Lupin kernel fibre-enriched foods beneficially modify serum lipids in men

Objective: To examine the effect of a diet containing a novel legume food ingredient, Australian sweet lupin (Lupinus angustifolius) kernel fibre (LKFibre), compared to a control diet without the addition of LKFibre, on serum lipids in men.

Design: Randomized crossover dietary intervention study.

Setting: Melbourne, Australia — Free-living men.

Subjects: A total of 38 healthy males between the ages of 24 and 64 y completed the intervention.

Intervention: Subjects consumed an LKFibre and a control diet for 1 month each. Both diets had the same background menus with seven additional experimental foods that either contained LKFibre or did not. Depending on energy intake, the LKFibre diet was designed to contain an additional 17 to 30 g/day fibre beyond that of the control diet.

Results: Compared to the control diet, the LKFibre diet reduced total cholesterol (TC) (meanplusminuss.e.m.; 4.5plusminus1.7%; P=0.001), low-density lipoprotein cholesterol (LDL-C) (5.4plusminus2.2%; P=0.001), TC: high-density lipoprotein cholesterol (HDL-C) (3.0plusminus2.0%; P=0.006) and LDL-C:HDL-C (3.8plusminus2.6%; P=0.003). No effects on HDL-C, triacylglycerols, glucose or insulin were observed.

Conclusions: Addition of LKFibre to the diet provided favourable changes to some serum lipid measures in men, which, combined with its high palatability, suggest this novel ingredient may be useful in the dietary reduction of coronary heart disease risk.

Lipid peroxidation in skeletal muscle of obese as compared to endurance-trained humans: a case of good vs. bad lipids?

Intra-myocellular triglycerides (IMTG) accumulate in the muscle of obese and endurance-trained (ET) humans and are considered a pathogenic factor in the development of insulin resistance, in the former. We postulate that this paradox may be associated with the peroxidation status of the IMTG. IMTG content was the same in the obese and ET subjects. The lipid peroxidation/IMTG ratio was 4.2-fold higher in the obese subjects. Hence, obesity results in an increased level of IMTG peroxidation while ET has a protective effect on IMTG peroxidation. This suggests a link between the lipid peroxidation/IMTG ratio and insulin resistance.

Short-term diets enriched in stearic or palmitic acids do not alter plasma lipids, platelet aggregation or platelet activation status

Objective: To determine whether healthy males who consumed increased amounts of dietary stearic acid compared with increased dietary palmitic acid through the consumption of commercially available foods, exhibited any changes in plasma lipids, platelet aggregation or platelet activation status.
Design: A randomised cross-over dietary intervention.
Subjects and interventions: Nine free-living healthy males consumed two experimental diets (stearic acid enriched, diet S, and palmitic acid enriched, diet P) for 3 weeks in a randomised cross-over design separated by a 3 week washout phase. The diets consisted of 30% of energy as fat (30% of which was derived from the treatment diets) providing 13 g=day as stearic acid and 17 g=day as palmitic acid on diet S and 7g=day as stearic acid and 22 g=day as palmitic acid on diet P. The dietary ratio of stearic to palmitic acids was 0.76 on diet S compared with 0.31 on diet P. Blood samples were collected on days 0 and 21 of each dietary period.
Results: LDL cholesterol levels and platelet aggregation response to the agonist ADP were significantly decreased (P <0.025) in subjects on diet S compared with day 0. Apart from that, there were no significant changes in plasma lipids, plateletaggregation, mean platelet volume and platelet reactivity between diets. There were no significant changes in stearic or palmitic acid levels in plasma phospholipid or triacylglycerol. There was a significant difference in palmitic acid levels in platelet phospholipids between the two diets.
Conclusions: Use of commonly available foods led to a 27% increase in stearic acid (diet S) and a 19% increase in palmitic acid (diet P), on diets S and P respectively, and no significant differences between the two diets in plasma lipoprotein concentrations, platelet aggregation or platelet activation status.

Lipids and FA analysis of canine prostate tissue

It is widely reported that an association exists between dietary fat intake and the incidence of prostate cancer in humans. To study this association, there is a need for an animal model where prostate carcinogenesis occurs spontaneously. The canine prostate is considered a suitable experimental model for prostate cancer in humans since it is morphologically similar to the human prostate and both humans and dogs have a predisposition to benign and malignant prostate disease. In this study, the FA and lipids profiles of the normal canine prostate tissue from nine dogs were examined. The total lipid content of the canine prostate tissue was 1.7±0.5% (wet weight). The lipid composition analysis using TLC-FID showed that the two major lipid classes were phospholipids and TAG. Total FA, phospholipid, and TAG FA analysis showed that the major FA were palmitic acid (16∶0), stearic acid (18∶0), oleic acid (18∶1), linoleic acid (18∶2n−6), and arachidonic acid (20∶4n−6), The n−3 FA were present at <3% of total FA and included α-linolenic acid (18∶3n−3) (in total and TAG tissue FA), EPA (20∶5n−3) (not in TAG), and DHA (22∶6n−3) (not in TAG). The n−3/n−6 ratio was 1∶11, 1∶13, and 1∶8 in total, phospholipid, and TAG FA, respectively. This study shows the canine prostate has a low level of n−3 FA and a low n−3/n−6 ratio. This is perhaps due to low n−3 content of the diet of the dogs. FA analysis of dogfoods available in Australia showed that the n−3 content in both supermarket and premium bran dogfoods was <3% (wet weight), and the n−3/n−6 ratio was low.

The occurrence of trans-18:1 isomers in plasma lipids classes in humans

Objective: The aim of this study was to examine the distribution of trans fatty acids (TFA) in plasma lipid classes and the relationship with dietary intake of TFA.

Design: After a 2 week baseline (habitual) diet, all subjects consumed a moderate fat (MF) diet for 3 weeks with the fat being derived mainly from margarine and the rest from lean beef, and then a very low fat (VLF) diet for 3 weeks with the TFA being derived only from the lean beef. Blood samples were collected 2 days prior to the end and also on the last day of each dietary period.

Setting: Deakin Institute of Human Nutrition, Deakin University, Geelong, Australia.

Subjects: Ten free-living mildly hypercholesterolaemic subjects aged 22-66 were recruited in Geelong.

Outcome measures: TFA intake was calculated from analyses of Australian margarines, butter, lean meat and animal fat. The TFA in plasma lipid fractions were separated by AgNO3 thin-layer chromatography and quantitated by capillary gas-liquid chromatography using internal standards.

Results: The phospholipid (PL) fraction contained more than 60% of the trans-18:1 isomers in the plasma lipids in all subjects. On the baseline diet, the predominant positional isomer of trans-18:1 in PL was Delta11, whereas in the other lipid classes it was the Delta9 isomer. The concentration of the Delta9 isomer increased on the MF diet, particularly in the PL fraction, while the concentration of the Delta11 isomer decreased in all fractions. On the VLF diet, the total TFA level decreased by approximately 50%, mainly due to decreases in the TFA isomers in the PL and TG fractions. Changes in plasma total and PL TFA, PL Delta9, Delta10 and Delta11 were strongly correlated with dietary TFA intake (P<0.0001). There were also significant association between dietary TFA intake and PL Delta12 (P=0.003), triacylglycerol Delta9 (P=0.009), Delta11 (P=0.0005), total triacylglycerol (P=0.023) and free fatty acid TFA (P=0.042).

Conclusions: The results suggest that the measurement of trans-18:1 in plasma PL and TAG, and plasma total TFA could be used to estimate the intake of TFA.

1-14C-Linoleic Acid distrubution in various tissue lipids of guinea pigs following an oral dose

A recent study on the metabolism of 1-¹⁴C-α-linolenic acid in the guinea pig revealed that the fur had the highest specific activity of all tissues examined, 48 h after dosing. The present study investigated the pattern of tissue lipid labeling following an oral dose of 1-¹⁴C-linoleic acid after the animals had been dosed for the same time as above. Guinea pigs were fed one of two diets with a constant linoleic acid content (18% total fatty acids) and a different content of α-linolenic acid (0.3 or 17.3%) from weaning for 3 wk and 1-¹⁴C-linoleic acid was given orally to each animal for 48 h prior to sacrifice. The most highly labeled tissues (dpm/mg of linoleic acid) were liver, followed by brain, lung and spleen, heart, kidney and adrenal and intestines, in both diet groups. The liver had almost a three-fold higher specific activity than skin and fur which was more extensively labeled than the adipose and carcass. Approximately two-thirds of the label in skin plus fur was found in the fur which, because of a low lipid mass, would indicate that the fur was highly labeled. All tissues derived from animals on the diet with the low α-linolenic acid level were significantly more labeled than the tissues from the animals on the high α-linolenic acid diet, by a factor of 1.5 to 3. The phospholipid fraction was the most highly labeled fraction in the liver, free fatty acids were the most labeled fraction in skin & fur, while triacyglycerols were the most labeled in the carcass and adipose tissue. In these tissues, more than 90% of the radioactivity was found in fatty acids with 2-double bonds in the tissue lipids. These data indicate that the majority of label found in guinea pig tissues 48 h after dosing was still associated with a fatty acid fraction with 2-double bonds, which suggests there was little metabolism of linoleic acid to more highly unsaturated fatty acids in this time frame. In this study, the labeling of guinea pig tissues with linoleic acid, 48 h after dosing, was quite different from the labeling with α-linolenic acid reported previously. The retention of the administered radioactivity from ¹⁴C-linoleic acid in the whole body lipids was 1.6 times higher in the group fed the low α-linolenic acid diet (diet contained a total of 1.8 g PUFA/100 g diet)compared with the group fed the high α-linolenic acid diet (diet contained 3.6 g PUFA/100 g diet). The lack of retention of ¹⁴C-labeled lipids in the whole body would be consistent with an increased rate of β-oxidation of the labeled fatty acid on the diet rich in PUFA, a result supported by other studies using direct measurement of labeled carbon dioxide.

Whey protein and gum arabic encapsulated Omega-3 lipids. The effect of material properties on coacervation

The effect of material properties on complex coacervation of whey protein and gum Arabic from various sources was investigated. In this study, it was demonstrated that material properties of whey protein isolates and gum Arabic affect the complex coacervation process significantly. For whey protein, the coacervation capability could be correlated with their level of denaturation and calcium content. For gum Arabic, both material sources and salt content were found to be attributing factors to their coacervation capability. This study facilitated the development of Omega-3 lipids microcapsules with promising performances in certain food applications.

Food patterns associated with blood lipids are predictive of coronary heart disease : the Whitehall II study

Analysis of the epidemiological effects of overall dietary patterns offers an alternative approach to the investigation of the role of diet in CHD. We analysed the role of blood lipid-related dietary patterns using a two-step method to confirm the prospective association of dietary pattern with incident CHD. Analysis is based on 7314 participants of the Whitehall II study. Dietary intake was measured using a 127-item FFQ. Reduced rank regression (RRR) was used to derive dietary pattern scores using baseline serum total and HDL-cholesterol, and TAG levels as dependent variables. Cox proportional hazard regression was used to confirm the association between dietary patterns and incident CHD (n 243) over 15 years of follow-up. Increased CHD risk (hazard ratio (HR) for top quartile: 2·01 (95 % CI 1·41, 2·85) adjusted for age, sex, ethnicity and energy misreporting) was observed with a diet characterised by high consumption of white bread, fried potatoes, sugar in tea and coffee, burgers and sausages, soft drinks, and low consumption of French dressing and vegetables. The diet-CHD relationship was attenuated after adjustment for employment grade and health behaviours (HR for top quartile: 1·81; 95 % CI 1·26, 2·62), and further adjustment for blood pressure and BMI (HR for top quartile: 1·57; 95 % CI 1·08, 2·27). Dietary patterns are associated with serum lipids and predict CHD risk after adjustment for confounders. RRR identifies dietary patterns using prior knowledge and focuses on the pathways through which diet may influence disease. The present study adds to the evidence that diet is an important risk factor for CHD.

Management of lipids in rural Australia : are the guidelines being followed?

Background: Hypercholesterolaemia is ranked seventh among the major factors contributing to the overall burden of disease in Australia. Guidelines for evidence-based lipid management were released in 2001 and updated in 2005, however little population level data has been published on the current gap between recommended management and actual practice in Australia.

Method: Three population stratified surveys were undertaken in the Greater Green Triangle. Three thousand three hundred and twenty adults aged 25–74 years were randomly selected, stratified by gender and 10-year age groups. Anthropometric, clinical and self-administered questionnaire data relating to cardiovascular disease risk were collected in accordance with the WHO MONICA protocol. Blood samples were collected for lipid profile analysis. Participants were divided into four groups—Group 1: treated, high CVD risk; Group 2: treated, primary prevention; Group 3: untreated, high CVD risk; Group 4: untreated, low CVD risk. For each of these groups we compared cholesterol, HDL cholesterol, triglyceride and LDL cholesterol with targets recommended by the National Heart Foundation's 2005 guidelines.

Results: All lipids were at target in 39.4% of the study population with marked differences between groups: Group 1, 11.2%; Group 2, 38.5%; Group 3, 1.8%; Group 4, 47.6%.

Only 50.8% of the untreated high CVD risk group reported having blood cholesterol measured within the last 12 months.

Conclusion: Current rates of detection and treatment practices in rural Australia are suboptimal. Although one-third of the study population age 25–74 years are at sufficiently high risk to warrant consideration of lipid lowering medication only just over half of these were on treatment at the time of the study. These results suggest that an intensive implementation plan is required for the management of hyperlipidaemia in rural Australia.

Eukaryotic microorganisms for producing lipids and antioxidants

Disclosed are compositions and methods related to eukaryotic microorganisms that can produce unsaturated fatty acids which can be purified and used.

Post-prandial remnant lipids impair arterial compliance

OBJECTIVES
We sought to examine the effects of plasma lipids, especially in remnants after a fat meal, on systemic arterial compliance (SAC), a newly recognized cardiovascular risk factor.
BACKGROUND
Post-prandial remnants correlate with coronary heart disease events through mechanisms that may include vascular dysfunction, although the effect on SAC has not been studied.
METHODS
Systemic arterial compliance was measured non-invasively over 6 h after a fat meal in 16 subjects with varying plasma triglyceride levels. Changes were related to rises in plasma lipids and remnant lipids. Systemic arterial compliance was measured in 20 subjects after a control low-fat meal.
RESULTS
The fat meal induced increments in plasma triglyceride and remnant cholesterol and triglyceride (respectively +54%, 50% and 290% at 3 h, analysis of variance <0.001). Systemic arterial compliance fell at 3 h and 6 h by 25% and 27% (analysis of variance <0.001). Baseline SAC correlated significantly with all lipid concentrations at 0, 3 h and 6 h, but only with triglyceride on stepwise regression analysis. The SAC response to the low-fat meal was very small and not significant.
CONCLUSIONS
This is the first demonstration of SAC becoming impaired after a fat meal. Remnant lipids and plasma total triglyceride appeared to contribute to the fall in SAC.

Isoflavones from red clover improve systemic arterial compliance but not plasma lipids in menopausal women

The possibility that the heightened cardiovascular risk associated with the menopause can be reduced by increasing dietary isoflavone intake was tested in 17 women by measuring arterial compliance, an index of the elasticity of large arteries such as the thoracic aorta. Compliance diminishes with age and menopause. An initial 3- to 4-week run-in period and a 5-week placebo period were followed by two 5-week periods of active treatment with 40 mg and then 80 mg isoflavones derived from red clover containing genistein, daidzein, biochanin, and formononetin in 14 and 13 women, respectively, with 3 others serving as placebo controls throughout. Arterial compliance, measured by ultrasound as a pressure (carotid artery) and volume (outflow into aorta) relationship, was determined after each period; plasma lipids were measured twice during each period. Urinary output of isoflavones was also determined. Arterial compliance rose by 23% relative to that during the placebo period with the 80-mg isoflavone dose and slightly less with the 40-mg dose (mean6SEM: placebo, 19.761.5; 40 mg, 23.760.7; 80 mg, 24.46 1.4). In the three women receiving continuous placebo, compliance was 16 6 2.2, similar to that during the run-in period for the remaining subjects (17 6 2.1). ANOVA showed a significant (P 5 , 0.001) difference between treatments; by Bonferroni multiple comparisons and by paired t test, differences were significant between placebo and 40- and 80-mg isoflavone doses (by paired t test: P50.039 for placebo vs. 40 mg; P 5 0.018 for placebo vs. 80 mg). Plasma lipids were not significantly affected. An important cardiovascular risk factor, arterial compliance, which diminishes with menopause, was significantly improved with red clover isoflavones. As diminished compliance leads to systolic hypertension and may increase left ventricular work, the findings indicate a potential new therapeutic approach for improved cardiovascular function after menopause.