Dietary restriction and fibre supplementation: Oxidative stress and metabolic shifting for cardiac health

Dietary modification ought to be the first line of strategy in prevention of the development of cardiac disease. The purpose of this study was to investigate whether dietary restriction, dietary-fibre-enriched diet, and their interactions might affect antioxidant capacity and oxidative stress in cardiac tissue. Male Wistar rats (180-200 g; n = 10) were divided into four groups: control ad libitum diet (C), 50% restricted diet (DR), fed with fibre-enriched diet (F), and 50% restricted fibre-enriched diet (DR-F). After 35 days of the treatments, F, DR, and DR-F rats showed low cholesterol, LDL-cholesterol, and triacylglycerol, and high HDL-cholesterol in serum. The DR, DR-F, and F groups had decreased myocardial lipoperoxide and lipid hydroperoxide. The DR-F and F treatments increased superoxide dismutase and glutatione peroxidase (GSH-Px). The DR treatment increased GSH-Px and catalase activities. Dietary fibre beneficial effects were related to metabolic alterations. The F and DR-F groups showed high cardiac glycogen and low lactate dehydrogenase/citrate synthase ratios, indicating diminished anaerobic and elevated aerobic myocardial metabolism in these animals. There was no synergistic effect between dietary restriction and dietary fibre addition, since no differences were observed in markers of oxidative stress in the F and DR-F groups. Dietary fibre supplementation, rather than energy intake and dietary restriction, appears to be the main process retarding oxidative stress in cardiac tissue.

Synergistic action of olive oil supplementation and dietary restriction on serum lipids and cardiac antioxidant defences

Caloric intake is higher than recommended in many populations. Therefore, enhancing olive oil intake alone may not be the most effective way to prevent cardiovascular diseases. The purpose of the present study was to analyse the association of olive oil and dietary restriction on lipid profile and myocardial antioxidant defences. Male Wistar rats (180-200 g, n = 6) were divided into 4 groups: control ad libitum diet (C), 50% restricted diet (DR), fed ad libitum and supplemented with olive oil (3 mL/(kg-day)) (OO), and 50% restricted diet and supplemented with olive oil (DROO). After 30 days of treatments, OO, DR, and DROO groups had increased total cholesterol and high-density lipoprotein cholesterol concentrations. DR and DROO animals showed decreased low-density lipoprotein cholesterol. DROO had the lowest low-density lipoprotein cholesterol concentration. Total lipids and triacylglycerols were raised by dietary restriction and diminished by olive oil. OO rats had higher myocardial Superoxide dismutase and lower catalase and glutathione peroxidase activities than C rats. DR and DROO showed enhanced cardiac Superoxide dismutase, catalase, and glutathione peroxidase activities from the control. Olive oil supplementation alone improved the lipid profile but was more effective when coupled with dietary restriction. There was a synergistic beneficial action of dietary restriction and olive oil on serum lipids and myocardial antioxidant defences.

Dietary intake and blood lipid profile in overweight and obese schoolchildren

Abstract. Background: The high blood lipid levels and obesity are one of the main risk factors for cardiovascular diseases, and the atherosclerotic process begins in childhood. Some environmental factors are supposed to be involved in this relationship, such as dietary factors. This study aimed to investigate the relationship between dietary intake and blood lipids levels in overweight and obese schoolchildren. Methods. This is a cross-sectional study with 147 overweight and obese schoolchildren in Botucatu city, Brazil. The anthropometric measurements (body weight, height, body mass index, waist circumference and skinfolds), pubertal staging evaluation and biochemical tests were taken in all children. Three 24h-recall were applied in order to estimate the dietary intake and its relationship with blood lipid levels. The Student t test and multiple linear regression analysis were used for statistical analysis. Statistical significance was assessed at the level of 0.05. The data were processed in SAS software (version 9.1.3; SAS Institute). Results: At this study, 63% of children were obese (body mass index higher than 95§ssup§th§esup§ percentile) and 80% showed high body fat percentage. The percentage of children with abnormal total cholesterol and triglycerides was 12% and 10%, respectively, and 28% presented at least one abnormal lipid levels. The average values of anthropometric measurements were higher in children with elevated lipid levels. Total cholesterol levels were positively related to full-fat dairy products and triglycerides levels to saturated fat percentage. Conclusions: Saturated fat was positively associated with elevated lipid levels in overweight and obese schoolchildren. These results reinforce the importance of healthy dietary habits since childhood in order to reduce the risks of cardiovascular diseases in adulthood. © 2012 Rinaldi et al.; licensee BioMed Central Ltd.

Dietary, anthropometric, and biochemical determinants of uric acid in free-living adults

Background: High plasma uric acid (UA) is a prerequisite for gout and is also associated with the metabolic syndrome and its components and consequently risk factors for cardiovascular diseases. Hence, the management of UA serum concentrations would be essential for the treatment and/or prevention of human diseases and, to that end, it is necessary to know what the main factors that control the uricemia increase. The aim of this study was to evaluate the main factors associated with higher uricemia values analyzing diet, body composition and biochemical markers. Methods. 415 both gender individuals aged 21 to 82 years who participated in a lifestyle modification project were studied. Anthropometric evaluation consisted of weight and height measurements with later BMI estimation. Waist circumference was also measured. The muscle mass (Muscle Mass Index - MMI) and fat percentage were measured by bioimpedance. Dietary intake was estimated by 24-hour recalls with later quantification of the servings on the Brazilian food pyramid and the Healthy Eating Index. Uric acid, glucose, triglycerides (TG), total cholesterol, urea, creatinine, gamma-GT, albumin and calcium and HDL-c were quantified in serum by the dry-chemistry method. LDL-c was estimated by the Friedewald equation and ultrasensitive C-reactive protein (CRP) by the immunochemiluminiscence method. Statistical analysis was performed by the SAS software package, version 9.1. Linear regression (odds ratio) was performed with a 95% confidence interval (CI) in order to observe the odds ratio for presenting UA above the last quartile (♂UA > 6.5 mg/dL and ♀ UA > 5 mg/dL). The level of significance adopted was lower than 5%. Results: Individuals with BMI ≥ 25 kg/m§ssup§2§esup§ OR = 2.28(1.13-4.6) and lower MMI OR = 13.4 (5.21-34.56) showed greater chances of high UA levels even after all adjustments (gender, age, CRP, gamma-gt, LDL, creatinine, urea, albumin, HDL-c, TG, arterial hypertension and glucose). As regards biochemical markers, higher triglycerides OR = 2.76 (1.55-4.90), US-CRP OR = 2.77 (1.07-7.21) and urea OR = 2.53 (1.19-5.41) were associated with greater chances of high UA (adjusted for gender, age, BMI, waist circumference, MMI, glomerular filtration rate, and MS). No association was found between diet and UA. Conclusions: The main factors associated with UA increase were altered BMI (overweight and obesity), muscle hypotrophy (MMI), higher levels of urea, triglycerides, and CRP. No dietary components were found among uricemia predictors. © 2013 de Oliveira et al.; licensee BioMed Central Ltd.

Long-term orange juice consumption is associated with low LDL-cholesterol and apolipoprotein B in normal and moderately hypercholesterolemic subjects

Abstract. Background: This study investigated the hypothesis that long-term orange juice consumption (≥ 12 months) was associated with low risk factors for cardiovascular disease in adult men and women with normal and moderately high cholesterol blood levels. Methods. The sample consisted of 103 men (18-66 y) and 26 women (18-65 y); all were employees of an orange juice factory with daily access to free orange juice. The results showed that 41% of the individuals consumed 2 cups (480 mL) of orange juice per day for at least twelve months, while 59% of the volunteers are non-consumers of orange juice. Results: Orange juice consumers with normal serum lipid levels had significantly lower total cholesterol (-11%, p <0.001), LDL-cholesterol (-18%, p < 0.001), apolipoprotein B (apo B) (-12%, p < 0.01) and LDL/HDL ratio (-12%, p < 0.04) in comparison to non-consumers, as did the consumers with moderate hypercholesterolemia: lower total cholesterol (-5%, p <0.02), LDL-cholesterol (-12%, p <0.03), apolipoprotein B (-12%, p <0.01) and LDL/HDL ratio (-16%, p <0.05) in comparison the non-consumers counterparts. Serum levels of homocysteine, HDL- cholesterol and apolipoprotein A-1, body composition and the dietary intake of food energy and macronutrients did not differ among orange juice consumers and non-consumers, but vitamin C and folate intake was higher in orange juice consumers. Conclusion: Long-term orange juice consumers had lower levels of total cholesterol, LDL-cholesterol, apo B and LDL/HDL ratio and an improvement of folate and vitamin C in their diet. © 2013 Aptekmann and Cesar; licensee BioMed Central Ltd.

Dietary supplementation with sunflower seeds and vitamin E for fattening lambs improves the fatty acid profile and oxidative stability of the Longissimus lumborum

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Daily intake of pasteurized orange juice decreases serum cholesterol, fasting glucose and diastolic blood pressure in adults

Previous studies have shown that fresh squeezed orange juice or juice from reconstituted concentrate can help prevent the development of atherosclerosis. Pasteurized orange juice presently represents the major orange juice available in the market, and because of this, it becomes necessary to determine the healthy benefits associated with this product. In this study we investigated the effect of regular consumption of pasteurized orange juice on the nutritional status, biochemical profile, and arterial blood pressure in healthy men and women. Men and women volunteered to consume pasteurized orange juice (500 mL·d–1 and 750 mL·d–1, respectively), for 8 weeks. Anthropometric, biochemical, hemodynamic, and dietary assessments were evaluated at baseline and at the end of the experimental period. Total cholesterol and LDL-C significantly decreased in both men and women after the consumption of orange juice, and an increase in HDL-C level was detected exclusively in women. Fasting glucose, diastolic blood pressure, and triglyceride levels dropped in men after the consumption of orange juice. Anthropometric variables did not change with orange juice consumption, only waist circumference decreased significantly in women. Consumption of orange juice increased the energy and carbohydrate intake for women; however, vitamin C and folate increased after the orange juice period for both men and women. Regular consumption of pasteurized orange juice by men (750 mL·d–1) and women (500 mL·d–1) reduced the risk of developing atherosclerosis, and increased the nutritional quality of their diets.

Simvastatin and ezetimibe in addition to nonpharmacological risk factor modification for achieving new low-density lipoprotein cholesterol targets

BACKGROUND: Though guidelines emphasize low-density lipoprotein cholesterol (LDL-C) lowering as an essential strategy for cardiovascular risk reduction, achieving target levels may be difficult. PATIENTS AND METHODS: The authors conducted a prospective, controlled, open-label trial examining the effectiveness and safety of high-dose fluvastatin or a standard dosage of simvastatin plus ezetimibe, both with an intensive guideline-oriented cardiac rehabilitation program, in achieving the new ATP III LDL-C targets in patients with proven coronary artery disease. 305 consecutive patients were enrolled in the study. Patients were divided into two groups: the simvastatin (40 mg/d) plus ezetimibe (10 mg/d) and the fluvastatin-only group (80 mg/d). Patients in both study groups received the treatment for 21 days in addition to nonpharmacological measures, including advanced physical, dietary, psychosocial, and educational activities. RESULTS: After 21 days of treatment, a significant reduction in LDL-C was found in both study groups as compared to the initial values, however, the reduction in LDL-C was significantly stronger in the simvastatin plus ezetimibe group: simvastatin plus ezetimibe treatment decreased LDL-C to a mean level of 57.7 +/- 1.7 mg/ml, while fluvastatin achieved a reduction to 84.1 +/- 2.4 mg/ml (p < 0.001). In the simvastatin plus ezetimibe group, 95% of the patients reached the target level of LDL-C < 100 mg/dl. This percentage was significantly higher than in patients treated with fluvastatin alone (75%; p < 0.001). The greater effectiveness of simvastatin plus ezetimibe was more impressive when considering the optional goal of LDL-C < 70 mg/dl (75% vs. 32%, respectively; p < 0.001). There was no difference in occurrence of adverse events between both groups. CONCLUSION: Simvastatin 40 mg/d plus ezetimibe 10 mg/d, on the background of a guideline-oriented standardized intensive cardiac rehabilitation program, can reach 95% effectiveness in achieving challenging goals (LDL < 100 mg/dl) using lipid-lowering medication in patients at high cardiovascular risk.

Cholesterol transporters in lactating and nonlactating human mammary tissue

In mammals milk is the principal nutrient for neonates at birth. The basic milk composition is similar between different mammals, but the content of individual constituents such as lipids may differ significantly from one species to another. The milk fat fraction is mainly composed of triglycerides which account for more than 95% of the lipids found in human and bovine milk. Though sterols and in particular cholesterol, the predominant milk sterol, represent less than 0.5% of the total milk lipid fraction, they are of ultimate importance for biological processes such as the formation of biological membranes or as precursors for steroid hormone synthesis. Cholesterol found in milk originates either from blood uptake or from local synthesis. This chapter provides an overview of cholesterol exchanges between the blood, the mammary tissue and the milk. The current knowledge on the expression, localization and function of candidate cholesterol transporters in mammary tissues of human, murine and bovine origin is summarized. Different mechanisms of how cholesterol can be transferred via the mammary tissue into milk, and which active cholesterol transporters are likely to play a role in this process will be discussed.

Toward individualized cholesterol-lowering treatment in end-stage renal disease.

There is broad evidence that lowering low-density lipoprotein (LDL) cholesterol will reduce cardiovascular risk. However, in patients on maintenance hemodialysis treatment, lowering LDL cholesterol is not as effective in preventing cardiovascular complications as in the general population. Cholesterol is either endogenously synthesized or absorbed from the intestine. It has been suggested that the benefit of using statins to prevent atherosclerotic complications is less pronounced in people with high absorption of cholesterol. Recent data indicate that patients on hemodialysis have high absorption of cholesterol. Therefore, these patients may benefit from dietary counseling to reduce cholesterol intake, from functional foods containing plant sterols and stanols, and from drugs that interfere with intestinal absorption of sterols (i.e., ezetimibe, bile acid resins, and sevelamer). This review discusses cholesterol homeostasis and the perspective of personalized treatment of hypercholesterolemia in hemodialysis.

Physiologic and psychosocial stage-based differences for dietary fat consumption in women with type 2 diabetes

Purpose. This cross-sectional, observational study explored differences among groups staged for intent to decrease dietary fat intake in women with type 2 diabetes in relation to demographic, weight concern, physiological, and psychosocial variables. ^ Methods. A sample of 100 community-dwelling, English-speaking women, who were over age 30 and had type 2 diabetes for at least a year, was accessed through a culturally diverse endocrinology clinic. Subjects completed 7 self-report instruments: demographic sheet, with 11-point weight satisfaction scale; staging algorithm; fat intake (MEDFICTS); depression (CES-D); diabetes-specific dietary knowledge (ADKnowl), social support and self-efficacy scales (SE-Type 2). Physiological variables were abstracted from the medical record (HbA 1c, blood pressure, serum cholesterol and triglycerides). ^ Results. The women's average age was 57.69 years ( SD = 3.07); 50% were married. Subjects were well-educated ( M = 14 years; SD = 3.33), with average diabetes duration of 10.57 years (SD = 9.11), high body mass index (M = 35.72; SD = 8.36), low diabetes-specific dietary knowledge, low weight satisfaction, but in good diabetes control. Racial/ethnic composition was 44% non-Hispanic-White-American, 18% Hispanic-White-American, 15% non-Hispanic-African-American, 16% Hispanic-African-American and 5% other. Fat intake was low and differed by racial/ethnic demographics. The highest fat intake scores were for non-Hispanic-African-Americans (M = 53), followed by Hispanic-White-Americans (M = 51), non-Hispanic-White-Americans (M = 45), and Hispanic-African-Americans (M = 32), who had the lowest fat intake scores. ^ MANOVA analyses revealed no significant differences between stages of behavior change in relation to psychosocial or weight concern variables, age, education, HbA1c, or cholesterol levels. Single women were more likely to be in the three preaction stages (precontemplation, contemplation, and preparation); married women were equally distributed across stages (the preaction stages plus action and maintenance). African-American women (Hispanic and non-Hispanic) were more likely in contemplation and preparation. Triglycerides were higher in women in the action stage than contemplation or preparation. Systolic blood pressure was higher in action than preparation; diastolic blood pressure was higher in action than preaction. ^ Conclusions. Healthcare professionals should consider race, ethnicity, and marital status in client interactions. Dietary intake can vary according to both race and ethnicity; collapsing racial/ethnic groups can alter means and distributions, generating faulty conclusions. Further research is warranted to explore relationships between dietary self-care and marital status, race, ethnicity, and physiological variables. ^

Blood pressure and dietary factors in Mexican-Americans of Starr County, Texas

This study examined the cross-sectional associations between blood pressure, hypertension and dietary factors among 580 Mexican-American adults residing in Starr County, Texas. The data were collected as part of Gallbladder Disease Study between April, 1985 and December, 1986.^ Dietary intake was assessed for the month previous to the interview by means of a 38 food item quantified frequency questionnaire representing foods and mixed dishes commonly consumed in the community. From the dietary information intake of calcium, cholesterol, total kilocalories, and percent of kilocalories contributed by total fat, saturated fat, monounsaturated fatty acids, polyunsaturated fatty acids, protein, carbohydrates were calculated. The effect of other factors associated with blood pressure, such as age, body mass index, body fat distribution, smoking, and drinking were controlled.^ Age was the most important predictor of both systolic and diastolic blood pressure and hypertension. For both males and females, systolic and diastolic blood pressure levels were consistently positively associated with body mass index but were not associated with waist hip ratio. However, a strong positive relationship between hypertension and waist hip ratio but not body mass index was observed.^ After controlling for age and body mass index it was noted that for males there were no significant associations between the dietary variables and systolic blood pressure. For diastolic blood pressure there were significant associations with percent fat, percent monounsaturated fatty acids, percent protein and percent carbohydrates.^ For females, there were significant associations between systolic blood pressure and percent protein, percent carbohydrates and cholesterol. There were no significant associations between dietary variables and diastolic blood pressure.^ After controlling for age and waist hip ratio significant associations between hypertension and percent fat, percent saturated fat, percent monounsaturated fatty acids, percent carbohydrate and percent protein were observed in males. Significant associations between hypertension and percent polyunsaturated fatty acids and percent protein were noted in females. ^

Altered cholesterol metabolism in a hypercholesterolemia -resistant rabbit colony

A colony of rabbits has been developed at the University of Texas Medical School at Houston that is resistant to dietary-induced hypercholesterolemia. The liver of resistant rabbits had higher levels of ($\sp{125}$I) $\beta$-VLDL binding and 3-hydroxy-3-methylglutaryl (HMGCoA) reductase activity, but lower acyl coenzyme A:cholesterol acyltransferase (ACAT) activity than normal rabbits. Direct quantitation of intracellular cholesterol content of the liver revealed that the resistant rabbits had $<$10% of the intracellular free cholesterol present in normal rabbits. Fibroblasts isolated from normal and resistant rabbits exhibited differences in ($\sp{125}$I) LDL binding, HMGCoA reductase activity and ACAT activity that were similar to those found in the liver. No structural differences were found in the LDL receptor of normal and resistant fibroblasts that would account for the increased binding capacity of the resistant cells. The regulation of LDL receptor levels by exogenous oxygenated sterols was similar in normal and resistant fibroblasts. The regulation of LDL receptor binding capacity by LDL was attenuated in the resistant compared to normal fibroblasts, suggesting that the resistant fibroblasts have an alternate pathway for processing lipoprotein-derived cholesterol. Sterol-balance studies revealed that the cholesterol-fed resistant rabbits increased lithocholic acid excretion compared to the basal state, and had higher levels of deoxycholic acid excretion than cholesterol-fed normal rabbits. In addition, the specific activity and mRNA levels of cholesterol 7$\alpha$-hydroxylase (C7$\alpha$H) were higher in resistant rabbits than normal rabbits, suggesting that the increased bile acid excretion was due to an increase in bile acid synthesis. Increased clearance of cholesterol relieves the negative feedback inhibition cholesterol exerts on expression of the LDL receptor. The number of cell surface LDL receptors is then increased in resistant rabbits and allows rapid clearance of lipoproteins from the plasma compartment, thereby reducing plasma cholesterol levels. The low intracellular cholesterol level also relieves the negative feedback inhibition cholesterol exerts on HMGCoA reductase. Increased synthesis of cholesterol from acetate provides cells with cholesterol for bile acid synthesis and/or homeostasis. The activity of ACAT is then decreased due to the flux of cholesterol through the bile acid synthetic pathways. ^

Characterization of the cholesterol 7$\alpha$-hydroxylase promoter in hypercholesterolemia -resistant rabbits

Our laboratory has developed and partially characterized a strain of New Zealand white rabbits that are resistant to the hypercholesterolemia which typically occurs in normal rabbits when fed a cholesterol-enriched diet. This phenotype is most likely attributed to an increase in bile acid excretion by hypercholesterolemia-resistant (CRT) rabbits as a result of elevated enzyme activity of cholesterol 7$\alpha$-hydroxylase (C7$\alpha$H), the rate-limiting enzyme in bile acid synthesis. Northern analysis revealed that CRT rabbits, in comparison to normal rabbits, have a 7-fold greater steady-state C7$\alpha$H mRNA levels irrespective of dietary regimen. The C7$\alpha$H gene in both phenotypes was determined to be a single copy gene. The hypothesis was that the elevated C7$\alpha$H mRNA levels in CRT rabbits, in comparison to normal animals, was due to an increase in the transcription rate of the C7$\alpha$H gene as a result of a mutation in a cis-acting element and/or a trans-acting factor within the hepatocyte. To isolate the C7$\alpha$H gene from both normal and CRT rabbits, genomic libraries were prepared from both phenotypes into $\lambda$GEM12 vectors using conventional techniques. Three CRT and one normal phage clones that contained the C7$\alpha$H gene were identified by screening the library with a series of probes located within different exons of the C7$\alpha$H cDNA. Sequencing analysis confirmed that approximately 1100 bp of the C7$\alpha$H 5'-flanking region from both normal and CRT phenotypes was identical. The increase in C7$\alpha$H mRNA levels was not attributed to a cis-acting mutation within this region. Liver nuclear extracts were prepared from normal and CRT rabbits maintained either on a basal or 0.25% cholesterol-enriched diet and incubated with several radiolabeled DNA fragments from the C7$\alpha$H gene. A 37 basepair region, located between nucleotides $-$452 to $-$416 was identified that had altered binding patterns between normal and CRT rabbits as a function of diet. Two additional regions, $-$747 to $-$575 and $-$580 to $-$442, produced banding patterns which were identical, irrespective of phenotype or diet. In conclusion, these studies suggested that the increase in C7$\alpha$H mRNA in CRT rabbits was due to differences in binding of a cholesterol-responsive transcription factor to the C7$\alpha$H promoter. ^

Effects of dietary restriction combined with different exercise programs or physical activity recommendations on blood lipids in overweight adults

Background and aim: Many exercise studies, although generally showing the beneficial effects of supervised aerobic, resistance or combined exercise on blood lipids, have sometimes reached equivocal conclusions. The aim of this study is to evaluate the impact of different programs that combined exercise and dietary restriction on blood lipids versus a clinical practice intervention for weight loss, in overweight adults. Methods: For this study 66 subjects participated in a supervised 22 weeks training program, composed of three sessions per week and they were randomized in three groups: strength training (S; n = 19), endurance training (E; n = 25), a combination of E and S (SE; n = 22). Eighteen subjects served as physical activity group (PA) that followed a clinical intervention consisted of physical activity recommendations. All groups followed the same dietary treatment, and blood samples were obtained for lipids measurements, at the beginning and end of the study. Results: Lipid profile improved in all groups. No significant differences for baseline and post-training values were observed between groups. In general, SE and PA decreased low-density lipoprotein cholesterol (LDL-C) values (p menor que 0.01). S decreased triglyceride levels (p menor que 0.01) and E, SE, and PA decreased total cholesterol levels (p menor que 0.05, p menor que 0.01 and p menor que 0.01, respectively). Conclusions: These results suggest that an intervention program of supervised exercise combined with diet restriction did not achieved further improvements in blood lipid profile than diet restriction and physical activity recommendations, in overweight adults. (Clinical Trials gov number: NCT01116856).