Effect Of Palm Oil Research Articles

Effects of palm oil and transesterified palm oil on chylomicron and VLDL triacylglycerol structures and postprandial lipid response

The effects of positional distribution of triacylglycerol (TAG) fatty acids to TAG structures in chylomicrons and VLDL, and to postprandial lipemia, were studied in 10 healthy premenopausal women using a 6-h oral fat load test and a randomized, double-blind cross-over design. Molecular level information of TAG regioisomerism was obtained with a tandem mass spectrometric method. The positional distribution of fatty acids in chylomicron TAGs was similar to the respective dietary fat; 79% of the analyzed regioisomers in palm oil and 84% of the analyzed regioisomers in transesterified oil were found in chylomicron TAGs 3 h after the oral fat loads. VLDL TAGs were equal after the two fat loads in all but one regioisomer. Similarities in the fatty acid compositions of chylomicron TAGs suggest that palmitic acid was absorbed equally from both test fats. The proportion of palmitoleic acid in the chylomicrons was increased. Fat with palmitic acid predominantly in the sn-1 and sn-3 positions caused a larger incremental area of total TAGs in plasma and reduced plasma insulin values at the beginning of the postprandial response (0–90 min) compared with fat with palmitic acid randomly distributed. The relationship between TAG molecular structures in dietary fats and in lipoproteins provides new means for understanding the effects of fatty acid positonal distribution on human lipid metabolism.—Yli-Jokipii, K., H. Kallio, U. Schwab, H. Mykkänen, J-P. Kurvinen, M. J. Savolainen, and R. Tahvonen. Effects of palm oil and transesterified palm oil on chylomicron and VLDL triacylglycerol structures and postprandial lipid response. J. Lipid Res. 2001. 42: 1618–1625.

Effect of palm oil on plasma lipoprotein concentrations and plasma low-density lipoprotein composition in non-human primates

Palm oil (PO) contains ~43% of palmitic acid. It is the most abundant saturated fatty acid in the diet and it is generally considered the primary cholesterol (C)-raising fatty acid. However, the effect of palmitic acid on plasma cholesterol appears to depend on the cholesterol content of the diet. The aim of this study was to determine the effect of PO with either a high-fat, high-C or moderate-fat, moderate-C diet on lipoprotein C and low-density lipoprotein (LDL) composition. Fifty adult, male vervet monkeys were randomly assigned to the high-fat diet group (HFD: 35%E fat, ~0.106 mg C/kJ; n =20) and the moderate-fat diet group (MFD: 30%E fat, ~0.027 mg C/kJ; n =30). Baseline LDL-C, high-density lipoprotein (HDL)-C and body weight were used to stratify the vervets into comparable experimental groups within each dietary group. The HFD group was divided into two groups of 10 each: one group continued with the HFD in which 8.1%E was derived from lard (AF); in the other group, AF was substituted isocalorically with PO. The MFD group was divided into three groups of 10 each: one group continued with the MFD in which 11.8%E was derived from AF; in the other two groups, the AF was substituted isocalorically with either sunflower oil (SO) or PO. This article presents preliminary results on plasma lipoproteins and LDL composition after 6 months of dietary intervention. Plasma total and LDL-C was higher in all the groups, but the mean changes elicited by PO with either the HFD or MFD were no different from that observed with AF and SO. There was no difference in the mean change of LDL molecular weight within the HFD and MFD. It is concluded that PO is no different from AF (HFD and MFD) or SO (MFD) in its cholesterolaemic effect.

Effect of palm oil on plasma lipoprotein concentrations and plasma low-density lipoprotein composition in non-human primates

Palm oil (PO) contains ˜43% of palmitic acid. It is the most abundant saturated fattyacid in the diet and it is generally considered the primary cholesterol (C)-raisingfatty acid. However, the effect of palmitic acid on plasma cholesterol appears todepend on the cholesterol content of the diet. The aim of this study was to determinethe effect of PO with either a high-fat, high-C or moderate-fat, moderate-C diet onlipoprotein C and low-density lipoprotein (LDL) composition. Fifty adult, malevervet monkeys were randomly assigned to the high-fat diet group (HFD: 35%E fat,˜0.106mg C/kJ; n = 20) and the moderate-fat diet group (MFD: 30%E fat, ˜0.027mgC/kJ; n = 30). Baseline LDL-C, high-density lipoprotein (HDL)-C and body weightwere used to stratify the vervets into comparable experimental groups within eachdietary group. The HFD group was divided into two groups of 10 each: one groupcontinued with the HFD in which 8.1%E was derived from lard (AF); in the othergroup, AF was substituted isocalorically with PO. The MFD group was divided intothree groups of 10 each: one group continued with the MFD in which 11.8%E wasderived from AF; in the other two groups, the AF was substituted isocalorically witheither sunflower oil (SO) or PO. This article presents preliminary results on plasmalipoproteins and LDL composition after 6 months of dietary intervention. Plasmatotal and LDL-C was higher in all the groups, but the mean changes elicited by POwith either the HFD or MFD were no different from that observed with AF and SO.There was no difference in the mean change of LDL molecular weight within theHFD and MFD. It is concluded that PO is no different from AF (HFD and MFD) orSO (MFD) in its cholesterolaemic effect.

The effect of palm oil, lard, and puff-pastry margarine on postprandial lipid and hormone responses in normal-weight and obese young women

Only a few studies have been published on the postprandial effects of different fatty acids in obese subjects. Therefore, the present study investigated the effects of three test meals containing palm oil (PO), lard (LD), or puff-pastry margarine (PPM), all normal dietary ingredients, on postprandial lipid and hormone responses in normal-weight and obese young women. The study was performed as a randomized, crossover design. The fats differed in the content of palmitic acid, stearic acid, and trans monounsaturated fatty acids allowing a dietary comparison of different 'solid' fatty acids. The obese women had significantly higher fasting concentrations and postprandial responses of plasma total triacylglycerol (TAG), chylomicron-TAG, and insulin compared with the normal-weight women but there was no significant difference in the postprandial responses between the three test meals. The obese women had fasting concentrations of leptin four times greater than the normal-weight women. There were no postprandial changes in the concentrations of leptin. The fasting concentrations of HDL-cholesterol were significantly lower in the obese women than in the normal-weight women, whereas there was no significant difference between the two groups in the concentrations of total cholesterol or LDL-cholesterol. These results provide evidence that obese women have exaggerated lipid and hormone responses compared with normal-weight women but the different contents of saturated and trans monounsaturated fatty acids provided by PO, LD, and PPM have no effect in either group.

Effects of palm oil and soybean oil as fat sources in isonitrogenous and isocaloric diets on the performance of broilers

Effects of palm oil and soybean oil as fat sources in isonitrogenous and isocaloric diets on the performance of broilers

Effect of palm oil, margarine, butter, and sunflower oil on the serum lipids and lipoproteins of normocholesterolemic middle-aged men

Twenty-nine healthy middle-aged men participated in a Latin square-designed study containing six dietary fats: butter; crude palm oil; hard margarine; refined palm oil; 80% refined palm oil + 20% sunflower oil blend; and sunflower oil. Each diet period was 6 weeks in duration followed by 6 weeks of habitual diet. Test fats were consumed in ice cream, milk, cookies, and as spreads and represented 50% of the total fat energy (38%) on all diets. Serum lipid responses to the high level of test fats in the diets were small relative to habitual diet values. Large changes in quantity and type of fatty acids consumed daily were not reflected in the fatty acid composition of the total serum lipids. Butter did not elevate total serum cholesterol or low density lipoprotein (LDL) cholesterol relative to habitual diet levels, but these values were significantly higher than sunflower oil-diet and palm oil-diet values. The sunflower oil diet produced the most dramatic changes: total serum cholesterol was reduced significantly relative to all diets except margarine, and apolipoprotein B values were the lowest of any diet. Unfortunately, the desirable high density lipoprotein (HDL) cholesterol and apolipoprotein A1 were also reduced on the sunflower oil diet. Diets containing either crude or refined palm oil did not elevate total serum cholesterol relative to habitual diet values or LDL cholesterol or apolipoprotein levels relative to any diet. Unexpectedly, the refined palm oil diet HDL-cholesterol and apolipoprotein A1 levels were the highest of all diets and significantly higher than sunflower oil diet values. The hard margarine diet, containing 26% trans fatty acids, reduced apolipoprotein B values relative to habitual diet levels, but HDL cholesterol was reduced significantly relative to the refined palm oil diet values. Comparison of the diet's fatty acid compositions suggests the decrease in the HDL cholesterol on the hard margarine diet is attributable to the trans fatty acids. The data indicate that the trans fatty acids, produced during the partial hydrogenation of fats and oils, are not neutral and adversely affect serum lipid profile.

Comparative Effects of Dietary Palm Oil, Perilla Oil, and Soybean Oil on Lipid Profiles in Differently Aged Rats Fed on Hypercholesterolemic Diets.

The effects of palm oil, soybean oil, and perilla oil on the lipid profiles of liver and serum were compared in young (1 month old) and adult (8 months old) rats fed on hypercholesterolemic diets. In young rats, the concentration of serum cholesterol was highest in the order of palm oil (PAO), soybean oil (SBO), and perilla oil (PEO), whereas it was comparable among the groups of adult rats, resulting in an age-dependent increase in the rats fed on PEO. In young rats, but not in adult rats, the ratio of HDL-/total-cholesterol was significantly increased with an increase in the degree of unsaturation of dietary fats. Dietary PAO, when compared with SBO or PEO, prevented the accumulation of liver cholesterol in adult rats, when expressed as mg per liver. No fat-effect on liver cholesterol was seen in young rats. SBO amd PEO, when compared with PAO, markedly enhanced fecal output of bile acids in adult rats. The concentration of serum triacylglycerol showed a fat-dependent response, whereas that of liver triacylglycerol showed both an ageand fat-dependent response. Thus, PAO showed an effect similar to that of SBO on the serum cholesterol level in adult animals fed on a hypercholesterolemic diet.

Effect of long term feeding of palm oil on growth and lipid metabolism in rats

The effect of palm oil on the lipid metabolism of rats was studied in an eighteen week-long experiment in rats. Four groups of male rats of Wistar strain (10 each) were fed ad lib for 18 weeks on diets containing casein, starch, vitamins and minerals to which oils were incorporated at 5% and 20% levels. Rats fed on peanut oil were used as controls. 20% oil-fed groups gained more weight than 5% oil-fed groups. However, the liver cholesterol values in 20% peanut oil-fed groups were lower when calculated in relation to liver weight. Triglycerides were higher in 20% oil-fed groups. Analysis of liver and plasma fatty acids indicated that palm oil-fed groups had a higher content of saturated fatty acids such as palmitic, stearic and monounsaturated fatty acids (oleic, palmitoleic) and low levels of linoleic acid. The oleic/linoleic acid ratio in the plasma and liver correlated with the types of fat consumed whereas the P/S ratios, although were the same in the plasma, indicated the storage of linoleic acid (182 n6) in the liver. Thus, our studies indicate long term feeding of palm oil does not have any adverse effect in rats.

Effects of different saturated fats on various aspects of lipid metabolism in rats hypersensitive to dietary cholesterol

Effects of palm oil (PO) and coconut oil (CO) mixed with corn on lipid metabolism were compared with those of lard in rats hypersensitive to dietary cholesterol. Rats were fed one of four cholesterol-enriched diets containing different dietary fats, equiweight mixtures of either soybean oil-lard or soybean oil-lard-PO-CO, at about 26 or 42 energy % levels. The concentration of serum cholesterol did not increase when polyunsaturated fat was replaced with saturated fat of plant origin, and it tended to be lower with an increase in the dietary fat level. In addition, the PO-CO mixture reduced the liver cholesterol concentration at both energy levels compared with lard. There was no fat-dependent difference in fecal steroid excretion and the fatty acid composition of serum and liver phospholipids. Zymosan injection caused a reduction of serum triglyceride in the PO-CO group and a reduction of liver cholesterol in the lard group. The elevation of serum cholesterol and the reduction of liver triglyceride upon injection of zymosan were independent of the source of dietary saturated fats. Thus, PO and CO in combination may specifically modulate lipid metabolism under the immunologically stimulated as well as non-stimulated situations.

Effect of palm oil on lipid and lipoprotein metabolism and eicosanoid production in rats

Palm oil (PA), which is very rich in palmitic acid, influenced the serum cholesterol concentration and tissue eicosanoid profile of rats characteristically. It increased the serum cholesterol concentration compared with safflower oil (SA), but the degree of the elevation was moderate compared with that of olive oil (OL). The proportion of arachidonic acid in tissue lipids was by no means lower on a PA diet than on an SA diet. The ratio of prostacyclin produced by the aorta to thromboxane A2 in plasma was not simply predicted by the dietary level of saturated fatty acid. PA tended to facilitate the utilization of arachidonate for prostacyclin in vitro in peritoneal macrophages compared with SA. Fatty acid profiles of PA rather than the glyceride structure or the tocotrienol appeared to be the major determinant for the specific features of lipid metabolism observed in rats fed PA.

Causes of high blood cholesterol.

Causes of high blood cholesterol.

Effect of Palm Oil on the Polymorphic Stability of Hydrogenated Canola Oil: A Kinetic Approach

Effect of Palm Oil on the Polymorphic Stability of Hydrogenated Canola Oil: A Kinetic Approach

Comparative studies on the effects of feeding different types of oils at two levels on the performance and carcass characteristics of growing pigs in the tropics

SUMMARYTwo feeding trials involving 105 pigs weighing approximately 14·5 kg were carried out to investigate the effects of palm oil, groundnut oil, locally produced lard, and beef tallow at 2·5% and 5% of the diet, on performance characteristics and carcass quality. The pigs were of the Yorkshire and Yorkshire × Landrace crosses, and of both sexes. The 23% protein basal diet had no oil added, and the other eight diets were made from the basal diet by the weight-for-weight substitution of the maize with the 2·5% or 5% levels of the four oil types. The results of the two trials were combined and considered as a 2 × 4 factorial experiment (2 levels and 4 types of oil) with the basal diet serving as the control. Only the pigs in the second trial were slaughtered and their carcasses graded at the average live weight of 57±1 kg. Correlation and regression analyses were made on some performance and carcass characteristics, on the average daily digestible energy intake. Results showed no significant treatment differences in the average daily gains, average daily feed intake, and average daily digestible energy intake, but there were highly significant treatment differences in feed consumed/kg of gain and average digestible energy (DE) consumed/kg of gain (P<0·01). None of the carcass quality parameters showed any significant treatment differences. Both the correlation and the regression coefficients for the average daily gain on DE intake were highly significant for all the oil types and levels, but the relationships were low and non-significant when the feed/gain ratio, average backfat thickness and the average percentage of lean cuts were regressed on the daily DE intake.