Diet and coronary heart disease: clinical trials

Influence of parental education levels on eating habits of pupils in Nigerian primary schools

This study investigated the eating habits of pupils in Nigerian primary schools based on the respective education levels of their parents.Data were obtained using the Child Eating Behavior Questionnaire (CEBQ). Participants included a total of 144 pupils who were purposively selected from 6 primary schools. Based on responses, a cross-sectional analytic study design was implemented to investigate how parental education levels (PELs) influenced the eating habits of their children. Data assessment was performed using a one-way between-group analysis of variance at the .05 probability level.PELs significantly affected the eating habits of participants, respectively. Specifically, low PEL was associated with more satiety responsiveness to food (F [2, 141] = 14.251, P < .001), higher responsiveness to food (F [2, 141] = 36.943, P = <.001) greater food enjoyment (F [2, 141] = 93.322, P < .001), greater drinking desires (F [2, 141] = 23.677, P < .001), and the tendency for emotional over-eating (F [2, 141] = 13.428, P < .001), while high PEL was associated with slower eating (F [2, 141] = 11.665, P < .001), fussier responses to food (F [2, 141] = 14.865, P < .001), and a higher tendency for emotional under-eating (F [2, 141] = 5.137, P < .01).This study examined PELs in relation to the respective eating habits of their children, who were attending Nigerian primary schools. Data showed that children with parents who had high, middle, and low education levels tended to exhibit progressively worse eating habits, in descending order.

Impacts and Echoes: The Lasting Influence of the White House Conference on Food, Nutrition, and Health

The 1969 White House Conference on Food, Nutrition, and Health had a significant influence on the direction of food and nutrition policy in the United States. The conference produced recommendations leading to federal legislation and programs to alleviate hunger and malnutrition, improve consumers' nutrition knowledge through education and labeling, and monitor the nutritional status of the population. Fifty years later, its legacy was revisited at a conference convened by Harvard University and Tufts University. This article reviews the literature contributing to the first author's keynote speech at the conference, its influencers, and its influences. We focus on the highlights of five domains that set the stage for the conference: the social environment, the food environment, nutrition science, public health data, and policy events. We briefly describe the conference, its proposed directions, and its lasting legacy in these five domains.

Kupffer cells ameliorate hepatic insulin resistance induced by high-fat diet rich in monounsaturated fatty acids: the evidence for the involvement of alternatively activated macrophages

BACKGROUND

Resident macrophages (Kupffer cells, KCs) in the liver can undergo both pro- or anti-inflammatory activation pathway and exert either beneficiary or detrimental effects on liver metabolism. Until now, their role in the metabolically dysfunctional state of steatosis remains enigmatic. Aim of our study was to characterize the role of KCs in relation to the onset of hepatic insulin resistance induced by a high-fat (HF) diet rich in monounsaturated fatty acids.

METHODS

Male Wistar rats were fed either standard (SD) or high-fat (HF) diet for 4 weeks. Half of the animals were subjected to the acute GdCl3 treatment 24 and 72 hrs prior to the end of the experiment in order to induce the reduction of KCs population. We determined the effect of HF diet on activation status of liver macrophages and on the changes in hepatic insulin sensitivity and triacylglycerol metabolism imposed by acute KCs depletion by GdCl3.

RESULTS

We found that a HF diet rich in MUFA itself triggers an alternative but not the classical activation program in KCs. In a steatotic, but not in normal liver, a reduction of the KCs population was associated with a decrease of alternative activation and with a shift towards the expression of pro-inflammatory activation markers, with the increased autophagy, elevated lysosomal lipolysis, increased formation of DAG, PKCε activation and marked exacerbation of HF diet-induced hepatic insulin resistance.

CONCLUSIONS

We propose that in the presence of a high MUFA content the population of alternatively activated resident liver macrophages may mediate beneficial effects on liver insulin sensitivity and alleviate the metabolic disturbances imposed by HF diet feeding and steatosis. Our data indicate that macrophage polarization towards an alternative state might be a useful strategy for treating type 2 diabetes.

Toll-like receptor signaling links dietary fatty acids to the metabolic syndrome

PURPOSE OF REVIEW

Dietary saturated fatty acids (SFAs) have been implicated in promoting the metabolic syndrome and atherosclerotic cardiovascular disease. Recent evidence suggests that SFAs promote the metabolic syndrome by activating Toll-like receptor 4 (TLR4). Here we examine emerging molecular evidence that SFAs directly engage pathways of innate immunity, thereby promoting inflammatory aspects of the metabolic syndrome.

RECENT FINDINGS

Accumulation of SFA in the body is tightly regulated by stearoyl-CoA desaturase 1, an enzyme that converts endogenous SFA to monounsaturated fatty acids. Recent studies have demonstrated that the accumulation of SFA seen with genetic deletion or inhibition of stearoyl-CoA desaturase 1 promotes inflammation, TLR4 hypersensitivity, and accelerated atherosclerosis. Therefore, stearoyl-CoA desaturase 1 may play an unexpected role in suppressing inflammation by preventing excessive accumulation of endogenous SFA-derived TLR4 agonists. In parallel, several independent laboratories have demonstrated that TLR4 is necessary for dietary SFAs to induce obesity, insulin resistance, and vascular inflammation in rodent models.

SUMMARY

The metabolic syndrome and atherosclerotic cardiovascular disease have long been linked to dietary SFA intake and inflammation. Recent mechanistic insights into how SFAs and downstream metabolites can potentiate inflammation-driven metabolic disease are discussed here.

Comparative effects of three popular diets on lipids, endothelial function, and C-reactive protein during weight maintenance

Although popular diets focus on weight loss and their favorable biochemical and physiological effects, fewer investigations have evaluated the biological impact of these diets during weight maintenance. To study this issue, three popular diets-Atkins, South Beach, and Ornish-were tested in a randomized and counterbalanced crossover study between January and December 2006. Participants completed each of the three 4-week isocaloric dietary intervention phases followed by a 4-week washout period. They were weighed weekly and caloric adjustments made if weight change exceeded 1 kg. At the completion of each dietary phase, 3-day food records were analyzed, fasting blood sampled, and brachial artery reactivity testing performed. Eighteen adults completed all three isocaloric dietary phases. During the South Beach and Ornish maintenance phase, there were significant reductions in low-density lipoprotein cholesterol (11.8%; P=0.01, 16.6%; P=0.0006, respectively) compared to prediet baseline. In addition, in contrast to the Atkins maintenance phase, significant reductions in low-density lipoprotein cholesterol and apolipoprotein B levels were observed after the South Beach (P=0.003, P=0.05; repeated measures analyses of variance) and Ornish maintenance phases (P=0.0004, P=0.006, repeated measures analyses of variance). Brachial artery testing revealed an inverse correlation between flow-mediated vasodilatation and intake of saturated fat (r=-0.33; P=0.016). These data suggest that during weight maintenance, less favorable biological effects are observed during a simulated, high-fat Atkins diet when compared to the South Beach and Ornish diet. The findings support additional study in subjects with visceral obesity and the metabolic syndrome, in whom an increased risk of coronary disease at baseline may be accentuated with chronic consumption of a diet that exhibits unfavorable effects on lipids and endothelial function.

Nonpharmacologic management of mixed dyslipidemia associated with diabetes mellitus and the metabolic syndrome: a review of the evidence

Patients with type 2 diabetes mellitus or metabolic syndrome typically exhibit atherogenic mixed dyslipidemia characterized by low levels of high-density lipoprotein cholesterol, elevated triglycerides, and an increase in small, dense low-density lipoprotein particles. Treatment guidelines recognize lifestyle intervention as a first step in the management of dyslipidemia in these patients. The aim of this article is to review evidence to support this approach. To achieve all recommended lipid goals in clinical practice, lifestyle intervention is likely to be adjunctive to pharmacotherapy.

Lifestyle and dietary modification for prevention of heart failure

This article discusses the factors that contribute most to systolic and diastolic heart failure (HF): ischemic heart disease, hypertension,obesity, diabetes, and nephropathy. Diabetes often follows the insulin resistance syndrome in which obesity and hypertension are combined with dyslipidemia, and obesity is likely causal. Diabetes and hypertension are common causes of nephropathy, which in turn is a common precursor to HF. Insulin resistance, obesity,dyslipidemia, diabetes, and hypertension are risk factors for atherosclerotic coronary disease and left ventricular ischemia. Each is also a risk factor for diastolic dysfunction.

Effects of dietary modification to reduce vascular risks and treatment of obesity

This article has considered a vast literature attesting to the efficacy of dietary intervention on risk factors for CHD and on vascular outcomes. Rather than relying solely on pharmacotherapy to improve risk factors and vascular outcomes, physicians, nurses, dietitians, pharmacists, and medical providers should emphasize the benefits of a well-balanced, nutritionally sound dietary program. The diet should be low in saturated fatty acids, controlled in calories to avoid (or reduce) obesity, and rich in fruits, vegetables, whole grain products, and good sources of protein. Emphasis on foods rich in n-3 fatty acids shows promise for reducing cardiovascular outcomes, particularly sudden death.

Oxidized fats in foods

PURPOSE OF REVIEW

Lipid oxidation is the cause of important deteriorative changes in chemical, sensory and nutritional food properties. In particular, the question of whether oxidized fats in the diet may be detrimental to health is nowadays of the upmost concern, but finding an answer is not easy and requires careful consideration of different aspects of lipid oxidation.

RECENT FINDINGS

In this review, the most recent works on the formation, nature and evaluation of oxidized dietary lipids are addressed; important issues such as the difficulties encountered in estimating their intake and the relationships between oxidants and antioxidants in the diet are discussed, and the latest studies on health implications of oxidized lipids are summarized.

SUMMARY

The current literature reflects various important points. At present, there is no information on the intake of oxidized fats, which is essential to know if the amount of oxidized lipids in normal diets is sufficient to cause the physiological effects claimed. Recently, relevant advances in analytical methodologies for quantitation of specific oxidation compounds have been reported, although their application to improve the analytical definition of the oxidized substrate used in nutritional studies is still a goal to be reached. Alternatively, one of the most promising current tendencies in this field is the study of the molecular targets by which dietary oxidized lipids can influence health. Overall, more selected research based on coordinated multidisciplinary studies is needed to define the role of dietary oxidized fats in health.

Therapeutic lifestyle change and Adult Treatment Panel III: evidence then and now

The Third Report of the National Cholesterol Education Program's Adult Treatment Panel (ATP III) has an extensive section on nonpharmacologic therapy for those with abnormal blood lipids. ATP III focused on the high-saturated fat atherogenic diet, obesity, and sedentary lifestyle and recommended a program of therapeutic lifestyle change (TLC). This review discusses several issues, including 1) why ATP III changed from the Step I and Step II diets to TLC; 2) the benefits of keeping trans fatty acid intake low and the addition of viscous fiber and plant stanol/sterol esters to reduce low-density lipoprotein cholesterol beyond that seen with the Step II diet; 3) the de-emphasis on total fat and a sharper focus on the kinds of fat ingested in the new guidelines; 4) the endorsement of regular physical activity and weight loss as important first steps in reversing the unwanted metabolic effects of the metabolic syndrome; and 5) the emphasis of health-promoting aspects of the diet that include, among other things, fish and omega-3 fatty acids. At all stages of TLC, ATP III encourages the referral to registered dietitians or other qualified nutritionists for medical nutrition therapy. TLC and the ATP III guidelines should provide guidance to practitioners who wish to get low-density lipoprotein cholesterol to goal (whether or not drugs are used), prevent or treat the metabolic syndrome, and improve the overall health of the patient.

Dietary fats and 16-year coronary heart disease mortality in a cohort of men and women in Great Britain

OBJECTIVE

The paper aims to investigate the relationships of dietary fats to subsequent coronary heart disease (CHD) mortality in men and women while taking account of other CHD-related behaviours.

DESIGN

A cohort of randomly selected men and women were interviewed in 1984-85 and monitored subsequently for 16 y for deaths. The interview covered health, health-related behaviours, physical measurements, socio-demographic details and a dietary questionnaire. Appropriate exclusions left 1225 men and 1451 women aged 40-75 with 98 and 57 CHD deaths, respectively. Saturated, polyunsaturated and total fat intakes were estimated.

SETTING

The sample was randomly selected from households in Great Britain. The interviews took place in participants' own homes.

RESULTS

Not consuming alcohol, smoking, not exercising and being socially disadvantaged were related to high saturated fat intake and CHD death. Cox survival analyses adjusting for these factors found that a level of saturated fat 100 g per week higher corresponded to a relative risk for CHD death for men of 1.00 (0.86-1.18) and 1.40 (1.09-1.79) for women. This difference between the effects of saturated fat in men and women was statistically significant (P=0.019). Results are also reported for total fat and the relative effects of polyunsaturated and saturated fats.

CONCLUSIONS

Strong evidence was found for the within cohort relationship of dietary fat and CHD death in women while no evidence was found for a relationship in men. Possible explanations for this are discussed.

Protective effect of dietary monounsaturated fat on arteriosclerosis: beyond cholesterol

The consumption of diets enriched in monounsaturated fat has been related to a lower rate of coronary heart disease. It is well known that this dietary model decreases LDL-cholesterol plasma levels when replacing a saturated fat enriched diet. For this reason, a high monounsaturated fat diet is now being advocated to prevent cardiovascular disease, especially in Mediterranean countries. However, some expert panels-the Joint Task Force of European and other Societies on Coronary Prevention and the International Task Force for Prevention of Coronary Heart Disease-recommend replacing dietary saturated fat by complex carbohydrates, limiting the intake of total fat to <30% of the energy and monounsaturated fat to no more than 10-15% of total calories, reaching a similar effect on LDL-cholesterol plasma levels to a high monounsaturated fat diet. The most appropriate nutritional model to prevent arteriosclerosis should be supported by research into other biological effects of both diets. Therefore, it is interesting to review the non-lipid effect of monounsaturated fat, starting with its influence on other cardiovascular risk factors, such as carbohydrate metabolism and blood pressure. Moreover, substantial evidence of the effect of dietary monounsaturated fat on a wide range of healthy benefits beyond cholesterol, which have been investigated in recent years, such as lipoprotein oxidation, coagulation, fibrinolysis and endothelium, will be discussed. Furthermore, many observational epidemiological studies suggest that a high intake of monounsaturated fat is associated with reduced coronary risk and this will be analyzed in accordance with the clinical evidence to discuss the best dietary model to prevent coronary artery disease.

[Dietary intake of n-3 fatty acids and the risk of acute myocardial infarction: a case-control study]

BACKGROUND

There is some dispute about the role of fish and n-3 polyunsaturated fatty acids (n-3 PUFA) consumption on the prevention of coronary heart disease. The aim of this study was to analyze the relationship between n-3 PUFA and fish consumption and the risk of a first acute myocardial infarction (AMI) in a low risk population from Navarre (Spain).

METHOD

A hospital-based case-control study was conducted in Pamplona (Spain). We included 171 patients (81% males, age < 80 years) who were admitted with a first acute myocardial infarction and 171 age, gender and hospital-matched controls were selected. A validated semi-quantitative food frequency questionnaire was administered and face-to-face interviews were performed. Conditional logistic regression modeling was used to take into account potential confounders.

RESULTS

Adjusted odds ratio (OR) and 95% confidence intervals (CI) for the second and third tertile of n-3 PUFA intake were 0.44 (95% CI, 0.21-0.91) and 0.47 (95% CI, 0.22-1.00), respectively. Trend test was not statistically significant. Adjusted OR and 95% CI for the second and third tertile of fish consumption were 0.40 (95% CI, 0.19-0.83) and 0.42 (95% CI, 0.19-0.93), respectively. Additional adjusting for n-3 PUFA led to a non-significant association between fish consumption and AMI.

CONCLUSIONS

This study reveals a protective effect of n-3 PUFA and fish consumption against AMI. Our results suggest that a threshold exists in the quantitative dose-response relationship between fish intake and AMI.

Oxidized fat in the diet, postprandial lipaemia and cardiovascular disease

Accumulating evidence suggests that oxidized fats and lipid oxidation products in the diet can contribute to the pathogenesis of atherosclerosis. The present review summarizes studies that show that oxidized fat and lipid oxidation products are present in human foods; that these compounds are absorbed by the intestine and appear in the blood circulation; and that these ingested substances can have deleterious cardiovascular effects in both humans and experimental animals. However, considerable additional research is required to establish the extent to which dietary fat oxidation poses a threat to human health and/or longevity.

The optimal dietary strategy to manage risk associated with various dyslipidemias

A successful dietary strategy should reduce coronary heart disease (CHD) endpoints, improve correctable risk factors for CHD, and provide for an overall healthful lifestyle. The therapeutic diet achieves a lowering of low-density lipoprotein cholesterol by limiting saturated fat and dietary cholesterol, avoiding an increase in trans fatty acids, and incorporates the use of dietary adjuncts such as an increase in dietary viscous fiber and dietary plant stanol/sterol esters. For those with elevated triglycerides and low high-density lipoprotein cholesterol, impaired fasting glucose, increased waist circumference and other stigmata of the metabolic syndrome, individualized and supervised weight loss, and regular physical activity is strongly recommended.

Cardiac rehabilitation: a comprehensive review

Cardiac rehabilitation (CR) is a commonly used treatment for men and women with cardiovascular disease. To date, no single study has conclusively demonstrated a comprehensive benefit of CR. Numerous individual studies, however, have demonstrated beneficial effects such as improved risk-factor profile, slower disease progression, decreased morbidity, and decreased mortality. This paper will review the evidence for the use of CR and discuss the implications and limitations of these studies. The safety, relevance to special populations, challenges, and future directions of CR will also be reviewed.