Effect of dietary monounsaturated fatty acids on plasma lipoproteins and apolipoproteins in women

Wine, Polyphenols, and Mediterranean Diets. What Else Is There to Say?

A considerable amount of literature has been published claiming the cardiovascular benefits of moderate (red) wine drinking, which has been considered a distinguishing trait of the Mediterranean diet. Indeed, red wine contains relevant amounts of polyphenols, for which evidence of their biological activity and positive health effects are abundant; however, it is also well-known that alcohol, even at a low level of intake, may have severe consequences for health. Among others, it is directly related to a number of non-communicable diseases, like liver cirrhosis or diverse types of cancer. The IARC classifies alcohol as a Group 1 carcinogen, causally associated with the development of cancers of the upper digestive tract and liver, and, with sufficient evidence, can be positively associated with colorectum and female breast cancer. In these circumstances, it is tricky, if not irresponsible, to spread any message on the benefits of moderate wine drinking, about which no actual consensus exists. It should be further considered that other hallmarks of the Mediterranean diet are the richness in virgin olive oil, fruits, grains, and vegetables, which are also good sources of polyphenols and other phytochemicals, and lack the risks of wine. All of these aspects are reviewed in this article.

Liquid Chicken Oil Could Be a Healthy Dietary Oil

Liquid chicken oil is similar to the human lipid ratio, and is similar to the ideal fatty acids ratio suggested by Hayes, but its benefits remain unclear (Hwang, K.N.; Tung, H.P.; Shaw, H.M. J. Oleo. Sci. 69, 199-206 (2020)). Using soybean oil as a control, liquid chicken oil, coconut oil, lard oil, and olive oil, were tested on SD rats with the rodent diet 5001 plus 1% of high cholesterol addition and moderate 10 % of test oils. Positive results showed that a 10% liquid chicken oil diet reduced LDL and triglycerides, atherogenic index while increasing superoxide dismutase more than the soybean oil control (0.05 ≦ p < 0.10). Moreover, increment of hepatic endogenous glutathione peroxidase was found to be significantly different from the soybean oil control (p < 0.05). In this study, liquid chicken oil had more benefits than vegetable soybean dietary oil, with little evidence of hyperlipidemia. Comparison of the test oils with categories of fatty acids to the idea ratio SFA : MUFA : PUFA = 1 : 1.5 : 1, scored by its average weight implied a parallel trend of lipidemia and hepatic antioxidant activity to its score. It is difficult to use the test of rat to reflect human physiology, it remain 19% different of the fatty acids ratio from human ratio, however, this study reveal that the healthiness of a dietary oil seems relate well to its compatibility to the idea ratio or the host oil ratio, in this case, it is the human ratio.

The Fluid Aspect of the Mediterranean Diet in the Prevention and Management of Cardiovascular Disease and Diabetes: The Role of Polyphenol Content in Moderate Consumption of Wine and Olive Oil

A growing interest has emerged in the beneficial effects of plant-based diets for the prevention of cardiovascular disease, diabetes and obesity. The Mediterranean diet, one of the most widely evaluated dietary patterns in scientific literature, includes in its nutrients two fluid foods: olive oil, as the main source of fats, and a low-to-moderate consumption of wine, mainly red, particularly during meals. Current mechanisms underlying the beneficial effects of the Mediterranean diet include a reduction in inflammatory and oxidative stress markers, improvement in lipid profile, insulin sensitivity and endothelial function, as well as antithrombotic properties. Most of these effects are attributable to bioactive ingredients including polyphenols, mono- and poly-unsaturated fatty acids. Polyphenols are a heterogeneous group of phytochemicals containing phenol rings. The principal classes of red wine polyphenols include flavonols (quercetin and myricetin), flavanols (catechin and epicatechin), anthocyanin and stilbenes (resveratrol). Olive oil has at least 30 phenolic compounds. Among them, the main are simple phenols (tyrosol and hydroxytyrosol), secoroids and lignans. The present narrative review focuses on phenols, part of red wine and virgin olive oil, discussing the evidence of their effects on lipids, blood pressure, atheromatous plaque and glucose metabolism.

The Nutraceutical Value of Olive Oil and Its Bioactive Constituents on the Cardiovascular System. Focusing on Main Strategies to Slow Down Its Quality Decay during Production and Storage

Cardiovascular diseases represent the principal cause of morbidity and mortality worldwide. It is well-known that oxidative stress and inflammatory processes are strongly implicated in their pathogenesis; therefore, anti-oxidant and anti-inflammatory agents can represent effective tools. In recent years a large number of scientific reports have pointed out the nutraceutical and nutritional value of extra virgin olive oils (EVOO), strongholds of the Mediterranean diet, endowed with a high nutritional quality and defined as functional foods. In regard to EVOO, it is a food composed of a major saponifiable fraction, represented by oleic acid, and a minor unsaponifiable fraction, including a high number of vitamins, polyphenols, and squalene. Several reports suggest that the beneficial effects of EVOO are linked to the minor components, but recently, further studies have shed light on the health effects of the fatty fraction and the other constituents of the unsaponifiable fraction. In the first part of this review, an analysis of the clinical and preclinical evidence of the cardiovascular beneficial effects of each constituent is carried out. The second part of this review is dedicated to the main operating conditions during production and/or storage that can directly influence the shelf life of olive oil in terms of both nutraceutical properties and sensory quality.

Plasma, Urine, and Adipose Tissue Biomarkers of Dietary Intake Differ Between Vegetarian and Non-Vegetarian Diet Groups in the Adventist Health Study-2

BACKGROUND

Differences in food composition, nutrient intake, and various health outcomes have been reported for vegetarians and non-vegetarians in the Adventist Health Study-2 (AHS-2) cohort.

OBJECTIVE

We sought to determine whether biomarkers of dietary intake also differed between individuals classified as vegetarian (vegan, lacto-ovo-vegetarian, pesco-vegetarian, semi-vegetarian) and non-vegetarians based on patterns of consumption of meat, dairy, and eggs.

METHODS

Fasting plasma, overnight urine, and adipose tissue samples were collected from a representative subset of AHS-2 participants classified into 5 diet groups (vegan, lacto-ovo-vegetarian, pesco-vegetarian, semi-vegetarian, non-vegetarian) who also completed food-frequency questionnaires. Diet-related biomarkers including carotenoids, isoflavones, enterolactone, saturated and polyunsaturated fatty acids, and vitamins were analyzed in 840 male and female participants. Multiple linear regression was used to examine the association between diet pattern and biomarker abundance, comparing each of 4 vegetarian dietary groups to non-vegetarians, and adjusted mean values were calculated. Bonferroni correction was applied to control for multiple testing.

RESULTS

Vegans had higher plasma total carotenoid concentrations (1.6-fold, P < 0.0001), and higher excretion of urinary isoflavones (6-fold, P < 0.0001) and enterolactone (4.4-fold) compared with non-vegetarians. Vegans had lower relative abundance of saturated fatty acids including myristic, pentadecanoic, palmitic, and stearic acids (P < 0.0001). Vegans had higher linoleic acid (18:2ω-6) relative to non-vegetarians (23.3% compared with 19.1%) (P < 0.0001), and a higher proportion of total ω-3 fatty acids (2.1% compared with 1.6%) (P < 0.0001). Results overall were similar but less robust for lacto-ovo- and pesco-vegetarians. 1-Methylhistidine was 92% lower in vegans, and lower in lacto-ovo- and pesco-vegetarians by 90% and 80%, respectively, relative to non-vegetarians (P < 0.0001).

CONCLUSION

AHS-2 participants following vegan, and lacto-ovo- or pesco-vegetarian diet patterns have significant differences in plasma, urine, and adipose tissue biomarkers associated with dietary intakes compared with those who consume a non-vegetarian diet. These findings provide some validation for the prior classification of dietary groups within the AHS-2 cohort.

Tea Seed Oil Prevents Obesity, Reduces Physical Fatigue, and Improves Exercise Performance in High-Fat-Diet-Induced Obese Ovariectomized Mice

Menopause is associated with changes in body composition (a decline in lean body mass and an increase in total fat mass), leading to an increased risk of metabolic syndrome, nonalcoholic fatty liver disease, and heart disease. A healthy diet to control body weight is an effective strategy for preventing and treating menopause-related metabolic syndromes. In the present study, we investigated the effect of long-term feeding of edible oils (soybean oil (SO), tea seed oil (TO), and lard oil (LO)) on female ovariectomized (OVX) mice. SO, TO, and LO comprise mainly polyunsaturated fatty acids (PUFA), monounsaturated fatty acids (MUFA), and saturated fatty acids (SFA), respectively. However, there have been quite limited studies to investigate the effects of different fatty acids (PUFA, MUFA, and SFA) on physiological adaption and metabolic homeostasis in a menopausal population. In this study, 7-week-old female Institute of Cancer Research (ICR) mice underwent either bilateral laparotomy (sham group, n = 8) or bilateral oophorectomy (OVX groups, n = 24). The OVX mice given a high-fat diet (HFD) were randomly divided into three groups: OVX+SO, OVX+TO, and OVX+LO. An HFD rich in SO, TO, or LO was given to the OVX mice for 12 weeks. Our findings revealed that the body weight and relative tissues of UFP (uterus fatty peripheral) and total fat (TF) were significantly decreased in the OVX+TO group compared with those in the OVX+SO and OVX+LO groups. However, no significant difference in body weight or in the relative tissues of UFP and TF was noted among the OVX+SO and OVX+LO groups. Furthermore, mice given an HFD rich in TO exhibited significantly decreased accumulation of liver lipid droplets and adipocyte sizes of UFP and brown adipose tissue (BAT) compared with those given an HFD rich in SO or LO. Moreover, replacing SO or LO with TO significantly increased oral glucose tolerance. Additionally, TO improved endurance performance and exhibited antifatigue activity by lowering ammonia, blood urea nitrogen, and creatine kinase levels. Thus, tea seed oil (TO) rich in MUFA could prevent obesity, reduce physical fatigue, and improve exercise performance compared with either SO (PUFA)- or LO(SFA)-rich diets in this HFD-induced obese OVX mice model.

A systematic review of high-oleic vegetable oil substitutions for other fats and oils on cardiovascular disease risk factors: implications for novel high-oleic soybean oils

High-oleic acid soybean oil (H-OSBO) is a trait-enhanced vegetable oil containing >70% oleic acid. Developed as an alternative for trans-FA (TFA)-containing vegetable oils, H-OSBO is predicted to replace large amounts of soybean oil in the US diet. However, there is little evidence concerning the effects of H-OSBO on coronary heart disease (CHD)(6) risk factors and CHD risk. We examined and quantified the effects of substituting high-oleic acid (HO) oils for fats and oils rich in saturated FAs (SFAs), TFAs, or n-6 (ω-6) polyunsaturated FAs (PUFAs) on blood lipids in controlled clinical trials. Searches of online databases through June 2014 were used to select studies that defined subject characteristics; described control and intervention diets; substituted HO oils compositionally similar to H-OSBO (i.e., ≥70% oleic acid) for equivalent amounts of oils high in SFAs, TFAs, or n-6 PUFAs for ≥3 wk; and reported changes in blood lipids. Studies that replaced saturated fats or oils with HO oils showed significant reductions in total cholesterol (TC), LDL cholesterol, and apolipoprotein B (apoB) (P < 0.05; mean percentage of change: -8.0%, -10.9%, -7.9%, respectively), whereas most showed no changes in HDL cholesterol, triglycerides (TGs), the ratio of TC to HDL cholesterol (TC:HDL cholesterol), and apolipoprotein A-1 (apoA-1). Replacing TFA-containing oil sources with HO oils showed significant reductions in TC, LDL cholesterol, apoB, TGs, TC:HDL cholesterol and increased HDL cholesterol and apoA-1 (mean percentage of change: -5.7%, -9.2%, -7.3%, -11.7%, -12.1%, 5.6%, 3.7%, respectively; P < 0.05). In most studies that replaced oils high in n-6 PUFAs with equivalent amounts of HO oils, TC, LDL cholesterol, TGs, HDL cholesterol, apoA-1, and TC:HDL cholesterol did not change. These findings suggest that replacing fats and oils high in SFAs or TFAs with either H-OSBO or oils high in n-6 PUFAs would have favorable and comparable effects on plasma lipid risk factors and overall CHD risk.

Dietary interventions (plant sterols, stanols, omega-3 fatty acids, soy protein and dietary fibers) for familial hypercholesterolaemia

BACKGROUND

A cholesterol-lowering diet and several other dietary interventions have been suggested as a management approach either independently or as an adjuvant to drug therapy in children and adults with familial hypercholesterolaemia (FH). However, a consensus has yet to be reached on the most appropriate dietary treatment. Plant sterols are commonly used in FH although patients may know them by other names like phytosterols or stanols.

OBJECTIVES

To examine whether a cholesterol-lowering diet is more effective in reducing ischaemic heart disease and lowering cholesterol than no dietary intervention in children and adults with familial hypercholesterolaemia. Further, to compare the efficacy of supplementing a cholesterol-lowering diet with either omega-3 fatty acids, soya proteins, plant sterols or plant stanols.

SEARCH METHODS

We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group Inborn Errors of Metabolism Trials Register, which is compiled from electronic searches of the Cochrane Central Register of Controlled Trials (CENTRAL) (updated with each new issue of The Cochrane Library), quarterly searches of MEDLINE and the prospective handsearching of one journal - Journal of Inherited Metabolic Disease. Most recent search of the Group's Inborn Errors of Metabolism Trials Register: 22 August 2013. We also searched PubMed to 05 February 2012.

SELECTION CRITERIA

Randomised controlled trials, both published and unpublished, where a cholesterol-lowering diet in children and adults with familial hypercholesterolaemia has been compared to other forms of dietary treatment or to no dietary intervention were included.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed the trial eligibility and risk of bias and one extracted the data, with independent verification of data extraction by a colleague.

MAIN RESULTS

In the 2014 update of the review, 15 trials have been included, with a total of 453 participants across seven comparison groups. The included trials had either a low or unclear risk of bias for most of the parameters used for risk assessment. Only short-term outcomes could be assessed due to the short duration of follow up in the included trials. None of the primary outcomes, (incidence of ischaemic heart disease, number of deaths and age at death) were evaluated in any of the included trials. No significant differences were noted for the majority of secondary outcomes for any of the planned comparisons. However, a significant difference was found for the following comparisons and outcomes: for the comparison between plant sterols and cholesterol-lowering diet (in favour of plant sterols), total cholesterol levels, mean difference 0.30 mmol/l (95% confidence interval 0.12 to 0.48); decreased serum LDL cholesterol, mean difference -0.60 mmol/l (95% CI -0.89 to -0.31). Fasting serum HDL cholesterol levels were elevated, mean difference -0.04 mmol/l (95% CI -0.11 to 0.03) and serum triglyceride concentration was reduced, mean difference -0.03 mmol/l (95% CI -0.15 to -0.09), although these changes were not statistically significant. Similarly, guar gum when given as an add on therapy to bezafibrate reduced total cholesterol and LDL levels as compared to bezafibrate alone.

AUTHORS' CONCLUSIONS

No conclusions can be made about the effectiveness of a cholesterol-lowering diet, or any of the other dietary interventions suggested for familial hypercholesterolaemia, for the primary outcomes: evidence and incidence of ischaemic heart disease, number of deaths and age at death,due to the lack of data on these. Large, parallel, randomised controlled trials are needed to investigate the effectiveness of a cholesterol-lowering diet and the addition of omega-3 fatty acids, plant sterols or stanols, soya protein, dietary fibers to a cholesterol-lowering diet.

Postprandial effect of dietary fat quantity and quality on arterial stiffness and wave reflection: a randomised controlled trial

Background

Arterial stiffness is a component of vascular function and an established risk factor for cardiovascular disease. There is a lack of conclusive evidence on the effect of a meal rich in monounsaturated fat (MUFA) compared with an isoenergetic meal rich in saturated fat (SFA) on postprandial vascular function and specifically on arterial stiffness.

Methods

Twenty healthy, non-smoking males (BMI 24 ± 2 kg/m²; age 37.7 ± 14.4 y) participated in this single-blind, randomised, cross-over dietary intervention study. Each subject was randomised to receive a high-fat test-meal (3 MJ; 56 ± 2 g fat) at breakfast on 2 separate occasions, one rich in oleic acid (MUFA-meal) and one rich in palmitic acid (SFA-meal), and the meals were isoenergetic. Blood pressure (BP), arterial stiffness (PWV) and arterial wave reflection (augmentation index, AIx) were measured using applanation tonometry at baseline and every 30 minutes up to 4 hours after the ingestion of the test-meals.

Results

All subjects completed both arms of the dietary intervention. There was no significant difference in BP parameters, PWV or AIx at baseline between the two treatments (P > 0.05). There was a significant increase in brachial and aortic BP, mean arterial pressure (MAP), heart rate and PVW (time, P < 0.05) over the four hours after consumption of the fat-rich test-meal although the increase in PWV was no longer significant when adjusted for the increase in MAP. There was no difference in PWV between the two treatments (treatment*time, P > 0.05). There was a significant reduction in AIx (time, P < 0.05) over the four hour postprandial period although this was no longer significant when adjusted for the increase in heart rate and MAP (time, P > 0.05). There was no difference in AIx between the two treatments (treatment*time, P > 0.05). However, the reduction in heart rate corrected augmentation index (AIx₇₅) was significant when corrected for the increase in MAP (time, P < 0.01) with no differential effect of the treatments (treatment*time, P > 0.05).

Conclusions

This study has demonstrated a BP dependent increase in PWV and a decrease in arterial wave reflection in the four hour period in response to a high-fat meal. There was no evidence however that replacement of some of the SFA with MUFA had a differential effect on these parameters. The study highlights the need for further research to understand the effects of the substitution of SFA with MUFA on non-serum, new and emerging risk factors for CVD such as arterial stiffness.

Effect of substituting saturated with monounsaturated fatty acids on serum visfatin levels and insulin resistance in overweight women: a randomized cross-over clinical trial

OBJECTIVE

This study aimed to determine the effects of a monounsaturated fatty acids (MUFA)-rich diet on serum visfatin, interleukin-6 and insulin levels among overweight women.

DESIGN

In this randomized cross-over clinical trial, 17 premenopausal overweight women were included. Participants were randomly assigned to consume either a hypocaloric, saturated fatty acids (SFA)-rich diet (16% SFA and 8% MUFA) or a hypocaloric, MUFA-rich diet (16% MUFA and 8% SFA) for 12 weeks crossing over after a 2-week washout period. Percentages of energy from other macronutrients were similar between the two diets. Biochemical and anthropometric assessments were done at the first and at the end of each period. Statistical analyses were done using paired t-test. In all statistical analysis, p < 0.05 was considered as significant.

RESULTS

The participant's mean body mass index was 27.6 kg/m². Mean percentages of MUFA intake were 13% during MUFA-rich diet and 7% during SFA-rich diet. The corresponding values for SFA intake were 8.5% and 14%, respectively. We failed to find any significant differences between two intervention diets in terms of their effect on the serum levels of IL-6, visfatin and insulin. However, serum visfatin and IL-6 levels increased during the SFA-rich diet (0.4 ± 0.4 ng/ml and 0.19 ± 0.3 pg/ml, respectively) and decreased during the MUFA-rich diet (-0.7 ± 0.5 ng/ml and -0.17 ± 0.3 pg/ml, respectively). In spite of a slight reduction in both periods, changes in serum insulin levels did not reach significant levels comparing the two periods.

CONCLUSIONS

Our findings did not support any significant effect of a MUFA-rich intake on serum IL-6 and insulin levels as compared with a SFA-rich diet; however, it has the potential to favourably affect serum visfatin levels.

Dietary treatment for familial hypercholesterolaemia

BACKGROUND

A cholesterol-lowering diet and several other dietary interventions have been suggested as a management approach either independently or as an adjuvant to drug therapy in children and adults with familial hypercholesterolemia. However, a consensus has yet to be reached on the most appropriate dietary treatment.

OBJECTIVES

To examine whether a cholesterol-lowering diet is more effective in reducing ischaemic heart disease and lowering cholesterol than no dietary intervention in children and adults with familial hypercholesterolaemia. Further, to compare the efficacy of supplementing a cholesterol-lowering diet with either omega-3 fatty acids, soya proteins, plant sterols or plant stanols.

SEARCH STRATEGY

We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group Inborn Errors of Metabolism Trials Register.Most recent search of the Group's Inborn Errors of Metabolism Trials Register: 09 October 2009.We also searched PubMed till 01 June 2008.

SELECTION CRITERIA

Randomised controlled trials, both published and unpublished, where a cholesterol-lowering diet in children and adults with familial hypercholesterolaemia has been compared to other forms of dietary treatment or to no dietary intervention were included.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed the trial eligibility and methodological quality and one extracted the data, with independent verification of data extraction by a colleague.

MAIN RESULTS

In the present update, four new trials have been added making eleven trials with a total of 331 participants eligible for inclusion. Only short-term outcomes could be assessed due to the short duration of follow up in the included studies. None of the primary outcomes, (incidence of ischaemic heart disease, number of deaths and age at death) were evaluated in any of the included studies. No significant difference was noted for the majority of secondary outcomes for any of the planned comparisons. However, a significant difference was found only for the following comparison and outcome: total cholesterol levels for the comparison between plant sterols and cholesterol-lowering diet, mean difference 0.70 (95% confidence interval 0.19 to 1.21).

AUTHORS' CONCLUSIONS

No conclusions can be made about the effectiveness of a cholesterol-lowering diet, or any of the other dietary interventions suggested for familial hypercholesterolaemia, due to the lack of adequate data. Large, parallel, randomised controlled trials are needed to investigate the effectiveness of a cholesterol-lowering diet and the addition of omega-3 fatty acids, plant sterols or stanols, soya protein to a cholesterol-lowering diet.

Dietary linoleic acid has no effect on arachidonic acid, but increases n-6 eicosadienoic acid, and lowers dihomo-gamma-linolenic and eicosapentaenoic acid in plasma of adult men

High intakes of linoleic acid (LA,18:2n-6) have raised concern due to possible increase in arachidonic acid (ARA, 20:4n-6) synthesis, and inhibition of alpha linolenic acid (ALA, 18:3n-3) desaturation to eicosapentaenoic (EPA, 20:5n-3) and docosahexaenoic acid (DHA, 22:6n-3). In healthy men, 10.5% energy compared to 3.8% energy LA with 1% energy ALA increased plasma phospholipid LA and 20:2n-6, the elongation product of LA, and decreased EPA, with no change in ARA. However, LA was inversely related to ARA at both 10.5% energy and 3.8% energy LA, (r=-0.761, r=-0.817, p<0.001, respectively). A two-fold variability in ARA among individuals was not explained by the dietary LA, ARA, ALA, or fish intake. Our results confirm LA requirements for ARA synthesis is low, <3.8% energy, and they suggest current LA intakes saturate Delta-6 desaturation and adversely affect n-3 fatty acid metabolism. Factors other than n-6 fatty acid intake are important modifiers of plasma ARA.

Is there a role for monounsaturated fat in the dietary management of obesity?

Animal and human studies indicate that high saturated fat (SFA) diets can be obesogenic. Monounsaturated fat (MUFA) has acute (meal related) effects that influence energy metabolism. These include increased postprandial fat oxidation and greater diet induced thermogenesis, factors that attenuate weight gain. Chronic (diet related) studies for 12 weeks or more, demonstrate that people following high MUFA diets do not gain excessive weight even when eating ad libitum. In fact, we have observed greater body weight and fat loss in men following an ad libitum MUFA diet, when compared to a SFA diet. High MUFA diets designed for weight loss should also incorporate a high vegetable intake according to traditional Mediterranean patterns. Such diets will promote the utilisation of fat and also have a low energy density. In our experience these diets are well accepted, and offer the prospect of greater long-term adherence to dietary advice.

Oleic acid content is responsible for the reduction in blood pressure induced by olive oil

Numerous studies have shown that high olive oil intake reduces blood pressure (BP). These positive effects of olive oil have frequently been ascribed to its minor components, such as alpha-tocopherol, polyphenols, and other phenolic compounds that are not present in other oils. However, in this study we demonstrate that the hypotensive effect of olive oil is caused by its high oleic acid (OA) content (approximately 70-80%). We propose that olive oil intake increases OA levels in membranes, which regulates membrane lipid structure (H(II) phase propensity) in such a way as to control G protein-mediated signaling, causing a reduction in BP. This effect is in part caused by its regulatory action on G protein-associated cascades that regulate adenylyl cyclase and phospholipase C. In turn, the OA analogues, elaidic and stearic acids, had no hypotensive activity, indicating that the molecular mechanisms that link membrane lipid structure and BP regulation are very specific. Similarly, soybean oil (with low OA content) did not reduce BP. This study demonstrates that olive oil induces its hypotensive effects through the action of OA.

Fatty acid composition of adipose tissue and blood in humans and its use as a biomarker of dietary intake

Accurate assessment of fat intake is essential to examine the relationships between diet and disease risk but the process of estimating individual intakes of fat quality by dietary assessment is difficult. Tissue and blood fatty acids, because they are mainly derived from the diet, have been used as biomarkers of dietary intake for a number of years. We review evidence from a wide variety of cross-sectional and intervention studies and summarise typical values for fatty acid composition in adipose tissue and blood lipids and changes that can be expected in response to varying dietary intake. Studies in which dietary intake was strictly controlled confirm that fatty acid biomarkers can complement dietary assessment methodologies and have the potential to be used more quantitatively. Factors affecting adipose tissue and blood lipid composition are discussed, such as the physical properties of triacylglycerol, total dietary fat intake and endogenous fatty acid synthesis. The relationship between plasma lipoprotein concentrations and total plasma fatty acid composition, and the use of fatty acid ratios as indices of enzyme activity are also addressed.

A cross-sectional study of dietary habits and lipid profiles. The Rivas-Vaciamadrid study

The relations between dietary habits and serum lipids have been firmly established in adults. In children, this relation has been less extensively studied. We have assessed the relations between dietary components, including the different types of fatty acids (saturated, polyunsaturated and monounsaturated) and serum lipids and apolipoproteins in a group of 673 6-year-old children of the town of Rivas-Vaciamadrid, Spain. Children in the highest tertile of total fat consumption, when compared with children in the lowest tertile, had higher mean levels of total cholesterol (188.3 mg/dl vs. 146.8 mg/dl), triglycerides (56.7 mg/dl vs. 51.3 mg/dl), LDL cholesterol (120.7 mg/dl vs. 92.6 mg/dl), HDL cholesterol (56.2 mg/dl vs. 54.5 mg/dl) and apolipoprotein B (86.8 mg/dl vs. 62.9 mg/dl). When compared with children in the lowest tertile, children in the highest tertile of saturated fat consumption had significantly higher mean levels of total cholesterol (206.3 mg/dl vs. 151.8 mg/dl), LDL cholesterol (140.6 mg/dl vs. 95.1 mg/dl) and apolipoprotein B (99.2 mg/dl vs. 64.3 mg/dl) and lower mean levels of HDL cholesterol (53.5 mg/dl vs. 57.5 mg/dl), whereas children in the highest tertile of monounsaturated fat consumption had significantly higher mean levels of HDL cholesterol (56.5 mg/dl vs. 51.8 mg/dl) and lower levels of total cholesterol (133.2 mg/dl vs. 201.6 mg/dl), LDL cholesterol (93.1 mg/dl vs. 137.5 mg/dl) and apolipoprotein B (68.6 mg/dl vs. 94.9 mg/dl) than children in the lowest tertile. No statistically significant relation between polyunsaturated fat and lipid levels was found. We have found a strong association between diet composition and lipid and apolipoprotein levels in 6-year-old children. Our findings strengthen the role of monounsaturated fatty acid consumption as a part of a healthy diet in childhood.

The influence of olive oil on human health: not a question of fat alone

Olive oil is the most representative food in the traditional Mediterranean diet and its most important source of MUFA. The healthy benefits of MUFA-rich diets on plasma cholesterol levels, were the first to generate interest in this dietary model. In addition to the benefits conferred by its lipids, olive oil has other biological effects, some of them also related to MUFA. However, most recent studies have shown that there are a number of properties that depend on, or are potentiated by, the consumption of olive oil, such as virgin olive oil, that is rich in microcomponents. This foodstuff, thanks to its double set of benefits, thus tends to produce a better lipid profile and a less prothrombotic environment, promoting antioxidant and anti-inflammatory effects, with a greater endothelial protective capacity. In view of these effects, it would appear that when olive oil is the basic source of dietary alimentary fat it has a major antiatherogenic capacity, which is not shared to the same extent by other oils that are rich in oleic acid but lack its characteristic micronutrients.

Effects of a supplement containing isoflavones and Actaea racemosa L. on asymmetric dimethylarginine, lipids, and C-reactive protein in menopausal women

OBJECTIVE

To investigate the effects of a supplement containing soy isoflavones and Actaea racemosa L. on several coronary heart disease (CHD) risk markers in menopausal women.

DESIGN

Randomized, placebo-controlled, double-blind study.

SETTING

Nine hospitals in The Netherlands.

PATIENT(S)

One hundred twenty-four menopausal women.

INTERVENTION(S)

Daily placebo (n = 64) or supplement containing soy isoflavones and Actaea racemosa L. (n = 60) for 12 weeks.

MAIN OUTCOME MEASURE(S)

Fasting blood concentrations of asymmetric dimethylarginine (ADMA), lipids, and C-reactive protein (CRP) at baseline and week 12.

RESULT(S)

In the supplement group, total cholesterol and low-density lipoprotein cholesterol showed a small absolute reduction at week 12 (-0.2, 95% confidence interval [CI] -0.3 to -0.0; and -0.2, 95% CI -0.3 to -0.0; respectively). Concentrations of ADMA, triglycerides, lipoprotein(a), and CRP did not change significantly. Analysis of covariance over the 12-week study period revealed no significant between-group differences for all parameters. No significant correlations were found between the concentrations of isoflavones and the CHD risk markers investigated.

CONCLUSION(S)

Twelve-week administration of a supplement containing soy isoflavones and Actaea racemosa L. had little or no influence on the CHD risk markers studied. This supplement probably has neither protective nor adverse effects on the cardiovascular system; however, large long-term studies are needed to test this.

Different effects of whole milk and a fermented milk with the same fat and lactose content on gastric emptying and postprandial lipaemia, but not on glycaemic response and appetite

Longitudinal studies indicate that milk and fermented milk products lower basal plasma cholesterol concentrations, despite their high content of saturated fat, and therefore have favourable health effects. However, there have been few studies on the postprandial effects of milk products. The present study compared the effect of whole milk with a fermented milk, A-38, on postprandial carbohydrate and lipid metabolism, gastric emptying and appetite. Eight healthy young men participated. On the two test days, they arrived fasting for collection of baseline values before consuming the meals, which for a 75 kg subject consisted of 1·4 litre milk or fermented milk, plus 165 mg [13C]acetate (for later determination of gastric emptying by a [13C]acetate breath test). Lactose (15 g) was added to the A-38 meal to equalize the lactose content. Postprandially the A-38 meal resulted in a slower gastric emptying rate than milk (P>0·001). Furthermore, the A-38 meal resulted in a greater increase and a quicker decrease of the triacylglycerol content in all lipoprotein fractions (LDL-fraction,P>0·05; other fractions,P>0·001) and of the gastrointestinal hormones (cholecystokinin and peptide YY,P>0·05; gastric inhibitory polypeptide and glucagon-like polypeptide-1,P>0·001). There were no significant differences in appetite sensations (measured by visual analogue scale) or in the glucose and insulin response (P<0·10). The slower emptying rate of the liquid phase after the A-38 meal is probably due to the higher viscosity of A-38. The lower and more prolonged triacylglycerol response after the milk meal might be caused by coagulation of milk in the stomach.

Effects of dietary maritime pine (Pinus pinaster)-seed oil on high-density lipoprotein levels and in vitro cholesterol efflux in mice expressing human apolipoprotein A-I

Maritime pine (Pinus pinaster)-seed oil contains two Δ5 unsaturated polymethylene interrupted fatty acids (all cis-5,9,12–18:3 and all cis-5,11,14–20:3 acids) one of which resembles eicosapentaenoic acid. The goal of the present study was to test whether maritime pine-seed oil consumption affects HDL and apolipoprotein (Apo) A-I levels as well as the ability of serum to promote efflux of cholesterol from cultured cells. To this end, wild type (WT) non-transgenic mice and transgenic mice expressing human ApoA-I (HuA-ITg) were fed on isoenergetic diet containing either 200 g maritime pine-seed oil/kg or 200 g lard/kg for 2 weeks. WT and HuA-ITg mice fed maritime pine-seed oil had lower cholesterol, HDL-cholesterol, LDL-cholesterol and HuA-ITg mice had lower human ApoA-I than those fed lard. The differences in cholesterol (P < 0·0001) and HDL-cholesterol (P < 0·003) levels between mice fed on the two diets were more pronounced in the HuA-ITg than in the WT mice. The ability of HuA-ITg serum to promote cholesterol efflux in cultured cells was greater (P < 0·008) than that of WT animals. However, the maritime pine-seed oil diet was associated with lower (P < 0·005) in vitro cholesterol efflux ability than the lard diet in both mice genotypes. This suggests a negative effect of the maritime pine-seed oil on reverse cholesterol transport. Cholesterol efflux was correlated with serum free or esterified cholesterol and phospholipid levels. The slope of the regression line was smaller in the HuA-ITg than in the WT mice indicating that overexpression of human ApoA-I reduces the negative impact of maritime pine-seed oil on cholesterol efflux. In conclusion, maritime pine-seed oil diet lowers HDL-cholesterol and diminishes in vitro cholesterol efflux. This potentially detrimental effect is attenuated by overexpression of human ApoA-I in mice.

Response of ApoA-IV in pigs to long-term increased dietary oil intake and to the degree of unsaturation of the fatty acids

ApoA-IV is a protein constituent of HDL particles; the gene coding for it is a member of the ApoA-I–ApoC-III–ApoA-IV cluster. To investigate the effects of the quantity and the degree of saturation of dietary lipid on the long-term response of this Apo, and on the hypothetical coordinated regulation of the clusterin vivo, pigs were fed isoenergetic, cholesterol-free, low-lipid or lipid-enriched diets (containing either extra olive oil (rich in MUFA) or sunflower oil (rich inn−6 PUFA)) for 42 d. In animals fed on the control diet, ApoA-IV was mainly associated with plasma lipoproteins. An increase in plasma ApoA-IV concentration, mainly in the lipoprotein-free fraction, was induced by the lipid-enriched diets, independent of the degree of saturation of the fatty acids involved. The latter diets also led to increases in hepatic ApoA-I, ApoA-IV and ApoC-III mRNA levels, more so with the sunflower oil-rich diet. The present results show that porcine plasma ApoA-IV levels and their association with lipoproteins are very sensitive to increases in dietary lipids, independent of the degree of fatty acid saturation. Furthermore, hepatic expression of RNA appears to be coordinated along with that of the other members of the gene cluster.

UK Food Standards Agencycis-monounsaturated fatty acid workshop report

The UK Food Standards Agency convened a group of expert scientists to review current research investigating the optimal dietary intake forn-9cis-monounsaturated fatty acids (MUFA). The aim was to review the mechanisms underlying the reported beneficial effects of MUFA on CHD risk, and to establish priorities for future research. The issue of optimal MUFA intake is contingent upon optimal total fat intake; however, there is no consensus of opinion on what the optimal total fat intake should be. Thus, it was recommended that a large multi-centre study should look at the effects on CHD risk of MUFA replacement of saturated fatty acids in relation to varying total fat intakes; this study should be of sufficient size to take account of genetic variation, sex, physical activity and stage of life factors, as well as being of sufficient duration to account for adaptation to diets. Recommendations for studies investigating the mechanistic effects of MUFA were also made. Methods of manipulating the food chain to increase MUFA at the expense of saturated fatty acids were also discussed.

G protein-coupled receptor systems and their lipid environment in health disorders during aging

Cells, tissues and organs undergo phenotypic changes and deteriorate as they age. Cell growth arrest and hyporesponsiveness to extrinsic stimuli are all hallmarks of senescent cells. Most such external stimuli received by a cell are processed by two different cell membrane systems: receptor tyrosine kinases (RTKs) and G protein-coupled receptors (GPCRs). GPCRs form the largest gene family in the human genome and they are involved in most relevant physiological functions. Given the changes observed in the expression and activity of GPCRs during aging, it is possible that these receptors are directly involved in aging and certain age-related pathologies. On the other hand, both GPCRs and G proteins are associated with the plasma membrane and since lipid-protein interactions regulate their activity, they can both be considered to be sensitive to the lipid environment. Changes in membrane lipid composition and structure have been described in aged cells and furthermore, these membrane changes have been associated with alterations in GPCR mediated signaling in some of the main health disorders in elderly subjects. Although senescence could be considered a physiologic process, not all aging humans develop the same health disorders. Here, we review the involvement of GPCRs and their lipid environment in the development of the major human pathologies associated with aging such as cancer, neurodegenerative disorders and cardiovascular pathologies.

The Effect of Nutritional Habits on Maternal-Neonatal Lipid and Lipoprotein Serum Levels in Three Different Ethnic Groups

AIM

To investigate the effect of nutritional habits on lipid profiles in mothers of three different ethnic groups and in their newborns.

SUBJECTS AND METHODS

Lipids and lipoproteins were determined in 7-day dietetic diaries of 9,134 mothers (Greeks n = 3,118, Albanians n = 3,050, Muslim Asians n = 2,966), in their sera and in the cord blood of their newborns with routine methods.

RESULTS

Monounsaturated fat intake (35 +/- 12 g/day) was similar among the groups. Total fat, saturated fat and cholesterol intakes were significantly lower in Asians than those in Albanians and Greeks. Significantly lower lipid and lipoprotein concentrations (cholesterol 5.09 +/- 0.85 mmol/l, triglyceride, TG, 2.38 +/- 0.58 mmol/l, low-density lipoprotein cholesterol, LDL-C, 2.90 +/- 0.78 mmol/l, very-low-density lipoprotein cholesterol, VLDL-C, 0.32 +/- 0.11 mmol/l) were measured in the Muslim Asian mothers and in their newborns (cholesterol 1.06 +/- 0.26 mmol/l, TG 0.52 +/- 0.16 mmol/l, LDL-C 0.49 +/- 0.10 mmol/l and VLDL-C 0.10 +/- 0.02 mmol/l; p < 0.001). Higher levels of the mentioned biochemical parameters were found in Greek mothers versus their newborns (cholesterol 5.20 +/- 0.98 mmol/l, TG 2.37 +/- 0.62 mmol/l, LDL-C 3.40 +/- 0.85 mmol/l and VLDL-C 0.48 +/- 0.13 mmol/l vs. cholesterol 1.55 +/- 0.31 mmol/l, TG 0.56 +/- 0.20 mmol/l, LDL-C 0.65 +/- 0.15 mmol/l and VLDL-C 0.12 +/- 0.01 mmol/l; p < 0.001) and Albanian mothers versus their newborns (cholesterol 7.1 +/- 0.78 mmol/l, TG 2.55 +/- 0.60 mmol/l, LDL-C 4.1 +/- 0.88 mmol/l and VLDL-C 0.52 +/- 0.13 mmol/l vs. cholesterol 1.6 +/- 0.40 mmol/l, TG 0.59 +/- 0.15 mmol/l, LDL-C 0.70 +/- 0.21 mmol/l and VLDL-C 0.12 +/- 0.01 mmol/l; p < 0.001). The highest HDL-C levels were observed in the Asian mothers (1.60 +/- 0.31 mmol/l vs. 1.4 +/- 0.39 mmol/l in Greeks and 1.31 +/- 0.39 mmol/l in Albanians; p < 0.001).

CONCLUSION

The normal lipid profile in Greeks, the high one in Albanians and the low profile in Muslim Asians may be due to their nutritional habits and their socioeconomic status affecting those of their newborns.

The use of fatty acid biomarkers to reflect dietary intake

PURPOSE OF REVIEW

This review compares fatty acid biomarkers to assess compliance in dietary intervention trials with their application in epidemiological studies.

RECENT FINDINGS

Although many studies have used fatty acid biomarkers to assess compliance in short-term dietary intervention trials and habitual diets in observational studies, there is little information on the reliability and comparability of these measures. In this review, we summarize the usefulness and limitations of fatty acid biomarkers in clinical and epidemiological studies. As there are very few recent publications in this area, a complete literature review is provided.

SUMMARY

Several options are available for the biological assessment of dietary fatty acids. The type of study (short or long-term), the metabolic characteristics and expected variability in the fatty acids of interest are major considerations when determining which tissues reflect a better measure of true intake. Certain fatty acids may not be suitable to assess differences in intake under non-isocaloric conditions and when trying to identify small differences. Serum cholesterol ester is the most suitable serum fraction to assess short-term dietary compliance, but given the multiple factors that affect response, the quantification of compliance should be interpreted with caution. Adipose tissue is the biomarker of choice for long-term intake, but a preferred blood constituent (plasma versus erythrocytes) is difficult to establish given the data available to date. Future studies should explore the use of whole blood as an alternative choice to measure fatty acid intake in epidemiological studies.

Dietary cholesterol suppresses the ability of olive oil to delay the development of atherosclerotic lesions in apolipoprotein E knockout mice

To test the hypothesis that cholesterol might suppress the beneficial effect of olive oil in atherosclerosis, we fed apoE KO mice diets containing extra virgin olive oil, either with or without cholesterol, for 10 weeks and assessed the development of atherosclerosis. Within each sex, mice were assigned randomly to one of the following four experimental groups: (1) a standard chow diet, (2) a chow diet supplemented with 0.1% cholesterol (w/w) cholesterol, (3) a chow diet enriched with 20% (w/w) extra virgin olive oil and (4) a chow diet containing 0.1% cholesterol and 20% extra virgin olive oil. On the standard chow diet, average plasma cholesterol levels were higher in males than in females. Olive oil- and cholesterol-enriched diets, separately or in combination, induced hypercholesterolemia in both sexes, and abolished the difference between the sexes in plasma cholesterol levels. The addition of cholesterol to chow or olive oil diets decreased apolipoprotein A-I significantly in females and serum paraoxonase activities in males. The latter activity was higher in females than in males. In both sexes, the size of aortic atherosclerotic lesions was similar in olive oil- and chow-fed animals and smaller than in cholesterol-supplemented groups. Size of aortic lesions were positively correlated with circulating paraoxonase activity, particularly in males, and the relationship remained after adjusting for apolipoprotein A-I and HDL cholesterol levels. Our results demonstrate that the nutritional regulation of paraoxonase is an important determinant of atherosclerotic lesions dependent on sex. They also suggest that the mere inclusion of olive oil in Western diets is insufficient and the adoption of Mediterranean diet would be more effective in retarding the development of atherosclerotic lesions.

Decreased aortic early atherosclerosis and associated risk factors in hypercholesterolemic hamsters fed a high- or mid-oleic acid oil compared to a high-linoleic acid oil

Currently, diets higher in polyunsaturated fat are believed to lower blood cholesterol concentrations, and thus reduce atherosclerosis, greater than diets containing high amounts of saturated or possibly even monounsaturated fat. The present study was designed to investigate the effect of diets containing mid- or high-linoleic oil versus the typical high-linoleic sunflower oil on LDL oxidation and the development of early atherosclerosis in a hypercholesterolemic hamster model. Animals were fed a hypercholesterolemic diet containing 10% mid-oleic sunflower oil, high-oleic olive oil, or high-linoleic sunflower oil (wt/wt) plus 0.4% cholesterol (wt/wt) for 10 weeks. After 10 weeks of dietary treatment, only the animals fed the mid-oleic sunflower oil had significant reductions in plasma LDL-C levels (-17%) compared to the high-linoleic sunflower oil group. The high-oleic olive oil-fed hamsters had significantly higher plasma triglyceride levels (+41%) compared to the high-linoleic sunflower oil-fed hamsters. The tocopherol levels in plasma LDL were significantly higher in hamsters fed the mid-oleic sunflower oil (+77%) compared to hamsters fed either the high-linoleic sunflower or high-oleic olive oil. Measurements of LDL oxidation parameters, indicated that hamsters fed the mid-oleic sunflower oil and high-oleic olive oil diets had significantly longer lag phase (+66% and +145%, respectively) and significantly lower propagation rates (-26% and -44%, respectively) and conjugated dienes formed (-17% and -25%, respectively) compared to the hamsters fed the high-linoleic sunflower oil. Relative to the high-linoleic sunflower oil, aortic cholesterol ester was reduced by -14% and -34% in the mid-oleic sunflower oil and high-oleic olive oil groups, respectively, with the latter reaching statistical significance. Although there were no significant associations between plasma lipids and lipoprotein cholesterol with aortic total cholesterol and cholesterol esters for any of the groups, the lag phase of conjugated diene formation was inversely associated with both aortic total and esterified cholesterol in the high-oleic olive oil-fed hamsters (r = -0.69, P < 0.05). The present study suggests that mid-oleic sunflower oil reduces risk factors such as lipoprotein cholesterol and oxidative stress associated with early atherosclerosis greater than the typical high-linoleic sunflower oil in hypercholesterolemic hamsters. The high-oleic olive oil not only significantly reduced oxidative stress but also reduced aortic cholesterol ester, a hallmark of early aortic atherosclerosis greater than the typical high-linoleic sunflower oil.

Sunflower oil does not protect against LDL oxidation as virgin olive oil does in patients with peripheral vascular disease

BACKGROUND & AIMS

The aim of this study was to compare the in vivo effects of a diet rich in virgin olive oil or sunflower oil on the lipid profile and on LDL susceptibility to oxidative modification in free-living Spanish male patients with peripheral vascular disease.

METHODS

A total of 20 Spanish male subjects diagnosed with peripheral vascular disease were randomly divided into two groups (n = 10) receiving different supplements, virgin olive oil and sunflower oil for 4 months.

RESULTS

The adaptation of patients to the experimental supplements was demonstrated since plasma and LDL fatty acids composition reflected dietary fatty acids. No differences in triglycerides, total cholesterol, LDL-cholesterol or HDL-cholesterol concentrations were found between the groups of patients. A significantly higher LDL susceptibility to oxidation was observed after sunflower oil intake in comparison with virgin olive oil, in spite of an increase in LDL alpha-tocopherol concentration in sunflower oil group.

CONCLUSIONS

The results of the present study provide further evidence that sunflower-oil-enriched diets does not protect LDL against oxidation as virgin olive oil does in patients with peripheral vascular disease.

2-hydroxyoleic acid: a new hypotensive molecule

Recent studies have shown that diets rich in monounsaturated fatty acids (MUFAs) from olive oil, a natural source of oleic acid, have beneficial effects on blood pressure (BP) in hypertensive patients. With this in mind, we investigated whether a synthetic derivative of the MUFA oleic acid, 2-hydroxyoleic acid (2-OHOA), was capable of regulating the BP of Sprague-Dawley rats. Intraperitoneal and oral administration of 2-OHOA to rats induced significant and sustained decreases in BP in a time-dependent manner. Without affecting heart rate, treatments for 7 days provoked reductions in systolic BP of 20 to 26 mm Hg. At the molecular level, the density of Galpha(s), but not Galpha(i2) or Galpha(o), increased in membranes from the hearts and aortas of 2-OHOA-treated rats, whereas in heart membranes, the density of Galpha(q)/11 and protein kinase Calpha proteins was also augmented. These molecular alterations were reflected in the increase in cAMP levels after Galpha(s) protein and beta-adrenergic receptor stimulation. On the contrary, inhibitory hormones reduced adenylyl cyclase activity to the same extent in 2-OHOA-treated rats as in vehicle-treated ones. Our results indicate that cardiovascular tissues from 2-OHOA-treated rats exhibited increased cAMP production in response to Galpha(s) activation, which might be attributed to enhanced expression of Galpha(s) proteins. As a result of this change, a significant reduction in systolic BP was observed. Therefore, BP can be lowered by administration of 2-OHOA, which might represent the first member of a new family of antihypertensive drugs.

Hypolipidemic and hypocholesterolemic effect of argan oil (Argania spinosa L.) in Meriones shawi rats

The potential health benefits of various dietary oils in relation to cardiovascular disease and cancer are recently receiving considerable attention. The main proposal of this study is to investigate the effect of dietary argan oil, obtained from seeds of Argania spinosa L. (Sapotaceae) endemic from Morocco, on serum lipids composition. Hyperlipidemia was induced by high calorie and cholesterol (HCC) diet administration in 16 rats (Meriones shawi, a rodent of the Gerbillideae family). Eight rats were treated with argan oil (1ml/100g weight) daily by oral route during 7 weeks (treated group). Control animals were also fed with HCC diet for 7 weeks. After 7-week treatment with argan oil, blood lipoproteins were significantly reduced. Total cholesterol decreased with 36.67% (P<0.01), low density lipoprotein (LDL)-cholesterol in 67.70% (P<0.001), triglycerides in 30.67% (P<0.05) and body weight in 12.7% (P<0.05). High density lipoprotein (HDL)-cholesterol concentration remained unaltered. These results indicate the beneficial effect of argan oil in the treatment of the hyperlipidemia and hypercholesterolemia. This effect will be related with the polyunsaturated fatty acids and other constituents of studied oil.

Nutritional assessment, health markers and lipoprotein profile in postmenopausal women belonging to a closed community

OBJECTIVE

To assess the dietary characteristics of a closed community and their relationship with several health markers and lipid and lipoprotein values in postmenopausal women.

DESIGN

Energy and nutrient intake, serum lipids, lipoproteins, antioxidants, peroxides and low-density lipoprotein (LDL) peroxides in addition to several health markers were measured in a closed, postmenopausal female community consuming a diet without meat, meat products and alcoholic beverages.

SETTING

Departamento de Nutrición and Sección Departamental de Química Analítica and Escuela de Especialización de Análisis Clínicos, Universidad Complutense de Madrid, Spain and Lerma, Burgos, Spain.

RESULTS

Cereals, vegetables, legumes and fruit, together with milk and eggs, constituted the most important ingredients of the diet consumed. Dietary carbohydrates contributed 42%en and lipids 46.4%en. The SFA/MUFA/PUFA ratio was 1/2/1 and the n-3/n-6 ratio 0.05 (SFA=saturated fatty acids, MUFA=monounsaturated fatty acids, PUFA=polyunsaturated fatty acids). The study community diet was monotonous and made for possible deficiencies of iron, magnesium, zinc, vitamin B(6) and vitamin D, in variable proportions. Routine biochemical and haematological normality markers indicate that only one woman presented hyperglycaemia and hyperuricaemia. Two women had haemoglobin levels <12 g/dl, but their mean corpuscular volume or mean corpuscular haemoglobin was normal. The prevalence of high cholesterol values (>6.21 mmol/l) was 42.8%, while that of high LDL-cholesterol levels (>3.88 mmol/l) was 35.7%, but none of the women displayed levels of high-density lipoprotein (HDL)-cholesterol <1.16 mmol/l, triglycerides >1.2 mmol/l or an LDL-cholesterol/HDL-cholesterol ratio>3. Only one woman had apolipoprotein (Apo) B levels >1.5 g/l, while most of the women presented Apo B values <1.2 g/l and an ApoA-1/ApoB ratio &<1.1. Plasma and LDL-peroxide levels, together with the tocopherol and carotene intakes, suggest a good antioxidant status in this population.

CONCLUSIONS

The diet of the study group seems compatible with a healthy life-profile and permits a more-than-acceptable degree of cardiovascular disease protection. However, the consumption of certain nutrients should be improved.

Substitution of saturated with monounsaturated fat in a 4-week diet affects body weight and composition of overweight and obese men

A randomised crossover study of eight overweight or obese men (aged 24-49 years, BMI 25.5-31.3 kg/m(2)), who followed two diets for 4 weeks each, was performed to determine whether substitution of saturated fat with monounsaturated fat affects body weight and composition. Subjects were provided with all food and beverages as modules (selected ad libitum) of constant macronutrient composition, but differing energy content. The % total energy from saturated fat, monounsaturated fat and polyunsaturated fat was 24, 13 and 3 % respectively on the saturated fatty acid (SFA)-rich diet and 11, 22 and 7 % respectively on the monounsaturated fatty acid (MUFA)-rich diet. MUFA accounted for about 80 % of the unsaturated fats consumed on both diets. Body composition, blood pressure, energy expenditure (resting and postprandial metabolic rates, substrate oxidation rate, physical activity), serum lipids, the fatty acid profile of serum cholesteryl esters and plasma glucose and insulin concentrations were measured before and after each diet period. Significant (P< or =0.05) differences in total cholesterol and the fatty acid composition of serum cholesteryl esters provided evidence of dietary adherence. The men had a lower weight (-2.1 (SE 0.4) kg, P=0.0015) and fat mass (-2.6 (SE 0.6) kg, P=0.0034) at the end of the MUFA-rich diet as compared with values at the end of the SFA-rich diet. No significant differences were detected in energy or fat intake, energy expenditure, substrate oxidation rates or self-reported physical activity. Substituting dietary saturated with unsaturated fat, predominantly MUFA, can induce a small but significant loss of body weight and fat mass without a significant change in total energy or fat intake.

Whole-body fat oxidation rate and plasma triacylglycerol concentrations in men consuming an ad libitum high-carbohydrate or low-carbohydrate diet

BACKGROUND

High-carbohydrate diets may increase plasma triacylglycerol concentrations either by increasing production of triacylglycerols or by reducing their clearance.

OBJECTIVE

We assessed whether the changes in plasma triacylglycerol concentrations induced by dietary interventions were associated with the changes in whole-body fat oxidation rates.

DESIGN

In a parallel study, 37 healthy male subjects [body mass index (in kg/m(2)): 28 +/- 5, age: 34 +/- 11 y (x +/- SD)] consumed an ad libitum high-carbohydrate (60% of energy; n = 19) or low-carbohydrate (46% of energy), high-fat (41% of energy, 23% as monounsaturated fatty acids; n = 18) diet for 7 wk. The following variables were measured before and after the dietary interventions: 1) plasma triacylglycerols before and 2, 4, 6, and 8 h after a meal (containing 40% of daily energy needs and 41% fat); 2) indirect calorimetry throughout the 8-h test; and 3) postheparin plasma lipoprotein lipase (phLPL) activity at time 8 h of the test.

RESULTS

The diets induced changes in 1) body weight: -2.5 +/- 2.8 kg (P < 0.01) and -1.7 +/- 3.1 kg (P < 0.05) and 2) fasting plasma triacylglycerols: 0.0 +/- 0.4 mmol/L (NS) and -0.3 +/- 0.3 mmol/L (P < 0.05) for the high-carbohydrate and the low-carbohydrate diets, respectively. In normoinsulinemic subjects (fasting insulin < 100 pmol/L), dietary changes in postprandial triacylglycerols were significantly predicted by changes in phLPL, body weight, respiratory quotient (or fat oxidation), and the type of diet (stepwise multiple linear regression).

CONCLUSION

Postprandial plasma triacylglycerol concentrations may depend at least partly on fat oxidation, body weight, and LPL activity.

Achievement of dietary fatty acid intakes in long-term controlled intervention studies: approach and methodology

OBJECTIVE

To describe the calculations and approaches used to design experimental diets of differing saturated fatty acid (SFA) and monounsaturated fatty acid (MUFA) compositions for use in a long-term dietary intervention study, and to evaluate the degree to which the dietary targets were met.

DESIGN, SETTING AND SUBJECTS

Fifty-one students living in a university hall of residence consumed a reference (SFA) diet for 8 weeks followed by either a moderate MUFA (MM) diet or a high MUFA (HM) diet for 16 weeks. The three diets were designed to differ only in their proportions of SFA and MUFA, while keeping total fat, polyunsaturated fatty acids (PUFA), trans-fatty acids, and the ratio of palmitic to stearic acid, and n-6 to n-3 PUFA, unchanged.

RESULTS

Using habitual diet records and a standardised database for food fatty acid compositions, a sequential process of theoretical fat substitutions enabled suitable fat sources for use in the three diets to be identified, and experimental margarines for baking, spreading and the manufacture of snack foods to be designed. The dietary intervention was largely successful in achieving the fatty acid targets of the three diets, although unintended differences between the original target and the analysed fatty acid composition of the experimental margarines resulted in a lower than anticipated MUFA intake on the HM diet, and a lower ratio of palmitic to stearic acid compared with the reference or MM diet.

CONCLUSIONS

This study has revealed important theoretical considerations that should be taken into account when designing diets of specific fatty acid composition, as well as practical issues of implementation.

Iron status in association with cardiovascular disease risk in 3 controlled feeding studies

BACKGROUND

The role of body iron stores in free radical-induced peroxidation and cardiovascular disease risk has been debated, but controlled feeding studies using measurements of non-transferrin-bound iron (NTBI) and LDL oxidation have not been conducted.

OBJECTIVE

We tested the hypothesis that NTBI and other measures of iron status do not affect oxidative susceptibility in healthy subjects with normal iron status.

DESIGN

Plasma samples were analyzed from 77 healthy men and women aged 20-65 y who participated in 3 controlled feeding studies in which the type and amount of dietary fat were controlled. Iron status and in vitro LDL oxidation were assessed at baseline and at the end of each feeding period (4-8 wk).

RESULTS

No significant relations were found between any measure of iron status (ferritin: 83 +/- 8.9 micro g/L; iron: 20.9 +/- 5.4 micro mol/L; TIBC: 74.4 +/- 11.0 micro mol/L; NTBI: 0.184 +/- 0.15 micro mol/L) and the in vitro measures of LDL oxidation (total dienes: 485 +/- 55 micro mol/mg LDL protein; lag time: 51.7 +/- 15.9 min; and rate of oxidation: 25.4 +/- 6.8 micro mol dienes.min(-1).g LDL protein(-1)). Equal-iron peanut butter-based diets were associated with higher plasma iron in men (22.4 +/- 3.8 micro mol/L) than was the olive oil diet (17.7 +/- 4.5 micro mol/L) (P = 0.02), but this slight elevation did not alter LDL oxidation.

CONCLUSIONS

Diet composition may affect plasma iron in men, but LDL oxidative susceptibility is unaffected by the subtle variation in iron status. Thus, the results do not support a relation between iron status and LDL oxidative susceptibility, a possible risk factor for cardiovascular disease.

Decreased aortic early atherosclerosis in hypercholesterolemic hamsters fed oleic acid-rich TriSun oil compared to linoleic acid-rich sunflower oil

Previous studies have demonstrated that low density lipoprotein (LDL) enriched in polyunsaturated fatty acids (PUFA) are more susceptible to oxidation (ex vivo) than those containing monounsaturated fatty acids (MUFA). To test whether this observation was associated with various parameters considered to be related with the development of early aortic atherosclerosis, hamsters were fed commercial hypercholesterolemic diets (HCD) containing either the PUFA, sunflower oil (SF) or the MUFA, TriSun oil (TS) at 10% with 0.4% cholesterol (wt/wt). LDL isolated from hamsters fed TS had significantly longer lag phase (30%, P < 0.05), a decreased propagation phase (-62%, P < 0.005), and fewer conjugated dienes formed (-37%, P < 0.007) compared to hamsters fed SF. Aortic vasomotor function, measured as degree of aortic relaxation, was significantly greater in the TS vs SF-fed hamsters whether acetylcholine or the calcium ionophore A23187 was used as the endothelium-dependent agonist. As a group, the SF-fed hamsters had significantly more early atherosclerosis than hamsters fed TS (46%, P < 0.006). When animals across the two diets were pair-matched by plasma LDL-C levels, there was an 82% greater mean difference (P < 0.002) in early atherosclerosis in the SF versus the TS-fed hamsters. While there were no significant associations with plasma lipids and lipoprotein cholesterol, early atherosclerosis was significantly correlated with lag phase (r = -0.67, p < 0.02), rate of LDL conjugated diene formation (r = 0.74, p < 0.006) and maximum dienes formed (r = 0.67, p < 0.02). Compared to TS-fed animals, aortic sections from hamsters fed the SF-containing diet revealed that the cytoplasm of numerous foam cells in the subendothelial space reacted positively with the monoclonal anti-bodies MDA-2 and NA59 antibody, epitopes found on oxidized forms of LDL. The present study suggests that compared to TS, hamsters fed the SF-diet demonstrated enhanced LDL oxidative susceptibility, reduced aortic relaxation, greater early aortic atherosclerosis and accumulation of epitopes found on oxidized forms of LDL.

Lipoproteins, nutrition, and heart disease

This article reviews the current status of our knowledge of lipoproteins, nutrition, and coronary heart disease (CHD). Special emphasis is placed on CHD risk assessment, dietary intervention studies, diet-gene interactions, and current dietary guidelines and the contributions of my laboratory to these areas. CHD remains a major cause of death and disability, and risk factors include age, sex, hypertension, smoking, diabetes, elevated serum LDL cholesterol, and low HDL cholesterol. Emerging independent risk factors include elevated serum concentrations of lipoprotein(a), remnant lipoproteins, and homocysteine. The cornerstone of CHD prevention is lifestyle modification. Dietary intervention studies support the concepts that restricting saturated fat and cholesterol and increasing the intake of essential fatty acids, especially n - 3 fatty acids, reduces CHD risk. The variability in LDL-cholesterol response to diet is large, related in part to APOE and APOA4 genotype. The use of antioxidants in intervention studies has not been shown to reduce CHD risk. Compliance with dietary recommendations remains a major problem, and directly altering the food supply may be the most effective way to ensure compliance. The available data indicate that the recommendation to use fats, oils, and sugars sparingly for CHD prevention should be modified to a recommendation to use animal, dairy, and hydrogenated fats; tropical oils; egg yolks; and sugars sparingly and to increase the use of vegetables, fruit, and whole grains.

Nutritional value of the marine invertebrates Anemonia viridis and Haliothis tuberculata and effects on serum cholesterol concentration in ratsopen star

The purpose of this study was to determine the nutritional value of diets with protein from two marine species (Haliotis tuberculata and Anemonia viridis) as compared to a high-quality protein reference based on casein or casein supplemented with olive oil. We also investigated the effects of these diets on serum lipid levels. Male rats were fed these diets for 23 days. Protein quality indicators (true digestibility, net protein utilization, biological value) were similar to those obtained for casein-based feeds except for lower true digestibility and net protein utilization values for the Anemonia viridis feed. HDL-cholesterol level was significantly higher (p < 0.05) in the groups fed marine species or casein supplemented with olive oil than in the casein group. Total-cholesterol level was higher in the group fed Haliotis tuberculata fed than in the other groups. These results suggest that these marine species are a good protein source, and that they may have positive effects on serum cholesterol level.

The cholesterolaemic effects of dietary fats in cholesteryl ester transfer protein transgenic mice

In order to investigate the role of cholesteryl ester transfer protein (CETP) in the cholesterolaemic response to dietary fats, we analysed plasma lipid profiles of CETP-transgenic and control C57BL/6 mice fed standard chow (AIN-93G; AIN), a low-fat diet, and diets high in butter (saturated fatty acids; SFA), high-oleic acid safflower oil (monounsaturated fatty acids; MUFA), and safflower oil (polyunsaturated fatty acids; PUFA) for 5 weeks. Each group contained four or five mice. There were significant diet and dietxgenotype effects on plasma total cholesterol (TC; and respectively), liver TC ( and respectively), and esterified cholesterol (EC; and respectively); diet effects on plasma triacylglycerol liver free cholesterol and body weight a genotype effect on body-weight gain and a dietxgenotype effect on energy intake In transgenic mice the SFA diet caused significantly higher plasma TC than the PUFA diet In control mice MUFA and PUFA diets, but not the SFA diet, caused significantly higher plasma TC than the low-fat and AIN diets Transgenic mice fed PUFA had lower plasma TC while transgenic mice fed MUFA had lower LDL+VLDL-cholesterol than controls in the same dietary groups. Transgenic mice fed MUFA and PUFA diets also had significantly higher liver TC and respectively) and EC and respectively) than controls fed the same diets. In the present study we showed that: (1) CETP transgenic mice had a cholesterolaemic response to dietary fats similar to that in human subjects; (2) CETP transgenic mice fed PUFA showed significantly lower plasma TC, while those fed MUFA had lower LDL+VLDL-cholesterol than controls; (3) hepatic accumulation of cholesterol, possibly resulting from the combination of the enhanced cholesteryl ester transfer to apolipoprotein B-containing lipoproteins and increased hepatic uptake of cholesterol, may contribute to the cholesterol-lowering effect of MUFA and PUFA in CETP-transgenic mice; (4) CETP may play a role in appetite and/or energy regulation.

Dietary monounsaturated fatty acids and haemostasis

Diets high in monounsaturated fatty acids (MUFA) are increasingly being recommended as a highly-effective cholesterol-lowering strategy in populations at risk of CHD. However, the need for a re-appraisal of the benefits of diets rich in MUFA became apparent as a result of recent studies showing that meals high in olive oil cause greater postprandial activation of blood coagulation factor VII than meals rich in saturated fatty acids. The present review evaluates the evidence for the effects of MUFA-rich diets on fasting and postprandial measurements of haemostasis, and describes data from a recently-completed long-term controlled dietary intervention study. The data show that a background diet high in MUFA has no adverse effect on fasting haemostatic variables and decreases the postprandial activation of factor VII in response to a standard fat-containing meal. Since the same study also showed a significant reduction in the ex vivo activation of platelets in subjects on the high-MUFA diet, the overall findings suggest that there is no reason for concern regarding adverse haemostatic consequences of high-MUFA diets.

Dietary treatment for familial hypercholesterolaemia

BACKGROUND

Familial hypercholesterolaemia is an inherited disorder characterised by a raised blood cholesterol, the presence of xanthomatosis and premature ischaemic heart disease. The aim of treatment is the reduction of blood LDL cholesterol concentrations in order to reduce the risk of ischaemic heart disease. Current treatment is based on a cholesterol lowering diet alone or in combination with drug therapy. Many of the drugs found to be effective in treating adults with this disease are not licensed for use in children, therefore diet is the main treatment of children with familial hypercholesterolaemia. In addition to the cholesterol-lowering diet, several other dietary interventions have been suggested and consensus has yet to be reached on the most appropriate dietary treatment for children and adults with familial hypercholesterolaemia.

OBJECTIVES

To examine the evidence that in children and adults with familial hypercholesterolaemia, a cholesterol lowering diet is more effective at lowering cholesterol and reducing incidence of ischaemic heart disease than no intervention or than other dietary interventions.

SEARCH STRATEGY

We searched the Cochrane Cystic Fibrosis and Genetic Disorders Trials Register, a specialist trials register which comprises references identified from comprehensive electronic database searches, handsearching relevant journals and handsearching abstract books of conference proceedings. Additional studies were identified from handsearching the Journal of Inherited Metabolic Disease (from inception, 1978 to 2000) and from the reference lists of identified studies.

SELECTION CRITERIA

Randomised controlled trials (RCTs), both published and unpublished, where a cholesterol lowering diet in children and adults with familial hypercholesterolaemia has been compared to other forms of dietary treatment or to no dietary intervention. Trials which include patients with familial hypercholesterolaemia alongside patients with non-familial hypercholesterolaemia were only included if the group of familial patients was well defined and the results for these patients were available.

DATA COLLECTION AND ANALYSIS

Two reviewers independently assessed the trial eligibility and methodological quality and one reviewer extracted the data, with independent verification of data extraction by a colleague.

MAIN RESULTS

Only short term outcomes could be assessed in this review due to the length of the five eligible studies. Compliance to treatment, quality of life, mortality and evidence of ischaemic or atheromatous disease were not assessed in the studies identified. No differences were found between the cholesterol-lowering diet and all other diets for all of the short term outcomes assessed.

REVIEWER'S CONCLUSIONS

No conclusions can be made about the effectiveness of the cholesterol-lowering diet, or any of the other dietary interventions suggested for familial hypercholesterolaemia, due to the lack of adequate data. A large, parallel, randomised controlled trial is needed to investigate the effectiveness of the cholesterol-lowering diet and other dietary interventions for FH. It is also possible that data from trials including subjects with both familial and non-familial hypercholesterolaemia could alter the results of future updates of this review and until further evidence is available current dietary treatment of FH should continue to be observed and monitored with care.

Occurrence and biochemical characteristics of natural bioactive substances in bovine milk lipids

Bovine milk lipids (BML) contain a number of bioactive substances with positive as well as negative properties, mainly in the class of fatty acids. Besides trans fatty acids (TFA), conjugated linoleic acids (CLA) are of particular interest. Apart from ruminant meat products the main source of CLA in food are BML. Although TFA as well as saturated fatty acids (12:0-16:0) are thought to be positively correlated with atherosclerosis and coronary heart disease, CLA are considered antiatherogenic. Further, CLA are reported to reduce adipose fat and to have anticarcinogenic properties. The varying CLA and TFA contents of lipids from milk and dairy products are positively correlated with one another. However, TFA are also negatively correlated with 12:0-16:0 in BML. Anticarcinogenic effects are also ascribed to butyric acid as well as to some phospholipids and ether lipids present in BML. Moreover, the essential fatty acids 18:2n-6 and 18:3n-3 are found in BML which are involved in a variety of biochemical processes and thus have numerous functions in human metabolism. Contents of the individual bioactive components of BML are summarised taking into account also seasonal variations. The total content of bioactive substances in BML is approximately 75 % but their overall impact on human health considering benefits and drawbacks is difficult to assess.