Reduction of dietary saturated fatty acids correlates with increased plasma lecithin cholesterol acyltransferase activity in humans

OBJECTIVE: Increased HDL-cholesterol (HDL-C) concentrations have been associated with lower coronary heart disease risk. On the other hand, dietary fats are known to influence the fatty acid profile of plasma lipids, including phospholipids that are substrates of lecithin cholesterol acyltransferase (LCAT), an important enzyme in HDL metabolism. The purpose of this study was to examine the association between the saturated fatty acid (SFA) intake and LCAT activity. DESIGN: An interventional study was performed in a monk community of 25 men. SETTING: A French monk community, South West of France. SUBJECTS AND INTERVENTIONS: The basal diet of the study cohort contained SFA in a proportion of 13.5% of their total energy intake (TEI). They were submitted to two experimental isocaloric diets containing either 8.4% of the TEI in SFA (diet A) or 11% (diet B), each lasting 5 weeks. RESULTS: The elevation of SFA in diet B was mainly obtained by decreasing carbohydrates. The only significant difference among total fats between diets A and B was the myristic acid content (0.6 and 1.2% of TEI, respectively). The elevation in SFA in diet B resulted in a significant increase of HDL-C (P<0.04), while plasma apo A-I concentration and LCAT activity both decreased (P<0.02). CONCLUSION: Altogether, these results are consistent with a negative effect of SFA on reverse cholesterol transport.     

Effects of adiposity on plasma lipid response to reductions in dietary saturated fatty acids and cholesterol

Dietary SFA and cholesterol are major targets for reducing plasma total and LDL cholesterol as a strategy to decrease cardiovascular disease risk. However, many studies show that excess adiposity attenuates the expected lipid and lipoprotein response to a plasma cholesterol-lowering diet. Diets low in SFA and cholesterol are less effective in improving the lipid profile in obese individuals and in patients with metabolic syndrome. In contrast, lean persons are more responsive to reductions in dietary SFA and cholesterol. Multiple mechanisms likely contribute to the altered plasma lipid responses to dietary changes in individuals with excess adiposity. The greater rate of hepatic cholesterol synthesis in obese individuals suppresses the expression of hepatic LDL receptors (LDLR), thereby reducing hepatic LDL uptake. Insulin resistance develops as a result of adipose-tissue induced inflammation, causing significant changes in enzymes necessary for normal lipid metabolism. In addition, the LDLR-mediated uptake in obesity is attenuated by alterations in neuroendocrine regulation of hormonal secretions (e.g. growth hormone, thyroid hormone, and cortisol) as well as the unique gut microbiota, the latter of which appears to affect lipid absorption. Reducing adipose tissue mass, especially from the abdominal region, is an effective strategy to improve the lipid response to dietary interventions by reducing inflammation, enhancing insulin sensitivity, and improving LDLR binding. Thus, normalizing adipose tissue mass is an important goal for maximizing the diet response to a plasma cholesterol-lowering diet.     

Macrophage cholesterol efflux elicited by human total plasma and by HDL subfractions is not affected by different types of dietary fatty acids

BACKGROUND: Plasma HDL concentrations and composition, important predictors of coronary heart disease, are modified by fatty acids (FAs) in high-fat diets. OBJECTIVE: Following the National Cholesterol Education Program Adult Treatment Panel III recommendation that 25%-30% of total calorie intake be in the form of fat, we compared the results of the intake of 30% of energy as fat in diets enriched with trans, polyunsaturated, or saturated FAs. These dietary effects on the composition and ability of HDL(2), HDL(3), and total plasma to efflux cholesterol from mouse peritoneal macrophages that previously were loaded with LDL-acetylated 14C-cholesteryl ester were evaluated by using ultracentrifugally isolated lipoproteins. DESIGN: After a 2-wk run-in period, 30 healthy persons (9 M, 21 F), were randomly distributed among 3 groups (n = 10/group) and fed for 4 wk with either an 8.3% trans FA, a 14.6% polyunsaturated FA, or a 13.2% saturated FA diet. The 3 diets had similar proportions of monounsaturated FAs. RESULTS: The percentage of radioactive cell cholesterol removal did not vary among these diets, possibly because of the small difference in the composition of the HDL fraction elicited by the different diets. However, the percentage was consistently higher for HDL(3) than for HDL(2). CONCLUSION: Differences in the cell cholesterol efflux with these diets were not observed, probably because the changes in the HDL composition were quite modest as a result of the limitation of the fat intake to 30% of total calories and because of the rigorous control of the proportions of FAs in the experimental diets used in this investigation.     

Intake of n-3 fatty acids from fish does not lower serum concentrations of C-reactive protein in healthy subjects

OBJECTIVE: High-sensitivity C-reactive protein (CRP), a marker of systemic inflammation, is a powerful predictor of cardiovascular risk. We hypothesised that n-3 fatty acids reduce underlying inflammatory processes and consequently CRP concentrations in healthy middle-aged subjects. DESIGN: Placebo-controlled, double-blind study. SUBJECTS: A total of 43 men and 41 postmenopausal women aged 50-70 y. Before and after intervention, we measured serum CRP concentrations with an enzyme immunoassay. INTERVENTIONS: Capsules with either 3.5 g/day fish oil (1.5 g/day n-3 fatty acids) or placebo for 12 weeks. RESULTS: The median CRP change in the fish oil group did not significantly differ from that in the placebo group (0.01 vs -0.17 mg/l, P = 0.057). CONCLUSION: The currently available data--including ours--do not support that beneficial effects on CRP are involved in a mechanism explaining the protective effect on heart disease risk of n-3 fatty acids as present in fish.     

Effect of dietary cholesterol with or without saturated fat on plasma lipoprotein cholesterol levels in the laboratory opossum (Monodelphis domestica) model for diet-induced hyperlipidaemia

Laboratory opossums (Monodelphis domestica) show extreme genetic variability in their responsiveness to dietary lipids; a great proportion of the genetic variability in responsiveness is due to a single major gene. To determine whether the major gene for dietary response detected by genetic analysis in opossums is responsive to dietary cholesterol or dietary saturated fat, or a combination of both, we used males and females of susceptible and resistant lines of laboratory opossums that were 5 to 7 months old. The animals were challenged with three different experimental diets (high-cholesterol diets with or without high saturated fat from lard or coconut oil) and plasma lipoproteins were measured. Plasma and VLDL+LDL-cholesterol concentrations increased several-fold when the animals were fed the diet containing elevated cholesterol (P<0.001) or elevated cholesterol and fat (P<0.001) and differed between the two lines when they were fed high-cholesterol diets with or without fat (P<0.001). Plasma HDL-cholesterol concentrations were higher (P<0.05) in animals of the resistant line than in the susceptible line when they were fed the basal diet (550 (SEM 30) v. 440 (SEM 20) mg/l) and when they were fed the low-cholesterol and high-fat diet (600 (SEM 30) v. 490 (SEM 30) mg/l). Dietary coconut oil and lard had similar effects on plasma lipoprotein cholesterol concentrations in the susceptible line of opossums. A reduction in dietary cholesterol by 50 % with either the lard or coconut oil blunted the plasma cholesterol response. The results from the present studies suggest that the major gene for dietary response previously detected by genetic analysis in laboratory opossums affects the response to dietary cholesterol but not to saturated fat.     

Effect on blood pressure of two diets differing in total fat but not in saturated and polyunsaturated fatty acids in healthy volunteers

The effects of a low-fat, carbohydrate-rich and a high-fat, olive-oil-rich diet on blood pressure were studied under strict dietary control. Forty-seven healthy normotensive men and women were fed a diet high in saturated fatty acids (20 en%) and total fat (38 en%) for 17 d. Twenty-four subjects then received a low-fat, carbohydrate-rich diet (total fat 22 en%) and the other 23 a high-fat, olive-oil-rich diet (oleic acid 24 en%, total fat 41 en%) for 36 d. Both test diets had the same level of saturated fatty acids (7-10 en%) and linoleic acid (4 en%). Systolic blood pressure fell by 2.3 and diastolic by 4.7 mm Hg in the carbohydrate group and by 2.7 and 4.4 mm Hg in the olive-oil group, respectively (differences between diets groups not significant). These results suggest that a high-fat diet rich in monounsaturated fatty acids has no deleterious effect on blood pressure in healthy normotensive subjects in comparison with a low-fat, carbohydrate-rich diet.     

Comparison of monounsaturated fatty acids and carbohydrates for reducing raised levels of plasma cholesterol in man

To compare monounsaturated fatty acids and carbohydrates for actions on lipid and lipoprotein levels from solid-food diets, 10 men were studied on three diets. One diet was high in saturated fatty acids and very high in cholesterol (High Sat + Chol), a second was high in monounsaturates but low in cholesterol (High Mono), and a third was low in fat, high in carbohydrates, and low in cholesterol (Low Fat). All diets were consumed for 6 wk. Compared with the High Sat + Chol diet, the High Mono and Low Fat diets significantly and similarly reduced plasma cholesterol and LDL cholesterol. In contrast, the Low Fat diet significantly lowered HDL cholesterol whereas the High Mono diet did not. Therefore, a solid-food diet rich in monounsaturated fatty acids is equivalent to a low-fat, high-carbohydrate diet for cholesterol lowering but does not reduce the HDL-cholesterol level.     

Validation of a short questionnaire to qualitatively assess the intake of total fat, saturated, monounsaturated, polyunsaturated fatty acids, and cholesterol

Background To validate a self‐administered 20‐item short questionnaire (SQ) for classifying individuals according to their intake of total fat, saturated (SFA), monounsaturated (MUFA), and polyunsaturated fatty acids (PUFA), as well as cholesterol. Methods The SQ was sent to a randomly selected subsample of 300 participants of the European Prospective Investigation into Cancer and Nutrition (EPIC) in Heidelberg. The SQ was sent back by 244 participants (52.5% women, 47.5% men). Intake of total fat, SFA, MUFA, PUFA, and cholesterol was calculated from a 148‐item food frequency questionnaire (FFQ). The intake was compared with the scores computed from the SQ. Results Spearman's correlation coefficient between the intake estimated from the FFQ and the score from the SQ ranged from r = 0.29 (PUFA) to r = 0.56 (cholesterol). When the participants were assigned to quartiles of intake according to both methods 29–42% were classified into the same quartile, 1–7% of the participants were grossly misclassified. Conclusions The SQ demonstrated a good validity with respect to SFA and cholesterol and an acceptable validity with respect to total fat and MUFA, while the results are less good for PUFA. The SQ can be used to classify persons according to their intake into categories of intake.     

Development and validation of a short food list to assess the intake of total fat, saturated, mono-unsaturated, polyunsaturated fatty acids and cholesterol

BACKGROUND: The aim of this study was the development and validation of a short list of food items to assess the intake of total fat, saturated, mono-unsaturated, polyunsaturated fatty acids, and cholesterol. The short list should be able to correctly classify persons according to their intake. METHODS: A short list of 20 food items was selected out of 1009 seven-day food records by means of the variance-based method Max_r. This list was validated using data from a further 479 persons who completed seven-day food records (validation sample 1, VS1) as well as a food frequency questionnaire (validation sample 2, VS2). The intake of total fat, different fatty acids, and cholesterol from the complete VS1 (VS1(complete)) and from the complete VS2 (VS2(complete)), respectively, was computed. Further, the intake in VS1 (VS1(short)) as well as in VS2 (VS2(short)) using only the 20 food items on the short list were calculated. RESULTS: Pearson correlation coefficients between the intake calculated from the items on the short list and the nutrient intake calculated from the full instrument in VS1 and VS2, respectively, were r = 0.81-0.91. In a quartile's cross-classification 53.4-64.1% of the participants were assigned to the same quartile. When comparing VS1(complete) with VS2(short), neither correlation coefficients nor the cross-classification differ much from the comparison of VS1(complete) with VS2(complete). CONCLUSIONS: The short list shows good results in both validation samples. Thus, the short list can assess the variability of fat intake and classify persons according to their intake.     

Relationship of dietary fat to plasma fatty acids,blood pressure,and urinary eicosanoids in adult men.

This experiment was conducted to determine the relationships between modest changes in dietary linoleate, blood pressure (BP) response, and levels of eicosanoid synthesis in humans. Products of eicosanoids which appear in blood were measured in urine: PGI2, 6-keto-PGF1 alpha (KPGI2); TXA2, (TXB2); PGF2 alpha, 13,14-dihydro-15-keto-PGF2 alpha, (MPGF2 alpha). Twenty-three adult men were fed controlled diets having 25 energy percent fat, and having P/S ratios of either 0.3 (low-PUFA) or 1.0 (high-PUFA), for a total of 12 weeks, with a switchover between P/S ratios at 6 weeks. The results showed that, under the conditions of this study, BP was significantly reduced by reducing dietary fat intake from about 37 to 25 energy percent. However, no further effects on BP were produced by increasing the P/S ratio from 0.3 to 1.0. KPGI2 excretion was significantly lowered on both controlled diets as compared to the self-selected (SS) diet. However, MPGF2 alpha was lowered only on the low-PUFA diet as compared to the self-selected diet. No significant decrease in TXB2 excretion was observed. Both MPGF2 alpha and KPGI2 excretion were positively correlated with urine volume and sodium excretion. On the SS diet, but not on the controlled diets, MPGF2 alpha excretion was negatively correlated with plasma linoleate and positively correlated with stearate. On the low-PUFA diet, MPGF2 alpha excretion increased with the intake of linoleate, while, on the high-PUFA diet, it decreased. This may have been due to the limited amounts of linoleate available in the low-PUFA diet (3.2-3.4 energy percent) as compared to that in the high-PUFA diet. Both KPGI2 and MPGF2 alpha excretion were positively correlated with systolic and diastolic BP. These results suggest that the amount of dietary linoleate is an important factor in the regulation of prostaglandin synthesis in humans.     

Replacing coconut santan with palm oil santan: impact on dietary C12-16 saturated fatty acids, serum total cholesterol and cardiovascular risk

The theoretical impact of the use of coconut cream (santan) powder and palm oil santan powder on the dietary levels of C12-16 saturated fatty acids (SFAs) and linoleic acid (18:2), and on serum total cholesterol (TC), was evaluated holding non-santan dietary variables constant. The prediction was based on a 2,300-kcal hypothetical diet, containing one santan-based dish or snack in each of the 5 daily meals with fat contributing 30% of total calories, while the santan contributed a total of 14% kcal (36g). Replacing coconut santan with palm oil santan reduced the overall dietary C12-16 SFAs from 10.8% kcal to 4.8% kcal (i.e. 6.0% kcal) and the virtual removal of lauric (12:0) + myristic (14:0) acids, while palmitic acid (16:0) rose by 3.3% kcal, and the polyunsaturated linoleic acid (18:2) increased by 1.13% kcal. Applying the Hegsted equation to these dietary fatty acid (FA) changes, predicted a serum TC reduction of 24 -31 mg/dL (0.62- 0.80 mM/L), with the hypocholesterolemic effect being influenced by the low-density lipoprotein receptor (LDLr) set-point of the individual(s) concerned. Thus, the prediction indicated that replacing coconut santan with palm oil santan in santan-based Malaysian dishes or snacks would have a significant beneficial impact on serum TC and hence, cardiovascular risk.     

Dietary fat intake in healthy adolescents: inverse relationships between the estimated intake of saturated fatty acids and serum cholesterol

The objective of the present study was to describe the intake of dietary fatty acids among healthy 15-year-old boys and girls and to relate the intake of specific fatty acids and the fatty acid composition of the serum cholesterol esters to serum lipid, apolipoprotein (Apo) and insulin concentrations respectively. Fifty-two girls and forty-two boys were randomly selected from the official population register. Unexpectedly, significant inverse associations were found between the dietary content of saturated fatty acids with a chain length of four to fifteen C atoms, mainly derived from milk fat, as well as the corresponding fatty acids in the serum cholesterol esters, on the one hand and the serum concentrations of cholesterol and ApoB on the other. The estimated dietary intake of 4:0-10:0, 12:0 and 14:0 respectively, were all significantly inversely related to the serum cholesterol (r -0.32, r -0.31, r -0.30, all and ApoB (r -0.42, r -0.42, and r -0.40, all concentrations in girls and 12:0 to the ApoB concentration (r -0.55, in boys. The proportions of 12:0 and 15:0 in the serum cholesterol esters were negatively correlated with the serum cholesterol concentrations in both girls (r -0.34, r -0.32, and boys (r -0.53, r -0.32, and with the ApoB concentrations among boys (r -0.61, r -0.43, It is conceivable that milk fat contains or is associated with some component in the diet, or some other characteristics of the food intake, which counterbalances the expected positive relationships between saturated fat intake and lipid levels.     

Dietary rhubarb (Rheum rhaponticum) stalk fibre does not lower plasma cholesterol levels in diabetic rats

Rhubarb (Rheum rhapontiam) stalk fibre was previously shown to be hypolipidaemic under clinical and experimental conditions. The present study was undertaken to investigate whether rhubarb stalk fibre has a hypolipidaemic effect under diabetic conditions. Two models of diabetic rats were used: streptozotocin-induced diabetic rats, and diabetes-prone BB (BBdp) rats. The plasma cholesterol and triacylglycerol concentrations were elevated after the onset of diabetes in BBdp rats, but not in sterptozotocin-induced diabetic rats. The rhubarb-fibre diet had no effect on the plasma cholesterol or triacylglycerol concentrations of diabetic rats. The hypolipidaemic effect of rhubarb stalk fibre has been suggested to be due to the bile-acid-binding capacity of rhubarb fibre, which in turn up regulates cholesterol 7alpha-hydroxylase (cyp7a) activity. cyp7a is the first and the rate-limiting enzyme in the breakdown of cholesterol to bile acids. We measured the cyp7a activity and mRNA levels in control and diabetic rats fed rhubarb- and cellulose-fibre diets. The cyp7a activity and mRNA abundance were increased in both diabetic rat models, indicating that bile acid synthesis is enhanced in diabetes. Feeding a diet enriched with rhubarb fibre caused a slight but significant increase (P<0.05) in cyp7a enzyme activity in BBdp rats, but no change in cyp7a mRNA abundance was detected. These results suggest that although a rhubarb-fibre-enriched diet increased cyp7a activity in BBdp rats, there was no apparent therapeutic benefit in terms of lowering plasma cholesterol concentrations.     

Effect of dietary n-3 polyunsaturated fatty acids on plasma total and high-molecular-weight adiponectin concentrations in overweight to moderately obese men and women

BACKGROUND: Recent studies indicated that dietary n-3 polyunsaturated fatty acids (PUFAs) increase circulating adiponectin concentrations in rodents. OBJECTIVE: We aimed to investigate whether a diet rich in n-3 PUFAs increased plasma concentrations of total or high-molecular-weight (HMW) adiponectin in healthy overweight-to-moderately obese men and women. DESIGN: Sixteen women and 10 men with a body mass index (in kg/m(2)) between 28 and 33 were randomly assigned to consume a diet rich in n-3 PUFAs (3.5% of energy intake) from both plant and marine sources or a control diet (0.5% of energy intake from n-3 PUFAs). For the first 2 wk, these diets were consumed under isocaloric conditions; then followed a 12-wk period of ad libitum consumption that was associated with a moderate loss of approximately 3.5% of body weight in both groups. Total and HMW adiponectin plasma concentrations were measured before and after each diet phase. RESULTS: Plasma fasting adiponectin concentrations did not change during the isocaloric period, but they increased modestly ( approximately 10%) during the ad libitum period when subjects lost weight [P = 0.009 for time in repeated-measures analysis of variance] and to a similar extent in subjects consuming the control (x +/- SD: 0.42 +/- 0.69 microg/mL) and n-3 PUFA (0.45 +/- 0.85 microg/mL) diets (P = 0.920 for time x treatment interaction). Plasma concentrations of HMW adiponectin did not change significantly during the study. CONCLUSION: Dietary n-3 PUFAs consumed at levels of 3.5% of energy intake do not significantly increase plasma or HMW adiponectin concentrations in overweight-to-moderately obese healthy men and women over the course of 14 wk.     

The effects of dietary fatty acids and cholesterol on the milk lipids of lactating women and the plasma cholesterol of breast-fed infants.

The plasma cholesterol concentration and the composition of the plasma fatty acids was altered by dietary means in 10 lactating women. The effects of these changes in the plasma on the lipid constituents of mature human milk were studied over periods of several weeks. In eight infants who were being breast-fed, the changes in the plasma cholesterol concentration were correlated with the changes that were induced in the milk lipids. Significant alteration in the women's plasma cholesterol levels did not change the cholesterol concentration in milk. The cholesterol content of milk was closely correlated with the concentrations of the other milk lipids, supporting a functional role for the cholesterol in the secretion of milk fat. In the maternal milk consumed by the eight infants the linoleate content rose from 9.4% to 15.5% of total fatty acids as a result of a moderate increase in dietary polyunsaturated fat. This led to a fall in the infants' plasma cholesterol levels, from an average of 185 to 157 mg/100 ml.     

Discrepancies in dietary intakes and plasma concentrations of fatty acids according to age among Japanese female dietitians

OBJECTIVE: To clarify the influences of age on dietary intakes and plasma concentrations of fatty acids (FAs) in Japanese female dietitians. SUBJECTS AND METHODS: In autumn 1996, we estimated dietary FA intakes based on 7 day weighed diet records and analyzed plasma FA concentrations in 79 healthy Japanese female dietitians, and investigated their relationships with age, dividing into three age groups (young (32-42 y), middle-aged (43-50 y) and elderly (51-66 y)). RESULTS: Dietary intakes of total FA, saturated FAs, monounsaturated FAs, n-3 polyunsaturated FAs (PUFAs) and alpha-linolenic acid (18:3n-3) were significantly highest in the middle-aged group, and lowest in the elderly. Similar trends were observed for dietary intakes of n-6 PUFAs and linoleic acid (18:2n-6), but there were no differences with regard to eicosapentaenoic acid (EPA; 20:5n-3), docosahexaenoic acid (DHA; 22:6n-3) and n-3 highly unsaturated FAs (HUFAs=EPA+22:5n-3+DHA). On the other hand, plasma concentrations of all FAs except for arachidonic acid (20:4n-6) demonstrated positive correlations with age. Moreover, plasma concentrations of EPA in all age groups, DHA in the elderly and n-3 HUFAs in the middle-aged and the elderly were all positively correlated with dietary intakes. CONCLUSIONS: We should take into account the influence of age on dietary habit and lipid metabolism when interpreting associations between dietary FA intakes and plasma FA concentrations.     

Relationship of dietary fat to plasma fatty acids, blood pressure, and urinary eicosanoids in adult men

This experiment was conducted to determine the relationships between modest changes in dietary linoleate, blood pressure (BP) response, and levels of eicosanoid synthesis in humans. Products of eicosanoids which appear in blood were measured in urine: PGI2, 6-keto-PGF1 alpha (KPGI2); TXA2, (TXB2); PGF2 alpha, 13,14-dihydro-15-keto-PGF2 alpha, (MPGF2 alpha). Twenty-three adult men were fed controlled diets having 25 energy percent fat, and having P/S ratios of either 0.3 (low-PUFA) or 1.0 (high-PUFA), for a total of 12 weeks, with a switchover between P/S ratios at 6 weeks. The results showed that, under the conditions of this study, BP was significantly reduced by reducing dietary fat intake from about 37 to 25 energy percent. However, no further effects on BP were produced by increasing the P/S ratio from 0.3 to 1.0. KPGI2 excretion was significantly lowered on both controlled diets as compared to the self-selected (SS) diet. However, MPGF2 alpha was lowered only on the low-PUFA diet as compared to the self-selected diet. No significant decrease in TXB2 excretion was observed. Both MPGF2 alpha and KPGI2 excretion were positively correlated with urine volume and sodium excretion. On the SS diet, but not on the controlled diets, MPGF2 alpha excretion was negatively correlated with plasma linoleate and positively correlated with stearate. On the low-PUFA diet, MPGF2 alpha excretion increased with the intake of linoleate, while, on the high-PUFA diet, it decreased. This may have been due to the limited amounts of linoleate available in the low-PUFA diet (3.2-3.4 energy percent) as compared to that in the high-PUFA diet. Both KPGI2 and MPGF2 alpha excretion were positively correlated with systolic and diastolic BP. These results suggest that the amount of dietary linoleate is an important factor in the regulation of prostaglandin synthesis in humans.     

Effect of dietary monounsaturated fatty acids on plasma lipoproteins and apolipoproteins in women.

To determine the effects of dietary fat saturation on plasma lipoproteins, we studied 21 free-living normolipidemic women (13 pre- and 8 postmenopausal) on three consecutive diet periods. During the first 4 wk they consumed a saturated diet rich in palm oil and butter [19% saturated fatty acids (S), 14% monounsaturated fatty acids (M), and 3.5% polyunsaturated fatty acids (P)], followed by 6 wk of a monounsaturated diet rich in olive oil (11% S, 22% M, and 3.6% P), and 6 wk of a polyunsaturated diet rich in sunflower oil (10.7% S, 12.5% M, and 12.8% P). Compared with the diet rich in saturated fatty acids, both diets rich in unsaturated fatty acids had similar lowering effects on total and low-density-lipoprotein cholesterol. High-density lipoprotein cholesterol and apolipoprotein A-I were higher in the monounsaturated-rich period than in the polyunsaturated-rich (10.5% and 12.7% respectively, P less than 0.001) and the saturated-rich period (5.3%, and 7.9%, respectively, P less than 0.05). These effects were independent of menopause status. Our data show that at this level of fat intake (36% as calories), a monounsaturated-rich diet results in a less atherogenic lipid profile than either polyunsaturated- or saturated-rich diets.