Asia Pacific Journal of Clinical Nutrition

Volume 11, supplement 5, 2002
Palm oil in human nutrition: Recent advances

Contents	Abstract	Paper
Dietary fat and heart health: in search of the ideal fat KC HAYES Asia Pac J clin Nutr. 2002;11(S5):S394-S400.	html	pdf
Cholesterolaemic effect of palmitic acid in relation to other dietary fatty acids MARGARET A FRENCH, KALYANA SUNDRAM, M THOMAS CLANDININ Asia Pac J clin Nutr. 2002;11(S5):S3401-S407.	html	pdf
Effect of dietary cholesterol, trans and saturated fatty acids on serum lipoproteins in non-human primates CHE ANISHAS CHE IDRIS, KALYANA SUNDRAM Asia Pac J clin Nutr. 2002;11(S5):S408-S415.	html	pdf
Effect of palm olein oil in a moderate-fat diet on low-density lipoprotein composition in non-humanprimates PAUL J VAN JAARSVELD, AJ SPINNLER BENADÉ Asia Pac J clin Nutr. 2002;11(S5):S416-S423.	html	pdf
Effect of palm olein oil in a moderate-fat diet on plasma lipoprotein profile and aortic atherosclerosis in non-human primates PAUL J VAN JAARSVELD, CORNELIUS M SMUTS, AJ SPINNLER BENADÉ Asia Pac J clin Nutr. 2002;11(S5):S424-S432.	html	pdf
Red palm oil in experimental atherosclerosis DAVID KRITCHEVSKY, SHIRLEY A TEPPER, SUSANNE K CZARNECKI, KALYANA SUNDRAM Asia Pac J clin Nutr. 2002;11(S5):S433-S437.	html	pdf
Bioavailability and vitamin a value of carotenes from red palm oil assessed by an extrinsic isotope reference method CHA-SOOK YOU, ROBERT S PARKER, JOY E SWANSON Asia Pac J clin Nutr. 2002;11(S5):S438-S442.	html	pdf
Vitamin E in cardiovascular disease: has the die been cast? KHALID YUSOFF Asia Pac J clin Nutr. 2002;11(S5):S443-S447.	html	pdf
Effect of vitamin E on plasma malondialdehyde, antioxidant enzyme levels and the rates of wound closures during wound healing in normal and diabetic rats MAZLAN MUSALMAH, ABD HALIM FAIRUZ, MAT TOP GAPOR, WAN ZURINAH WAN NGAH Asia Pac J clin Nutr. 2002;11(S5):S448-S451.	html	pdf
Role of GTP-binding proteins in reversing the antiproliferative effects of tocotrienols in preneoplastic mammary epithelial cells PAUL W SYLVESTER, ANIL NACHNANI, SUMIT SHAH, KAREN P BRISKI Asia Pac J clin Nutr. 2002;11(S5):S452-S459.	html	pdf
17-Estradiol epoxidation as the molecular basis for breast cancer initiation and prevention FU-LI YU Asia Pac J clin Nutr. 2002;11(S5):S460-S466.	html	pdf
Polyphenol-enriched extract of oil palm fronds (Elaeis guineensis) promotes vascular relaxation via endothelium-dependent mechanisms Asia Pac J clin Nutr. 2002;11(S5):S467-S472.	html	pdf
Potential of palm oil utilisation in aquaculture feeds WING-KEONG NG Asia Pac J clin Nutr. 2002;11(S5):S473-S476.	html	pdf

top
Dietary fat and heart health: in search of the ideal fat S394
KC HAYES
see pdf
top

Cholesterolaemic effect of palmitic acid in relation to other dietary fatty
acids S401
MARGARET A FRENCH, KALYANA SUNDRAM, M THOMAS CLANDININ
The effect of dietary intake of high palmitic acid levels in combination with other fatty acids in normal subjects was assessed. Palmitic acid (10% of energy) was fed in conjunction with decreasing levels of linoleic acid to determine if a threshold level of linoleic acid prevented palmitic acid from being hypercholesterolaemic. Healthy subjects received each of the diet treatments for 21 days, followed by washout periods of 7 days. In a second experiment, the effect of exchanging palmitic acid for trans fatty acids on plasma lipoprotein cholesterol levels and on rates for endogenous synthesis of cholesterol in normal subjects was investigated. Diet treatment lasted for 30 days. On day 30 of each diet treatment, a priming dose of deuterium was consumed, followed by a subsequent blood sample at 24 h. Blood cholesterol fractions were isolated and analysed by isotope ratio mass spectrometry to measure cholesterol fractional synthetic rates. In the first experiment, total plasma cholesterol levels increased as the percentage of linoleic acid decreased. The data indicated that high levels of palmitic acid were not hypercholesterolaemic if intake of linoleic acid was greater than 4.5% of energy. When the diet contained trans fatty acids plasma total and low-density lipoprotein-cholesterol increased and cholesterol synthesis increased with a decrease in high-density lipoprotein-cholesterol.
.
top

Effect of dietary cholesterol, trans and saturated fatty acids on serum lipoproteins in non-human primates S408
CHE ANISHAS CHE IDRIS, KALYANA SUNDRAM
Nine cynomolgus monkeys were rotated randomly through four dietary treatments with each treatment lasting 6 weeks. A wash-out period of 4 weeks was maintained between each dietary rotation. The animals were fed diets containing 32% energy fat derived from palm olein (POL), lauric-myristic-rich oil blend (LM), American Heart Association (AHA) rich oil blend and hydrogenated soybean oil blend (trans). Diets were fed with (phase 1) or without (phase 2) the addition of dietary cholesterol (0.1%). In phase 1, when animals were fed without dietary cholesterol, plasma total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) was significantly raised and high-density lipoprotein cholesterol (HDL-C) was significantly depressed by the trans diets relative to all other dietary treatments. The resulting LDL-C/HDL-C ratio was also significantly increased. The LM diet increased TC significantly relative to the AHA diet while LDL-C was significantly increased compared to both POL and AHA. Apolipoprotein (apo) B was not affected significantly by these dietary treatments. Apo A1 was significantly increased by POL relative to all other dietary treatments. The trans diet reduced apo A1 and the resulting apo B/A1 ratio was increased significantly by trans relative to all other dietary treatments. Addition of 0.1% dietary cholesterol to these diets almost doubled the plasma TC and LDL-C in all dietary treatments. However, HDL-C was only marginally higher with the addition of dietary cholesterol. The LM + C (cholesterol added) diet resulted in the highest TC and LDL-C that was significant compared to all other dietary treatments. Trans + C increased TC compared to POL + C and AHA + C diets while increases in the LDL-C did not attain significance. The addition of dietary cholesterol did not affect HDL-C between treatments whereas plasma triglycerides were significantly increased by the trans + C diet relative to all other treatments. Both the trans + C and LM + C diets increased apo B and decreased apo A1 relative to the POL + C and AHA + C diets. The resulting apo B/A1 ratio was similarly altered. These results affirm that the lauric + myristic acid combination, along with trans fatty acids, increased lipoprotein-associated coronary heart disease risk factors compared to either POL or AHA.

top

Effect of palm olein oil in a moderate-fat diet on low-density lipoprotein composition in non-humanprimates S416
PAUL J VAN JAARSVELD, AJ SPINNLER BENADÉ
Plasma low-density lipoprotein cholesterol (LDL-C) concentrations in vervet monkeys (Cercopithecus aethiops) can be modulated by the type and amount of fat in the diet. There is, however, a paucity of information on the effect of different types and quantity of dietary fat on the plasma LDL composition in vervets. The objective of this study was to determine the effect of different sources of dietary fat on the
concentrations and composition of circulating plasma LDL in vervets consuming moderate-fat diets containing either animal fat, sunflower oil or palm olein. Fifty adult male vervets, never exposed to a Western-type atherogenic diet, were randomly assigned to two groups. For 6 weeks 30 vervets were fed a moderate-fat (28%E) moderate-cholesterol (26 mg cholesterol/1000 kJ) diet (MFD) with a polyunsaturated to saturated fatty acid ratio (P/S) of 0.4; 20 vervets were fed a high-fat (34%E) high-cholesterol (98 mg cholesterol/1000 kJ) diet (HFD) with a P/S ratio of 0.6. Fasting blood samples were collected from all 50 vervets for plasma lipid measurements. The 30 vervets receiving the MFD were stratified into three comparable experimental groups of 10 each according to their LDL-C and high-density lipoprotein cholesterol (HDL-C) concentrations and bodyweight. One group continued with the MFD, in which 11%E was derived from lard (MFD-AF); in the other two groups the lard was substituted isocalorically with either sunflower oil (SO) (MFD-SO) or palm olein oil (PO) (MFD-PO). The three groups were fed the respective experimental diets for 24 months and LDL component concentrations and composition were assessed at 6monthly intervals. In the long-term study the MFD-AF, MFD-SO and MFD-PO groups showed no significant time-specific group differences at 6, 12, 18 or 24 months with regard to the LDL component concentrations, composition, as well as the LDL molecular weight. As expected, after 6 weeks of dietary exposure the HFD group had significantly higher plasma and lipoprotein total cholesterol, LDL component and apolipoprotein AI concentrations, as well as a higher LDL-C : HDL-C ratio compared to the MFD group (P 0.0005). LDL particle size was not significantly different between the HFD and MFD groups, but the HFD group had significantly fewer triacylglycerol and significantly more unesterified cholesterol molecules per LDL particle compared to the MFD group (P 0.0018). PO in a MFD is no different from AF or SO in its effect on LDL component concentrations, composition or particle size. The increased LDL-C concentration seen with the HFD could be accounted for by a more than two-fold increase in the number of circulating LDL particles and not as a result of enrichment of particles with cholesterol.
.
top

Effect of palm olein oil in a moderate-fat diet on plasma lipoprotein profile and aortic atherosclerosis in non-human primates S424
PAUL J VAN JAARSVELD, CORNELIUS M SMUTS, AJ SPINNLER BENADÉ
Several studies have reported on the effect of palm olein oil (PO; palmitic acid content 38%) incorporation into the diet on blood cholesterol concentration. Information on the effect of PO on atherosclerosis is, however, lacking. In vervet monkeys (Cercopithecus aethiops), low-density lipoprotein cholesterol (LDL-C) concentrations can be modulated by the type and amount of fat in the diet. The vervet is a proven model for both the type and composition of human atherosclerotic lesions. The aim of this study was to determine the effect of PO in a moderate-fat moderate-cholesterol diet (MFD) on plasma lipoproteins and the progression of atherosclerosis in a non-human primate model after 25.5 months of dietary exposure. Thirty adult male vervets, never exposed to a Western-type atherogenic diet, were stabilised on a MFD (28%E fat; 26 mg cholesterol/1000 kJ) with a polyunsaturated to saturated fatty acid (P/S) ratio of 0.4 for six weeks. Baseline LDL-C, high-density lipoprotein (HDL)-C and bodyweight were used to stratify the vervets into three comparable groups of 10 each. One group continued with the MFD in which 11.0%E was derived from lard (AF). In the other two groups, the AF was substituted isocalorically with either sunflower oil (SO) or PO. Plasma lipids were measured at 6-monthly intervals and atherosclerosis was assessed in the aorta and in five peripheral arteries after 25.5 months of dietary exposure. The frequency of atherosclerosis in peripheral arteries and aortas was low. PO, relative to SO and AF, significantly reduced the risk for developing early lesions in peripheral arteries (P = 0.0277 and P = 0.0038, respectively) and, relative to AF, in aortas (P = 0.0335). The cholesterolaemic effect of MFD-PO was not significantly different from MFD-SO and MFD-AF. However, at 24 months the plasma total cholesterol concentration with MFD-AF was significantly higher than with MFD-SO (P = 0.0256). It is confirmed that a MFD with PO is no different from AF or SO in its cholesterolaemic effect. The anti-atherogenic efficacy of a MFD with PO, relative to SO and AF, was demonstrated in a non-human primate model of atherogenesis.
.
top

Red palm oil in experimental atherosclerosis S433
DAVID KRITCHEVSKY, SHIRLEY A TEPPER, SUSANNE K CZARNECKI, KALYANA SUNDRAM
see pdf
top

Bioavailability and vitamin a value of carotenes from red palm oil assessed by an extrinsic isotope reference method S438
CHA - SOOK YOU, ROBERT S PARKER, JOY E SWANSON
see pdf
top
Vitamin E in cardiovascular disease: has the die been cast? S443
KHALID YUSOFF
Cardiovascular disease, in particular coronary artery disease (CAD), remains the most important cause of morbidity and mortality in developed countries and, in the near future, more so in the developing world. Atherosclerotic plaque formation is the underlying basis for CAD. Growth of the plaque leads to coronary stenosis, causing a progressive decrease in blood flow that results in angina pectoris. Acute myocardial infarction and unstable angina were recently recognised as related to plaque rupture, not progressive coronary stenosis. Acute thrombus formation causes an abrupt coronary occlusion. The characteristics of the fibrin cap, contents of the plaque, rheological factors and active inflammation within the plaque contribute to plaque rupture. Oxidative processes are important in plaque formation. Oxidized low density lipoproteins (LDL) but not unoxidized LDL is engulfed by resident intimal macrophages, transforming them into foam cells which develop into fatty streaks, the precursors of the atherosclerotic plaque. Inflammation is important both in plaque formation and rupture. Animal studies have shown that antioxidants reduce plaque formation and lead to plaque stabilisation. In humans, high intakes of antioxidants are associated with lower incidence of CAD, despite high serum cholesterol levels. This observation suggests a role for inflammation in CAD and that reducing inflammation using
antioxidants may ameliorate these processes. Men and women with high intakes of vitamin E were found to have less CAD. Vitamin E supplementation was associated with a significant reduction in myocardial infarction and cardiovascular events in the incidence of recurrent myocardial infarction. In the hierarchy of evidence in evidence-based medicine, data from large placebo-controlled clinical trials is considered necessary. Results from various mega-trials have not shown benefits (nor adverse effects) conferred by vitamin E supplementation, suggesting that vitamin E has no role in the treatment of CAD. These results do not seem to confirm, at the clinical level, the effect of antioxidants against active inflammation during plaque rupture. However, a closer examination of these studies showed a number of limitations, rendering them inconclusive in addressing the role of vitamin E in CAD prevention and treatment. Further studies that specifically address the issue of vitamin E in the pathogenesis of atherosclerosis and in the treatment of CAD need be performed. These studies should use the more potent antioxidant property of -tocotrienol vitamin E.
.
top

Effect of vitamin E on plasma malondialdehyde, antioxidant enzyme levels and the rates of wound closures during wound healing in normal and diabetic rats S448
MAZLAN MUSALMAH, ABD HALIM FAIRUZ, MAT TOP GAPOR, WAN ZURINAH WAN NGAH
Vitamin E is composed of various subfamilies that include tocopherols and tocotrienols. These compounds have antioxidant properties but differ in structure, dietary source and potency. In this study we evaluated the efficacy of -tocopherol as an antioxidant and its role in wound closure in normal and streptozotocin-induced diabetic rats. The healing of 6 cm linear incisions created on the back of each male SpragueDawley rat (250300 g) was monitored by measuring the length of the wounds daily. The rats were divided into two categories; normal and streptozotocin-induced diabetic rats. For each category, the animals were further divided into two groups; those untreated and those receiving 200 mg/kg bodyweight -tocopherols daily by oral gavage. All rats were fed standard food and water ad libitum. Blood samples were taken at 0, 5 and 10 days after the wounds were created for the determination of malondialdehyde levels and red cell superoxide dismutase, catalase and glutathione peroxidase activities. The results showed that -tocopherol reduced plasma malondialdehyde levels, increased glutathione peroxidase activity and accelerated the rate of wound closure in treated rats.

top

Role of GTP-binding proteins in reversing the antiproliferative effects of tocotrienols in preneoplastic mammary epithelial cells S452
PAUL W SYLVESTER, ANIL NACHNANI, SUMIT SHAH, KAREN P BRISKI
see pdf

top

17-Estradiol epoxidation as the molecular basis for breast cancer initiation and prevention S460
FU-LI YU
see pdf

top

Polyphenol-enriched extract of oil palm fronds (Elaeis guineensis) promotes vascular relaxation via endothelium-dependent mechanisms S467
Plant-based polyphenolic compounds have been reported to possess cardiovascular health benefits. Several dietary sources, including herbs and spices, fruits and vegetables, and tea and wine, contain an array of biologically active compounds that have been shown to be effective in retarding oxidation of low-density lipoproteins (LDL) and promoting vascular relaxation. In the present study four different plant sources, both edible and non-edible, were evaluated for potential activity. Organic extracts enriched in polyphenols were prepared from palm fronds (Elaesis guineensis); lemongrass (Cymbopogon citrates); papaya shoots (Carica papaya) and green chilli (Capsicum frutescenes) and tested for their ability to prevent in vitro oxidation of LDL, and for potential vascular relaxation actions. Rings of rat thoracic aorta and isolated perfused mesenteric vascular beds were mounted in organ baths, contracted using a half-maximal dose of noradrenaline and exposed to cumulative additions of test extracts. Palm frond extract resulted in considerable relaxation (>75%) in both preparations and was found to be endothelium-dependent as removal of endothelium or inhibition of endogenous nitric oxide (NO) led to a total loss in relaxant activity. Lemongrass extract caused a greater relaxation action in the mesenteric preparation compared to aortic rings, and appears to be mediated via NO-independent and non-prostanoid mechanisms. Of the extracts tested, palm fronds also demonstrated the highest antioxidant capacity, as determined by the ferric reducing activity/potential assay, and resulted in a significant delay (P < 0.05) in the oxidation of LDL. Collectively, these preliminary findings lend further support to the potential cardiovascular actions of plant polyphenols and also identify oil palm fronds as containing constituents that promote vascular relaxation via endothelium-dependent mechanisms.
.
top

Potential of palm oil utilisation in aquaculture feeds S473
WING-KEONG NG
One key ingredient used in the formulation of aquafeed is fish oil, which is produced from small marine pelagic fish and represents a finite fishery resource. At the present time, global fish oil production has reached a plateau and is not expected to increase beyond current levels. Recent estimates suggest that fish oils may be unable to meet demands from the rapidly growing aquaculture industry by as early as 2005. Therefore, there is currently great interest within the aquafeed industry in evaluating alternatives to fish oils. The ever-expanding oil palm cultivation in Malaysia and other tropical countries offers the possibility of an increased and constant availability of palm oil products for aquafeed formulation. Research into the use of palm oil in aquafeed begun around the mid-1990s and this review examines some of the findings from these studies. The use of palm oil in fish diets has generally shown encouraging results. Improved growth, feed efficiency, protein utilisation, reproductive performance and higher concentrations of -tocopherol in fish fillets have been reported. Recent evidence for the ability of palm oil to substitute for fish oil in catfish diets is reviewed. The potential of palm oil use in aquafeed and future experimental directions are suggested. The aquaculture feed industry offers a great avenue to increase and diversify the use of palm oil-based products.

top

 

Last Updated: September 2004