Reduction of plasma cholesterol levels in normal men on an American Heart Association Step 1 diet or a Step 1 diet with added monounsaturated fat

Pentapeptide IIAEK ameliorates cholesterol metabolism via the suppression of intestinal cholesterol absorption in mice

Dietary protein-derived peptides are effective in improving dyslipidemia and hypercholesterolemia. We previously identified a novel cholesterol-lowering pentapeptide IIAEK from milk beta-lactoglobulin. However, it remains unclear whether IIAEK affects the micellar solubility of cholesterol and the bile acid-binding ability to lower cholesterol. Moreover, there is no direct evidence that IIAEK inhibits intestinal cholesterol absorption and affects hepatic cholesterol and fecal steroid excretion in vivo. Herein, we showed that IIAEK did not affect the micellar solubility of cholesterol and the bile acid-binding ability. However, we found that IIAEK decreased serum and liver cholesterol levels and increased fecal steroid excretion in mice. Interestingly, IIAEK markedly suppressed the intestinal absorption of [3H]-cholesterol in mice. In conclusion, we found that IIAEK ameliorated cholesterol metabolism by suppressing intestinal cholesterol absorption without affecting in vitro micellar solubility of cholesterol and the bile acid-binding ability in mice.

Plant-derived peptides improving lipid and glucose metabolism

Plant protein-derived peptides, focusing especially on soybean protein-derived peptides have considerable effects on metabolic regulation and modulation such as cholesterol lowering, triglyceride lowering, anti-obesity, inhibition of fatty acid synthase, and antidiabetic effects. The molecules targeted to study the metabolic regulatory functions of the peptides included the following: intestinal cholesterol micelle, cholesterol metabolism-related genes for cholesterol lowering, triglyceride metabolism-related genes for triglyceride lowering and anti-obesity, dipeptidyl peptidase-IV (DPP-IV), α-amylase, α-glucosidase, or glucose metabolism-related genes for lowering blood glucose levels. This review article outlines the physiological functions of plant protein-derived peptides for the improvement of lipid and glucose metabolism in vitro or in vivo.

Effects of vitamin E on stroke: a systematic review with meta-analysis and trial sequential analysis

There are several previous studies on the association of vitamin E with prevention of stroke but the findings remain controversial. We have conducted a systematic review, meta-analysis together with trial sequential analysis of randomised controlled trials to evaluate the effect of vitamin E supplementation versus placebo/no vitamin E on the risk reduction of total, fatal, non-fatal, haemorrhagic and ischaemic stroke. Relevant studies were identified by searching online databases through Medline, PubMed and Cochrane Central Register of Controlled Trials. A total of 18 studies with 148 016 participants were included in the analysis. There was no significant difference in the prevention of total stroke (RR (relative risk)=0.98, 95% CI 0.92-1.04, p=0.57), fatal stroke (RR=0.96, 95% CI 0.77-1.20, p=0.73) and non-fatal stroke (RR=0.96, 95% CI 0.88-1.05, p=0.35). Subgroup analyses were performed under each category (total stroke, fatal stroke and non-fatal stroke) and included the following subgroups (types of prevention, source and dosage of vitamin E and vitamin E alone vs control). The findings in all subgroup analyses were statistically insignificant. In stroke subtypes analysis, vitamin E showed significant risk reduction in ischaemic stroke (RR=0.92, 95% CI 0.85-0.99, p=0.04) but not in haemorrhagic stroke (RR=1.17, 95% CI 0.98-1.39, p=0.08). However, the trial sequential analysis demonstrated that more studies were needed to control random errors. Limitations of this study include the following: trials design may not have provided sufficient power to detect a change in stroke outcomes, participants may have had different lifestyles or health issues, there were a limited number of studies available for subgroup analysis, studies were mostly done in developed countries, and the total sample size for all included studies was insufficient to obtain a meaningful result from meta-analysis. In conclusion, there is still a lack of statistically significant evidence of the effects of vitamin E on the risk reduction of stroke. Nevertheless, vitamin E may offer some benefits in the prevention of ischaemic stroke and additional well-designed randomised controlled trials are needed to arrive at a definitive finding. PROSPERO registration number: CRD42020167827.

IIAEK Targets Intestinal Alkaline Phosphatase (IAP) to Improve Cholesterol Metabolism with a Specific Activation of IAP and Downregulation of ABCA1

IIAEK (Ile-Ile-Ala-Glu-Lys, lactostatin) is a novel cholesterol-lowering pentapeptide derived from bovine milk β-lactoglobulin. However, the molecular mechanisms underlying the IIAEK-mediated suppression of intestinal cholesterol absorption are unknown. Therefore, we evaluated the effects of IIAEK on intestinal cholesterol metabolism in a human intestinal model using Caco-2 cells. We found that IIAEK significantly reduced the expression of intestinal cholesterol metabolism-associated genes, particularly that of the ATP-binding cassette transporter A1 (ABCA1). Subsequently, we chemically synthesized a novel molecular probe, IIXEK, which can visualize a complex of target proteins interacting with photoaffinity-labeled IIAEK by fluorescent substances. Through photoaffinity labeling and MS analysis with IIXEK for the rat small intestinal mucosa and intestinal lipid raft fractions of Caco-2 cells, we identified intestinal alkaline phosphatase (IAP) as a specific molecule interacting with IIAEK and discovered the common IIAEK-binding amino acid sequence, GFYLFVEGGR. IIAEK significantly increased IAP mRNA and protein levels while decreasing ABCA1 mRNA and protein levels in Caco-2 cells. In conclusion, we found that IIAEK targets IAP to improve cholesterol metabolism via a novel signaling pathway involving the specific activation of IAP and downregulation of intestinal ABCA1.

Effect of milk fat on LDL cholesterol and other cardiovascular risk markers in healthy humans: the INNOVALAIT project

BACKGROUND

Milk has a specific saturated fatty acid profile and its calcium content may change the kinetics of fat absorption.

OBJECTIVE

The goal of this study was to compare the effect on LDL Cholesterol and other risk markers of four isolipidic diets differing by their fat food source, vegetable fat, spring milk fat, winter milk fat or winter milk fat supplemented with calcium, in healthy moderately hypercholesterolemic humans.

INDIVIDUALS AND METHODS

This double-blind, randomized trial with four parallel arms included 172 healthy adults with plasma LDL cholesterol (LDL-C) from 130 to 220 mg/dL and triglycerides below 300 mg/dL. Individual meal plans ensured a stable energy intake. In the three diets containing milk fat, milk fat provided 38% of energy. Vegetable fat and spring milk fat diets provided the same amount of saturated fatty acids while the winter milk fat diets were slightly richer in saturated fatty acids. Vegetable fat diet and winter milk fat diets provided the same amount of palmitic acid (7.0% EI), while the spring milk fat diet was slightly poorer in this fatty acid (5.1% EI). Cardiovascular risk markers were analyzed after 8 weeks of dietary intervention.

RESULTS

There was no significant difference in LDL-C and other markers, except total cholesterol (TC), apo C3 and CRP. TC was significantly higher with spring milk fat than with vegetable fat.

CONCLUSIONS

In this trial, the chosen vegetable fat did not have a significant beneficial effect on LDL-C compared to dairy fat. However, sub-group analysis showed differences in TC, apo C3 and CRP. These results need confirmation and long-term studies aiming at cardiovascular endpoints are warranted.

Ellagic acid affects mRNA expression levels of genes that regulate cholesterol metabolism in HepG2 cells

Ellagic acid has been shown to improve cholesterol metabolism in animal studies, but the molecular mechanisms underlying this function have not been fully understood. We performed DNA microarray analysis to elucidate the effects of ellagic acid on cholesterol metabolism in HepG2 hepatocytes. This revealed that the expression levels of several genes related to cholesterol metabolism, including the low-density lipoprotein receptor (LDLR), were changed by ellagic acid treatment. Using a real-time PCR and immunoblot we confirmed that ellagic acid treatment up-regulated mRNA and protein expression level of the LDLR. Moreover, In the presence of 25 μM ellagic acid, extracellular apoB protein and MTP mRNA levels were significantly decreased. These findings indicate that ellagic acid improves cholesterol metabolism through the up-regulation of LDLR, down-regulation of MTP mRNA and reduces extracellular apoB levels. The ellagic acid-induced up-regulation of LDLR occurred via the extracellular signal-regulated kinase (ERK) signaling pathway in HepG2 hepatocytes. Abbreviations: LDLR: low-density lipoprotein receptor; apoB: apolipoprotein B; PKC: diacylglycerol-protein kinase C; MAPK: mitogen-activated protein kinase; ERK: p42/44 extracellular signal-regulated kinase; JNK: c-Jun N-terminal kinase; VLDLR: very low density lipoprotein receptor; PPARδ: peroxisome proliferator-activated receptor δ; SREBPs: sterol regulatory element-binding proteins; MTP: microsomal triacylglycerol transfer protein; LPDS: lipoprotein-deficient serum.

Seasonal Variability of the Biochemical Composition and Antioxidant Properties of Fucus spiralis at Two Azorean Islands

This study evaluates, for the first time, the seasonal (winter and summer) and geographical (São Miguel⁻SMG and Santa Maria⁻SMA Islands) variability of Fucus spiralis (Fs) biochemical composition (dry weight basis) and antioxidant properties. Protein and carbohydrates presented higher values in Fs-SMGwinter, lipids, total dietary fiber, and energy value in Fs-SMAsummer, and ash and soluble dietary fiber/insoluble dietary fiber ratio in Fs-SMAwinter. The fatty acid (FA) profiles showed a lower SFA in Fs-SMGsummer, whereas MUFA and PUFA presented higher values in Fs-SMGsummer and Fs-SMGwinter, respectively. Excellent dietary ratios of n6/n3 PUFA and hypocholesterolemic/hypercholesterolemic FA were found, with lower values in Fs-SMAwinter and higher in Fs-SMGsummer, respectively. The highest total phenolics was found in Fs-SMAsummer acetone:water extract and total flavonoids showed the higher value in Fs-SMGwinter methanol extract. The best free radical-scavenging activity was observed in the Fs-SMAwinter methanol (EC50 = 0.045 mg/mL) and acetone:water (EC50 = 0.059 mg/mL) extracts. The ferric-reducing antioxidant power showed the best results in Fs-SMAwinter methanol extract (EC50 = 0.016 mg/mL) and Fs-SMAsummer acetone:water extract (EC50 = 0.017 mg/mL). The best ferrous ion-chelating activity was found in Fs-SMGwinter acetone:water extract. Overall, results revealed that F. spiralis nutritional and functional bioactivity values have geographical and seasonal variations and that its regular consumption may add benefits to human health.

Structure-function properties of hypolipidemic peptides

This review addresses the structure-function properties of hypolipidemic peptides. The cholesterol-lowering peptide (lactostatin: IIAEK) operates via a new regulatory pathway in the calcium-channel-related mitogen-activated protein kinase (MAPK) signaling pathway of cholesterol degradation. The bile acid binding peptide (soystatin, VAWWMY) inhibits the micellar solubility of cholesterol in vitro and cholesterol absorption in vivo. VVYP is the most effective peptide having hypotriglyceridemic action in globin digests. The suppressive effect of globin digest on postprandial hyperlipidemia has been reported in humans. The ability of peptides (KRES, Apolipoprotein A-I mimetic peptides) to interact with lipids, remove LOOH and activate antioxidant enzymes associated with high-density lipoprotein determines their anti-inflammatory and anti-atherogenic properties. The β-conglycinin derived peptides KNPQLR, EITPEKNPQLR, and RKQEEDEDEEQQRE inhibit fatty acid synthase in vitro. These promising findings indicate the need for more conclusive molecular, cellular, and animal and human studies to design innovative new peptides that ameliorate cholesterol and lipid metabolism. PRACTICAL APPLICATIONS: Prevention and amelioration of hypercholesterolemia by dietary regulation are important. Dietary protein and peptides are very useful as regulators of serum cholesterol concentration. Diets low in saturated fat and cholesterol that include soy protein may reduce the risk of heart disease. In Japan, the concept of "food for specified health use" has been introduced for the prevention and treatment of life-style related disease. Thus, peptides derived from food proteins and sources other than food proteins such as peptide-rich functional foods and nutraceutical products, have considerable potential to prevent lifestyle-related diseases, especially hyperlipidemia, as discussed in this review. Furthermore, various strategies have been used for the efficient screening, development, and application of new hypolipidemic peptides. These include the use of phage display (for anti-obesity peptide), peptide mimetics (for anti-atherogenic peptide), and molecular targets such as CYP7A1 (for hypocholesterolemic peptide) and prohibitin (for anti-obesity peptide).

Effects of dietary therapy on post renal transplant hyperlipidemia. A prospective study

Hyperlipidemia often occurs after renal transplantation and may contribute to increased cardiovascular morbidity. The National cholesterol education program guidelines (NCEP) recommend dietary modification as the initial therapeutic intervention. We evaluated the effects of the AHA Step I and Step II diets on the serum total cholesterol (TC) and the triglyceride (TG) levels in nondiabetic renal transplant patients. Both the AHA Step I (TC 296 ± 7 vs 294 ± 9 mg/dL, p = ns) and Step II diets (TC 282 ± 8 vs 292 ± 16 mg/dL, p = ns) failed to significantly lower the serum total cholesterol and the triglycerides levels. During this dietary intervention, the patients' body weight and serum creatinine level remained stable. Our data suggest that neither the AHA Step 1 nor the Step II diet are effective in significantly lowering elevated serum lipids in nondiabetic renal transplant recipients.

Nutritional and Functional Bioactivity Value of Selected Azorean Macroalgae: Ulva compressa, Ulva rigida, Gelidium microdon, and Pterocladiella capillacea

This study presents information on the biochemical composition (dry weight basis), nutritional aspects, and angiotensin I-converting enzyme (ACE) inhibitory properties of selected macroalgae (Ulva compressa, Ulva rigida, Gelidium microdon, and Pterocladiella capillacea) from Azores. Moisture content was very high (83.2% to 90.0% of fresh weight). Total dietary fiber (33.7% to 41.0%) that presented a good balance of both soluble and insoluble fibers (15.5% to 19.2% and 18.2% to 21.8%, respectively) was the most abundant component in these macroalgae. Protein and ash (ranged from 15.7% to 23.4% and 10.7% to 20.7%, respectively) were the 2nd most abundant components in red and green macroalgae, respectively. Moderate soluble carbohydrate contents (14.5% to 19.8%) were found in all species. Lipid contents were low (1.0% to 4.3%), particularly in Ulva species (1.0% to 1.7%), but contained higher unsaturated fatty acids (FAs) (7.5% to 32.9% and 29.6% to 69.2% of total FA for monounsaturated fatty acid and polyunsaturated fatty acid groups, respectively) than saturated fatty acid (23.3% to 46.8% of total FA) contents. All the macroalgal proteins had high digestibility in vitro (82.2% to 89.4%, relatively to sodium caseinate), contained high quantity of essential amino acids (45.3% to 58.1% of total amino acids), but in different proportions, and were rich in aspartic and glutamic acids that together account for 17.2% to 36.2% of the total amino acids. These results suggested that regular consumption of the selected macroalgae may improve human health and revealed that they can be used for producing food supplements for human and animal nutrition and/or pharmaceuticals with potential effect on the regional economy. Furthermore, the ACE-inhibitory IC₅₀ values of 0.095 to 0.695 mg/mL for the <1 kDa protein hydrolysate fraction revealed a potential impact on hypertension disorder.

High-Molecular-Weight β-Glucan Decreases Serum Cholesterol Differentially Based on the CYP7A1 rs3808607 Polymorphism in Mildly Hypercholesterolemic Adults

BACKGROUND

β-Glucan, a soluble fiber with viscous property, has a documented cholesterol-lowering effect. The molecular weight (MW) of β-glucan, which contributes to viscosity, and an individual's genotype might influence the cholesterol-lowering efficacy of β-glucan.

OBJECTIVES

This study was designed to determine whether the cholesterol-lowering efficacy of barley β-glucan varied as a function of MW and the daily dose consumed. Our second aim was to determine whether any gene-diet interactions are associated with the cholesterol-lowering efficacy of β-glucan.

METHODS

In a randomized controlled crossover trial, 30 mildly hypercholesterolemic adults [12 men and 18 women, aged 27-78 y; body mass index (in kg/m(2)): 20-40; total cholesterol (TC): 5.0-8.0 mmol/L; LDL cholesterol: 2.7-5.0 mmol/L] were randomly assigned to receive a breakfast that contained either barley β-glucan at 3 g high MW (HMW)/d, 5 g low MW (LMW)/d, or 3 g LMW/d or a control diet, each for 5 wk. The washout period between the phases was 4 wk. Fasting blood samples were collected at the start and end of each phase for blood lipid analysis and genotyping.

RESULTS

Consumption of 3 g HMW β-glucan/d lowered TC by -0.12 mmol/L (95% CI: -0.24, -0.006 mmol/L) compared with the control diet (P= 0.0046), but the LMW β-glucan, at either 3 g/d or 5 g/d, did not change serum cholesterol concentrations. This effect of HMW β-glucan was associated with gene-diet interaction, whereby individuals with the single nucleotide polymorphism (SNP) rs3808607-G allele (GG or GT) of the cytochrome P450 family 7 subfamily A member 1 gene (CYP7A1) had greater responses to 3 g HMW β-glucan/d in lowering TC than TT carriers (P= 0.0006).

CONCLUSIONS

The HMW β-glucan rather than LMW β-glucan reduced circulating TC effectively in mildly hypercholesterolemic adults. The cholesterol-lowering effect of β-glucan may also be determined by the genetic characteristics of an individual. These data show that individuals carrying theCYP7A1SNP rs3808607-G allele are more responsive to the cholesterol-lowering effect of β-glucan with HMW than TT carriers. This trial was registered atclinicaltrials.govasNCT01408719.

Fatty acid profile of different species of algae of the Cystoseira genus: a nutraceutical perspective

The fatty acid (FA) composition of six macroalgae from the Cystoseira genus, namely Cystoseira compressa, Cystoseira humilis, Cystoseira tamariscifolia, Cystoseira nodicaulis, Cystoseira baccata and Cystoseira barbata, was determined. Polyunsaturated fatty acids (PUFA) corresponded to 29-46% of the total FA detected. C. compressa, C. tamariscifolia and C. nodicaulis stood out for their low PUFA/saturated fatty acid, low n-6 PUFA/n-3 PUFA ratios as well as favourable unsaturation, atherogenicity and thrombogenicity indices, suggesting a high nutritional value with potential applications in the nutraceutical industry.

Current evidence on healthy eating

Large nutritional epidemiology studies, with long-term follow-up to assess major clinical end points, coupled with advances in basic science and clinical trials, have led to important improvements in our understanding of nutrition in primary prevention of chronic disease. Although much work remains, sufficient evidence has accrued to provide solid advice on healthy eating. Good data now support the benefits of diets that are rich in plant sources of fats and protein, fish, nuts, whole grains, and fruits and vegetables; that avoid partially hydrogenated fats; and that limit red meat and refined carbohydrates. The simplistic advice to reduce all fat, or all carbohydrates, has not stood the test of science; strong evidence supports the need to consider fat and carbohydrate quality and different protein sources. This article briefly summarizes major findings from recent years bearing on these issues.

Cholesterol-lowering effect of continuous enteral nutrition in man

We have studied the effect of polymeric cholesterol-free enteral nutrition (EN) on serum lipid and apolipoprotein levels in 30 consecutive non-diabetic, non-hyperlipaemic gastrointestinal patients. EN-40 +/- (SEM) 2 kcal/kg/day including 35% vegetable lipids (50% highly polyunsaturated fat, 50% medium chain triglycerides)-was delivered continuously (24h) via the gastric route for at least 2 weeks (mean duration: 35 +/- 4 days). In the entire group, serum total cholesterol decreased by 10.5% (p < 0.01) on day 7 and 17.5% (p < 0.01) on day 28 (n = 12); this was accompanied by 21% and 20% decreases in LDL-cholesterol and apolipoprotein B (p < 0.05) levels respectively, on day 28. In the 19 patients who were normocholesterolaemic on day 0, serum total cholesterol decreased by 15% (p < 0.01) on day 7 and by 28% (p < 0.05) on day 28 (n = 7). Conversely, in the other 11 patients with a low (<3.7 mmol/L) pre-EN serum total cholesterol level, no significant changes were observed during EN. We conclude that continuous, cholesterol-free EN has, in normocholesterolaemic patients, a marked cholesterol-lowering effect; the respective role of the composition of the diet and the continuous delivery of nutrient within the gut have yet to be investigated.

Fatty acid composition of selected macrophytes

The content of total lipids and the fatty acid (FA) profile were determined for eight macroalgae (Cystoseira abies-marina, Fucus spiralis, Chaetomorpha pachynema, Codium elisabethae, Porphyra sp., Osmundea pinnatifida, Pterocladiella capillacea and Sphaeroccoccus coronopifolius). Total lipids were extracted using a solvent mixture of methanol/chloroform (2/1, v/v) and further derivatised to FA methyl esters (FAME). The analyses of FAME samples were performed by gas chromatography coupled to a flame ionisation detector. The total lipid content ranged from 0.06 to 3.54 g (per 100 g). The most abundant saturated FA were palmitic (C16:0) and myristic (C14:0), while oleic (C18:1 n-9) was the dominant monounsaturated acid. All seaweeds contained linoleic FA (C18:2 n-6). The α-linolenic (C18:3 n-3) and eicosapentaenoic (20:5 n-3) acids were present only in Porphyra sp. (3.34% ± 0.13) and C. pachynema (0.47% ± 0.12), respectively. The n-6/n-3 and h/H ratios were low, suggesting a high nutritional value of the algae studied.

Nutrition in the primary and secondary prevention of stroke

Stroke is a worldwide major health issue. As some of the risk factors are modifiable, it is of high importance to understand how we can minimize the risk for stroke. Multifactorial interventions should be provided to patients in the frame of primary and secondary prevention. Obesity is a well-established modifiable factor as well as the dietary pattern that mostly depends on the social environment, the lifestyle and the habits of each individual. So, dietary changes should be part of the holistic approach which includes improvements in the regulation of hypertension, hyperlipidaemia and hyperglycaemia. In the present review, we try to provide a global approach on how diet can influence the risk of stroke and especially the nutritional influence on lipid profile and vessel disease and the role of dietary modification in the secondary stroke prevention. The importance of salt restriction, DASH and Mediterranean diet low in saturated and high in polyunsaturated fats, and the management of obesity seem to be the most important dietary priorities.

Dietary cholesterol and egg yolks: not for patients at risk of vascular disease

A widespread misconception has been developing among the Canadian public and among physicians. It is increasingly believed that consumption of dietary cholesterol and egg yolks is harmless. There are good reasons for long- standing recommendations that dietary cholesterol should be limited to less than 200 mg/day; a single large egg yolk contains approximately 275 mg of cholesterol (more than a day's worth of cholesterol). Although some studies showed no harm from consumption of eggs in healthy people, this outcome may have been due to lack of power to detect clinically relevant increases in a low-risk population. Moreover, the same studies showed that among participants who became diabetic during observation, consumption of one egg a day doubled their risk compared with less than one egg a week. Diet is not just about fasting cholesterol; it is mainly about the postprandial effects of cholesterol, saturated fats, oxidative stress and inflammation. A misplaced focus on fasting lipids obscures three key issues. Dietary cholesterol increases the susceptibility of low-density lipoprotein to oxidation, increases postprandial lipemia and potentiates the adverse effects of dietary saturated fat. Dietary cholesterol, including egg yolks, is harmful to the arteries. Patients at risk of cardiovascular disease should limit their intake of cholesterol. Stopping the consumption of egg yolks after a stroke or myocardial infarction would be like quitting smoking after a diagnosis of lung cancer: a necessary action, but late. The evidence presented in the current review suggests that the widespread perception among the public and health care professionals that dietary cholesterol is benign is misplaced, and that improved education is needed to correct this misconception.

Dietary olive oil effect on antioxidant status and fatty acid profile in the erythrocyte of 2,4-D- exposed rats

Background

Oxidative stress produced by reactive oxygen species (ROS) has been linked to the development of several diseases such as cardiovascular, cancer, and neurodegenerative diseases. This study investigates the possible protective effect of extra virgin olive oil (EVOO), lipophilic fraction (OOLF) and hydrophilic fraction (OOHF) on oxidative stress and fatty acid profile of erythrocytes in 2,4-D treated rats.

Methods

Male Wistar rats were divided randomly into eight groups: control (C), (2,4-D) at a dose of 5 mg/kg b.w., (2,4-D/EVOO) was given 2,4-D plus EVOO, (2,4-D/OOHF) that received 2,4-D plus hydrophilic fraction, (2,4-D/OOLF) treated with 2,4-D plus lipophilic fraction, (EVOO) that received only EVOO, (OOHF) was given hydrophilic fraction and (OOLF) treated with lipophilic fraction. These components were daily administered by gavages for 4 weeks.

Results

2,4-D treatment lead to decrease of antioxidant enzyme activities, namely, superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and glutathione reductase (GR) associated with a higher amount of MDA level. Erythrocyte membranes' fatty acid composition was also significantly modified with 2,4-D exposure. EVOO and hydrophilic fraction supplemented to rats with or not 2,4-D treatment enhanced the antioxidant enzyme activities and reduced the MDA level. However, lipophilic fraction did not show any improvement in oxidative damage induced by 2,4-D in spite its richness in MUFA and vitamins.

Conclusion

EVOO administered to 2,4-D-treated rats protected erythrocyte membranes against oxidative damage by means of preventing excessive lipid peroxidation to increase the MUFA composition and increase maintaining antioxidants enzymes at normal concentrations.

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.

Comparison of monounsaturated fat with carbohydrates as a replacement for saturated fat in subjects with a high metabolic risk profile: studies in the fasting and postprandial states

BACKGROUND

In subjects with a high prevalence of metabolic risk abnormalities, the preferred replacement for saturated fat is unresolved.

OBJECTIVE

The objective was to study whether carbohydrate or monounsaturated fat is a preferred replacement for saturated fat.

DESIGN

Fifty-two men and 33 women, selected to have any combination of HDL cholesterol < or = 30th percentile, triacylglycerol > or = 70th percentile, or insulin > or = 70th percentile, were enrolled in a 3-period, 7-wk randomized crossover study. The subjects consumed an average American diet (AAD; 36% of energy from fat) and 2 additional diets in which 7% of energy from saturated fat was replaced with either carbohydrate (CHO diet) or monounsaturated fatty acids (MUFA diet).

RESULTS

Relative to the AAD, LDL cholesterol was lower with both the CHO (-7.0%) and MUFA (-6.3%) diets, whereas the difference in HDL cholesterol was smaller during the MUFA diet (-4.3%) than during the CHO diet (-7.2%). Plasma triacylglycerols tended to be lower with the MUFA diet, but were significantly higher with the CHO diet. Although dietary lipid responses varied on the basis of baseline lipid profiles, the response to diet did not differ between subjects with or without the metabolic syndrome or with or without insulin resistance. Postprandial triacylglycerol concentrations did not differ significantly between the diets. Lipoprotein(a) concentrations increased with both the CHO (20%) and MUFA (11%) diets relative to the AAD.

CONCLUSIONS

In the study population, who were at increased risk of coronary artery disease, MUFA provided a greater reduction in risk as a replacement for saturated fat than did carbohydrate.

Nutritional strategies in the prevention and treatment of metabolic syndrome

The metabolic syndrome (MetS) is a clustering of metabolic abnormalities that increase the risk of developing atherosclerotic cardiovascular disease and type 2 diabetes. The exact etiology remains unclear, but it is known to be a complex interaction between genetic, metabolic, and environmental factors. Among environmental factors, dietary habits are of central importance in the prevention and treatment of this condition. However, there is currently no firm consensus on the most appropriate dietary recommendations. General recommendations include decreasing obesity, increasing physical activity, and consuming an anti-atherogenic diet, and have traditionally focused on low total fat intake. A major problem with the focus on low fat is that high-carbohydrate diets can contribute to increasing triglyceride and decreasing high-density lipoprotein (HDL) concentrations. Low-carbohydrate diets have been popular in recent years. However, such diets are typically higher in saturated fat and lower in fruits, vegetables, and whole grains than national dietary recommendations. More recently the quality of carbohydrate has been studied in relation to MetS, including a focus on dietary fiber and glycemic index. Similarly, there has been a move from limiting total fat to a focus on the quality of the fat, with evidence of beneficial effects of replacing some carbohydrate with monounsaturated fat. Other nutrients examined for possible importance include calcium, vitamin D, and magnesium. Together, the evidence suggests that the components of diet currently recommended as "healthy" are likely also protective against MetS, including low saturated and trans fat (rather than low total fat) and balanced carbohydrate intake rich in dietary fiber, as well as high fruit and vegetable intake (rather than low total carbohydrate); and the inclusion of low-fat dairy foods. Accelerating research on gene-diet interactions is likely to contribute interesting information that may lead to further individualized dietary guidance in the future.

Effects of hazelnut-enriched diet on plasma cholesterol and lipoprotein profiles in hypercholesterolemic adult men

OBJECTIVE

Frequent consumption of nuts is associated with favorable plasma lipid profiles and reduced risk of coronary heart disease (CHD). This study was conducted to investigate the effects of hazelnut-enriched diet on plasma cholesterol and lipoprotein profiles in hypercholesterolemic adult men compared with baseline and control diet, and also to measure the anthropometric parameters, habitual physical activities, nutrient intake and endothelial function.

SUBJECTS AND DESIGN

Fifteen hypercholesterolemic men aged 48+/-8 years were recruited voluntarily. A well-controlled, 2-period (P1 and P2) study design with a total of 8-week was implemented. In the P1, subjects consumed a control diet (low-fat, low-cholesterol and high-carbohydrate). During the P2, the control diet was supplemented with MUFA-rich hazelnut (40 g/day), which provided 11.6% of total energy content. Anthropometric parameters and habitual physical activities were recorded. Plasma total and HDL cholesterol, TAG, ApoA-1, Apo B, total homocysteine and glucose concentrations were measured. All parameters and measurements were obtained at baseline and end of each 4-week diet period.

RESULTS

Body weights of subjects remained stable throughout the study. Compared with baseline, the hazelnut-enriched diet decreased (P<0.05) the concentrations of VLDL cholesterol, triacylglycerol, apolipoprotein B by 29.5, 31.8, and 9.2%, respectively, while increasing HDL cholesterol concentrations by 12.6%. Total/HDL cholesterol and LDL/HDL cholesterol ratios favorably decreased (P<0.05). Although insignificant there was a decreasing trend for the rest of parameters, particularly in total (5.2%) and LDL cholesterol (3.3%) in subjects consuming a hazelnut-enriched diet compared to that of the baseline. No changes were found in fasting levels of glucose, Apo A-1 and homocysteine between the control and hazelnut-enriched diets.

CONCLUSIONS

This study demonstrated that a high-fat and high-MUFA-rich hazelnut diet was superior to a low-fat control diet because of favorable changes in plasma lipid profiles of hypercholesterolemic adult men and, thereby positively affecting the CHD risk profile.

SPONSORSHIP

Funding provided by a grant from the Hazelnut Promotion Group, Giresun, Turkey.

Nutrition and Stroke Prevention

Nutrition is much more important in prevention of stroke than is appreciated by most physicians. The powerful effects of statin drugs in lowering the levels of fasting cholesterol, combined with an unbalanced focus on fasting lipids (as opposed to postprandial fat and oxidative stress), have led many physicians and patients to believe that diet is relatively unimportant. Because the statins can lower fasting lipids by &50% to 60%, and a low-fat diet only lowers fasting cholesterol by &5% to 10%, this error is perhaps understandable. However, a Cretan Mediterranean diet, which is high in beneficial oils, whole grains, fruits, and vegetables and low in cholesterol and animal fat, has been shown to reduce stroke and myocardial infarction by 60% in 4 years compared with the American Heart Association diet. This effect is twice that of simvastatin in the Scandinavian Simvastatin Survival Study: a reduction of myocardial infarction by 40% in 6 years. Vitamins for lowering of homocysteine may yet be shown to be beneficial for reduction of stroke; a key issue is the high prevalence of unrecognized deficiency of vitamin B(12), requiring higher doses of vitamin B(12) than have been used in clinical trials to date. Efforts to duplicate with supplementation the evidence of benefit for vitamins E, C, and beta carotene have been largely fruitless. This may be related to the broad combination of antioxidants included in a healthy diet. A Cretan Mediterranean diet is probably more effective because it provides a wide range of antioxidants from fruits and vegetables of all colors.

The Changing Roles of Dietary Carbohydrates

The dietary recommendations made for carbohydrate intake by many organizations/agencies have changed over time. Early recommendations were based on the need to ensure dietary sufficiency and focused on meeting micronutrient intake requirements. Because carbohydrate-containing foods are a rich source of micronutrients, starches, grains, fruits, and vegetables became the foundation of dietary guidance, including the base of the US Department of Agriculture’s Food Guide Pyramid. Dietary sufficiency recommendations were followed by recommendations to reduce cholesterol levels and the risk for cardiovascular disease; reduction in total fat (and hence saturated fat) predominated. Beginning in the 1970s, carbohydrates were recommended as the preferred substitute for fat by the American Heart Association and others to achieve the recommended successive reductions in total fat and low-density lipoprotein cholesterol (LDL-C). Additional research on fats and fatty acids found that monounsaturated fatty acids could serve as an alternative substitution for saturated fats, providing equivalent lowering of LDL-C without concomitant reductions in high-density lipoprotein cholesterol and increases in triglycerides witnessed when carbohydrates replace saturated fat. This research led to a sharper focus in the guidelines in the 1990s toward restricting saturated fat and liberalizing a range of intake of total fat. Higher-fat diets, still low in saturated fatty acids, became alternative strategies to lower-fat diets. As the population has become increasingly overweight and obese, the emergence of the metabolic syndrome and its associated disruptions in glucose and lipid metabolism has led to reconsiderations of the role of carbohydrate-containing foods in the American diet. Consequently, a review of the evidence for and against high-carbohydrate diets is important to put this controversy into perspective. The current dietary recommendations for carbohydrate intake are supported by the evidence.

Effect of low and high fat diets on nutrient intakes and selected cardiovascular risk factors in sedentary men and women

OBJECTIVE

The desired level of dietary fat intake is controversial. The effect of decreasing fat intake to 19% and increasing it to 50% from a control diet of 30% on nutritional status and cardiovascular risk factors in healthy individuals was studied.

METHODS

Eleven healthy subjects (5 men and 6 women) were randomized to consume diets with 19% and 50% calories from fat. Each diet lasted 3 weeks, with a one-week washout. The habitual and washout diets were determined to be 30% fat. At the beginning and the end of each diet, fasting blood was collected to determine plasma lipoproteins, and physiological factors were measured.

RESULTS

Total caloric expenditure was similarly balanced to intake on the 30% and 50% fat diets, but intake was significantly lower on the 19% fat diet and led to a loss of 0.6 kg body weight. Consumptions of essential fatty acids, vitamin E and zinc were improved with increased fat intake, but folate intake was compromised on the 30% and 50% fat diets. Compared with the 50% fat diet, subjects consuming the 19% fat diet had significantly lower HDL cholesterol (HDL-C) (54 +/- 3 vs. 63 +/- 3 mg. dL(-1), p < 0.05) and apolipoprotein A1 (ApoA1) (118 +/- 4 vs. 127 +/- 3 mg/dL, p < 0.05). Changing the levels of fat intake did not affect % body fat, heart rate, blood pressure, blood triglycerides, total cholesterol (TC), LDL cholesterol, apolipoprotein B (ApoB), TC/HDL-C and ApoA1/ApoB ratios.

CONCLUSION

A low fat diet (19%) may not provide sufficient calories, essential fatty acids, and some micronutrients (especially vitamin E and zinc) for healthy untrained individuals, and it also lowered ApoA1 and HDL-C. Increasing fat intake to 50% of calories improved nutritional status, and did not negatively affect certain cardiovascular risk factors.

Monounsaturated fatty acid intake by children and adults: temporal trends and demographic differences

Epidemiologic evidence suggests that dietary monounsaturated fatty acids (MUFA) may have a beneficial health effect. Twenty-four-hour dietary intake data collected on 10-year-olds from 1978 to 1994 and on children and adults (ages 0-30 years) were examined for time, age, gender, ethnic, and geographic location differences in MUFA intake. Children's percent energy from MUFA decreased significantly from 1978 (14.1%) to 1994 (11.9%) with intake of oleic acid decreasing from 33.9 g/day (1973) to 25.7 g/day (1994). In 1994-96, percent energy from MUFA was 13% for children and adults aged 12 to 30 years, with 5% from palmitoleic acid and 93% from oleic acid. Males and blacks had significantly higher MUFA intake across all age groups than females and whites. Intakes of MUFA increased from 0 to 11 years of age to young adulthood (12-19 years), with no further increase at 20 to 30 years of age. Intakes of MUFA were lowest in the Northeast and highest in the Midwest. There were differences in food sources of MUFA by age group. For children 0 to 5 years of age, major sources were whole milk, peanut butter, 2% milk, and French fries; for children 6 to 11 years of age, major sources were whole milk, peanut butter, French fries, and 2% milk; for children 12 to 19 years of age, French fries, salt snacks, whole milk, and meat pizza were the major sources; for adults, French fries, whole milk, potato chips, and ground beef were the most common sources of MUFA. U.S. children and adults displayed temporal trends and demographic differences in intakes and food sources of MUFA. The implications of these changes and differences on biologic risk factors for specific chronic diseases warrant further investigation.

Effects of dietary fatty acids and carbohydrates on the ratio of serum total to HDL cholesterol and on serum lipids and apolipoproteins: a meta-analysis of 60 controlled trials

BACKGROUND

The effects of dietary fats on the risk of coronary artery disease (CAD) have traditionally been estimated from their effects on LDL cholesterol. Fats, however, also affect HDL cholesterol, and the ratio of total to HDL cholesterol is a more specific marker of CAD than is LDL cholesterol.

OBJECTIVE

The objective was to evaluate the effects of individual fatty acids on the ratis of total to HDL cholesterol and on serum lipoproteins.

DESIGN

We performed a meta-analysis of 60 selected trials and calculated the effects of the amount and type of fat on total:HDL cholesterol and on other lipids.

RESULTS

The ratio did not change if carbohydrates replaced saturated fatty acids, but it decreased if cis unsaturated fatty acids replaced saturated fatty acids. The effect on total:HDL cholesterol of replacing trans fatty acids with a mix of carbohydrates and cis unsaturated fatty acids was almost twice as large as that of replacing saturated fatty acids. Lauric acid greatly increased total cholesterol, but much of its effect was on HDL cholesterol. Consequently, oils rich in lauric acid decreased the ratio of total to HDL cholesterol. Myristic and palmitic acids had little effect on the ratio, and stearic acid reduced the ratio slightly. Replacing fats with carbohydrates increased fasting triacylglycerol concentrations.

CONCLUSIONS

The effects of dietary fats on total:HDL cholesterol may differ markedly from their effects on LDL. The effects of fats on these risk markers should not in themselves be considered to reflect changes in risk but should be confirmed by prospective observational studies or clinical trials. By that standard, risk is reduced most effectively when trans fatty acids and saturated fatty acids are replaced with cis unsaturated fatty acids. The effects of carbohydrates and of lauric acid-rich fats on CAD risk remain uncertain.

Dose response of almonds on coronary heart disease risk factors: blood lipids, oxidized low-density lipoproteins, lipoprotein(a), homocysteine, and pulmonary nitric oxide: a randomized, controlled, crossover trial

BACKGROUND

Although recent studies have indicated that nut consumption may improve levels of blood lipids, nuts are not generally recommended as snacks for hyperlipidemic subjects because of their high fat content. Furthermore, the effective dose is still unknown.

METHODS AND RESULTS

The dose-response effects of whole almonds, taken as snacks, were compared with low-saturated fat (<5% energy) whole-wheat muffins (control) in the therapeutic diets of hyperlipidemic subjects. In a randomized crossover study, 27 hyperlipidemic men and women consumed 3 isoenergetic (mean 423 kcal/d) supplements each for 1 month. Supplements provided 22.2% of energy and consisted of full-dose almonds (73+/-3 g/d), half-dose almonds plus half-dose muffins, and full-dose muffins. Fasting blood, expired air, blood pressure, and body weight measurements were obtained at weeks 0, 2, and 4. Mean body weights differed <300 g between treatments. The full-dose almonds produced the greatest reduction in levels of blood lipids. Significant reductions from baseline were seen on both half- and full-dose almonds for LDL cholesterol (4.4+/-1.7%, P=0.018, and 9.4+/-1.9%, P<0.001, respectively) and LDL:HDL cholesterol (7.8+/-2.2%, P=0.001, and 12.0+/-2.1%, P<0.001, respectively) and on full-dose almonds alone for lipoprotein(a) (7.8+/-3.5%, P=0.034) and oxidized LDL concentrations (14.0+/-3.8%, P<0.001), with no significant reductions on the control diet. No difference was seen in pulmonary nitric oxide between treatments.

CONCLUSIONS

Almonds used as snacks in the diets of hyperlipidemic subjects significantly reduce coronary heart disease risk factors, probably in part because of the nonfat (protein and fiber) and monounsaturated fatty acid components of the nut.

Survival of a 300-g infant ventilated by high-frequency oscillatory ventilation for respiratory distress syndrome

We report a case of an infant delivered before the completion of 26 wks' gestation, weighing 300 g at birth, and treated with high-frequency oscillatory ventilation for respiratory distress syndrome. Her neurologic examination at 18 months of age is compatible with mild delay in gross and fine motor skills.

Almonds and almond oil have similar effects on plasma lipids and LDL oxidation in healthy men and women

Epidemiologic and clinical studies have shown that nut consumption is associated with favorable plasma lipid profiles and reduced cardiovascular risk. These effects may result from their high monounsaturated fat (MUFA) content but nuts contain constituents other than fatty acids that might be cardioprotective. We conducted a study to compare the effects of whole-almond vs. almond oil consumption on plasma lipids and LDL oxidation in healthy men and women. Using a randomized crossover trial design, 22 normolipemic men and women replaced half of their habitual fat (approximately 14% of approximately 29% energy) with either whole almonds (WA) or almond oil (AO) for 6-wk periods. Compliance was ascertained by monitoring dietary intake via biweekly 5-d food records, return of empty almond product packages and weekly meetings with a registered dietitian. Fat replacement with either WA and AO resulted in a 54% increase in percentage of energy as MUFA with declines in both saturated fat and cholesterol intake and no significant changes in total energy, total or polyunsaturated fat intake. The effects of WA and AO on plasma lipids did not differ compared with baseline; plasma triglyceride, total and LDL cholesterol significantly decreased, 14, 4 and 6% respectively, whereas HDL cholesterol increased 6%. Neither treatment affected in vitro LDL oxidizability. We conclude that WA and AO do not differ in their beneficial effects on the plasma lipid variables measured and that this suggests that the favorable effect of almonds is mediated by components in the oil fraction of these nuts.

Effect of a rapeseed oil substituting diet on serum lipids and lipoproteins in children and adolescents with familial hypercholesterolemia

OBJECTIVE

Familial hypercholesterolemia (FH) is a predominantly inherited disorder, which contributes to a defect of the LDL-cholesterol receptor. For adults with familial hypercholesterolemia (FH), it is known that a supplementary diet of monounsaturated fatty acids reduces elevated levels of total cholesterol and LDL-cholesterol and may further increase HDL-cholesterol. In particular the reduced intake of dietary fat reduces total serum cholesterol and LDL-cholesterol in the range of 10% to 15% and inhibits LDL-oxidation. Once the diagnosis of familial hypercholesterolemia is made in early childhood a supplementary diet with rapeseed oil should be started as early as possible to prevent development of atherosclerosis and subsequent complications. So far there are no reports of a lipid lowering diet enriched with rapeseed oil in children and adolescents.

METHODS

Seventeen children and young adolescents (male = 6, female = 11, ages 4 to 19 years) diagnosed with FH were enrolled in this study. They received dietary training and a classical low fat/low cholesterol diet enriched with rapeseed oil over five months. In the first two months they received orally mean 15 g/day (8-23 g/day), for the remaining three months mean 22 g/day (15-30 g/day) rapeseed oil. The calculation of the three-days dietary protocols showed the following characteristics: 29.5% calories from fat, 14.3% calories from protein and 54.6% calories from carbohydrates. The subjects had six sessions of dietary counseling, and serum lipids levels and lipoprotein(a) were estimated; each month's diet adherence was controlled by a dietitian and discussed with the patients and their families during this five-month study.

RESULTS

During five months of rapeseed oil diet serum triglycerides decreased by 29% (119.2+/-62.8 mg/dL vs. 84.9 mean +/- 39.7 mg/dL), VLDL-cholesterol by 27% (23+/-12 mg/dL vs. 17+/-8 mg/dL), total cholesterol by 10% (233+/-35 mg/dL vs. 213+/-36 mg/dL), LDL-cholesterol by 7% (151+/-31 mg/dL vs. 142+/-31 mg/dL). HDL-cholesterol (59+/-15 mg/dL vs. 57+/-11 mg/dL) and Lp(a) (29.8+/-36.3 mg/dL vs. 32.6+/-40.7 mg/dL) were not changed significantly. The diet was well accepted; in most families a sustained change was reported.

CONCLUSIONS

Our results indicate that in children and adolescents with FH a lipid-lowering diet with rapeseed oil has a similar effect on total serum cholesterol and LDL-cholesterol compared to classical cholesterol reduction diets (step I). However, an additional pronounced effect on lowering of triglycerides and VLDL-cholesterol can be observed.

High-protein diets in hyperlipidemia: effect of wheat gluten on serum lipids, uric acid, and renal function

BACKGROUND

The metabolic effects of diets high in vegetable protein have not been assessed despite much recent interest in the effect of soy proteins in reducing serum cholesterol.

OBJECTIVE

We assessed the metabolic effects of diets high in vegetable protein (specifically, wheat gluten) on serum lipids, uric acid concentrations, and renal function.

DESIGN

Twenty hyperlipidemic men and women consumed isoenergetic test (high-protein) and control metabolic diets for 1 mo in a randomized crossover design. In the high-protein diet, 11% of the total dietary energy from starch in the control bread was replaced by vegetable protein (wheat gluten), resulting in 27% of total energy from protein compared with 16% in the control diet. In other respects, the 2 diets were identical.

RESULTS

Compared with the control, the high-protein diet resulted in lower serum concentrations of triacylglycerol (by 19.2 +/- 5.6%; P = 0.003), uric acid (by 12.7 +/- 2.0%; P < 0.001), and creatinine (by 2.5 +/- 1.1%; P = 0.035) and higher serum concentrations of urea (by 42.2 +/- 5.8%; P < 0.001) and a higher 24-h urinary urea output (by 99.2 +/- 17.2%; P < 0.001). No significant differences were detected in total or HDL cholesterol or in the renal clearance of creatinine. LDL oxidation, assessed as the ratio of conjugated dienes to LDL cholesterol in the LDL fraction, was lower with the high-protein diet (by 10.6 +/- 3.6%; P = 0.009).

CONCLUSIONS

High intakes of vegetable protein from gluten may have beneficial effects on cardiovascular disease risk by reducing oxidized LDL, serum triacylglycerol, and uric acid. Further studies are required to assess the longer-term effects on renal function.

Treatment of hypertriglyceridemia by two diets rich either in unsaturated fatty acids or in carbohydrates: effects on lipoprotein subclasses, lipolytic enzymes, lipid transfer proteins, insulin and leptin

BACKGROUND

There is lack of agreement on which dietary regimen is most suitable for treatment of hypertriglyceridemia, especially if high triglyceride concentrations are not due to obesity or alcohol abuse. We compared the effects on blood lipids of a diet high in total and unsaturated fat with a low-fat diet in patients with triglyceride concentrations of > 2.3 mmol/l.

METHODS

Nineteen non-obese male outpatients with triglycerides ranging from 2.30 to 9.94 mmol/l received two consecutive diets for 3 weeks each: first a modified high-fat diet (39% total fat, 8% SFA, 15% monounsaturated fatty acids, 1.6% marine n-3 polyunsaturated fatty acids), and then a low-fat diet (total fat 28%, carbohydrates 54%).

RESULTS

The high-fat diet significantly decreased triglycerides (-63%), total cholesterol (-22%), VLDL cholesterol (-54%), LDL cholesterol ( 16%), total apoC-III (-27%), apoC-III in apoB containing lipoproteins (apoC-III LpB; -31%) and in HDL (apoC-III nonLpB; -29%), apoE in serum (-33%) and apoB-containing lipoproteins (nonHDL-E; -42%), LpA-I (-16%), insulin (-36%), and leptin (-26%) and significantly increased the means of HDL cholesterol (+8%), LDL size (+6%), lipoprotein lipase (LPL, +11%), hepatic lipase (+13%), and lecithin: cholesterol acyltransferase (LCAT, +2%). The subsequent low-fat diet increased triglycerides (+63%), VLDL cholesterol (+19%), apoC-III (+23%), apoC-III LpB (+44%) apoC-III nonLpB (+17%), apoE (+29%) and nonHDL-E (+43%), and decreased HDL cholesterol (-12%), LPL (-3%), and LCAT (-3%). Changes in triglycerides correlated with changes in LPL activity and insulin levels.

CONCLUSIONS

In hypertriglyceridemic patients, a modified diet rich in mono- and n-3 polyunsaturated fatty acids is more effective than a carbohydrate-rich low-fat diet in correcting the atherogenic lipoprotein phenotype.