/- 6.7 years) were randomized to a regular diet group and the other half (12 men and 10 women, mean age 33.4 +/- 7.2 years) were randomized to a pistachio group which involved substituting pistachio nuts for 20% of their daily caloric intake for 3 weeks. Plasma total cholesterol, low-density lipoprotein (LDL), high-density lipoprotein (HDL), triglyceride, malondialdehyde (MDA) and antioxidant potential (AOP) were measured before and after the dietary modification from all the subjects. After 3 weeks, with the pistachio diet, the mean plasma total cholesterol, MDA levels and, total cholesterol/HDL and LDL/HDL ratios were found to be significantly decreased (P < 0.05, P < 0.05, P < 0.001 and P < 0.01, respectively); on the contrary, HDL and AOP levels, and AOP/MDA ratios were significantly increased (P < 0.001, P < 0.05 and P < 0.01, respectively). Triglyceride and LDL levels also decreased but this was not statistically significant (P > 0.05). CONCLUSION: These results indicated that consumption of pistachio nuts decreased oxidative stress, and improved total cholesterol and HDL levels in healthy volunteers.     

Combined effect of vegetable protein (soy) and soluble fiber added to a standard cholesterol-lowering diet.

Dietary treatment of hyperlipidemia focuses on reducing saturated fat and dietary cholesterol. Other aspects of diet are not emphasized at present, despite growing evidence that a number of plant components decrease serum cholesterol. We therefore determined whether a combination of two plant components, vegetable protein and soluble fiber, further reduce serum lipids when incorporated into the currently advocated low-saturated-fat diet. Thirty-one hyperlipidemic men and women ate two 1-month low-fat (<7% of total energy from saturated fat), low-cholesterol (<80 mg cholesterol/d) metabolic diets in a randomized crossover study. The major differences between test and control diets were an increased amount of vegetable protein (93% v 23% of total protein), of which 33 g/d was soy, and a doubling of soluble fiber. Fasting blood samples were obtained at the start and end of each phase. On the last 3 days of each phase, fecal collections were obtained. Compared with the low-fat control diet, the test diet decreased total cholesterol (6.2% +/- 1.2%, P < .001), low-density lipoprotein (LDL) cholesterol (6.7% +/- 1.7%, P < .001), apolipoprotein B (8.2% +/- 1.2%, P < .001), and the ratios of LDL to high-density lipoprotein (HDL) cholesterol (6.3% +/- 2.0%, P = .004) and apolipoprotein B to A-I (5.4% +/- 1.5%, P = .001). A combination of vegetable protein and soluble fiber significantly improved the lipid-lowering effect of a low-saturated-fat diet. The results support expanding the current dietary advice to include increased vegetable protein and soluble fiber intake so that the gap in effectiveness between a good diet and drug therapy is reduced.     

Ern?hrung bei diabetischer Dyslipid?mie

Dyslipidemia in diabetes is characterized by low high-density lipoprotein (HDL) cholesterol, high triglyceride levels and higher concentrations of atherogenic lipoprotein molecules. Various interventions are of importance in the nutritional therapy of dyslipidemia. An increased intake of unsaturated fatty acids from vegetable oils at the expense of saturated fatty acids lowers low-density lipoprotein (LDL) cholesterol. Trans-fatty acids (food sources: fat spreads and foods with partially hydrogenated fat, fried foods, fat-rich baked goods and sweets) cause an even more detrimental lipoprotein profile compared to saturated fatty acids and their intake should be limited. Significant reductions of LDL cholesterol are also achievable by fiber-rich foods and foods enriched with plant sterols and stanols. A reduction of body weight, an increase in physical activity and a limitation of alcohol consumption to moderate amounts are effective interventions to control triglyceride and HDL cholesterol levels. Triglycerides can also be reduced by supplementation with long-chain ??3 fatty acids (fish oil). Higher proportions of dietary carbohydrates cause higher triglyceride levels, therefore, moderation of carbohydrates in favor of unsaturated fatty acids can be an effective dietary strategy and the major focus is to limit the consumption of foods and beverages with added saccharose or fructose.     

Effects of acarbose on serum lipoproteins in healthy individuals during prolonged administration of a fiber-free formula diet

The effects of the disaccharidase inhibitor acarbose on serum lipoprotein lipid concentrations were investigated in healthy subjects during prolonged feeding of a fiber-free formula diet. Acarbose was shown to decrease cholesterol and fasting triglyceride concentrations, whereas the postprandial increment of triglycerides was not diminished. The response of fasting triglycerides to acarbose treatment appeared to be related to dietary fat intake, but not to the drug-induced reduction of postprandial glucose and insulin concentrations. Both the triglyceride and the cholesterol lowering efficacy were less pronounced with a higher amount of saturated fat than with a lower intake of fat mainly composed of polyunsaturated fatty acids. The decrease in total cholesterol was shown to be a consequence of a significant reduction in low density lipoprotein (LDL) cholesterol. Since high density lipoprotein (HDL) cholesterol concentrations remained unaltered, the ratio of HDL/LDL cholesterol changed in a beneficial way.     

Effect of yogurt intake on plasma lipid and lipoprotein levels in normolipidemic males

To determine the effect of yogurt intake on plasma lipid and lipoprotein levels, studies were carried out in 18 normolipidemic males during 3 dietary phases. Phase 1 was a low-fat, low-cholesterol baseline diet consumed for 3 weeks. The baseline diet was supplemented with low-fat yogurt (16 oz/day) for 4 weeks during phase 2, and during phase 3 the supplement consisted of a non-fermented dairy product (16 oz low-fat milk plus 10% milk solids). Average body weights and dietary intakes of fat, cholesterol and polyunsaturate/saturate fat ratios were not significantly different for the 3 dietary phases. Plasma total, LDL- and HDL-cholesterol were unaffected by either the yogurt of low-fat milk concentrate. The results indicate that yogurt, as an example of a fermented dairy product, has no effect on plasma cholesterol levels of normolipidemic males.     

Effects of soy protein and casein in low cholesterol diets on plasma lipoproteins in normolipidemic subjects

Dietary plant proteins may lower plasma cholesterol and LDL concentrations in hypercholesterolemic patients when substituted for animal proteins, particularly in diets with low cholesterol and saturated fat content. Plant protein diets appear, however, to be without effect on plasma lipoprotein levels in normal subjects. In the present study, we have examined whether the origin of the dietary protein, i.e. plant (soy) or animal (casein), affects the plasma lipoproteins in normolipidemic subjects when these proteins are presented as components of diets low in cholesterol and saturated fat. The study followed a crossover design. Five men and 5 women consumed liquid formula diets containing 20% of calories as casein or soy protein, 28% as fat (mainly monounsaturated), and 52% as carbohydrate; the intake of cholesterol was less than 100 mg per day. The two dietary periods, each of 1 month duration, were separated by an interim period of 1 month on self-chosen food. Following an initial 30% reduction of cholesterol and LDL plasma levels on both diets, the concentrations of each of the major lipoprotein classes (VLDL, IDL, LDL, HDL2 and HDL3) were similar during the two experimental dietary periods. Body weights were essentially constant. Dietary soy protein and casein could not be distinguished in their effects on the plasma concentrations and chemical composition of the major lipoprotein classes in normolipidemic subjects.     

The effect of dietary intervention on serum lipid levels in type 2 diabetes mellitus

Dietary therapy is the cornerstone of lipid management in patients with type 2 diabetes mellitus. The key strategies are the reduction of intake of saturated fat, trans unsaturated fat and cholesterol, and the reduction of energy intake to promote weight loss. This approach will produce significant improvements in the serum levels of low-density lipoprotein (LDL) cholesterol, triglycerides, and high-density lipoprotein (HDL) cholesterol. According to both the American Diabetes Association and the National Cholesterol Education Program (NCEP), the primary target of therapy is the serum LDL cholesterol level, with the secondary targets being non-HDL cholesterol, triglycerides, and HDL cholesterol. The recently updated guidelines of the NCEP place new emphasis on increasing soluble fiber intake to 10 to 25 g/d and adding foods fortified with plant stanols/sterols (2 g/d) as options to enhance the LDL cholesterol-lowering effect of diet.     

Effect of dietary sodium intake on blood lipids: results from the DASH-sodium trial

We evaluated the effect on serum lipids of sodium intake in 2 diets. Participants were randomly assigned to a typical American control diet or the Dietary Approaches to Stop Hypertension (DASH) diet, each prepared with 3 levels of sodium (targeted at 50, 100, and 150 mmol/d per 2100 kcal). The DASH diet is increased in fruits, vegetables, and low-fat dairy products and is reduced in saturated and total fat. Within assigned diet, participants ate each sodium level for 30 days. The order of sodium intake was random. Participants were 390 adults, age 22 years or older, with blood pressure of 120 to 159 mm Hg systolic and 80 to 95 mm Hg diastolic. Serum lipids were measured at baseline and at the end of each sodium period. Within each diet, sodium intake did not significantly affect serum total cholesterol, LDL cholesterol, HDL cholesterol, or triglycerides. On the control diet, the ratio of total cholesterol-to-HDL cholesterol increased by 2% from 4.53 on higher sodium to 4.63 on lower sodium intake (P=0.04). On the DASH diet, sodium intake did not affect this ratio. There was no dose-response of sodium intake on serum lipids or the cholesterol ratio in either diet. At each sodium level, total cholesterol, LDL cholesterol, and HDL cholesterol were lower on the DASH diet versus the typical American diet. There were no significant interactions between the effects of sodium and the DASH diet on serum lipids. In conclusion, changes in dietary sodium intake over the range of 50 to 150 mmol/d did not affect blood lipid concentrations.     

Deleterious metabolic effects of high-carbohydrate, sucrose-containing diets in patients with non-insulin-dependent diabetes mellitus

The effects of variations in dietary carbohydrate and fat intake on various aspects of carbohydrate and lipid metabolism were studied in patients with non-insulin-dependent diabetes mellitus (NIDDM). Two test diets were utilized, and they were consumed in random order over two 15-day periods. One diet was low in fat and high in carbohydrate, and corresponded closely to recent recommendations made by the American Diabetes Association (ADA), containing (as percent of total calories) 20 percent protein, 20 percent fat, and 60 percent carbohydrate, with 10 percent of total calories as sucrose. The other diet contained 20 percent protein, 40 percent fat, and 40 percent carbohydrate, with sucrose accounting for 3 percent of total calories. Although plasma fasting glucose and insulin concentrations were similar with both diets, incremental glucose and insulin responses from 8 a.m. to 4 p.m. were higher (p less than 0.01), and mean (+/- SEM) 24-hour urine glucose excretion was significantly greater (55 +/- 16 versus 26 +/- 4 g/24 hours p less than 0.02) in response to the low-fat, high-carbohydrate diet. In addition, fasting and postprandial triglyceride levels were increased (p less than 0.001 and p less than 0.05, respectively) and high-density lipoprotein (HDL) cholesterol concentrations were reduced (p less than 0.02) when patients with NIDDM ate the low-fat, high-carbohydrate diet. Finally, since low-density lipoprotein (LDL) concentrations did not change with diet, the HDL/LDL cholesterol ratio fell in response to the low-fat, high-carbohydrate diet. These results document that low-fat, high-carbohydrate diets, containing moderate amounts of sucrose, similar in composition to the recommendations of the ADA, have deleterious metabolic effects when consumed by patients with NIDDM for 15 days. Until it can be shown that these untoward effects are evanescent, and that long-term ingestion of similar diets will result in beneficial metabolic changes, it seems prudent to avoid the use of low-fat, high-carbohydrate diets containing moderate amounts of sucrose in patients with NIDDM.     

Dietary fat and hormonal influences on lipoprotein fluidity and composition in premenopausal women

LDL and HDL became more fluid when health, free-living, premenopausal women were fed reduced fat diets with higher proportions of polyunsaturated fatty acids. Lipoproteins were isolated from plasma of 31 female subjects fed one of two sets of diets from typical U.S.A. foods with P/S ratios of 0.3 or 1.0. All subjects were fed high-fat diets (40% of energy) for the duration of four menstrual cycles followed by low-fat diets (20% of energy) for the next four cycles. Blood samples were collected during mid-follicular and mid-luteal phases of the fourth menstrual cycle of each diet period to assess interactive dietary and hormonal control of lipoprotein fluidity. LDL was significantly more fluid, as determined by DPH fluorescence, upon reducing fat consumption from 40 to 20% of energy for subjects eating foods with P/S = 1.0 or 0.3. Generally LDL was more fluid during the follicular phase than the luteal phase of the cycles, thus indicating hormonal influences on LDL fluidity. HDL results were similar but not as pronounced as with LDL. Lipoprotein phospholipid (PL) and cholesteryl ester (CE) fatty acyl compositions were also subject to dietary and hormonal influences. Effects were noted in several fatty acids depending upon diet and hormonal state; however, generally diet fat reduction resulted in reduced linoleate and increased oleate contents. Regression analyses showed that fluidity was more dependent upon the lipoprotein cholesterol content than upon fatty acyl composition.     

Influence of apolipoprotein A-1 promoter polymorphism on lipid levels and responses to dietary change in Finnish adults

Objectives. To analyse the association between the G/A polymorphism in the apolipoprotein A-1 (apo A-1) promoter region and plasma lipid levels, as well as their responses to dietary change, in Finnish adults.
Subjects and design. Blood samples from 86 subjects (42 men, 44 women) who attended a dietary intervention study carried out in North Karelia in 1993 were available for the current analysis. The diet study consisted of a 2-week baseline period, followed by an 8-week intervention period, and an 8-week switchback period.
Intervention. Diet was modified to a low-fat, low-cholesterol diet during the dietary intervention.
Main outcome measures. Fasting plasma lipid, lipoprotein and apolipoprotein levels were determined.
Results. At baseline, the high-density lipoprotein (HDL) cholesterol and apo A-1 levels were higher ( P <0.01) and the triglyceride levels were lower ( P <0.05) in men, but not in women, with the A allele. The differences in HDL cholesterol and apo A-1 levels between genotypes remained during the low-fat, low-cholesterol diet and switchback periods. Apart from the difference between responses in apo A-1 during switchback to the original diet, lipid responses to dietary change did not differ significantly between genotypes.
Conclusion. Our findings indicate a significant association between the apo A-1 promoter polymorphism and plasma apo A-1 and HDL-cholesterol in men. In theory, the higher plasma HDL-cholesterol and apo A-1 levels in the GA/AA group may confer some protection against coronary artery disease. The differences in HDL-cholesterol and apo A-1 levels between genotypes persisted during different diets suggesting that the possible benefit is independent of fat and cholesterol intake.     

Lipoprotein risk factors in vegetarian women of Indian descent are unrelated to dietary intake.

Dietary intakes, anthropometric indices and plasma lipoprotein and alpha-tocopherol concentrations were measured in premenopausal vegetarian women of Indian descent (n = 22) and in white women of European descent consuming either mixed (n = 22) or vegetarian diets (n = 18). The Indian women were shorter in height than the white women and had a higher proportion of body fat. Energy intakes were lower in the Indian women, both in absolute terms and per kg body weight. The proportion of energy derived from saturated fatty acids was lower and that from polyunsaturated fatty acids was greater in both Indian and white vegetarians compared with the subjects on mixed diets. Intakes of dietary fibre and vitamins C and E were higher in the white vegetarians compared with the other groups. Plasma concentrations of total and LDL cholesterol and apolipoprotein B and the ratio of apolipoprotein B/apolipoprotein AI were lower and HDL and HDL2 cholesterol, alpha-tocopherol concentrations and the ratio of alpha-tocopherol/cholesterol were greater in the white vegetarian group than in the other groups. Total plasma cholesterol was associated with measures of truncal obesity, especially subscapular skinfold thickness and the percentage energy derived from saturated fatty acids. Plasma concentrations of apo(a) were higher and those of HDL and HDL2 cholesterol and sex hormone binding globulin (SHBG) were lower in the Indian vegetarian women compared with both groups of white women. No relationship could be found between apo(a), HDL and HDL2 cholesterol concentration and nutrient intake but HDL and HDL2 were negatively associated with the proportion of body fat and apo(a) weakly with subscapular skinfold thickness.(ABSTRACT TRUNCATED AT 250 WORDS)     

Effect of low fat-high carbohydrate diets in hypertensive patients with non-insulin-dependent diabetes mellitus

Effects of variations in dietary fat and carbohydrate content on various aspects of glucose, insulin, and lipoprotein metabolism were evaluated in 11 patients with hypertension, who also had non-insulin-dependent diabetes mellitus (NIDDM). All of these patients were being treated with sulfonylureas, thiazides, and beta-adrenergic receptor antagonists. The comparison diets contained either 40 or 60% of total calories as carbohydrate, with reciprocal changes in fat content from 40 to 20%. The diets were consumed in a random order for 15 days in a crossover experimental design. The ratio of polyunsaturated to saturated fat and total cholesterol intake were held constant in the two diets. Plasma glucose and insulin concentrations were significantly (P less than .001) elevated throughout the day when patients consumed the 60% carbohydrate diet. Fasting plasma total and very-low-density lipoprotein (VLDL) and triglyceride (TG) concentrations increased by 30% (P less than .001) after 15 days on the 60% carbohydrate diet. Total plasma cholesterol concentrations were similar on both diets, as were low-density lipoprotein (LDL) and high-density lipoprotein (HDL) cholesterol concentrations.     

Treatment of hypertriglyceridemia by two diets rich either in unsaturated fatty acids or in carbohydrates: effects on lipoprotein subclasses, lipolytic enzymes, lipid transfer proteins, insulin and leptin

BACKGROUND: There is lack of agreement on which dietary regimen is most suitable for treatment of hypertriglyceridemia, especially if high triglyceride concentrations are not due to obesity or alcohol abuse. We compared the effects on blood lipids of a diet high in total and unsaturated fat with a low-fat diet in patients with triglyceride concentrations of > 2.3 mmol/l. METHODS: Nineteen non-obese male outpatients with triglycerides ranging from 2.30 to 9.94 mmol/l received two consecutive diets for 3 weeks each: first a modified high-fat diet (39% total fat, 8% SFA, 15% monounsaturated fatty acids, 1.6% marine n-3 polyunsaturated fatty acids), and then a low-fat diet (total fat 28%, carbohydrates 54%). RESULTS: The high-fat diet significantly decreased triglycerides (-63%), total cholesterol (-22%), VLDL cholesterol (-54%), LDL cholesterol ( 16%), total apoC-III (-27%), apoC-III in apoB containing lipoproteins (apoC-III LpB; -31%) and in HDL (apoC-III nonLpB; -29%), apoE in serum (-33%) and apoB-containing lipoproteins (nonHDL-E; -42%), LpA-I (-16%), insulin (-36%), and leptin (-26%) and significantly increased the means of HDL cholesterol (+8%), LDL size (+6%), lipoprotein lipase (LPL, +11%), hepatic lipase (+13%), and lecithin: cholesterol acyltransferase (LCAT, +2%). The subsequent low-fat diet increased triglycerides (+63%), VLDL cholesterol (+19%), apoC-III (+23%), apoC-III LpB (+44%) apoC-III nonLpB (+17%), apoE (+29%) and nonHDL-E (+43%), and decreased HDL cholesterol (-12%), LPL (-3%), and LCAT (-3%). Changes in triglycerides correlated with changes in LPL activity and insulin levels. CONCLUSIONS: In hypertriglyceridemic patients, a modified diet rich in mono- and n-3 polyunsaturated fatty acids is more effective than a carbohydrate-rich low-fat diet in correcting the atherogenic lipoprotein phenotype.     

Dietary trans fatty acid

Trans fatty acids are unsaturated fatty acids that contain at least one double bond in the trans configuration. In the diet they occur at relatively low levels in meat and dairy products as a by-product of fermentation in ruminant animals or in hydrogenated fats as a consequence of the hydrogenation process. In general, dietary hydrogenated fat/trans fatty acids have been reported to increase LDL cholesterol levels relative to oil in the natural state or cis fatty acids. In contrast, dietary hydrogenated fat/trans fatty acids have been reported have to have little effect or decrease HDL cholesterol levels, the later observation restricted to relatively high intakes of trans fatty acids. These two effects result in higher, therefore less favorable, total or LDL cholesterol/HDL cholesterol ratios. Significant increases in Lp(a) levels have been reported after consumption of diets relatively high in trans fatty acids compared with either unsaturated or saturated fatty acids. However, the magnitude of the change is for the most part small and the physiological significance of this observation has yet to be resolved. Data related to the mechanism by which hydrogenated fat/trans fatty acids alter serum lipid levels and other risk factors for cardiovascular disease are in the nascent stages. At this time it would appear prudent that public health recommendations should be aimed at encouraging the moderate consumption of products low in saturated fat or minimally hydrogenated. Trans fatty acids intake should not be stressed at the expense of saturated fat but should augment it.