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1.
Arne T. Høstmark Øystein Spydevold Einar Lystad Eva Kristensen Ida Goffeng Bay 《Lipids》1982,17(7):489-499
The effect of varying the dietary sunflower oil/sucrose (SO/SU) ratio on rat plasma lipid concentration and lipoprotein distribution
was studied. Four groups of 10 rats were fed for 4 weeks diets with varying SO/SU ratios. Lipoprotein components were then
estimated in whole plasma and after cumulative density ultracentrifugation. Whole plasma triacylglycerol (TG), total cholesterol
(TC) and free cholesterol (FC) decreased with increasing SO/SU ratio; the CE/FC ratio increased, because CE remained virtually
unaltered. Plasma TG-lowering was due to a decrease in VLDL and LDL-TG. Protein, CE and FC in d=1.063–1.100 g/ml (HDL2b) and d=1.100–1.125 g/ml (HDL2a) lipoproteins decreased upon increasing the SO/SU ratio. In contrast, in d=1.125–1.200 g/ml (HDL3) lipoproteins, there was a concomitant increase in these components. Although increasing the SO/SU ratio effected more protein
and CE transportation in HDL3 and less in HDL2, the total amount of these components in high density lipoproteins (d=1.063–1.200 g/ml) remained constant. Apo A-I and apo
C-III decreased in HDL2 but increased in HDL3 upon increasing the SO/SU ratio. Also, HDL2 apo E, and the apo C-II/apo C-III and small apo B/large apo B ratios in VLDL and LDL were lowered by increasing the SO/SU
ratio. The hepatic VLDL-TG output during isolated liver perfusion was lowest in rats fed the diet with the highest SO/SU ratio.
In perfusate, like in plasma, the VLDL and LDL apo C-II/apo C-III ratio, as well as the small apo B/large apo B ratio, decreased
upon increasing the dietary SO/SU ratio. The results indicate that there can be appreciable diet-dependent variations in plasma
HDL subgroup distribution in spite of unchanged total HDL levels. 相似文献
2.
Maria Luz Fernandez A. Karin Conde Laura R. Ruiz Carlos Montano John Ebner Donald J. McNamara 《Lipids》1995,30(7):619-626
To test the effects of exchanging dietary complex and simple carbohydrate for fat calories on lipoprotein metabolism, guinea
pigs were fed two different fat/carbohydrate ratios: 2.5∶58% (w/w) or 25∶29% (w/w) with either sucrose or starch as the carbohydrate
source. Animals fed high-fat had higher plasma low-density lipoprotein (LDL) and hepatic cholesterol concentrations than animals
fed low-fat diets (P<0.01). The cholesteryl ester content per particle was higher, and the number of triacylglycerol (TAG) molecules was lower
in very low density lipoprotein (VLDL) and LDL from animals fed high-fat diets. Intake of high-fat/sucrose resulted in higher
plasma LDL concentrations than intake of high-fat/starch, and animals fed low-fat/starch had the highest plasma TAG concentrations
associated with VLDL particles containing more TAG molecules, as well as a TAG-enriched LDL. The activity of plasma lecithin
cholesteryl:acyl transferase (LCAT) was highest in animals fed high-fat/sucrose, and heart lipoprotein lipase (LPL) activity
was higher in animals fed high-fat diets. Hepatic apoprotein B/E (apo B/E) receptor number (Bmax) was increased 21% with low-fat diets (P<0.01). These results suggest that the hypercholesterolemia induced by high-fat and by sucrose intake are associated with
a higher plasma LCAT activity which results in a cholesteryl ester-enriched VLDL which, by the action of LPL, might be more
readily converted to LDL through the delipidation cascade leading to downregulation of hepatic apo B/E receptors. The hypertriglyceridemia
associated with low-fat intake may result from increased production of VLDL TAG, which would explain the increased TAG content
and the higher TAG/CE ratio of VLDL from animals fed the low-fat/starch diet. 相似文献
3.
Because lipoproteins and platelet aggregation have been implicated in atherogenesis, relative differences in the response
of these variables to dietary fat saturation were compared in three species of monkeys differing in their susceptibility to
atherosclerosis (cebus, rhesus, and squirrel monkeys). Both long-term (8–12 years) and short-term (8 weeks) responses to diets
containing 31% fat calories were examined in the same monkeys. As expected, long-term feeding of coconut oil by comparison
to corn oil produced significantly higher plasma concentrations of total cholesterol, LDL cholesterol, apoB, and triglycerides,
as well as higher ratios of LDL/HDL cholesterol and apo B/apo A-I. These responses were characteristic of all species with
cebus being most responsive and rhesus the least. The shortterm plasma cholesterol response to animal fats (butter, lard,
beef tallow) was significantly less than that to coconut oil. When fish oil was substituted for two-thirds of either corn
oil or coconut oil, exceptional decreases occurred in plasma cholesterol and triglycerides, as well as in HDL cholesterol
and apo A-I concentrations despite the fact that the fish oil diets contained more saturated fat and less polyenes than the
corn oil diet. Platelet aggregation tended to increase with saturated fat consumption and greatly decreased with fish oil
intake in all monkeys, although cebus monkeys were ten-fold more resistant to platelet aggregation than the other two species.
The molecular species of platelet phosphatidylcholine (PC) varied with both the dietary fat fed and species of monkey. An
inverse correlation (r=−0.60; p<0.001) was found between changes in one such PC molecular species (18∶0−20∶4) induced by diet
and the platelet aggregation threshold. These results demonstrate that the lipemic and platelet responses to dietary saturated
fat depend upon both the type of fat (i.e., the specific combination of dietary fatty acids, including the chain length of saturated fatty acids and the degree of polyunsaturation)
and the species of monkey (genetic component) in which the response is elicited. 相似文献
4.
Response of free and esterified plasma cholesterol levels in the mongolian gerbil to the fatty acid composition of dietary lipid 总被引:2,自引:0,他引:2
The present study was undertaken to investigate the potential suitability of the Mongolian gerbil as a useful animal model
to study the effects of dietary fats on plasma cholesterol levels. Semipurified diets containing either 20% lard, 20% safflower
oil, or 19.5% beef tallow +0.5% safflower oil were equalized to contain 0.01% cholesterol and 0.05% plant sterol and were
fed for a four week experimental period. The proportions of total calories contributed by fat, protein and carbohydrate (starch/sucrose
ratio of 2∶1) were 40, 14 and 46%, respectively, so as to approach the distribution of calories within the average North American
diet. Free, esterified, and total plasma cholesterol levels of male gerbils were determined weekly by gas liquid chromatography
after drawing blood via a serial sampling technique. After 1, 2, 3, and 4 weeks of feeding the experimental diets, total cholesterol
levels were lowest in the safflower oil fed animals; the corresponding values were 19–64% greater in gerbils fed lard and
68–91% greater in those consuming the beef tallow diet. Cholesterol in the free form generally responded more dramatically
to the type of dietary lipid than did cholesterol in the ester form. Irrespective of the type of dietary lipid or the length
of the feeding trial, 18–23% of the total plasma cholesterol was in the free form and 77–82% was present as the ester. In
view of the similarity to the human of the relative proportions of free versus esterified cholesterol, the type of cholesteryl
esters, and their response to dietary manipulation, the gerbil appears to be a useful animal model for studying the regulatory
effect of dietary lipid on plasma cholesterol levels.
Presented in part at the A.O.C.S. Annual Meeting, San Francisco, CA, May 1979. 相似文献
5.
Preterm guinea pigs were delivered on day 65 of gestation (term=68 d) and were allowed either free or restricted access to
food for the subsequent 48 h. Plasma phosphatidylcholine (PC) concentration increased postnatally from 190 (range 144–307)
to 751 (426–1039) and 883 (758–977) μM for fed and starved pups, respectively. Plasma PC composition in both groups of pups
was characterized by selective and equivalent relative increases to individual molecular species containing 18∶0 at thesn-1 position. Hepatic PC concentration increased from 6.75 (5.41–8.20) to 8.65 (6.54–10.63) and 9.23 (8.18–10.17) μmol/g for
fed and starved pups, respectively, and, under all conditions, hepatic PC molecular composition closely mirrored that of plasma
PC. These results support the hypothesis that the molecular species composition of plasma PC for the guinea pig in the immediate
postnatal period is determined largely by the composition of the hepatic PC pool destined for lipoprotein secretion. Hepatic
PC composition and concentration of the starved neonatal guinea pig were maintained independently of any dietary nutrient
intake, at the expense of mobilization of extra hepatic lipid reserves. While this adaptive mechanism has inherent limited
survival potential in neonatal starvation, it has implications for studies measuring plasma phospholipid fatty acid compositions
as biochemical markers of dietary fat intake in preterm infants. 相似文献
6.
For four weeks, groups of eight male and eight female F344/N rats were fed diets containing 15.5, 20, 30 or 40% of energy
(en%) as fat. The fat was composed of corn oil and beef tallow with 9 en% from linoleate in all diets. Females had greater
mean hepatic α-tocopherol levels, whereas males had greater plasma α-tocopherol and cholesterol concentrations. In males,
the plasma ratio of α-tocopherol/cholesterol was significantly greater than in females (P<0.05). Plasma α-tocopherol increased with increasing en% fat (r=0.51,P<0.001) in both sexes, but dietary fat did not alter hepatic α-tocopherol levels. These results suggest that plasma α-tocopherol
may serve as a biomarker of total dietary fat intake and that in F344/N rats gender differences affect α-tocopherol and cholesterol
status. 相似文献
7.
M. Kruger C. M. Smuts A. J. S. Benadé J. E. Fincham C. J. Lombard E. A. Albertse K. J. van der Merwe 《Lipids》1992,27(10):733-739
The effects of the degree of unsaturation and of the amount of dietary fat on low density lipoprotein (LDL) concentration
and composition were determined in vervet monkeys. Diets with fat contents of 41, 31 and 18% energy, each with a low and a
high polyunsaturated to saturated fatty acid ratio (P/S; 0.27–0.38 and 1.13–1.47) were fed to six female vervet monkeys for
two months. Another six females were given a low fat, high P/S diet for the same period of time, to serve as a reference.
The cholesterol contents of the diets were low (21–33 mg per day) and relatively constant. LDL cholesterol concentrations
decreased significantly (P≤0.01) when the dietary fat content decreased from 31 to 18% of energy. The dietary P/S ratio only affected LDL cholesterol
concentrations during moderate (31% of energy) fat intake, where LDL cholesterol increased (P≤0.01) with a decrease in dietary P/S. Substantial individual variations were observed in LDL cholesterol concentration responses
to dietary fat changes. The changes in LDL cholesterol concentrations were the result of changes in the concentration of LDL
particles, as the molecular composition did not differ significantly between dietary periods. The high density lipoprotein
choelsterol and the plasma triacylglycerol concentrations were not influenced by the dietary fat changes. During the high
P/S diets, the percentage of 18∶2 (linoleic acid) increased (P≤0.01) and that of 18∶1 (oleic acid) decreased (P≤0.01) in LDL esterified cholesterol, as compared to the low P/S diets. In adipose tissue triacylglycerol the percentage of
18∶2 was three times higher (P≤0.01) during the high P/S diets than during the low P/S diets. A decrease in the amount of dietary fat (from 31 to 18% of
energy) was associated with an increase in the percentage of 18∶1 in LDL esterified cholesterol. 相似文献
8.
Interrelationship of stearic acid content and triacylglycerol composition of lard,beef tallow and cocoa butter in rats 总被引:4,自引:0,他引:4
We investigated modes whereby stearic acid (18∶0) exerts a neutral or cholesterol-lowering effect using dietary fats which
provided graded levels of 18∶0 and distinct triacylglycerol (TAG) profiles. Male Sprague-Dawley rats (150–175 g) were fed
diets containing 0.2% cholesterol and 16% fat from corn oil, or from 1% corn oil plus 15% lard (13.2% 18∶0), beef tallow (19.2%
18∶0) or cocoa butter (34.7% 18∶0) for 3 wk, and then killed in a fasted or fed state. Chylomicron (CM) fatty acid profiles
suggested reduced absorption of 18∶0 with greater 18∶0 intake. CM TAG profiles indicated a reduction or loss of two TAG species
compared to the TAG profiles of the stearate-rich diets: 1-palmitoyl-2-oleoyl-3-stearoyl glycerol (POS) and 1,3-distearoyl-2-oleoyl
glycerol (SOS). Hepatic total cholesterol concentrations were 54–77% lower (P<0.01) in the cocoa butter-fed than the lard- and beef tallow-fed groups. The cocoa butter group showed a significantly lower
ratio of high-density lipoprotein esterified/free cholesterol than all other groups. Hepatic stearoyl-CoA and oleoyl-CoA concentrations,
the substrate and product for hepatic δ9 desaturase, were not significantly different for corn oil-fed and cocoa butter-fed
groups in spite of a large difference in 18∶0 intake. These data suggest that the neutral or cholesterol-lowering effect of
18∶0 is not due to hepatic conversion of stearic to oleic acid, and that POS and SOS are poorly absorbed from stearate-rich
dietary fats. 相似文献
9.
Mixtures of triglycerides containing deuterium-labeled hexadecanoic acid (16∶0), octadecanoic acid (18∶0),cis-9-octadecenoic acid (9c–18∶1),cis-9,cis-12-octadecadienoic acid (9c, 12c–18∶2) andcis-12,trans-15-octadecadienoic acid (12c,15t–18∶2) were fed to two young-adult males. Plasma lipid classes were isolated from samples
collected periodically over 48 hr. Incorporation and turnover of the deuterium-labeled fats in plasma lipids were followed
by gas chromatography-mass spectrometry (GC-MS) analysis of the methyl ester derivatives. Absorption of the deuterated fats
was followed by GC-MS analysis of chylomicron triglycerides isolated by ultracentrifugation.
Results were the following: (i) endogenous fat contributed about 40% of the total fat incorporated into chylomicron triglycerides;
(ii) elongation, desaturation and chain-shortened products from the deuterated fats were not detected; (iii) the polyunsaturated
isomer 12c,15t–18∶2 was metabolically more similar to saturated and 9c–18∶1 fatty acids than to 9c,12c–18∶2 (iv) relative
incorporation of 9c,12c–18∶2 into phospholipids did not increase proportionally with an increase of 9c,12c–18∶2 in the mixture
of deuterated fats fed; (v) absorption of 16∶0, 18∶0, 9c–18∶1, 9c,12c–18∶2 and 12c,15t–18∶2 were similar; and (vi) data for
the 1- and 2-acyl positions of phosphatidylcholine and for cholesteryl ester fractions reflected the known high specificity
of phosphatidylcholine acyltransferase and lecithin:cholesteryl acyltransferase for 9c,12c–18∶2.
These results illustrate that incorporation of dietary fatty acids into human plasma lipid classes is selectively controlled
and that incorporation of dietary 9c,12c–18∶2 is limited. These results suggest that nutritional benefits of diets high in
9c,12c–18∶2 may be of little value to normal subjects and that the 12c,15t–18∶2 isomer in hydrogenated fat is not a nutritional
liability at the present dietary level. 相似文献
10.
Effects of expansion of the hepatic free cholesterol pool on bile acid and cholesterol metabolism and homeostasis were examined
in rats fed cholesterol in high-fat diets or treated with oleyl-p-(n-decyl)-benzenesulfonate (ODS) or progesterone. Cholesterol feeding for 10–16 days, which increased free (33%) and esterified
(6-fold) cholesterol, had no effect on cholate synthesis, total bile acid synthesis, or cholate turnover, whereas these activities
were increased 60–80% by ODS and progesterone, which produced only small increases (19%) in free cholesterol. Cholesterol
feeding reduced β-hydroxy-β-methylglutaryl (HMG)-CoA reductase (72%) and cholesteryl ester hydrolase (48%) and increased acyl-CoA:cholesterol
acyltransferase (184%), whereas ODS and progesterone reversed these compensatory responses in cholesterol-fed rats. Cholesterol
7α-hydroxylase was changed no more than 22% by any treatment. A bolus of ODS elevated biliary cholesterol output 41% and shifted
biliary bile acid synthesis and composition toward 12-deoxy bile acids. These effects were not seen in ODS-fed or progesterone-treated
rats, in which cholesteryl ester stores were depleted. It is concluded that effects of free cholesterol on bile acid synthesis
and biliary cholesterol are probably mediated by specific precursor or regulatory pools which can be independently regulated
and which represent a relatively small fraction of hepatic free cholesterol. 相似文献
11.
Trans, trans-linoleate at 50 and 100% of dietary fat decreased kidney size and altered its composition.Trans, trans-linoleate as the sole source of dietary fat imparied growth and caused more severe symptoms of essential fatty acid deficiency
than was observed with hydrogenated coconut oil (HCO). The concentration of renal cholesterol, phospholipids (PL), triglycerides
(TG) and cholesteryl esters (CE) were also decreased. Linoleic (18∶2), homo-γ-linolenic acid (20∶3n6) and arachidonic acid
(20∶4n6) were significantly depressed in lipid classes, especially in PL and CE, by dietarytrans, trans-linoleate. The increase in eicosatrienoate (20∶3n9), especially in PL and CE of kidneys of rats fed HCO (essential fatty
acid deficient), was slight in rats fed 100%trans, trans-linoleate, indicating that thetrans, trans acid probably inhibited acyl elongation and desaturation. 相似文献
12.
Sathanur R. Srinivasan Bhandaru Radhakrishnamurthy Edward R. Dalferes Jr. Gerald S. Berenson 《Lipids》1979,14(6):559-565
Serum α-lipoprotein responses to variations in dietary cholesterol, protein, and carbohydrate were studied in different nonhuman
primate species. Chimpanzee, rhesus, green, patas, squirrel and spider monkeys all showed significant interspecies differences
in serum total cholesterol responses to 1.84 mg/kcal exogenous cholesterol. Dietary cholesterol significantly increased the
α-lipoprotein cholesterol in all species except rhesus and chimpanzee. Among these species, there was no relationship between
the basal serum lipoprotein profile and subsequent lipoprotein responses to dietary cholesterol. Although the level of dietary
protein at 6%, 12%, and 37% of calories had no appreciable main effect on serum total cholesterol in spider monkeys, very
low protein diet (6% of calories) produced a significant elevation in α-lipoprotein cholesterol. Serum α-lipoprotein responses
to exogenous cholesterol (1.84 mg/kcal) was highest for the very low protein diet and lowest for low protein diet (12% of
calories). Diets with high sucrose (76.5% of calories) and low saturated fat (12.5% of calories) containing no added cholesterol
were tested in squirrel and spider monkeys and produced a consistent serum total cholesterol response; the α-lipoprotein response
was significantly higher in squirrel monkeys than in spider monkeys. The above findings have implications in experimentally
induced and comparative atherogenesis.
Presented at the Lipoprotein Symposium AOCS meeting, St. Louis, Missouri, May 1978. 相似文献
13.
Male Wistar rats were maintained for 30 days on an independent and continuous intragastric infusion of ethanol and nutritionally
defined liquid diet containing only a small amount of corn oil (CO-4.9% calories). Ethanol intake was progressively increased
from 32% to 40.4% of the total calories to maintain a high degree of intoxication during this period. Rats in the control
group were infused with an isocaloric diet in which alcohol was replaced by dextrose. The liver triglyceride (TG) content
of rats given alcohol (61.5±16.4 mg/g) was ca. 10-fold greater than that of controls (5.9±2.1 mg/g) and similar to that observed
previously in rats fed an ethanol diet containing high levels of fat (35% and 43% calories). In TG of fatty liver, the level
of 18∶2 was small (3%), even though CO in the diet contained a high level of this acid. Furthermore, 16∶1 and 16∶0 contents
were markedly elevated (16% and 40%, respectively) despite the fact that CO did not contain 16∶1 and had only a small amount
of 16∶0. Liver TG having a fatty acid (FA) composition markedly different from that of CO and the presence of high levels
of 16∶1 and 16∶0 indicate that the TG accumulated in the fatty liver originated from hepatic lipogenesis rather than from
dietary fat. 相似文献
14.
In the prairie dog model of cholesterol cholelithiasis, a high incidence of gallstones is achieved by feeding a semipurified
lithogenic diet containing 0.4% cholesterol for 2 mo. On occasion, we noted a decrease in the percentage of animals with gallstones
from 90–100% to 50–55%. To explain this phenomenon, we studied the effect of dietary history on gallstone formation. After
weaning, animals were fed either rodent chow or alfalfa plus corn (mo 0–3) followed by a cross-over experiment at mo 4–6.
Gallstone formation then was studied by feeding the lithogenic diet from mo 7 to 8. At sacrifice, the incidences of gallstones,
biliary lipids and tissue cholesterol levels were correlated with dietary history. The incidence of gallstones was 100% only
in animals fed the alfalfa-corn diet from weaning to 3 mo. In addition, the feeding of the alfalfa-corn diet at mo 4–6 increased
gallstone incidence from 65% to 86%. The lithogenic index of all groups was highest when the animals received only alfalfa-corn
prior to the lithogenic stimulus. The activity of hepatic HMG-CoA reductase was elevated in animals fed alfalfa-corn from
weaning to 8 mo, suggesting that this diet stimulates hepatic cholesterol synthesis, leading to increased biliary cholesterol
secretion. It is concluded that previous nutritional conditioning affects the incidence of gallstones. The prairie dog is
a useful model of cholesterol cholelithiasis, but the dietary history of the animals plays an important role in lithogenesis. 相似文献
15.
This experiment was designed to evaluate the effects of dietary red wine phenolic compounds (WP) and cholesterol on lipid
oxidation and transport in rats. For 5 wk, weanling rats were fed polyunsaturated fat diets (n−6/n−3=6.4) supplemented or
not supplemented with either 3 g/kg diet of cholesterol, 5 g/kg diet of WP, or both. The concentrations of triacylglycerols
(TAG, P<0.01) and cholesterol (P<0.0002) were reduced in fasting plasma of rats fed cholesterol despite the cholesterol enrichment of very low density lipoprotein
+ low density lipoprotein (VLDL+LDL). The response was due to the much lower plasma concentration of high density lipoprotein
(HDL) (−35%, P<0.0001). In contrast, TAG and cholesteryl ester (CE) accumulated in liver (+120 and +450%, respectively, P<0.0001). However, the cholesterol content of liver microsomes was not affected. Dietary cholesterol altered the distribution
of fatty acids mainly by reducing the ratio of arachidonic acid to linoleic acid (P<0.0001) in plasma VLDL+LDL (−35%) and HDL (−42%) and in liver TAG (−42%), CE (−78%), and phospholipids (−28%). Dietary WP
had little or no effect on these variables. On the other hand, dietary cholesterol lowered the α-tocopherol concentration
in VLDL+LDL (−40%, P<0.003) and in microsomes (−60%, P<0.0001). In contrast, dietary WP increased the concentration in microsomes (+21%, P<0.0001), but had no effect on the concentration in VLDL+LDL. Cholesterol feeding decreased (P<0.006) whereas WP feeding increased (P<0.0001) the resistance of VLDL+LDL to copper-induced oxidation. The production of conjugated dienes after 25 h of oxidation
ranged between 650 (WP without cholesterol) and 2,560 (cholesterol without WP) μmol/g VLDL+LDL protein. These findings show
that dietary WP were absorbed at sufficient levels to contribute to the protection of polyunsaturated fatty acids in plasma
and membranes. They could also reduce the consumption of α-tocopherol and endogenous antioxidants. The responses suggest that,
in humans, these substances may be beneficial by reducing the deleterious effects of a dietary overload of cholesterol. 相似文献
16.
Malondialdehyde (MDA) production and cytosolic aldehyde dehydrogenase (ALDH) response were examined in rat liver tissues after
feeding different levels of dietary vitamin E and/or selenium and polyunsaturated fat for 12–38 wk. MDA production was significantly
increased by vitamin E deficiency or by high levels of polyunsaturated fat intake, but not by selenium deficiency. The activity
of cytosolic ALDH increased upon increased production of MDA after 12–16 wk of feeding the lipid peroxidation-inducing diets.
However, ALDH activity was suppressed after 38 wk of feeding the vitamin E-deficient diet. The results indicate that the hepatic
cytosolic ALDH may be involved in the metabolism of MDA during a relatively short-term increase inin vivo lipid peroxidation, but that ALDH activity becomes suppressed after more severein vivo lipid peroxidation has been produced. Hepatic and plasma α-tocopherol levels and lipid peroxidation products were measured
for the various dietary groups. 相似文献
17.
In this study, the relationships between dietary fat [as measured by serum cholesterol ester fatty acids (CE-FA)], age, smoking,
body mass index, and serum lipids were analyzed in 151 subsistence horticulturalists, aged 20–86 yr, from Kitava, Trobriand
Islands, Papua New Guinea. Their diet consists of tubers, fruit, coconut, fish, and vegetables with a negligible influence
of western food and alcohol. Total fat intake is low [21% of energy (en%)], while saturated fat intake from coconuts is high
(17 en%, mainly lauric and myristic acid). In multivariate analysis, 11–43% of the variation of the serum lipoprotein composition
was explained by CE-FA, age, and smoking habits. The proportion of CE20∶5n-3 explained much of the variation of triglycerides
(TG, negative relation) and high density lipoprotein-cholesterol (HDL-C, positive) in both sexes and serum apolipoprotein
A1 (ApoA1, positive) in the males. CE16∶0 was positively related to TG and negatively related to HDL-C and ApoA1 in both sexes,
and in males it related negatively to total cholesterol (TC) and low density lipoprotein-cholesterol (LDI-C). In males, negative
relationships were present between CE18∶2n-6 and TC and between CE14∶0 and serum lipoprotein(a). Smoking was independently
associated with lower ApoA1 in both sexes and with lower HDL-C and higher TG, TC, LDL-C, and apolipoprotein B in males. In
conclusion, marine n-3 fatty acids and linoleic acid showed the same potentially beneficial relationships with lipoproteins
and apolipoproteins as in western populations. The relations of palmitic acid to serum lipids may be explained in terms of
endogenous fat synthesis at a low-fat intake, rather than reflecting its relative intake. 相似文献
18.
To compare the relative impact of dietary lauric acid (12∶0) and palmitic acid (16∶0) on plasma lipids, two fat-sensitive
species, Mongolian gerbils and cebus monkeys, were fed cholesterol-free, purified diets enriched with either 12∶0-rich or
16∶0-rich fats, while all other fatty acids were held constant by selective blending of up to five natural fats or oils. The
two gerbil diets (40 en% from fat) allowed for an 8 en% exchange between 12∶0 and 16∶0, and the monkey diets (31 en% from
fat) allowed for 6 en% exchange beteen these two fatty acids. Eight gerbils received the diets for eight weeks, and 12 cebus
monkeys were fed each diet in a cross-over design for up to 22 wk. Both diets resulted in similar plasma cholesterol, triglyceride,
and high density lipoprotein cholesterol concentrations within each species. Additionally, separation of cebus lipoproteins
by discontinuous density-gradient ultracentrifugation failed to show any dietary differences in concentration or composition
of the three major lipoprotein classes (d<1.019, 1.019–1.055, and 1.055–1.168 g/mL). Thus, in two species sensitive to manipulations
in dietary fat while consuming cholesterol-free diets, 16∶0 was not hypercholesterolemic relative to 12∶0.
Based on a paper presented at the PORIM International Palm Oil Congress (PIPOC) held in Kuala Lumpur, Malaysia, September
1993. 相似文献
19.
Rats were fed ethanol and a fat-free diet for 30 days to determine whether dietary fat is needed for the development of fatty
liver. The severity of fatty liver was similar to that of rats fed an isocaloric diet with 35% fat. Small amounts (29 mg/day)
of dietary arachidonic acid prevented alcoholic fatty liver. Rats fed either the alcohol (AF) or control (CF) fat-free diets
developed essential fatty acid deficiency (EFAD) as measured by the triene/tetraene ratio of liver and plasma lipids. Rats
fed arachidonic acid (AA, alcohol and CA, control diets) did not develop EFAD. Although EFAD alone did not cause the development
of fatty liver, the combination of dietary ethanol and EFAD did. The ratios of 16∶1/16∶0 and 18∶1/18∶0 in liver lipids indicated
that desaturase enzymes were less active and lipogenesis was reduced in rats fed the AA diet compared to those fed the AF
diet. In contrast, stimulated lipogenesis appears to have been the cause of fatty liver in rats fed the AF diet.
Presented at the XII International Congress of Nutrition, San Diego, CA, August 1981.
Abbreviations: Diets are indicated as fat-free with ethanol (AF), fat-free without ethanol (CF), or similar diets with 0.9%
of the calories as arachidonic acid with (AA) or without (CA) ethanol. The composition of these diets is discribed in the
text and Table 1. 相似文献
20.
This study examined the effect on the plasma lipids and plasma phospholipid and cholesteryl ester fatty acids of changing
from a typical western diet to a very low fat (VLF) vegetarian diet containing one egg/day. The effect of the addition of
saturated, monounsaturated or polyunsaturated fat (PUFA) to the VLF diet was also examined. Three groups of 10 subjects (6
women, 4 men) were fed the VLF diet (10% energy as fat) for two weeks, and then in the next two weeks the dietary fat in each
group was increased by 10% energy/week using butter, olive oil or safflower oil. The fat replaced dietary carbohydrate. The
VLF diet reduced both the low density lipoprotein (LDL)-and high density lipoprotein (HDL)-cholesterol levels; addition of
the monounsaturated fats and PUFA increased the HDL-cholesterol levels, whereas butter increased the cholesterol levels in
both the LDL- and HDL-fractions. The VLF diet led to significant reductions in the proportion of linoleic acid (18∶2ω6) and
eicosapentaenoic acid (20∶5ω3) and to increases in palmitoleic (16∶1), eicosatrienoic (20∶3ω6) and arachidonic acids (20∶4ω6)
in both phospholipids and cholesteryl esters. Addition of butter reversed the changes seen on the VLF diet, with the exception
of 16∶1, which remained elevated. Addition of olive oil resulted in a significant rise in the proportion of 18∶1 and significant
decreases in all ω3 PUFA except 22∶6 compared with the usual diet. The addition of safflower oil resulted in significant increases
in 18∶2 and 20∶4ω6 and significant decreases in 18∶1, 20∶5ω3 and 22∶5ω3. These results indicate that the reduction of saturated
fat content of the diet (<6% dietary energy), either by reducing the total fat content of the diet or by exchanging saturated
fat with unsaturated fat, reduced the total plasma cholesterol levels by approximately 12% in normocholesterolemic subjects.
Although the VLF vegetarian diet reduced both LDL- and HDL-cholesterol levels, the long-term effects of VLF diets are unlikely
to be deteterious since populations which habitually consume these diets have low rates of coronary heart disease. The addition
of safflower oil or olive oil to a VLF diet produced favorable changes in the lipoprotein lipid profile compared with the
addition of butter. The VLF diets and diets rich in butter, olive oil or safflower oil had different effects on the 20 carbon
eicosanoid precursor fatty acids in the plasma. This suggests that advice on plasma lipid lowering should also take into account
the effect of the diet on the fatty acid profile of the plasma lipids. 相似文献