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Cholesterol Vehicle in experimental Atherosclerosis. 22. Refined, Bleached, Deodorized (RBD) Palm oil, Randomized palm oil and red palm oil
Abstract
The atherogenic effects of refined, bleached and deodorized (RBD) palm oil were compared with those of randomized RBD palm oil and red palm oil. RBD palm oil contains 41.2% palmitic acid, 2.6% at the SN2 position. In randomized palm oil, 13.6% of the palmitic acid is in the SN2 position. Randomized palm oil is significantly more atherogenic for rabbits than is RBD palm oil, supporting our earlier findings that the increasing amounts of palmitic acid in the SN2 position of a fat lead to an increased atherogenic effect. Red palm oil is the oil initially obtained from the palm fruit which contains carotenes and Vitamin E that are removed during refining. Red palm oil was significantly less atherogenic than RBD palm oil supporting the hypothesis that carotenoids and Vitamin E may protect against atherosclerosis. The oils tested had similar effects on serum and liver lipids.
... Red palm oil was also well accepted by the volunteers as a new edible oil. 68 Kritchevsky et al. 69 conducted 2 studies in an atherogenic rabbit model using 0.1% and 0.2% cholesterol intake for 90 and 60 days, respectively. 69 The atherogenic potential of different palm oils with different percentages of palmitic acid at the sn-2 position was tested. ...
... 68 Kritchevsky et al. 69 conducted 2 studies in an atherogenic rabbit model using 0.1% and 0.2% cholesterol intake for 90 and 60 days, respectively. 69 The atherogenic potential of different palm oils with different percentages of palmitic acid at the sn-2 position was tested. The test fats (14% of total energy) compared were refined, bleached, and deodorized palm oil, red palm oil, and interesterified randomized palm oil. ...
... Higher amounts of antioxidants (carotenoids and vitamin E) in red palm oil than in refined, bleached, and deodorized palm oil conferred better antiatherogenic potency. 69,70 The effects of different vegetable oils (red palm olein, palm olein, corn oil, and coconut oil) fed for 4 and 8 weeks were studied by examining lipid profiles in a Sprague Dawley rat model. Groups supplemented with red palm oil, palm olein, and coconut oil showed decreased LDL cholesterol compared with the control group fed standard rat chow. ...
The fruit of the oil palm tree (Elaeis guineesis) is the source of antioxidant-rich red palm oil. Red palm oil is a rich source of phytonutrients such as tocotrienols, tocopherols, carotenoids, phytosterols, squalene, and coenzyme Q10, all of which exhibit nutritional properties and oxidative stability. Mutagenic, nutritional, and toxicological studies have shown that red palm oil contains highly bioavailable b-carotene and vitamin A and is reasonably stable to heat without any adverse effects. This review provides a comprehensive overview of the nutritional properties of red palm oil. The possible antiatherogenic, antihemorrhagic, antihypertensive, anticancer, and anti-infective properties of red palm oil are examined. Moreover, evidence supporting the potential effectiveness of red palm oil to overcome vitamin A deficiency in children and pregnant women, to improve ocular complications of vitamin A deficiency, to protect against ischemic heart disease, to promote normal reproduction in males and females, to aid in the management of diabetes, to ameliorate the adverse effects of chemotherapy, and to aid in managing hypobaric conditions is presented.
... Human clinical trials [11,12,32] and animal studies [21,22] have been carried out to determine the effects of stereospecific fats on their lipid profiles. The position of a SFA in TAG exerts two effects on plasma TC. ...
... Consistent with circulating LDL-C and high density lipoprotein cholesterol (HDL-C) concentrations, there were also no differences in the clearance of LDL-C and HDL-C. [21] compared the atherogenic effects of refined, bleached, and deodorized (RBD) palm oil with those of randomized RBD palm oil. The RBD palm oil contained 41.2% palmitic acid, of which 2.6% was at the sn-2 position. ...
... 6-monthly intervals and atherosclerosis was assessed in the aorta and arteries after 25.5 months of dietary exposure. POo, relative to SFO and lard, significantly reduced the risk of developing early lesions in the peripheral arteries. Therefore, in this primate model of atherogenesis, the isocaloric substitution of lard with POo seems beneficial.Kritchevsky et al. (2000a) ...
Palm oil is the major oil produced, with annual world production in excess of 50 million tonnes. About 85% of global palm oil produced is used in food applications. Over the past three decades, research on nutritional benefits of palm oil have demonstrated the nutritional adequacy of palm oil and its products, and have resulted in transitions in the understanding these attributes. Numerous studies have demonstrated that palm oil was similar to unsaturated oils with regards to effects on blood lipids. Palm oil provides a healthy alternative to trans-fatty acid containing hydrogenated fats that have been demonstrated to have serious deleterious effects on health. The similar effects of palm oil on blood lipids, comparable to other vegetable oils could very well be due to the structure of the major triglycerides in palm oil, which has an unsaturated fatty acid in the sn-2 position of the glycerol backbone. In addition, palm oil is well endowed with a bouquet of phytonutrients beneficial to health, such as tocotrienols, carotenoids and phytosterols. This review will provide an overview of studies that have established palm oil as a balanced and nutritious oil.
... Like humans, high fat diets can induce elevated LDL-C [3,4] and atherosclerosis in certain rodent models such as rats, mice, hamsters, rabbits and guinea pigs. Red palm oil was shown to be significantly less atherogenic than refined, bleached and deodorized (RBD) palm oil in rabbits [5]. They also had similar effects on serum and liver lipids. ...
... This high level of PUFA dietary intake can improve the blood lipid profile status [7]. In addition, with its high content of tocopherols, soya oil is known to exhibit various antioxidant actions against lipid peroxidation [5]. ...
... 9 In addition, with its high content of tocopherols, soya oil is known to exhibit various antioxidant actions against lipid peroxidation. 26 In our study, diabetic rats fed on RBD-PO had high levels of HDL-C and low AI. Our study showed that RBD-PO has a better lipid profile and AI than olive oil and soya oil in diabetic rats. ...
... Our study showed that RBD-PO has a better lipid profile and AI than olive oil and soya oil in diabetic rats. This is in line with various studies in animals 26 and humans [27][28][29] that showed that palm oil has the effect of decreasing TC and "bad" LDL-C and increasing the level of "good" HDL-C. However, in their study, soya oil and peanut oil had no effect on the blood cholesterol. ...
BACKGROUND
Diabetic state potentiates atherosclerosis and the type of edible oil consumed by the individual may affect this further. This study aimed to determine if the common edible oils in Nigeria have any effects on the lipid profiles and arteries of alloxan-induced diabetic male Wistar rats.
METHODS
Thirty male Wistar rats were randomly divided into five groups of normal control, diabetic control, animals on diet enriched with refined, bleached deodorized palm oil (RBD-PO), animals on diet enriched with soya oil, and animals on diet enriched with olive oil. At the end of 8 weeks, the lipid profiles of the animals were determined before sacrificing them. Their aortas were subsequently harvested for histological examination.
RESULTS
The olive oil fed group had the highest level of total cholesterol (TC), non-high-density lipoprotein cholesterol (non-HDL-C), lowest HDL-C, and highest artherogenic index (AI). Diabetic animals fed on RBD-PO had a lower non-HDL-C, higher HDL-C, and lower AI than diabetic animals fed on olive oil or soya oil. However, the diabetic animals fed on RBD-PO had the highest triglyceride level. When the aortas were examined histologically, there were no atherosclerotic lesions in all the control and experimental groups except those fed on 10% soya oil enriched diet that had type II atherosclerotic lesions according to American Heart Association (AHA).
CONCLUSION
The result of our study showed that RBD-PO appears to offer a better lipid profile in the diabetic animals compared with olive oil and soya oil. Soya oil appears to cause the development of atherosclerosis in diabetic state.
... A peculiarity reported in rabbit studies, is that interesterified fats are associated with the development of artherogenesis, even without abnormalities in lipid and lipoprotein metabolism. When native cottonseed oil (2% sn-2 C16:0) was compared to the randomized version (8 to14%, sn-2 C16:0), atherogenicity increased in rabbits fed randomized cottonseed oil, without change in TC and TAG concentrations [98,99]. Kritchevsky et al. [100] hypothesize that enhanced absorption, combined with prolonged postprandial effects of sn-2 C16:0 brings about increased exposure of the aorta to C16:0 and subsequent increased fat deposition. ...
... A peculiarity reported in rabbit studies, is that interesterified fats are associated with the development of artherogenesis, even without abnormalities in lipid and lipoprotein metabolism. When native cottonseed oil (2% sn-2 C16:0) was compared to the randomized version (8 to14%, sn-2 C16:0), atherogenicity increased in rabbits fed randomized cottonseed oil, without change in TC and TAG concentrations[98,99]. Kritchevsky et al.[100]hypothesize that enhanced absorption, combined with prolonged postprandial effects of sn-2 C16:0 brings about increased exposure of the aorta to C16:0 and subsequent increased fat deposition. ...
Most studies on lipid lowering diets have focused on the total content of saturated, polyunsaturated and monounsaturated fatty acids. However, the distribution of these fatty acids on the triacylglycerol (TAG) molecule and the molecular TAG species generated by this stereospecificity are characteristic for various native dietary TAGs. Fat randomization or interesterification is a process involving the positional redistribution of fatty acids, which leads to the generation of new TAG molecular species. A comparison between native and randomized TAGs is the subject of this review with regards to the role of stereospecificity of fatty acids in metabolic processing and effects on fasting lipids and postprandial lipemia. The positioning of unsaturated versus saturated fatty acids in the sn-2 position of TAGs indicate differences in early metabolic processing and postprandial clearance, which may explain modulatory effects on atherogenecity and thrombogenecity. Both human and animal studies are discussed with implications for human health.
... PO is known to exert precious nutritional values due to its high content of phytosterols, tocotrienols and tocophenols, which exhibited antioxidant, anticancer and anti-inflammatory properties 40,45,46 . RPO is rich in carotenoids and vitamin E and its preclinical studies demonstrated health beneficial effects in terms of reduction in LDL level and TC to high-density lipoprotein ratio TC:HDL 47 , as well as lowered atherogenic effect 48 if compared to that of PO. In addition, RPO supplementation exhibited heart protection against the consequences of ischemia/reperfusion injury 49 . ...
Oxidative stress occurs due to the imbalance amount of the free radicals and antioxidants in human body which often associated with numerous chronic diseases. The antioxidant properties of red palm-pressed mesocarp olein (PPMO) have not been widely studied. Therefore, antioxidant properties of PPMO relative to commercially available edible oils, namely red palm olein (RPO), palm olein (PO), extra virgin olive oil (OO) and extra virgin coconut oil (CNO) were studied. PPMO exhibited significant higher phytonutrients which more than 2-fold compared to the edible oils. Overall, antioxidant screening indicated that PPMO has significantly higher antioxidant activities than RPO, PO and CNO in term of DPPH, H2O2, NO scavenging and FIC; and significantly higher H2O2 and FIC than OO. The outcomes of this study reveal that PPMO is as good as commercially available edible oil, also a good source for food applications and dietary nutritional supplements. More importantly, the utilization of PPMO could mitigate oil palm waste problem and results in positive environmental impact.
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... Natural tocopherol, especially a-tocopherol, is a superior radical chain-breaking antioxidant compared with synthetic ones (Teh and Lau, 2020). These natural antioxidant vitamins have been suggested to provide protection against several diseases involving free radical reactions (Kritchevsky et al., 2000;Absalome et al., 2020). Kumar et al. (2020) have reported that alpha-and gamma-tocopherols intakes by pregnant mother gave better lung functions in their offsprings during mid-childhood. ...
The objective of this research work was to produce acceptable quality functional foods, namely, extruded snacks, digestive biscuits and pan bread, on a pilot scale, using vitamin E and β-carotene-rich red palm olein (RPOL) and red palm shortening (RPS). These products were evaluated for their chemical composition and sensory quality along with the antioxidants and vitamin contents during the six months of storage at room temperature (22±1°C). Extruded snacks and digestive biscuits prepared with RPOL and RPS were found to be good sources of these antioxidant vitamins. The average β-carotene content of the control and test snacks at the end of six months of storage ranged from 26.8 to 56.1 mg/kg fat, and from 430.9 to 468.9 mg/kg fat, respectively. The total vitamin E content in control and test snacks made in Plant No. 1 decreased after six months of storage from 786.1 to 704.4 mg/kg fat, and from 765.1 to 695.4 mg/kg fat, respectively. As expected, the total tocotrienol content was four to five times higher than the total tocopherols in control biscuits. The RPOL containing 600-750 ppm of carotenes (mainly α- and β-carotenes), 710-774 ppm of vitamin E, was found to be suitable for industrial application in producing acceptable quality pan bread, digestive biscuits and snacks. These functional foods contained significant amounts of β-carotene and total vitamin E, indicating the possibility of producing such foods rich in these two of the important antioxidant vitamins coming from a natural source. The research findings strongly indicate that good-quality pan bread, extruded snacks and digestive biscuits can successfully be produced to offer healthier eating choices to the consumers of this region, thereby promoting better health and productivity among the population.
... Feeding studies conducted in both rabbits (Kritchevsky et al. 2000a(Kritchevsky et al. , 2000b and mice (Afonso et al. 2016) have reported more severe atherosclerosis when animals were given diets with IE palm oil, containing more sn-2 palmitic acid, compared to native palm oil. However, due to the practical and cost implications of conducting such studies in humans, research to date has instead focused on lipid markers (e.g. ...
Interesterification rearranges the position of fatty acids within triacylglycerols, the main component of dietary fat, altering physical properties such as the melting point and providing suitable functionality for use in a range of food applications. Interesterified (IE) fats are one of a number of alternatives which have been adopted to reformulate products to remove fats containing trans fatty acids generated during partial hydrogenation, which are known to be detrimental to cardiovascular health. The use of IE fats can also reduce the saturated fatty acid (SFA) content of the final product (e.g. up to 20% in spreads), while maintaining suitable physical properties (e.g. melt profile). A novel analysis was presented during the roundtable which combined data from the UK National Diet and Nutrition Survey (2012/2013–2013/2014) with expert industry knowledge of the IE fats typically used in food products, to provide the first known estimate of population intakes of IE fats among UK children and adults. IE fats were found to contribute approximately 1% of daily energy across all ages. The major contributors to overall IE fat intakes were fat spreads (~54%) and bakery products (~22%), as well as biscuits (~8%), dairy cream alternatives (~6%) and confectionery (~6%). Increasing use of IE fats could contribute towards reducing total SFA intakes in the population, but would depend on which food products were reformulated and their frequency of consumption among sub‐groups of the population. Studies comparing the effect of IE and non‐IE fats on markers of lipid metabolism have not shown any consistent differences, either in the fasted or in the postprandial state, suggesting a neutral effect of IE fats on cardiovascular disease risk. However, these studies did not use the type of IE fats present in the food supply. This issue has been addressed in two studies by King's College London, which measured the postprandial response to a commercially relevant palm stearin/palm kernel (80:20) IE ‘hard stock’, although again no consistent effects of the IE fat on markers of lipid metabolism were found. Another study is currently investigating the same IE hard stock, consumed as a fat spread (blended with vegetable oil), and will measure a broader range of postprandial cardiometabolic risk factors. However, further long‐term trials using commercially relevant IE fats are needed. Subsequent to the roundtable, a consumer survey of UK adults (n = 2062; aged 18+ years) suggested that there is confusion about the health effects of dietary fats/fatty acids, including trans fats and partially hydrogenated fats. This may indicate that providing evidence‐based information to the public on dietary fats and health could be helpful, including the reformulation efforts of food producers and retailers to improve the fatty acid profile of some commonly consumed foods.
... Other studies showed hypocholesterolemic effect of intake of other components of palm oil, the polyunsaturated fatty acids such as linoleic and linolenic acids (Purushothama et al., 1994). No increase in total cholesterol was observed in rabbits fed 0.1% cholesterol diet (Kritchevsky et al., 2000) while increases on total cholesterol and high density lipoprotein were reported in rabbits (Kamsiah and Nafeeza, 1997). Palm oil, as part of a low-fat diet (<30% energy) was shown to be effective in maintaining desirable plasma cholesterol and lipoprotein cholesterol levels (Sundram, 1990). ...
The effect of palm oil-supplemented diet on plasma lipid profile of Wistar albino rats was investigated by feeding the experimental animals with 20% palm oil-supplemented diets for 12 weeks. The plasma levels of Total cholesterol (TC), Triglycerides (TG), Low-density lipoprotein (LDL), and High-density lipoprotein (HDL) were determined at 4-, 8-, and 12-week intervals. The results showed significant (p<0.05) increases in TC (from 2.44+0.44 to 3.41+0.41), TG (from 1.72+0.51 to 2.46+0.19), and LDL (from 0.87+0.21 to 1.33+0.30) at the 4th week. However, the level of HDL (0.97+0.06) did not show significant difference from control value (0.87+0.21). The TC/HDL ratio increased non-significantly from 3.12+0.29 to 3.55+0.29. At the 12th week, significant decreases (p<0.05) were observed for TC (1.50+0.08), LDL (0.28+0.06), while no significant difference was noted for TG and HDL. The TC/HDL ratio decreased significantly (p<0.05) to 2.56+0.13. Analysis of organ weights showed significant (p<0.05) increase for lungs and liver while no significant differences were noted for heart and kidneys at the 12th week of feeding the diets. The findings of the present study suggest that palm oil may be beneficial as its intake produces decreases in TC/HDL, a useful index for possible cardiovascular problems in individuals.
© 2010 International Formulae Group. All rights reserved.
Keywords: Palm oil, cardiovascular, HDL, LDL, Total cholesterol, Triglycerides.
... As discussed, unrefined oils with moderate LA content and high in antioxidant factors may be protective against vascular disease [162,163]. Antioxidant factors in red palm oil were protective in atherogenic rabbits [164], but refined palm oil was significantly more atherogenic [165]. Reheated palm oil increased vascular damage in rats [166]. ...
The heart, an organ with high ATP requirements, derives 70 % of its energy from fats, primarily delivered by LDL in the fasted state and chylomicrons in the fed state. The primary ‘cause’ of cardiovascular disease is not pure dietary ‘saturated’ fats per se, although excessively oxidised linoleic acid (LA)-rich non-ruminant animal so-called ‘saturated’ fats may well be significant factors, but is arguably due to a mixture of: excess Omega 6 LA intake within the context of a nutrient including antioxidant depleted pre-oxidised western diet, raised plasma oxidative stress including of LDL, damage to cardiolipin species and consequent release of LA oxylipins including 9- and 13-HODE 4-HNE and MDA so increased oxidised stress, consequential and wider oxidative stress related damage to mitochondria including their DNA, hence reduction in cardiac mitochondrial energy output; excess LA oxylipins of dietary and endogenous origin leading to consequent overactivation of oxidised LDL receptors and PPAR gamma pathways, so excess inflammation and immune activation including of iNOS hence raised peroxisomal peroxide-related oxidative stress; PPAR gamma activation by LA HODEs including 9 and 13 HODE and resultant PPAR gamma-related shunting of peroxisomal beta-oxidation product ACoA to lipid and cholesterol production and deposition rather than mitochondrial energy substrate production; and lack of PPAR alpha activation through exercise, fasting, or to a lesser extent by omega 3s, of mitochondrial energy substrate production-related pathways, combined with consequent damage to cell tissue as well as mitochondria, so energy inhibition and resultant malfunction including; inflammation, tissue destruction, and macrophage foam cell related and wider intra and inter-cellular lipid deposition; all facilitated by pre-oxidised excessively refined nutrient and antioxidant depleted, AGE and cross-linked protein, oxidised lipid product-rich, LA ALA-imbalanced, ‘Western’ diets, combined with constant food accessibility, exacerbated by lack of intermeal ‘fasting’ and energy expenditure including exercise.
... Random interesterification of vegetable oils therefore increases the proportion of SFA in the sn-2 position. Animal studies have demonstrated that consumption of TAG-containing palmitic acid in the sn-2 position promotes atherogenesis to a greater extent than TAG-containing palmitic acid in the sn-1 or sn-3 positions [3][4][5]. However, human dietary intervention studies have not demonstrated that there are any chronic effects of sn-positional composition or interesterification of palmitic acid-rich plant fats (whereby the proportion of palmitic acid in the sn-2 position is increased) on blood lipids or insulin sensitivity [6][7][8][9][10]. ...
Purpose:
Interesterification of palm stearin and palm kernal (PSt/PK) is widely used by the food industry to create fats with desirable functional characteristics for applications in spreads and bakery products, negating the need for trans fatty acids. Previous studies have reported reduced postprandial lipaemia, an independent risk factor for CVD, following interesterified (IE) palmitic and stearic acid-rich fats that are not currently widely used by the food industry. The current study investigates the effect of the most commonly consumed PSt/PK IE blend on postprandial lipaemia.
Methods:
A randomised, controlled, crossover (1 week washout) double-blind design study (n = 12 healthy males, 18-45 years), compared the postprandial (0-4 h) effects of meals containing 50 g fat [PSt/PK (80:20); IE vs. non-IE] on changes in plasma triacylglycerol (TAG), glucose, glucose-dependent insulinotropic polypeptide (GIP), peptide YY (PYY), insulin, gastric emptying (paracetamol concentrations) and satiety (visual analogue scales).
Results:
The postprandial increase in plasma TAG was higher following the IE PSt/PK versus the non-IE PSt/PK, with a 51 % greater incremental area under the curve [mean difference with 95 % CI 41 (23, 58) mmol/L min P = 0.001]. The pattern of lipaemia was different between meals; at 4-h plasma TAG concentrations declined following the IE fat but continued to rise following the non-IE fat. Insulin, glucose, paracetamol, PYY and GIP concentrations increased significantly after the test meals (time effect; P < 0.001 for all), but did not differ between test meals. Feelings of fullness were higher following the non-IE PSt/PK meal (diet effect; P = 0.034). No other significant differences were noted.
Conclusions:
Interesterification of PSt/PK increases early phase postprandial lipaemia (0-4 h); however, further investigation during the late postprandial phase (4-8 h) is warranted to determine the rate of return to baseline values.
Trial registration number:
Clinicaltrials.gov as NCT02365987.
... Red Palm Oil was 25% less atherogenic than randomised Palm Oil and 47% more atherogenic than Red Palm Oil. Red Palm Oil is rich in both carotenoids and vitamin E and this study did not indicate if one or both of the components of Red Palm Oil were responsible for the findings [14]. ...
... Chylomicrons (transport des triglycérides dans le plasma) proportion de C16:0 est erifi e en position sn-2 est elev ee par rapport aux positions externes, plus l'effet ath erog ene, evalu e par l'appr eciation visuelle des d epôts dans l'aorte apr es 60 jours, est important (Kritchevsky et al., 1998a(Kritchevsky et al., , 1998b. En effet, selon cette evaluation, le saindoux est plus ath erog ene a l' etat natif, dans lequel le C16:0 est principalement en position sn-2, que lorsqu'il est interest erifi e (Kritchevsky et al., 1998a) tandis que les huiles de palme et de graines de coton natives, dont le C16:0 est principalement en sn-1 et sn-3, sont moins ath erog enes que les mêmes huiles interest erifi ees (Kritchevsky et al., 1998b(Kritchevsky et al., , 2000a. Les auteurs sugg erent que ces effets seraient dus a une meilleure absorption et une r emanence du C16:0 dans la circulation lorsque celui-ci est est erifi e en position sn-2 comme cela a et e montr e par Redgrave et al. (1988) et Mortimer et al. (1994). ...
From the nutrition point of view, lipids are primarily considered as energy suppliers, their dietary intake having to be limited. In fact, lipids are sources of various fatty acids, and dietary recommendations include the required daily intakes in different fatty acids (fatty acid profile). Beyond these quantitative aspects, fatty acids are part of larger molecules, mainly triacylglycerols (TAG), that are organized in supramolecular structures as for example fat crystals and lipid droplets. Recent advances in nutrition research have demonstrated that these structures, and lipid organization in food matrices, influence digestibility and metabolism of fatty acids. Therefore, the members of the technological network Listral propose a synthesis of the knowledge about the influence of molecular and supramolecular structures of lipids on digestion and metabolic fate of dietary fatty acids originating from for the main food industry sectors. Fatty acids are mainly provided in the diet in the form of TAG, or phospholipids (PL) where they are esterified in external (sn-1, sn-3) or internal (sn-2) position of the glycerol backbone. They can also be found as ethyl esters (EE) in specific formulations. These molecular characteristics of the lipid molecules affect their hydrolysis and their absorption rate but also their metabolism in indifferent organs, as assessed in studies often using inter esterified fat sources. The results depend on the types of fatty acids (saturated or polyunsaturated fatty acids) but also on the model used for the studies: in vitro or in vivo studies ; animal model, human newborn or adult, either healthy or exhibiting some diseases. Among others, it was found that the crystal form and fat melting point as affected by the fatty acid profiles and the lipid molecular structures directly impact fatty acid absorption kinetics through modifications of lipolytic enzyme activities. However, in these studies, the relative effect of the thermal properties of lipids and the proportion of saturated fatty acids chains in sn-2 position were hardly distinguished. Supramolecular structures, namely type and size of the fat droplets and their interfacial composition, of lipids, either in their native forms or obtained after food processes, also affect the digestibility and absorption of lipids. This aspect is reviewed with specific focus on dairy, marine, meat, oil plant and egg products. The impact of other nutritional components present in these food matrices on the absorption of lipids is also discussed.
... Red palm oil is a product from the fruits of the oil palm tree, Elaeis guineensis (Family Arecaceae) which has been shown to have protective effects against hypercholesterolemia and atherosclerotic plaque formation, despite being high in saturated fatty acids [10,11]. In addition to the various fatty acids that RPO contains, it is also a rich source of a wide spectrum of different lipid soluble antioxidants such as tocopherols, tocotrienols, carotenoids, lycopene and co-enzyme Q10, among others [12][13][14]. ...
Red palm oil (RPO) and rooibos have been shown to exhibit cardioprotective properties. RPO is rich in essential fatty acids and fat soluble antioxidants while rooibos contains polyphenolic compounds with a unique composition of flavonoids. They exert their biological effects in different cellular compartments. Therefore the combination of these two natural food compounds has the potential to enhance the spectrum of available dietary antioxidants in different cellular compartments, which could result in an enhanced protection against certain pathological conditions such as inflammation.
Male Wistar rats weighing 150-200 g were supplemented with RPO, rooibos or their combination for 28 days. The Langendorff system and the lipoposaccharide (LPS)-induced inflammatory model were used to establish if RPO and rooibos, when supplemented alone or in combination, will reverse the negative effects of LPS on cardiac function at baseline. The effect of dietary intervention was also investigated on modulation of pro-inflammatory and anti-inflammatory cytokines in plasma and myocardial tissue.
The LPS resulted in induction of systemic inflammation as evidenced by increased levels of IL-1β in plasma of LPS-treated rats compared to their non-treated control counterparts. Dietary supplementation and LPS treatment did not have an effect on baseline cardiac functional parameters. However, the elevation of IL-1β levels in plasma of LPS-induced rats consuming either RPO or rooibos alone were paralleled with increased levels of the anti-inflammatory cytokine, IL-10. The combination of rooibos and RPO was associated with enhanced endogenous production of myocardial IL-10 in LPS-induced rats.
The results of this study indicate that RPO and rooibos when supplemented individually showed anti-inflammatory effect at systemic level while their combination exhibited an enhanced anti-inflammatory effect in the myocardial tissue. Therefore, the findings in the current study argue that the combination of these two natural food substances could be beneficial in clinically relevant conditions where inflammation plays a role.
... Chylomicrons (transport des triglycérides dans le plasma) proportion de C16:0 est erifi e en position sn-2 est elev ee par rapport aux positions externes, plus l'effet ath erog ene, evalu e par l'appr eciation visuelle des d epôts dans l'aorte apr es 60 jours, est important (Kritchevsky et al., 1998a(Kritchevsky et al., , 1998b. En effet, selon cette evaluation, le saindoux est plus ath erog ene a l' etat natif, dans lequel le C16:0 est principalement en position sn-2, que lorsqu'il est interest erifi e (Kritchevsky et al., 1998a) tandis que les huiles de palme et de graines de coton natives, dont le C16:0 est principalement en sn-1 et sn-3, sont moins ath erog enes que les mêmes huiles interest erifi ees (Kritchevsky et al., 1998b(Kritchevsky et al., , 2000a. Les auteurs sugg erent que ces effets seraient dus a une meilleure absorption et une r emanence du C16:0 dans la circulation lorsque celui-ci est est erifi e en position sn-2 comme cela a et e montr e par Redgrave et al. (1988) et Mortimer et al. (1994). ...
... Many researchers have reported FFA content (Saad et al., 2007) and IV (Haryati et al., 1997) of PO, but most of the material of PO were refined PO, not extracted from fresh PM. The fatty acid components of PO (Sundram et al., 2003) and PKO (Kritchevsky et al., 2000), the tocopherol and carotene content of PO (Ping et al., 2002) were also studied. ...
The proximate composition, mineral concentration of fleshy mesocarp, palm meat (PM) and palm kernel (PK) of oil palm fruit (Elaeis guineensis S.L.Dura) produced in Hainan, China were investigated. The fatty acid composition, chemical properties and minor constituents of palm oil (PO) and palm kernel oil (PKO) were also studied. The crude fat of PM and PK were 68.09±3.57% and 49.36±2.61%, respectively. The PM and PK were found to be good sources of minerals. The acid value (AV) and free fatty acid (FFA) of PO extracted from fresh PM were much higher. If the fresh PM were heated at 100ºC for 30 min, the AV and % FFA could be reduced to 4.62±0.04 mgKOH/g and 2.72±0.002%, respectively. The major fatty acid of PO was palmitic acid 39.93±1.66% and that of PKO was lauric acid 48.01±0.69%. Tocopherol isomer (α-, (β+γ)-and δ-) contents in PO were 68.8±1.84, 22.8±0.54 and 11.8±0.12 mg/kg, respectively. The β-carotene content in PO was 901.5±11.95 mg/kg. The content of sterols in PO and PKO were 880.0±5.23 and 858.0±4.37 mg/kg, respectively. PO and PKO exhibited good chemical properties and could be used as edible oils and for industrial applications. There are almost no data about Chinese palm fruit now and this study systematically researched on it, which can provide useful information for Chinese oil palm industry.
... In rabbits, interesterification of fats and oils did not change plasma lipid and lipoprotein concentrations; however, increasing the proportion of palmitic acid on sn-2 compared to sn-1,3 resulted in increased TAG atherogenicity. Native lard with 16:0 mainly on sn-2 may be more atherogenic than interesterified lard [65] while native palm oil and cottonseed oil (with 16:0 mainly on sn-1,3) may be less atherogenic than their interesterified counterparts [66,67]. These effects would be due to a better absorption and in vivo residence of palmitic acid in blood when esterified on sn-2 [33,68]. ...
On a nutritional standpoint, lipids are now being studied beyond their energy content and fatty acid (FA) profiles. Dietary FA are building blocks of a huge diversity of more complex molecules such as triacylglycerols (TAG) and phospholipids (PL), themselves organised in supramolecular structures presenting different thermal behaviours. They are generally embedded in complex food matrixes. Recent reports have revealed that molecular and supramolecular structures of lipids and their liquid or solid state at the body temperature influence both the digestibility and metabolism of dietary FA. The aim of the present review is to highlight recent knowledge on the impact on FA digestion, absorption and metabolism of: (i) the intramolecular structure of TAG; (ii) the nature of the lipid molecules carrying FA; (iii) the supramolecular organization and physical state of lipids in native and formulated food products and (iv) the food matrix. Further work should be accomplished now to obtain a more reliable body of evidence and integrate these data in future dietary recommendations. Additionally, innovative lipid formulations in which the health beneficial effects of either native or recomposed structures of lipids will be taken into account can be foreseen.
... However, these new REAO may also have deleterious effects. Several studies have demonstrated that feeding diets containing random esterified fats in comparison with native fats has resulted in an increased incidence of atherosclerotic lesions in rabbits (Kritchevsky et al., 1998(Kritchevsky et al., , 2000. It has been suggested that the combination of enhanced absorption and persistence in the circulation of fats with palmitic acid in the sn-2 position increases the exposure of the aorta to blood lipids, even when levels in blood do not differ compared with native fat (Kritchevsky et al., 1998). ...
It has been reported that applying a chemical reesterification process to a native fat results in a new fat source with different physicochemical properties due to their different fatty acid (FA) positional distribution within the glycerol moiety and their different proportions of mono (MAG)-, di (DAG)- and triacylglycerides (TAG). Thus, this reesterification could affect fat digestion, absorption and metabolism; and this effect could vary among species given their differences in fat metabolism. The aim of this study was to compare the effect of feeding two different random esterified acid oils (REAO), presenting different MAG, DAG and TAG proportions, with their corresponding native oil on postprandial lipaemia in broiler chickens and dogs. For this purpose, 18 dogs and 54 broiler chickens were fed a basal diet supplemented with palm native oil, palm REAO low MAG or palm REAO high MAG. The inclusion level of the oils was 10% of the diet in dogs and 6% in broiler chickens. Serum postprandial TAG concentration (mg/dl) after feeding a single meal was measured at different time points during 12 h in dogs and 3 h in chickens. Although fasting serum TAG concentration values were similar for both species (47 ± 2.4 mg/dl for dogs and 44 ± 3.0 mg/dl for broilers; p = 0.522), postprandial TAG concentrations tended to be higher in broilers than in dogs (p = 0.058). Treatment had no effect on TAG concentration at any time point in any species (p = 0.768 for dogs, p = 0.947 for broilers). However, the postprandial TAG curves were very different between species; in broiler chickens, TAG concentration returned to the fasting values 3 h after feeding while in dogs, the TAG concentration still had not returned to basal levels 12 h after feeding.
... Supplementation of palm olein tr yglyceride (POTG) with 162 ppm of tocotrienols lowered the serum total cholesterol level significantly, but it did not significantly lower the LDL-C, HDL-C and serum TG compared to the POTG group without tocotrienol supplement (Khor and Chieng, 1996). There were no significant differences in serum lipids although the percentage of HDL cholesterol was highest in rabbits fed with refined bleached and deodorized palm oil (Kritchevsky et al., 2000). ...
Processed meat products, such as burgers, sausages, meatballs, salami and nuggets are currently popular with urban consumers. However, in general, they are high in cholesterol, total lipid and saturated fatty acids. Four beef burger formulations were prepared, each containing 15% fat from either beef fat (control), palm fat (PF), red PF or a blend of PF and red PF at a ratio of 1:1 at 15% fat. A rat assay was carried out to determine lipid profile, apparent digestibility (AD) and protein efficiency ratio (PER) of rats fed with beef burger diets containing palm based fats. Treatment with PF and red PF beef burger diets did not affect the total cholesterol concentration but resulted in higher HDL-cholesterol concentration in their blood serum. The rats fed with dried burger diets containing PF and red PF had higher AD value (90.0% and 89.3%, respectively) and was not significantly different (P < 0.05) compared to the group fed with dried burger containing beef fat (90.7) over the 10 days experimental diet period. PER values of all treatments except for casein were not significantly different (P < 0.05). There was also no difference (P < 0.05) in food intake and body weight gain between all rats fed with dried burger containing different types of palm based fats. In summary, the utilization of PF and red PF in beef burger increased the HDL-cholesterol and had no effect on the concentration of total cholesterol in rat blood serum. Addition of palm based fats into beef burgers did not change AD and PER.
... Atherosclerosis was similar following SOS and SSO, but more severe following PPO compared with POP, suggesting that the positional composition of palmitic acid-rich TAG, but not stearic acid-rich TAG, determines their effects on atherogenicity. Kritchevsky et al. (59) also observed that randomly chemically interesterified palm oil was more atherogenic in rabbits compared with native palm oil. Furthermore, lard, which contains virtually all its palmitic acid in the sn-2 position, was found to be more atherogenic in rabbits than beef tallow which only has a small proportion of palmitic acid the sn-2 position (60) , and randomisation of lard rendered it less atherogenic (61) . ...
The position of fatty acids in the TAG molecule (sn-1, sn-2 and sn-3) determines the physical properties of the fat, which affects its absorption, metabolism and distribution into tissues, which may have implications for the risk of CHD. The TAG structure of fats can be manipulated by the process of interesterification, which is of increasing commercial importance, as it can be used to change the physical characteristics of a fat without the generation of trans-fatty acids. Interesterified fats rich in long-chain SFA are commercially important, but few studies have investigated their health effects. Evidence from animal and human infant studies suggests that TAG structure and interesterification affect digestibility, atherogenicity and fasting lipid levels, with fats containing palmitic and stearic acid in the sn-2 position being better digested and considered to be more atherogenic. However, chronic studies in human adults suggest that TAG structure has no effect on digestibility or fasting lipids. The postprandial effects of fats with differing TAG structure are better characterised but the evidence is inconclusive; it is probable that differences in the physical characteristics of fats resulting from interesterification and changes in TAG structure are key determinants of the level of postprandial lipaemia, rather than the position of fatty acids in the TAG. The present review gives an overview of TAG structure and interesterified palmitic and stearic acid-rich fats, their physical properties and their acute and chronic effects in human adults in relation to CHD.
... Absorption 1-5 and metabolism [6][7][8][9][10][11][12][13] of dietary triglycerides (TAGs) depend on stereochemical configuration. As a result, the positional arrangement of the fatty acid moieties in TAGs has an impact on an array of lipotoxic diseases, [14][15][16][17][18][19][20][21] such as heart disease, obesity, and diabetes. Development of efficient methods for the positional analysis of TAGs is needed to facilitate research in these areas, as well as in the area of basic nutrition. ...
A series of positionally pure triglycerides (TAGs) of the form OXO and YOY, where O is the oleate moiety and X and Y are large arrays of different fatty acid moieties, was synthesized and analyzed by reversed-phase high-performance liquid chromatography/tandem mass spectrometry. The intensities of the collision-induced decomposition (CID) products of ammoniated TAGs (ammonium ion adducts) were examined as a function of chain length, degree of unsaturation, double-bond position, and cis/trans configuration of X and Y. The major CID products, the diglyceride fragment ions and the MH+ ion, were plotted as functions of chain length for the saturated and mono-unsaturated series of X and Y. Different trends for each of these series were observed. Trends in the abundances of these fragment ions were also characterized as a function of degree of unsaturation in the TAGs. In general, the fractional abundances of the MH+ ions vary linearly with degree of unsaturation. However, the presence of double bonds positioned close to the carbonyl carbon of the fatty acid chain promotes the formation of the diglyceride fragment ion corresponding to loss of that fatty acid. Mechanisms of the formation and decomposition of ammoniated TAGs are proposed that fit the trends observed in the data. Extensions of this work are described, and a vision of a derived library of CID spectra is discussed as a platform for comprehensive analysis of complex TAG mixtures.
The fatty acid profile of fats and oils are always the main target of the discussions on how cholesterol body levels could be increased or decreased by the feed habits. Specially, medium chain saturated fatty acids and palmitic acid are related to the blood LDL increase, promoting cardiovascular diseases. Otherwise, the same fatty acids are also related to a better digestion, increasing the popularity of some oils, such as coconut oil. This work was then aimed to contribute with this discussion in a thermodynamic point of view. Mixtures with cholesterol and these fatty acids (caprylic, capric, myristic and palmitic acids) were formulated in several concentrations and their crystallization and melting profiles analyzed. Solid-liquid equilibrium phase diagrams were built and evaluated by using classical thermodynamic models. Results showed that lower fatty acids were significantly able to modify the cholesterol crystal structure, forming solid solutions. The performance of the thermodynamic models was mild good. The UNIFAC model showed limitations in representing the cholesterol structure, as expected, with highlights that its literature's parameter databank should be improved, considering the complexity of molecules such as cholesterol. Additionally, coconut and palm oils were also evaluated in mixtures with cholesterol, showing that despite its high melting temperature and molecular complexity, cholesterol could be solubilized in such oils. The palm oil, specially, presented liquid crystalline structures when mixed with cholesterol. All these phenomena observed could probably affects cholesterol solubility in lipidic media, being a factor that could influence their absorption in the gastrointestinal tract.
Rationale:
The development of an automated platform for the positional analysis of triglycerides (TAGs) based on electrospray ionization tandem mass spectrometry (ESI-MS/MS) continues to be pursued. This work evaluates the positional sensitivities of the collision-induced dissociation (CID) spectra of a representative set of XYZ triglycerides using sodium, lithium, and ammonium salts as complexing agents.
Methods:
A set of triglycerides were synthesized and analyzed via ESI-MS/MS using an ion trap mass spectrometer. Using three different complexing agents, the product ion spectra of the corresponding precursor ions for twelve XYZ TAGs were collected, where X, Y, and Z represent C16:0 , C18:1(c-9) , C18:2(cc-9,12) , and C20:4(cccc-5,8,11,14) fatty acid chains. These data were then used to prepare ternary plots for four positional isomer systems to evaluate the positional sensitivity differences among the three different complexing agents RESULTS: The positional sensitivities for each of the four positional isomer systems were robust for the sodium and lithium adducts. The CID data for the sodium and lithium TAGs demonstrated an unfavorable loss of the fatty acid in the center position and showed a higher sensitivity to fatty acid position, when compared to the CID data for ammonium adducts, especially for the arachidonic acid containing triglycerides.
Conclusions:
The data shows that that the relative abundances of the DAG product ions for the XYZ-type TAGs when using sodium and lithium complexing agents adducts are sensitive to fatty acid position and are consistent for the diverse array of TAGs studied in this work. This suggests that using sodium or lithium as the complexing agent may be advantageous for the development of an automated platform for the positional analysis of complex TAG mixtures based on ESI-MS/MS.
Palm oil is consumed in over 150 countries worldwide. It plays a pivotal role in the socioeconomic development of Asian, Latin American, and African regions. Of all the palm oil and palm kernel oil entering global trade, Malaysia and Indonesia account for more than half the market share, dominating the international trade in palm oil. The increasing importance of palm oil has naturally led to a steady buildup of scientific, technical, and trade data and information. The success of the palm oil industry in Malaysia and Indonesia, in particular, has never been easy. It has been wrought with obstacles and has gotten harder in recent years. The industry has been inundated with issues of mistrusts and misconceptions about the oil, its composition, and its nutritional benefits. Other issues that have garnered attention include its trade and traceability, new process contaminants, environmental management, and other issues relating to the sustainable development of the palm oil industry. This article overviews the role of palm oil industry in the international oils and fats market, the technology involved in oil extracting and processing, palm oil quality parameters, and the applications of palm oil in food and nonfood products. The issues that are becoming relevant, namely the existence of process contaminants such as 3‐monochloropropane‐1,2‐diol (3‐MCPD) esters and glycidol esters, trade and traceability, together with other issues related to a sustainable development of the palm oil industry, have also been included.
Rational
The development of an automated platform for the positional analysis of triglycerides based on electrospray tandem mass spectrometry continues to be pursued. This work compares the positional sensitivities of the collisional‐induced dissociation spectra for a representative set of YXY/YYX triglycerides using ammonium, silver, sodium and lithium as complexing agents.
Methods
A set of triglycerides were synthesized and analyzed by electrospray tandem mass spectrometry using an ion trap mass spectrometer. Using different salt additives, the product ion spectra of the corresponding parent ions for twelve systems of the form YXY/YYX, where Y and X represent C16:0, C18:1(c‐9), C18:2(cc‐9,12) and C20:4(cccc‐5,8,11,14), were collected. The data was used to prepare two‐point calibration plots for each of the twelve positional isomer systems using each of the four complexing agents.
Results
The positional sensitivities for all twelve positional isomer systems were robust for both the sodium and lithium TAG adducts. The CID data for both the sodium and lithium TAG adducts are much less sensitive to the degree of unsaturation and double bond position of the fatty acids constituents than the CID data for the ammonium adducts.
Conclusion
Using sodium or lithium TAG adducts may be advantageous for the development of an accurate predictive model for performing positional analysis of complex TAG mixtures based on electrospray tandem mass spectrometry. Ammonium adducts are likely complicated by the ability of the ammonium ion to provide extra stability to some parent ions through hydrogen bond‐like interactions.
Rational:
Positional analysis of intact triglycerides could provide greater insights into the link between fatty acid position and lipotoxic diseases. However, this methodology has been impeded by lack of commercial availability of positionally pure triglycerides. This work reports on a strategy for defining calibration plots for YXY/YYX triglyceride systems based on the product ion intensities in the collisional-induced dissociation spectra of ammoniated parent ions.
Methods:
A set of triglycerides were synthesized and analyzed by electrospray tandem mass spectrometry using an ion trap mass spectrometer. The product ion spectra of the ammoniated parent ions were collected for 42 triglyceride systems of the form YXY/YYX, where Y represents C16:0 , C18:1(c-9) and C20:4(cccc-5,8,11,14) . Three-point calibration plots were prepared by plotting the relative abundance of the YY(+) product ion vs. the relative abundance of the YYX positional isomer.
Results:
The calibration plots were shown to give relative abundances of positional isomers accurate to within ±0.02 for most systems. Using an ion trap, under a controlled set of collision parameters, the slopes of the calibration plots can be used to compare the sensitivities of the product ion intensities to fatty acid position for various triglyceride systems. The average slopes of the calibration plots for the C16:0 , C18:1(c-9) and C20:4(cccc-5,8,11,14) systems were 0.29±0.05, 0.21±0.05 and 0.045±0.005, respectively.
Conclusion:
While the presence of multiple unsaturated fatty acids tends to slightly decrease the slopes of the calibration plots, the data suggest that the sensitivities are sufficient for performing positional analysis of most triglyceride systems. However, the presence of unsaturated fatty acids that contain double bonds close to the carbonyl group, such as arachidonic acid, tends to dramatically decrease positional sensitivity.
Elaeis dybowskii Hua, Elaeis guineensis f. androgyna A.Chev., Elaeis guineensis f. caryolitica Becc., Elaeis guineensis f. dioica A.Chev., Elaeis guineensis f. dura Becc., Elaeis guineensis f. fatua Becc., Elaeis guineensis f. ramosa A.Chev., Elaeis guineensis f. semidura Becc., Elaeis guineensis f. tenera Becc., Elaeis guineensis subsp. nigrescens A.Chev., nom. inval., Elaeis guineensis subsp. virescens A.Chev., Elaeis guineensis var. albescens Becc., Elaeis guineensis var. angulosa Becc., Elaeis guineensis var. ceredia A.Chev., Elaeis guineensis var. compressa Becc., Elaeis guineensis var. gracilinux A.Chev., Elaeis guineensis var. idolatrica A.Chev., Elaeis guineensis var. intermedia A.Chev., Elaeis guineensis var. leucocarpa Becc., Elaeis guineensis var. macrocarpa A.Chev., Elaeis guineensis var. macrocarya Becc., Elaeis guineensis var. macrophylla A.Chev., Elaeis guineensis var. macrosperma Welw., Elaeis guineensis var. madagascariensis Jum. & H.Perrier, Elaeis guineensis var. microsperma Welw., Elaeis guineensis var. pisifera A.Chev., Elaeis guineensis var. repanda A.Chev., Elaeis guineensis var. rostrata Becc., Elaeis guineensis var. sempernigra A.Chev., Elaeis guineensis var. spectabilis A.Chev., Elaeis macrophylla A.Chev., nom. nud., Elaeis madagascariensis (Jum. & H.Perrier) Becc., Elaeis melanococca Gaertn., Elaeis melanococca var. semicircularis Oerst., Elaeis nigrescens (A.Chev.) Prain, nom. inval., Elaeis virescens (A.Chev.) Prain, Palma oleosa Mill.
Revue réalisée en hommage à Michel Ollivon (Directeur de Recherche au CNRS, UMR8612, Châtenay-Malabry), décédé en juin 2007, qui a été à l’origine de la création du RMT Listral. Ce Réseau Mixte Technologique avec pour thématique les Lipides Structurés Alimentaires est coordonné par l’ACTIA et animé par Actilait. Les autres partenaires du réseau sont : F Sobolewski & JP Bodin (Enilia-Ensmic), K Duhem & JP Guyonnet (Cniel), JP Bergé & JP Gouygou (Ifremer Nantes), G Nassy (Ifip), Lebois & D Majou (Actia), P Gaborit & R Richoux (Actilait).
Four diets with crude oil from Attalea butyracea mesocarp (AB) and one diet with maize oil were compared in rabbits. The design was completely randomized with five treatments: AB0, AB3, AB6 and AB9 (0, 3, 6 and 9% AB, respectively) and AM3 with maize oil (3%); and four replicates per treatment (1 rabbit/cage). The diets included 30 to 33% soybean meal, 32 to 44% maize meal and 25% grass hay.The trial lasted 15 days, 10 for diet adaptation and 5 days for assessment. Feed intake and apparent digestibility of dry matter (DM), organic matter (OM), crude protein (CP), cell wall (NDF), acid detergent insoluble fiber (ADF) and hemicellulose were higher for AB3, except for digestibility of fiber components, where AB6 had the highest value, but with lower intake. For plasma variables: glucose and urea were highly significant (P <0.01), while for total cholesterol, HDL and triglycerides were significant differences (P <0.05), with no differences for LDL between treatments. There were no problems with 6% AB in the plasma profile of rabbits, with normal glucose and urea and a higher value of HDL.
Among the edible oils, palm oil is produced and consumed maximum in the world followed by soybean oil. This is an extremely important commodity all over the world today, not only as cooking oil but also for several other food and non-food uses. There are two types of oil derived from oil palm fruits: a) mesocarp oil - which is known as palm oil and b) kernel oil - which is more saturated in nature derived from the kernel. Fat or Oil is an essential part of human nutrition, which performs several biological functions and also acts as energy source. In spite of essentiality of this nutrition, in recent time fat is looked as an evil, especially by the elite society, where the basic requirement of nutrition is not a factor. Though palm oil is relatively of higher saturation in comparison to many other vegetable oils, the triglyceride profile of it and other nutritionally beneficial compounds present in it proved to be healthy oil for human consumption. A detailed discussion has been made in this article regarding saturated, mono-unsaturated, and polyunsaturated fats; dietary fats and serum cholesterol; major triglycerides in fats and oils, fatty acid composition of oils and fats. Clinical studies in humans and in animals with respect to palm oil has been elaborated to know whether palmitic acid is cholesterol elevating. Triglyceride structure in different types of palm oil and their effect on health has been discussed. With the experimental evidences, it is elaborated that palm oil does not behave like a saturated fat; though it has approximately 50% saturated fatty acids and this might be due the presence of important minor components of palm oil like carotenoids, tocopherols, tocotrienol, phytosterols, ubiquinone, squalene etc. Palm Oil use with respect to its zero trans-fat content is very relevant since trans-fat and has become an important component in any food products containing fat. For domestic cooking, people have a choice of quite a few oils, but for many of the industries (both food and non food), palm oil or its derivatives are essential. It is the source of many oleochemicals as well as nutraceuticals. A brief sketch has also been drawn for the non food use of palm oil but the main emphasis has been given to food uses in this article. Value addition of the oil starts right from the Crude Palm Oil (CPO) stage. In this article different food uses have been described mentioning different value added products like palmolein, red palmolein, shortening, vanaspati, margarine, confectionary fats, dairy products etc. When the population explosion is continuous, palm oil has a major role to provide required dietary fat for entire world, since production of this oil is maximum from unit area and at the same time it is nutritionally safe. As this oil is used in most of the commercial food products, effect of this single commodity on human health as well as socio-economic status of many of the countries is quite evident. Multifaceted impact of this oil can be seen when it gets more and more popular. A discussion on its impact is also made in this article.
The positional distribution of fatty acids in fats and oils influences their chemical, physical and nutritional properties. Eight types of cooking oils retailed in Australia: canola, olive, sunflower, cottonseed, palm, flaxseed, sesame and coconut oils, were analysed for regiospecific fatty acid distribution. In general, saturated fatty acids were preferentially distributed in the sn-1 and sn-3 positions of the oil triacylglycerols, whereas mono- and polyunsaturated acids were preferentially distributed at sn-2 position. Exceptions were palm and coconut oils in which significant proportions of palmitic and lauric acid were located at sn-2. Cottonseed oil, despite containing appreciable amounts of total palmitic acid, had negligible amounts located at sn-2. In sunflower oil, the oleic and linoleic acids exhibited little or no regiospecificity; however, the low levels of linolenic acid were almost exclusively distributed at sn-1 and sn-3. In flaxseed and canola oils, the linolenic acid was preferentially distributed at sn-2.
Lipids consist of a broad group of compounds that are generally soluble in organic solvents but only sparingly soluble in water. They are major components of adipose tissue, and together with proteins and carbohydrates, they constitute the principal structural components of all living cells. Glycerol esters of fatty acids, which make up to 99% of the lipids of plant and animal origin, have been traditionally called fats and oils. The difference between oils and fats is that fats are solids at room temperatures.
Four diets with crude oil from Attalea butyracea mesocarp (AB) and one diet with maize oil were compared in rabbits.
The design was completely randomized with five treatments: AB0, AB3, AB6 and AB9 (0, 3, 6 and 9% AB,
respectively) and AM3 with maize oil (3%); and four replicates per treatment (1 rabbit/cage). The diets included 30 to
33% soybean meal, 32 to 44% maize meal and 25% grass hay.The trial lasted 15 days, 10 for diet adaptation and 5 days
for assessment.
Feed intake and apparent digestibility of dry matter (DM), organic matter (OM), crude protein (CP), cell wall (NDF),
acid detergent insoluble fiber (ADF) and hemicellulose were higher for AB3, except for digestibility of fiber
components, where AB6 had the highest value, but with lower intake. For plasma variables: glucose and urea were highly
significant (P <0.01), while for total cholesterol, HDL and triglycerides were significant differences (P <0.05), with no
differences for LDL between treatments. There were no problems with 6% AB in the plasma profile of rabbits, with
normal glucose and urea and a higher value of HDL.
The effect of red palm olein on bone metabolism was investigated in growing rats. Fifty weanling male Sprague-Dawley rats were randomly assigned to five groups and fed ad libitum the following diets: Reference diet, 70 g soybean oil/kg diet; Red-35, 35 g red palm olein + 35 g soybean oil/kg diet; Red-50, 50 g red palm olein + 20 g soybean oil/kg diet; RPO-35, 35 g refined palm oil + 35 g soybean oil/kg diet; RPO-50, 50 g refined palm oil + 20 g soybean oil/kg diet. Rat growth was not affected by the dietary lipid treatments after 42 d of feeding. Rats demonstrated significant differences in tissue fatty acid composition that reflected the dietary lipid treatments. The concentrations of saturated fatty acids and monounsaturated fatty acids were higher but polyunsaturated fatty acids (PUFA) lower in tibia marrow of rats given the palm oil treatments compared with those given soybean oil. The reduction in total n-6 PUFA concentration in bone of rats given palm oil was associated with higher bone specific alkaline phosphatase activity and endosteal mineral apposition rate and bone formation rate in tibia. No difference was found in ex vivo PGE2 production in femur from rats. The histomorphometric analyses indicated that red palm olein might support bone formation and bone modeling in growing rats. Palm oil or palm antioxidants may play a role in bone formation.
As part of a trial to improve the fatty acid profile, vitamin E content and shelf-life of rabbit meat, this work studied the effects of level and source of vitamin E dietary addition on growth and carcass traits in NZW rabbits. A 10.6MJ/kg digestible energy diet without added oil and with 60mg/kg synthetic vitamin E (dl-α-tocopheryl-acetate) served as a control (C). Five other diets were 4% oil-enriched, i.e. with 2% sunflower and 2% linseed oils and so having slightly higher digestible energy contents (11.4MJ/kg) than the C feed. In three oil-rich diets, only synthetic (S) vitamin E was used at 60, 150 or 300mg/kg concentration (diet 60-S, 150-S or 300-S, respectively). In two oil-rich diets, 60mg/kg synthetic plus 90mg/kg or 240mg/kg natural (N) vitamin E (a fatty acid distillate, i.e. d-α-tocopherol) were used to reach the 150mg/kg (diet 150-SN) or 300mg/kg (diet 300-SN) level of added vitamin E contents. In each group, 11 litters of 7 to 9 kits were studied in the pre-weaning period from 21 to 35days and post-weaning to harvest at 84days (n=46–50). Litter and doe performance were poorer in the 300-SN rabbits than with lower levels of vitamin E. Compared to the C rabbits, the 35–84-day mortality was significantly higher only in the 60-S rabbits. The 84-day final weight of the 300-S and 300-SN rabbits was higher than the controls (2745 and 2733 vs 2594g, P=0.049). The 35–84-day feed conversion of the C rabbits was poorer than any other rabbits (3.3 vs 3.0–3.1, P=0.001). Carcass traits were assessed with sub-samples of 15 rabbits per group and were differently affected by both the level and origin of added vitamin E. Chilled and reference carcass weights (P=0.001) and dressing out percentages (P=0.001) were higher in the 60-S and 150-S than in the C, 300-S and 150-SN rabbits. Considering all traits studied, the 150mg/kg synthetic vitamin E dietary addition was best for maximising production. However, the effects on meat quality and shelf-life should also be considered to give correct practical advices. Our results confirm the importance of both the level and source of vitamin E when it is used as a dietary additive in oil-enriched diets.
Triacylglycerol (TAG) structure affects the biochemical properties of fat. According to studies with animals and infants, absorption of palmitic and stearic acids is inferior from the stereospecifically numbered (sn) positions sn-1 and sn-3 compared with from the sn-2 position of TAGs, and saturated fatty acids in the sn-2 position, delay the clearance of chylomicron remnants. Medium chain fatty acids are transported both in lymph and in portal blood, lymphatic absorption being more efficient from the sn-2 position.Recently, new information has arisen on the variation in TAG composition within the postprandial period and on differences in the TAG structure-dependent formation and clearance of chylomicron and very low density lipoprotein TAGs. This article reviews the metabolism of TAG fatty acids in different sn positions.
Carotino oil is a viscous refined derivative of palm oil and has a deep orange-red colour. It contains valuable nutrients and has the potential to be considered as a functional food. Carotino oil has been used in some developing countries to overcome vitamin A deficiency; however, it is unfamiliar to North America. Consumer taste panels were conducted to evaluate the sensory properties of food products fried in Carotino oil versus canola oil. There were no significant differences (P ≤ 0.05) in appearance, flavour, texture, and overall quality between zucchini, shrimp, and scallop samples fried in Carotino oil versus canola oil. However, potatoes fried in Carotino oil were significantly (P ≤ 0.05) rated lower than those fried in canola oil. There were also no significant differences (P ≤ 0.05) in flavour, texture, and overall quality between perogies fried in Carotino oil versus canola oil. Our results indicate that Carotino oil has potential for acceptance in certain food products.
Diabetes and hypertension are closely associated with impaired endothelial function. Studies have demonstrated that regular consumption of edible palm oil may reverse endothelial dysfunction. The present study investigates the effect of palm oil fractions: tocotrienol rich fraction (TRF), alpha-tocopherol and refined palm olein (vitamin E-free fraction) on the vascular relaxation responses in the aortic rings of streptozotocin-induced diabetic and spontaneously hypertensive rats (SHR). We hypothesize that the TRF and alpha-tocopherol fractions are able to improve endothelial function in both diabetic and hypertensive rat aortic tissue. A 1,1-diphenyl picryl hydrazyl assay was performed on the various palm oil fractions to evaluate their antioxidant activities. Endothelium-dependent (acetylcholine) and endothelium-independent (sodium nitroprusside) relaxations were examined on streptozotocin-induced diabetic and SHR rat aorta following preincubation with the different fractions. In 1-diphenyl picryl hydrazyl antioxidant assay, TRF and alpha-tocopherol fractions exhibited a similar degree of activity while palm olein exhibited poor activity. TRF and alpha-tocopherol significantly improved acetylcholine-induced relaxations in both diabetic (TRF, 88.5% +/- 4.5%; alpha-tocopherol, 87.4% +/- 3.4%; vehicle, 65.0 +/- 1.6%) and SHR aorta (TRF, 72.1% +/- 7.9%; alpha-tocopherol, 69.8% +/- 4.0%, vehicle, 51.1% +/- 4.7%), while palm olein exhibited no observable effect. These results suggest that TRF and alpha-tocopherol fractions possess potent antioxidant activities and provide further support to the cardiovascular protective effects of palm oil vitamin E. TRF and alpha-tocopherol may potentially improve vascular endothelial function in diabetes and hypertension by their sparing effect on endothelium derived nitric oxide bioavailability.
Palm olein (PO) and red palm olein (RPO) are rich in tocopherols and tocotrienols. In addition, RPO also contains a high content of carotene. This study was to determine the effect of chronic intake of diets containing palm oils, varying in their vitamin E and carotene contents, on lipid profile in rats. Weaning male Wistar rats were fed either 18% RPO, 18% PO or 18% vitamin E-stripped palm olein (SPO) for 12 weeks. Plasma total cholesterol (TC), triglyceride (TG), high density lipoprotein cholesterol (HDL) and low density lipoprotein cholesterol (LDL) were measured at weeks 4, 8 and 12. Feeding the different types of palm oil did not affect TC and HDL from week 4 through week 12, but there were reductions in TG in all dietary groups at week 12 compared to week 4 but differences between groups were not observed. The RPO group had lower LDL at week 12 (vs weeks 4 and 8) but LDL was not reduced in the PO and SPO groups. TC/HDL was reduced in the RPO group at week 12 compared to both weeks 4 and 8, but the PO group only reduced this ratio at week 12 compared to week 4. This finding suggests that chronic feeding of diets high in palm oils did not cause any detrimental effects on blood lipid profile. In addition, red palm olein which is rich in antioxidants in the forms of vitamin E and carotene, showed better effect in terms of reduction in LDL and TC/HDL.
Human milk contains palmitic acid predominantly in the triglyceride sn-2 position, and differs from the palmitic acid positional distribution found in most infant formulas (predominantly positions sn-1 and sn-3). Following lipolysis by pancreatic lipase, 2-monoglycerides and free fatty acids are produced. All 2-monoglycerides are well absorbed, including 2-monopalmitin, thus providing one reason for the efficient absorption of palmitic acid in breast-fed infants. If infants are fed fat blends with palmitic acid located in the sn-1 and sn-3 positions, the resulting free fatty acids may form poorly absorbed calcium soaps. Therefore, many infant formulas contain only modest levels of palmitic acid.
Fat absorption studies were conducted in rats with preparations containing various amounts of palmitic acid in the triglyceride sn-2 position. Determining total fat absorption, specific fatty acid absorption, and the presence of calcium-fatty acid soaps.
Betapol, a new triacylglycerol, similar to human milk in its palmitic acid content and positional distribution, demonstrated excellent absorption characteristics compared to fat blends derived from either palm olein or oleo (similar in fatty acid profile to Betapol, but with most palmitic acid in the sn-1 and sn-3 positions). A five-point dose response was used to further evaluate the relationship of positional distribution and fat loss. Palmitic acid excretion and fecal fatty acid soaps were negatively correlated to the presence of palmitic acid in the sn-2 position.
These studies provide evidence that palmitic acid can be efficiently absorbed, avoiding fatty soap formation of it is present in the sn-2 position.
This article reviews published literature on how the stereospecific structure of dietary triglycerides may affect lipid metabolism in humans. Animal studies have shown enhanced absorption of fatty acids in the sn-2 position of dietary triglycerides. Increasing the level of the saturated fatty acid palmitic acid in the sn-2 position (e.g., by interesterification of the fat to randomize the positions of the fatty acids along the glycerol backbone) has been shown in rabbits to increase the atherogenic potential of the fat without impacting levels of blood lipids and lipoproteins. In contrast, enhancing the level of stearic acid in the sn-2 position has not been found to affect either atherogenic potential or levels of blood lipids and lipoproteins in rabbits. Fatty acids other than palmitic and stearic have not been studied systematically with respect to possible positional effects. A limited number of human studies have shown no significant effects of interesterified fats on blood lipid parameters. However, it is unknown whether modifying the stereospecific structure of dietary triglycerides would affect atherogenicity or other long-term health conditions in humans. It is possible that incorporation of palmitic acid into the sn-2 position of milk fat is beneficial to the human infant (as a source of energy for growth and development) but not to human adults. Additional research is needed to determine whether processes like interesterification, which can be used to alter physical parameters of dietary fats (e.g., melting characteristics), may result in favorable or unfavorable long-term effects in humans.
A reversed-phase HPLC-tandem mass spectrometry (RP-HPLC-MS-MS) method was refined for the positional analysis of complex mixtures of TAG. This method has the advantages of speed, ease of automation, and specificity over traditional digestion-based methods for the positional analysis of TAG. Collision-induced dissociation (CID) of ammoniated TAG in an ion-trap mass spectrometer produced spectra that were dependent on the FA position. Dominant DAG fragments were formed from the loss of a FA moiety from the ammoniated TAG species. The loss of FA in the outer positions was favored over their loss in the central position. The combination of RP-HPLC and CID produced spectra that were free of the isotope effects that can complicate spectral interpretation in existing methods. The combination also provided selectivity based on the chromatographic fractionation of TAG, in addition to the selectivity inherent in the CID process. Proof-of-concept experiments were performed with binary mixtures of TAG from the SOS/SSO, OSO/OOS, and the PSO/POS/SPO positional isomer systems (where S is 18:0, stearic acid; O is 18:1 (cis-9), oleic acid; and P is 16:0, palmitic acid). Plots of fractional DAG fragment intensities vs. fractional composition of the binary mixtures were linear. These plots were used to determine the fractional composition of each of these isomeric systems in a variety of vegetable oils and animal fats. Current limitations, future developments, and applications of this method are discussed.
Several studies have reported on the effect of refined, bleached and deodorized palm oil (RBD-PO) incorporation into the diet on blood cholesterol concentrations and on the development of atherosclerosis. However, very little work has been reported on the influence of red palm oil (RPO), which is higher in carotenoid and tocopherol content than RBD-PO. Thus, we studied the influence of RPO, RBD-PO and a RBD-PO plus red palm oil extract (reconstituted RBD-PO) on plasma cholesterol concentrations and aortic accumulation vs. hamsters fed coconut oil. Forty-eight F1B Golden Syrian hamsters (Mesocricetus auratus) (BioBreeders, Watertown, MA) were group housed (three/cage) in hanging polystyrene cages with bedding in an air-conditioned facility maintained on a 12-h light/dark cycle. The hamsters were fed a chow-based hypercholesterolemic diet (HCD) containing 10% coconut oil and 0.1% cholesterol for 2 weeks at which time they were bled after an overnight fast and segregated into four groups of 12 with similar plasma cholesterol concentrations. Group 1 continued on the HCD, Group 2 was fed the HCD containing 10% RPO in place of coconut oil, Group 3 was fed the HCD containing 10% RBD-PO in place of coconut oil and Group 4 was fed the HCD with 10% reconstituted RBD-PO for an additional 10 weeks. Plasma total cholesterol (TC) and non-high-density lipoprotein-cholesterol (HDL-C) (very low- and low-density lipoprotein) concentrations were significantly lower in the hamsters fed the RPO (-42% and -48%), RBD-PO (-32% and -36%) and the reconstituted RBD-PO (-37% and -41%) compared to the coconut oil-fed hamsters. Plasma HDL-C concentrations were significantly higher by 14% and 31% in hamsters fed the RBD-PO and RPO compared to the coconut oil-fed hamsters. Plasma triglyceride (TG) concentrations were significantly lower in hamsters fed RBD-PO (-32%) and the reconstituted RBD-PO (-31%) compared to the coconut oil-fed hamsters. The plasma gamma-tocopherol concentrations were higher in the coconut oil-fed hamsters compared to the hamsters fed the RPO (60%), RBD-PO (42%) and the reconstituted RBD-PO (49%), while for plasma alpha-tocopherol concentrations, the coconut oil-fed hamsters were significantly higher than only the RPO-fed hamsters (21%). The coconut oil-fed hamsters also had significantly higher plasma lipid hydroperoxide concentrations compared to RBD-PO (112%) and the reconstituted RBD-PO (485%). The hamsters fed the coconut oil diet excreted significantly more fecal total neutral sterols and cholesterol compared to the hamsters fed the RBD-PO (158% and 167%, respectively). The coconut oil-fed hamsters had significantly higher levels of aortic total, free and esterified cholesterol compared to the hamsters fed the RPO (74%, 50% and 225%, respectively), RBD-PO (57%, 48% and 92%, respectively) and the reconstituted RBD-PO (111%, 94% and 94%, respectively). Also, aortic free/ester cholesterol ratio in the aortas of hamsters fed RPO was significantly higher than in those fed the coconut oil (124%). In conclusion, hamsters fed the three palm oil preparations had lower plasma TC and non-HDL-C and higher HDL-C concentrations while accumulating less aortic cholesterol concentrations compared to hamsters fed coconut oil.
The effects of structured triglycerides containing one long chain fatty acid (oleic acid, C18:1) and one short chain saturated fatty acid (caprylic acid, 8:0) on lipidemia, liver and aortic cholesterol, and fecal neutral sterol excretion were investigated in male Golden Syrian hamsters fed a hypercholesterolemic regimen consisting of 89.9% commercial ration to which was added 10% coconut oil and 0.1% cholesterol (w/w). After 2 weeks on the HCD diet, the hamsters were bled, following an overnight fast (16 h) and placed into one of three dietary treatments of eight animals each based on similar plasma cholesterol levels. The hamsters either continued on the HCD diet or were placed on diets in which the coconut oil was replaced by one of two structured triglycerides, namely, 1(3),2-dicaproyl-3(1)-oleoylglycerol (OCC) or 1,3-dicaproyl-2-oleoylglycerol (COC) at 10% by weight. Plasma total cholesterol (TC) in hamsters fed the OCC and COC compared to the HCD were reduced 40% and 49%, respectively (P<0.05). Similarly, hamsters fed the OCC and COC diets reduced their plasma nonHDL cholesterol levels by 47% and 57%, respectively (P<0.05), compared to hamsters fed the HCD after 2 weeks of dietary treatment. Although hamsters fed the OCC (-26%) and COC (-32%) had significantly lower plasma HDL levels compared to HCD, (P<0.05), the plasma nonHDL/HDL cholesterol ratio was significantly lower (P<0.05) compared to the HCD for the OCC-fed (-27%) and the COC-fed (-38%) hamsters, respectively. Compared to the HCD group, aortic esterified cholesterol was 20% and 53% lower for the OCC and COC groups, respectively, with the latter reaching statistical significance, P<0.05. In conclusion, the hamsters fed the structured triglyceride oils had lower blood cholesterol levels and lower aortic accumulation of cholesterol compared to the control fed hamsters.
The atherogenic potential of a fat may be influenced by its structure. We tested 4 synthetic fats whose triglycéride structures were: SOS, SSO, POP and PPO (S=Stearic acid; O=oleic acid; P=palmitic acid). The fats were fed in a semipurified diet containing 15% fat (of which 34% = special fat; 38%=O-rich safflower oil (SFO); 28% =SFO and 0.05% cholesterol (C). Weanling rabbits were acclimated to a semi purified diet then 4 groups of 10 rabbits each were fed the diets for 20 weeks. Survival (%): SOS, 50; SSO, 70; POP, 70; PPO, 60. Serum lipids (mg/dl) C and % HDL-C: SOS 328 ±81 and 7.1 ±1.9; SSO, 272 ±55 and 9.3 ±3.0; POP, 308±55and8.3±3.0;PPO,415±103 and 7.9±3.1. Triglycérides: SOS, 68±8: SSO, 83±10; POP, 94±16;PPO, 81±25. Average atherosclerosis (severity in arch plus thoracic aorta+2) : SOS, 2.70±0. 41; SSO, 1.93±0.57; POP, 1.64±0.37; PPO-3.58±0.64. The result could not have been anticipated from the serum lipid levels. These findings confirm our earlier observations that randomization of fats affects their atherogenicity but not their lipidemic effects.
Earlier studies have suggested that the presence of palmitic acid in the SN2 position of a triglyceride increases its atherogenic potential. Cottonseed oil contains about 24% palmitic acid of which only 2% is present at SN2. After randomization one third of the palmitic acid of cottonseed oil is at SN2. Rabbits were fed a semipurified diet containing 14% native or randomized cottonseed oil and 0.10% cholesterol. After 90 days the rabbits fed the randomized cottonseed oil exhibited significantly more severe atherosclerosis than those fed the native cottonseed oil. Plasma lipid levels were similar in the two groups. The increased atherogenicity of the randomized cottonseed oil may reflect the increased absorbability of fats with palmitic acid at the SN2 position.
Tallow and lard are used as representative animal fats in experimental diets. We have compared their respective atherogenic properties by feeding each fat (14%) as part of a semi-purified diet containing 0.5% cholesterol. The lard containing diet was significantly (P < 0.001) more atherogenic than the diet containing tallow. Lard and tallow both contain approximately 24% palmitic acid (16:0) but the palmitic acid is distributed differently in their component triglyceride molecules. Over 90% of 16:0 of lard is at the SN2 position, whereas only approximately 15% of the 16:0 of tallow is in that position. The fats were randomized so that every component fatty acid was present at each triglyceride carbon to approximately one third of its total concentration. Randomized tallow and lard had 8.5% and 7.6% of their component 16:0 at the SN2 position, respectively. The atherogenicity of diets containing either randomized lard or tallow was virtually the same and significantly lower than the atherogenicity of the diet containing native lard. This study confirms earlier studies from our laboratory that suggest that the level of 16:0 at the SN2 position of a triglyceride influences its atherogenicity.
A comparison was made of the effects of cholesterol feeding in normal rabbits and in rabbits rendered persistently diabetic by means of alloxan. In the two groups of animals hypercholesterolemia of comparable degree was induced by the feeding procedure. Nevertheless, the severity of the atherosclerosis of the aorta produced in the diabetic rabbits was much less than in the non-diabetic control animals. Indeed, a large proportion of the diabetic animals presented no atherosclerosis whatever. There was a similar inhibition of the deposit of lipid substances in the liver, spleen, and adrenal glands of the diabetic rabbits.
The inhibition of the development of experimental cholesterol atherosclerosis which was associated with the presence of alloxan diabetes was independent of the administration of alloxan per se. It was not dependent on the sex or weight of the animal, nor upon the daily dosage of cholesterol, the form in which it was administered, nor the duration of cholesterol feeding. It was also independent of changes in body weight occurring during the course of our experiments and of the actual degree of hypercholesterolemia induced by the administration of cholesterol. In addition, there was no gross or histological evidence of a morphological basis for the inhibitory effect either in the aorta or in the other organs in which it was observed.
Only two factors were observed to be consistently associated with the inhibition of the expected morphological effects of cholesterol feeding, namely, the diabetic state and a degree of visible lipemia considerably greater than that observed in the control animals.
The inhibitory effect observed in these experiments would appear to depend upon some as yet undetermined factor or factors implicit in the diabetic state or closely associated with it. The experimental data presented demonstrate clearly that hypercholesterolemia is not the sole factor concerned in the genesis of experimental cholesterol atherosclerosis, but that another factor, or factors, rendered inoperative in our experiments must be essential to the production of the arterial lesions.
In view of the inhibitory effect on the development of experimental cholesterol atherosclerosis observed in alloxan-diabetic rabbits, the effect of alloxan diabetes on the retrogression of such arterial lesions was studied in another series of experiments. No effect on retrogression could be demonstrated within periods lasting up to a maximum of 4 months after the cessation of cholesterol feeding.
The results of our two series of experiments, considered together, indicate that the process of deposition of lipids in the arterial walls is governed by factors different from those that are operative in the process of removal of lipids after they have been deposited. The inhibition of the development of experimental cholesterol atherosclerosis in alloxan-diabetic rabbits must depend on interference with the process of deposition of lipids and not on a process of removal of lipids as fast as they are deposited.
Our experimental results find no direct application to the problem of arterial disease in human diabetes. Nevertheless, the experimental procedures that we have employed provide a new basis for the design of further experiments directed toward the elucidation of the nature of the unknown factors that govern the process of lipid deposition in the walls of arteries.
The purpose of this study was to evaluate the effects of large amounts of dietary vitamin E and butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT) in rabbits fed a low-cholesterol, atherogenic diet, and to seek for evidence of lipid peroxidation in the atherosclerotic lesions. Rabbits were fed a purified atherogenic diet, containing butter or the basal diet supplemented with either 1.0% of vitamin E or 0.1% each of BHA and BHT for periods up to 3 years; a negative control group was fed the basal diet with corn oil replacing butter. Aortic and coronary atherosclerosis were more frequent and extensive in rabbits fed either the basal diet or the basal diet supplemented with BHA and BHT than in rabbits fed either the basal diet supplemented with vitamin E or the negative control diet. Dietary vitamin E inhibited atherogenesis by preventing hypercholesterolemia. No evidence of lipid peroxidation was detected in the arterial lesions.
Marked hypercholesterolemia and moderate lipid infiltration of the aorta were induced by feeding rabbits a diet containing 1% cholesterol + 3% corn oil for 70 days. In the liver the concentration and pool size of cholesterol increased and those of triglycerides (TG) decreased. On dietary addition of vitamin A and vitamin E (44 000 I.U. and 125 mg respectively, once daily for 5 days a week) the following changes were noted in comparison with the fat-fed rabbits not receiving extra addition of vitamins. There was a slight decrease of the levels of plasma cholesterol and an increase of those of plasma TG. The liver cholesterol concentration increased but, according to the concomitant reduction of the liver weight, there was no significant change in lever cholesterol or TG pools. In the aorta the vitamins markedly reduced the lipid infiltrated area as well as the cholesterol content. Both niceritrol** and S-2040 [pyridine-2,5-dicarboxylic acid di(beta-pyridylcarbinol ester)] in a dietary concentration of 0.5% decreased plasma cholesterol by about 20%. This reduction, as well as that induced by the vitamins, was confined to the VLDL-fractions only. S-2040 slightly reduced the cholesterol accumulation in the aorta. In rabbits given both the vitamins and niceritrol or S-2042 there was an additive reduction of plasma cholesterol. Here the nicotinic acid derivatives were partly able to counteract the increases of plasma TG induced by the vitamins. In the aorta the combination vitamins + S-2042 but not that of vitamins + niceritrol tended to give a better protection than the vitamins alone. On a normal diet vitamins A + E significantly increased the liver cholesterol concentration and pool and decreased the liver TG pool, but did not affect the other parameters. Possible mechanisms for the prophylactic action of the vitamins against lipid infiltration of the aorta of cholesterol-fed rabbits are discussed.
For fifteen years, we have been conducting numerous experiments on the induction of atherosclerosis in male Dutch belted rabbits, testing a variety of dietary fats and several hypolipidemic drugs. In all of these experiments, the standard atherogenic regimen that provided the basis for comparison of treatments was 2% cholesterol and 6% corn oil added to laboratory ration. Although each experiment contained its own control, we noted that the atheromata in the control rabbits varied from experiment to experiment. In an effort to ascertain a possible seasonal variation in atherosclerosis we have collated by month of autopsy data from 74 experimental identical 2-month feeding periods.
Diacylglycerols have been separated as their (S)-(+)-or (R)-(-)-1-(1-naphthyl)ethyl urethanes by high performance liquid chromatography (HPLC) on a column of silica gel with 0.5% 2-propanol in hexane as the mobile phase. The elution order of components derivatized with the (S)-form of the reagent was 1,3-, followed by 1,2-, and finally 2,3-diacyl-sn-glycerols. The elution order of 1,2- and 2,3-diasteromers was reversed when the (R)-form of 1-(1-naphthyl)ethyl isocyanate was used for derivatization. Single-acid 1,2- and 2,3-diastereomers were separated to the baseline with a resolution factor from 5.2-5.7, and the resolution factor between 1,3- and 1,2- or 2,3-diacyl-sn-glycerol derivatives was more than 23. Molecular species of single-acid diacylglycerol derivatives were separated in the sequence 18:1 less than 18:0 less than 18:2 less than 16.0. In order to assess this methodology as part of a procedure for the stereospecific analysis of triacyl-sn-glycerols, we prepared diacyl-rac-glycerols from maize oil, evening primrose oil and egg yolk triacylglycerols by partial hydrolysis with ethyl magnesium bromide. The 1,3-, 1,2- and 2,3-diacyl-sn-glycerols as (S)-(+)-1-(1-naphthyl)ethyl urethanes were isolated and their fatty acid compositions were determined. Although this only permitted an indirect determination of the compositions of positions sn-1, -2 and -3, it was sufficient to indicate the potential of the methodology because results comparable to those published earlier were achieved.
Atherosclerosis and hypercholesterolemia have been produced in rabbits since 1913 by feeding them cholesterol. These experiments have a great influence on current thinking about the etiology and possible prevention of ischemic heart disease. Male, New Zealand White rabbits were fed 0.5% dietary cholesterol. Cholesterol and copper in plasma increased sixty-fold and 50%, respectively. Liver copper decreased 74% and hematocrit decreased 26%. Iron was unchanged in heart and liver, but was increased in kidney. Zinc was decreased in heart, but was unchanged in liver or kidney. Changes in organ iron and zinc were smaller than the decrease in liver copper. Similar experiments with higher doses of dietary cholesterol may have resulted in copper deficiency. It may be appropriate to revise interpretations of data from these experiments and to reformulate hypothesis based on the data. Results are consonant with the theoretical implication of copper metabolism and copper deficiency in the etiology and pathogenesis of ischemic heart disease.
There is no longer any doubt that high plasma levels of LDL are atherogenic and that lowering them can reduce the risk of coronary heart disease, but the specific events induced by high levels of LDL in the artery wall are only now being elucidated. Once these processes are understood, we may find that there are ways to intervene at the level. Recent advances have brought us closer to being able to do this with regard to the uptake of LDL by macrophages and the development of the fattty streak, the earliest lesion in atherogenesis. Studies both in vitro and in vivo support the hypothesis that LDL undergoes an oxidative modification that targets it for uptake by the macrophage through a specific receptor - the acetyl LDL or scavenger receptor. Intervention studies in the LDL receptor-deficient animal model for atherosclerosis (the WHHL rabbit), using probucol as an antioxidant, show that the progression of the fatty streak can be slowed under conditions that do not lower plasma cholesterol levels. Much more remains to be done to establish the clinical relevance of these findings. Nevertheless, the experimental data available to date encourage aggressive additional research on the oxidative modification of LDL. This review has emphasized the oxidative modification of LDL because the evidence for its occurrence in vivo and for its role in atherogenesis is already persuasive. However, we recognize that with further study additional modifications may prove to be equally important or even more important. For example, the glycation of LDL may help explain the increased susceptibility of diabetic subjects to atherosclerotic complications. If so, rigid control of hyperglycemia may reduce such complications. As we learn more about these and other postsecretory modifications of LDL, we can hope to find ways of preventing them. To the extent that modifications of these kinds play an important part in atherogenesis, we may be able to intervene and obtain protection beyond that obtained by lowering plasma LDL levels.
A metabolic balance study was performed with 11 newborn infants fed formulas identical except for the type of fat. Five infants received a formula containing natural lard (palmitic acid primarily in the 2-position of the triglyceride molecule) while six infants received a formula containing randomized lard (palmitic acid equally distributed among the 1-, 2-, and 3-positions of the triglyceride molecule). Excretion of fat by infants fed the formula containing natural lard averaged 0.30 g/kg per day (range 0.15 to 0.50) while that by infants fed randomized lard averaged 1.79 g/kg per day (range 1.09 to 3.11). All of the fatty acids of the natural lard were absorbed better, but this was most marked in the case of palmitic and stearic acids. The greater absorption of palmitic acid from lard is believed to result from the greater content of 2-monopalmitin and the lower content of free palmitic acid present in the intestine after hydrolysis. Although there is no obvious mechanism to explain the greater absorption of stearic acid from lard, it may be due to a more rapid rate or greater extent of micellization in the presence of greater amounts of 2-monopalmitin.
A fat absorption study was conducted in rats to determine if the unusually high proportion of palmitic acid in the 2-position of triglycéridescould be related to the superior absorption of human milk fat. Digestion yields free fatty acids and 2-monoglycerides. The monoglycerides of the saturated fatty acids are more readily absorbed than the free acids. Tests run on a number of fats commonly fed to infants, showed that the high absorption of human milk fat, 94.6 (%), was equaled by a fat blend of a similar fatty acid composition with a high content of 2-palmitoyltriglyceride, 96.3, in contrast to one with low content, 89.9. Absorption of butterfat was 89.5, lard 92.4 and oleo 79.9. Individual fatty acid absorption was influenced by total fat absorption. A linear relationship between absorption and the proportion in the 2 position was demonstrated for palmitic, and to a lesser extent, for myristic and oleic, but net for stearic acid. Equations predicting fat absorption required emphasis of the product of stearic acid and palmitic acid esterified in the primary positions.
Human milk contains palmitic acid predominantly in the triglyceride sn-2 position, and differs from the palmitic acid positional distribution found in most infant formulas (predominantly positions sn-1 and sn-3). Following lipolysis by pancreatic lipase, 2-monoglycerides and free fatty acids are produced. All 2-monoglycerides are well absorbed, including 2-monopalmitin, thus providing one reason for the efficient absorption of palmitic acid in breast-fed infants. If infants are fed fat blends with palmitic acid located in the sn-1 and sn-3 positions, the resulting free fatty acids may form poorly absorbed calcium soaps. Therefore, many infant formulas contain only modest levels of palmitic acid.
Fat absorption studies were conducted in rats with preparations containing various amounts of palmitic acid in the triglyceride sn-2 position. Determining total fat absorption, specific fatty acid absorption, and the presence of calcium-fatty acid soaps.
Betapol, a new triacylglycerol, similar to human milk in its palmitic acid content and positional distribution, demonstrated excellent absorption characteristics compared to fat blends derived from either palm olein or oleo (similar in fatty acid profile to Betapol, but with most palmitic acid in the sn-1 and sn-3 positions). A five-point dose response was used to further evaluate the relationship of positional distribution and fat loss. Palmitic acid excretion and fecal fatty acid soaps were negatively correlated to the presence of palmitic acid in the sn-2 position.
These studies provide evidence that palmitic acid can be efficiently absorbed, avoiding fatty soap formation of it is present in the sn-2 position.