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1.
An animal feeding trial was conducted to investigate whether olive oil phenolics can act as functional antioxidants in vivo. To this end, hamsters were exposed for a period of 5 wk to a dietary regime with either a phenol-rich extra virgin olive
oil or extra virgin olive oil from which phenols were removed by ethanol/water-washing. The original oil used in the high
olive phenol diet was also used for the preparation of the low phenol diet in order to keep the FA compositions exactly the
same. In addition, the vitamin E content was kept identical in both diets. This careful preparation of the diets was undertaken
in order to prevent these factors from influencing the antioxidative status in plasma and LDL. Removal of olive oil phenols
was shown to reduce both the vitamin E level in plasma and the resistance of LDL to ex vivo oxidation. The results of this study support the idea that extra virgin olive oil phenols improve the antioxidant defense
system in plasma by sparing the consumption of vitamin E under normal physiological circumstances. 相似文献
2.
Postprandial lipemia impairs insulin sensitivity and triggers the pro-inflammatory state which may lead to the progression
of cardiovascular diseases. A randomized, crossover single-blind study (n = 10 healthy men) was designed to compare the effects of a high-fat load (50 g fat), rich in palmitic acid from both plant
(palm olein) or animal source (lard) versus an oleic acid-rich fat (virgin olive oil) on lipemia, plasma glucose, insulin
and adipocytokines. Serum triacylglycerol (TAG) concentrations were significantly lower after the lard meal than after the
olive oil and palm olein meals (meal effect P = 0.003; time effect P < 0.001). The greater reduction in the plasma non-esterified free fatty acids levels in the lard group compared to the olive
oil meal was mirrored by the changes observed for serum TAG levels (P < 0.05). The magnitude of response for plasma glucose, insulin and adipocytokines [interleukin-6 (IL-6), tumor necrosis factor-α
(TNF-α), interleukin-1β (IL-1β) and leptin] were not altered by the type of dietary fats. A significant difference in plasma
IL-1β was found over time following the three high fat loads (time effect P = 0.036). The physical characteristics and changes in TAG structure of lard may contribute to the smaller increase in postprandial
lipemia compared with palm olein. A high fat load but not the type of fats influences concentrations of plasma IL-1β over
time but had no effect on other pro-inflammatory markers tested in the postprandial state. 相似文献
3.
Roberta Masella Claudio Giovannini Rosaria Varì Roberta Di Benedetto Ettore Coni Roberto Volpe Nadia Fraone Antonello Bucci 《Lipids》2001,36(11):1195-1202
The aim of this study was to assess the effects of the dietary intake of extra virgin olive oil on the oxidative susceptibility
of low density lipoproteins (LDL) isolated from the plasma of hyperlipidemic patients. Ten patients with combined hyperlipidemia
(mean plasma cholesterol 281 mg/dL, triglycerides 283 mg/dL) consumed a low-fat, low-cholesterol diet, with olive oil (20
g/d) as the only added fat, with no drug or vitamin supplementation for 6 wk. Then they were asked to replace the olive oil
they usually consumed with extra virgin olive oil for 4 wk. LDL were isolated at the beginning, and after the 4 wk of dietary
treatment. LDL susceptibility to CuSO4-mediated oxidation was evaluated by measuring the extent of lipid peroxidation. We also determined fatty acid composition
and vitamin E in plasma and LDL and plasma phenolic content. Extra virgin olive oil intake did not affect fatty acid composition
of LDL but significantly reduced the copper-induced formation of LDL hydroperoxides and lipoperoxidation end products as well
as the depletion of LDL linoleic and arachidonic acid. A significant increase in the lag phase of conjugated diene formation
was observed after dietary treatment. These differences are statistically correlated with the increase in plasma phenolic
content observed at the end of the treatment with extra virgin olive oil; they are not correlated with LDL fatty acid composition
or vitamin E content, which both remained unmodified after the added fat change. This report suggests that the daily intake
of extra virgin olive oil in hyperlipidemic patients could reduce the susceptibility of LDL to oxidation, not only because
of its high monounsaturated fatty acid content but probably also because of the antioxidative activity of its phenolic compounds. 相似文献
4.
Patrizia Comandini Vito Verardo Paola Maiocchi Maria Fiorenza Caboni 《European Journal of Lipid Science and Technology》2009,111(9):933-940
Accelerated oxidation tests, such as the determination of the induction period, increase the lipid oxidation rate by exposing a food to elevated temperatures, in the presence of excess quantities of air or oxygen. In addition to the well‐founded oxidative stability index (OSI) method, an innovative and promising technique is the oxidation test (OXITEST) reactor. A new analytical method was developed with OXITEST to oxidize vegetable oils. At a preliminary stage of the investigation, the induction periods of sunflower and extra‐virgin olive oil obtained by the OXITEST reactor were plotted against temperature, on the basis of the Arrhenius law; the activation energy and the frequency factor of lipid oxidation were calculated and resulted in 98.61 kJ/mol and 2.33×1010 s–1, respectively, for sunflower oil and 106.48 kJ/mol and 6.27×1010 s–1, respectively for extra‐virgin olive oil. The new oxidative technique was employed to determine the induction periods of vegetable oils; the results obtained were well correlated with those achieved with OSI technology, with a Pearson correlation coefficient r = 0.9785 (p <0.05) for oilseeds and palm oil and r = 0.9501 (p <0.05) for extra‐virgin olive oils. 相似文献
5.
Effect of n−3 fatty acid-rich fish oil supplementation on the oxidation of low density lipoproteins 总被引:4,自引:0,他引:4
This study was aimed at determining the effect of fish oil supplementation on copper-catalyzed oxidation of low density lipoproteins
(LDL) from nine hypertriglyceridemic human subjects. A rapid headspace gas chromatographic method was used to measure the
volatile oxidation products from LDL. Propanal and hexanal were the major volatile products formed in the oxidation of n−3
and n−6 polyunsaturated fatty acids (PUFA), respectively. Fish oil supplementation resulted in a significant increase in propanal
formation from 3.7 to 13.4 nmol/mL LDL (P<0.01); it also resulted in small decreases in pentanal formation from 14.7 to 11.4 nmol/mL LDL and in hexanal formation from
138 to 108 nmol/mL LDL (P<0.05). The changes in peroxidation products paralleled the changes in LDL composition, which showed a significant increase
in n−3 PUFA from 3.2 to 14.6% (P<0.01) and a decrease in n−6 PUFA from 43.7 to 35.0% (P<0.05). Propanal formation was highly and significantly correlated with n−3 PUFA content (r=0.950,P<0.001). Since total volatiles remained unchanged, this indicated that the two groups of LDL samples did not differ in overall
oxidative susceptibility. Although fish oil intake did not alter the oxidative susceptibility of LDL, the chemically modified
LDL particles generated a distinct pattern of volatile oxidation products that reflected changes in their fatty acid composition. 相似文献
6.
Coni E Di Benedetto R Di Pasquale M Masella R Modesti D Mattei R Carlini EA 《Lipids》2000,35(1):45-54
On the basis of the results obtained with pilot studies conducted in vitro on human low density lipoprotein (LDL) and on cell cultures (Caco-2), which had indicated the ability of certain molecules
present in olive oil to inhibit prooxidative processes, an in vivo study was made of laboratory rabbits fed special diets. Three different diets were prepared: a standard diet for rabbits
(diet A), a standard diet for rabbits modified by the addition of 10% (w/w) extra virgin olive oil (diet B), a modified standard
diet for rabbits (diet C) differing from diet B only in the addition of 7 mg kg−1 of oleuropein. A series of biochemical parameters was therefore identified, both in the rabbit plasma and the related isolated
LDL, before and after Cu-induced oxidation. The following, in particular, were selected: (i) biophenols, vitamins E and C,
uric acid, and total, free, and ester cholesterol in the plasma; (ii) proteins, triglycerides, phospholipids, and total, free,
and ester cholesterol in the native LDL (for the latter, the dimensions were also measured); (iii) lipid hydroperoxides, aldehydes,
conjugated dienes, and relative electrophoretic mobility (REM) in the oxidized LDL (ox-LDL). In an attempt to summarize the
results obtained, it can be said that this investigation has not only verified the antioxidant efficacy of extra virgin olive
oil biophenols and, in particular, of oleuropein, but has also revealed a series of thus far unknown effects of the latter
on the plasmatic lipid situation. In fact, the addition of oleuropein in diet C increased the ability of LDL to resist oxidation
(less conjugated diene formation) and, at the same time, reduced the plasmatic levels of total, free, and ester cholesterol
(−15, −12, and −17%, respectively), giving rise to a redistribution of the lipidic components of LDL (greater phospholipid
and cholesterol amounts) with an indirect effect on their dimesions (bigger by about 12%). 相似文献
7.
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
8.
Anu M. Turpeinen Georg Alfthan Liisa Valsta Eino Hietanen Jukka T. Salonen Hanna Schunk Kristiina Nyyssönen Marja Mutanen 《Lipids》1995,30(6):485-492
The effects of natural mixed diets on lipid peroxidation were investigated in humans. In the first study, 59 subjects were
fed a rapeseed oil-based diet rich in monounsaturated fatty acids (MUFA) and a sunflower oil-based diet rich in polyunsaturated
fatty acids (PUFA) in a cross-over manner for three and a half weeks. The lipid peroxidation products in plasma were determined
by measuring conjugated dienes and malondialdehyde (MDA). In a second study, plasma thiobarbituric acid reactive substances
(TBARS), lipid hydroperoxides, and the susceptibility of very low density lipoprotein + low-density lipoprotein (LDL) toin vitro oxidation were measured from subjects fed similar MUFA and PUFA diets for six week diets. No significant differences in plasma
MDA or conjugated diene concentrations were found after the rapeseed oil diet or the sunflower oil diet in Study 1. In the
second study, a small but significant decrease (P<0.05) in both lipid hydroperoxides and TBARS was observed in the LDL fraction after the sunflower oil diet. Thein vitro oxidation gave opposite results, showing increased oxidation after the sunflower oil diet. Despite a high intake of α-tocopherol
during the oil peroids, no increase in plasma α-tocopherol was noticed in either study. The results suggest that moderate
changes in the fatty acid composition in the Western-type diet may be adequate to affect lipoprotein susceptibility to oxidationin vitro, but there is considerable disparity with some indices ofin vivo lipid peroxidation. 相似文献
9.
Ana Paula de Queiroz Mello Isis Tande da Silva Aline Silva Oliveira Valéria Sutti Nunes Dulcineia Saes Parra Abdalla Magnus Gidlund Nágila Raquel Teixeira Damasceno 《Lipids》2010,45(7):619-625
Dyslipidemias and physicochemical changes in low-density lipoprotein (LDL) are very important factors for the development
of coronary artery disease (CAD). However, pathophysiological properties of electronegative low-density lipoprotein [LDL(−)]
remain a controversial issue. Our objective was to investigate LDL(−) content in LDL and its subfractions (phenotypes A and
B) of subjects with different cardiovascular risk. Seventy-three subjects were randomized into three groups: normolipidemic
(N; n = 30) and hypercholesterolemic (HC; n = 33) subjects and patients with CAD (n = 10). After fasting, blood samples were collected and total, dense and light LDL were isolated. LDL(−) content in total
LDL and its subfractions was determined by ELISA. LDL(−) content in total LDL was lower in the N group as compared to the
HC (P < 0.001) and CAD (P = 0.006) groups. In the total sample and in those of the N, HC, and CAD groups, LDL(−) content in dense LDL was higher than
in light LDL (P = 0.001, 0.001, 0.001, and 0.033, respectively) The impact of LDL(−) on cardiovascular risk was reinforced when LDL(−) content
in LDL showed itself to have a positive association with total cholesterol (β = 0.003; P < 0.001), LDL-C (β = 0.003; p < 0.001), and non-HDL-C (β = 0.003; P < 0.001) and a negative association with HDL-C (β = −0.32; P = 0.04). Therefore, LDL(−) is an important biomarker that showed association with the lipid profile and the level of cardiovascular
risk. 相似文献
10.
Fitó M Covas MI Lamuela-Raventós RM Vila J Torrents L de la Torre C Marrugat J 《Lipids》2000,35(6):633-638
The protective effect of phenolic compounds from an olive oil extract, and of olive oils with (extra-virgin) and without (refined)
phenolic components, on low density lipoprotein (LDL) oxidation was investigated. When added to isolated LDL, phenolics [0.025–0.3
mg/L caffeic acid equivalents (CAE)] increased the lag time of conjugated diene formation after copper-mediated LDL oxidation
in a concentration-dependent manner. Concentrations of phenolics greater than 20 mg/L inhibited formation of thiobarbituric-acid
reactive substances after AAPH-initiated LDL oxidation. LDL isolated from plasma after preincubation with phenolics (25–160
mg/L CAE) showed a concentration-dependent increase in the lag time of conjugated diene formation after copper-mediated LDL
oxidation. Refined olive oil (0 mg/L CAE) and extra-virgin olive oil (0.1 and 0.3 mg/L CAE) added to isolated LDL caused an
increase in the lag time of conjugated diene formation after copper-mediated LDL oxidation that was related to olive oil phenolic
content. Multiple regression analysis showed that phenolics were significantly associated with the increase in lag time after
adjustment for effects of other antioxidants; α-tocopherol also achieved a statistically significant effect. These results
indicate that olive oil phenolic compounds protect LDL against peroxyl radical-dependent and metal-induced oxidation in vitro and could associate with LDL after their incubation with plasma. Both types of olive oil protect LDL from oxidation. Olive
oil containing phenolics, however, shows more antioxidant effect on LDL oxidation than refined olive oil. 相似文献
11.
Paolino Ninfali Mara Bacchiocca Enrica Biagiotti Maurizio Servili Gianfrancesco Montedoro 《Journal of the American Oil Chemists' Society》2002,79(10):977-982
The induction period (IP), determined using accelerated methods such as the Rancimat test, is a parameter that has been used
to predict the shelf life of virgin olive oil. The oxygen radical absorbance capacity (ORAC) has recently been proposed as
a quality index of virgin olive oil because it measures the efficiency of phenolic compounds in the protection against peroxyl
radicals. This study aims to investigate relationships between the ORAC and IP values and proposes ORAC as a new parameter
of virgin olive oil stability. The concentrations of phenolics, o-diphenols, tocopherol, β-carotene, lutein, and ORAC and IP values were determined in 33 virgin olive oils. Regression analyses
showed that both ORAC and IP values correlate with total phenols and o-diphenols with highly significant indices, whereas the correlations of both ORAC and IP with tocopherols, β-carotene, and
lutein were not significant. The ORAC values correlate with the IP values with low but significant indices (R=0.42; P<0.02). The results confirm the key role of phenolic compounds in accounting for the shelf life of virgin olive oil and suggest
that the ORAC parameter may be used as a new index of quality and stability. 相似文献
12.
The purpose of this study was to investigate in healthy humans the effect of eicosapentaenoic acid (EPA) and docosahexaenoic
acid (DHA) intake, alone or in combination with dL-α-tocopherol acetate (vitamin E) supplements on lipid peroxidation. Eightly
men were randomly assigned in a double-blind fashion to take daily for 6 wk either menhaden oil (6.26 g, n−3 fatty acids)
or olive oil supplements with either vitamin E (900 IU) or its placebo. Antioxidant vitamins, phospholipid composition, malondialdehyde
(MDA), and lipid peroxides were measured in the plasma at baseline and week 6. At the same time, breath alkane output was
measured. Plasma α-tocopherol concentration increased in those receiving vitamin E (P<0.0001). In those supplemented with n−3 fatty acids, EPA and DHA increased in plasma phospholipids (P<0.0001) and plasma MDA and lipid peroxides increased (P<0.001 and P<0.05, respectively). Breath alkane output did not change significantly and vitamin E intake did not prevent the increase
in lipid peroxidation during menhaden oil supplementation. The results demonstrate that supplementing the diet with n−3 fatty
acids resulted in an increase in lipid peroxidation, as measured by plasma MDA release and lipid peroxide products, which
was not suppressed by vitamin E supplementation. 相似文献
13.
G. E. Onibi J. R. Scaife I. Murray V. R. Fowler 《Journal of the American Oil Chemists' Society》1998,75(2):189-198
Thirty-two pigs were allocated to one of four diets, FFRD0 and FFRD200, containing full-fat rapeseed (FFR), 150 g/kg [25–50
kg liveweight (LW)], and 250 g/kg (50–90 kg LW), or CD0 and CD200, containing equivalent quantities of rapeseed meal and 34
g/kg (25–50 kg LW) or 59.2 g/kg (50–90 kg LW) coconut oil and lard (0.5:0.5, w/w). Diets FFRD200 and CD200 were supplemented
with 200 mg/kg α-tocopherol acetate (ATA). ATA supplementation significantly (P<0.001) reduced muscle drip loss. The melting point (°C) of subcutaneous fat was significantly lowered by FFR (P<0.001) but increased by ATA supplementation (P<0.05). Tissue α-tocopherol (AT) concentrations were significantly increased by ATA supplementation. Longissimus dorsi AT concentration was positively correlated with AT concentration in subcutaneous fat (r=0.86) and in plasma at 35 (r=0.65) and 77 (r=0.85) days of feeding (P<0.001). In both L. dorsi and subcutaneous adipose tissue lipids, FFRD caused a significant (P<0.001) decrease in the ratio of n-6 to n-3 fatty acids and a significant (P<0.001) increase in the ratio of polyunsaturated to saturated fatty acids. AT supplementation significantly reduced the susceptibility
of L. dorsi and subcutaneous fat to lipid oxidation during storage at 4°C for up to 16 d. For all dietary treatments and storage times,
lipid oxidation [mg malondialdehyde (MDA)/kg muscle] was greater in the surface layer (0–2.5 mm) of L. dorsi than below the surface (2.5–5 mm). Oxidative stability of L. dorsi lipids to iron-induced lipid peroxidation was significantly improved (P<0.001) by AT supplementation. Meat from pigs fed FFRD diets was significantly less stable to iron-induced oxidation (nmoles
MDA/mg protein) at the longer incubation periods (100 and 200 min). The susceptibility of L. dorsi to iron-induced lipid oxidation decreased as the ratio of the tissue concentration of AT to unsaturated fatty acid increased. 相似文献
14.
Paraoxonase 1 (PON 1) has antioxidant and cardioprotective properties and is abnormally low in type 2 diabetic serum. This
study aimed to determine the effect of type 2 diabetes and meals rich in saturated fat and oleic acid on PON1 activity in
chylomicrons and very low density lipoproteins (VLDL). PON1 arylesterase activity was measured in chylomicrons and VLDL that
were isolated in serum from 20 patients with type 2 diabetes and 20 age- and gender-matched, overweight controls 3 h after
meals rich in cream or olive oil in a randomized, cross-over study. Chylomicron–PON1 activity (45%, P = 0.02), ratio chylomicron–PON1/chylomicron–triacylglycerides (TAG) (42%, P = 0.03) and chylomicron–protein content (46%, P < 0.001) were significantly lower in patients with type 2 diabetes compared with controls after the olive oil meal with comparable
findings after the meal rich in cream. After ingestion of olive oil, chylomicron–PON1 activity was significantly higher in
controls (P = 0.01) and marginally higher (P = 0.06) in diabetic patients and chylomicron–TAG were significantly (P < 0. 05) higher in both groups of subjects, compared with values after ingestion of cream. VLDL–PON1 increased (two-fold)
significantly (P < 0.003) during both meals. Chylomicron-PON1 activity was correlated significantly with chylomicron–protein (P < 0.001, n = 40) and with postprandial serum PON1 activity (P ≤ 0.001, n = 40). Our data suggest that type 2 diabetes is associated with abnormally low chylomicron–PON1 activity after fatty meals
and this may be linked to lower chylomicron–protein content and serum PON1 activity. Switching from saturated fat to olive
oil in the meal increases PON1 activity in the chylomicron fraction largely due to increased numbers of chylomicron particles. 相似文献
15.
Contrary to other long chain saturated fatty acids (SFA), fats high in stearic acid do not raise plasma cholesterol concentrations,
however, a slight elevation in inflammatory markers, plasma fibrinogen and interleukin-6 (IL-6), has been observed in the
fasting state. The effect of stearic acid on inflammation in the postprandial state has not yet been reported. We conducted
a single blind crossover, randomized, postprandial study to compare the effects of a fat load of cocoa butter high in stearic
acid and olive oil in ten healthy women. The test meals contained 1 g of fat per kg body weight (mean 62 g). Blood samples
were collected at 0 (fasting), 4 and 6 h. Both diets resulted in a significant increase in serum triacylglycerol (TAG) concentration
over time (P = 0.003) and a decrease in serum IL-6 concentration after 4 h followed by an increase to post absorptive values after 6 h
(P < 0.001); whereas serum high sensitivity C-reactive protein (hsCRP) concentration was not affected. There was no difference
between diets in effects on serum TAG, hsCRP and IL-6 concentrations and no association between postprandial lipemia and inflammatory
markers. High intake of dietary fats increase postprandial serum TAG, however, may not affect inflammatory markers postprandially.
Thus, fat rich in stearic acid does not seem to increase postprandial inflammation. 相似文献
16.
Although the reduction of serum triacylglycerol concentrations by dietary fish oil is a well-known effect, the exact mechanism
of this effect has not been previously studied in human subjects. Therefore, the aim of this study was (i) to examine the
effect of short-term fish oil supplementation on blood concentrations of ketone bodies, free fatty acids and triacylglycerol
in healthy humans and (ii) to verify whether the observed relationships between these variables would be consistent with reduced
lipolysis and/or enhanced hepatic fatty acid oxidation after fish oil supplementation. Twenty subjects (21–23 years, normal
liver function tests) were randomly divided into two groups to supplement their usual diet with either 30 g/d of fish oil
(n=11) or olive oil (n=9). Venous blood samples were drawn after an overnight fast, before and after 1, 3 and 7 d of fish
oil/olive oil supplementation. Blood concentrations of triacylglycerol and free fatty acids decreased consistently after fish
oil supplementation; the reduction was already significant after one day of fish oil (P<0.001 for triacylglycerol andP=0.01 for free fatty acids). In contrast, neither of these blood values changed after olive oil supplementation (P>0.10). No significant changes in glucose, insulin or ketone body levels were observed in either group after supplementation.
After fish oil, but not after olive oil supplementation, the ratio of blood ketone body levels to free fatty acid levels increased
significantly (P<0.05). Furthermore, after fish oil supplementation only, free fatty acid levels were significantly correlated with levels
of ketone bodies (day 7 of supplementation: r=0.90,P<0.001) and triacylglycerol (maximum value on day 3: r=0.77,P<0.01). These findings suggest that reduced lipolysis and increased hepatic β-oxidation/ketogenesis may contribute to reduced
triacylglycerol levels after ω3 fatty acid supplementation in humans. Turnover studies are needed in order to further quantitate
these processes. 相似文献
17.
The purpose of this investigation was to compare the performance of the bromthymol blue (BTB) method and the Uniform Oil Color
Scale (UOCS) method with different sets of virgin olive oil samples from Andalusia (Spain), namely, 1213 samples from olives
at three stages of ripeness, 1008 samples from eight olive varieties, and 1700 samples from olives harvested in four different
crop seasons. All oils were extracted in the laboratory by the same procedure. The performance of the two color scales was
compared using CIELAB color differences between the oil samples and the nearest standard from each scale. The UOCS performed
at least 2.0 times better than the BTB for each of the three stages of olive ripeness, and the difference between the two
color scales was statistically significant (P<0.001). The UOCS performed at least 1.3 times better than the BTB for each of the eight olive varieties studied, and the
differences between the two color scales were statistically significant (P<0.02). The UOCS also performed at least 1.6 times better than the BTB for each of the four harvests analyzed, and the differences
between the two color scales were statistically significant (P<0.001). Using the current oil samples, we could discern no substantial improvements to the UOCS standards. 相似文献
18.
Changes of lipoprotein composition have been mainly reported in conditions of sepsis. This study characterized compositional
changes in LDL and HDL during the acute phase response following cardiac surgery with cardiopulmonary bypass. Twenty-one patients
undergoing cardiac surgery were included in this study. Blood samples were drawn before operation and on day 2 post-surgery.
In parallel to plasma lipids and antioxidant status, lipoproteins were analyzed for lipid, apolipoprotein (apo), hydroperoxide
and alpha-tocopherol content. Beyond decreases in lipid concentrations and antioxidant defenses, cardiac surgery induced substantial
modifications in plasma lipoproteins. ApoB decrease in LDL fraction (−46%; P < 0.0001) reflected a marked reduction in the circulating particle number. LDL cholesteryl ester content relative to apoB
concentration remained unchanged post-surgery while triglyceride (+113%; P < 0.001), free cholesterol (+22%; P < 0.05) and phospholipid (+23%; P < 0.025) were raised relative to apoB indicating increased particle size. In HDL, an abrupt rise of apoSAA (P < 0.05) was observed together with a decrease of apoA1 (−22%; P < 0.005). Cholesteryl ester content in HDL fraction decreased in parallel to apoA1 concentration while triglycerides, free
cholesterol and phospholipids increased relative to apoA1. In contrast to unchanged alpha-tocopherol content, hydroperoxide
content was increased in LDL and HDL. By comparison to sepsis, cardiac surgery induces a comparable reduction in circulating
LDL but a more limited decrease in HDL particles. Furthermore, in contrast, cardiac surgery induces an increase in polar and
non-polar lipids, as well as of particle size in both LDL and HDL.
M. Hacquebard is recipient of a fellowship from the Danone Institute, Belgium. 相似文献
19.
Le Yu Yongjin Wang Gangcheng Wu Jun Jin Qingzhe Jin Xingguo Wang 《Journal of the American Oil Chemists' Society》2020,97(4):341-353
The characteristics of eight varieties of virgin olive oil (Arbosana, Arbequina, Coratina, Cornicabra, Frantoio, Koroneiki, Picual, and Ezhi 8) obtained in two successive crops in the southwest of China (Xichang, Sichuan Province) were investigated. Significant differences (P < 0.05) were observed in physicochemical properties, fatty acid profile, minor component contents, and oxidative stability between different varieties of olive oils. The physicochemical properties of all samples met IOC standards for extra virgin olive oil, while in Koroneiki, olive oils were present the optimum oxidation stability among studied varieties. The results of hierarchical cluster analysis and principal component analysis (PCA) showed a good classification between varieties based on their qualitative characteristics. Koroneiki and Ezhi 8 olive oils were significantly different from other varieties mainly due to color, fatty acid profile, and minor components. PCA result also showed that harvest crop influences the characteristics of samples mainly due to the variance of temperature and rainfall. 相似文献
20.
The objective of the study was to evaluate potential benefits of docosahexaenoic acid (DHA) rich fish oil supplementation
as an adjunct to statin therapy for hyperlipidaemia. A total of 45 hyperlipidaemic patients on stable statin therapy with
persistent elevation of plasma triglycerides (averaging 2.2 mmol/L) were randomised to take 4 g/day (n = 15) or 8 g/day (n = 15) of tuna oil or olive oil (placebo, n = 15) for 6 months. Plasma lipids, blood pressure and arterial compliance were assessed initially and after 3 and 6 months
in 40 subjects who completed the trial. Plasma triglycerides were reduced 27% by 8 g/day DHA-rich fish oil (P < 0.05) but not by 4 g/day when compared with the placebo and this reduction was achieved by 3 months and was sustained at
6 months. Even though total cholesterol was already well controlled by the statin treatment (mean initial level 4.5 mmol/L),
there was a further dose-dependent reduction with fish oil supplementation (r = −0.344, P < 0.05). The extent of total cholesterol reduction correlated (r = −0.44) with the initial total cholesterol levels (P < 0.005). In the subset with initial plasma cholesterol above 3.8 mmol/L, plasma very low density lipoprotein (VLDL), intermediate-density
lipoprotein (IDL) and low-density lipoprotein (LDL) were isolated and assayed for cholesterol and apolipoprotein B (apoB)
at the commencement of the trial and at 3 months of intervention. Fish oil tended to lower cholesterol and apoB in VLDL and
raise both in LDL. There were no changes in IDL cholesterol, IDL apoB and high-density lipoprotein cholesterol. The results
demonstrate that DHA-rich fish oil supplementation (2.16 g DHA/day) can improve plasma lipids in a dose-dependent manner in
patients taking statins and these changes were achieved by 3 months. Fish oil in addition to statin therapy may be preferable
to drug combinations for the treatment of combined hyperlipidaemia. 相似文献