Instruct: Given a question, retrieve relevant passages that answer the question.
Query: Heart Attacks and Cholesterol: Agribusiness Sees It Differently
OBJECTIVES: The study aimed to analyze the use of intensive lipid-lowering therapy (LLT) at discharge in a broad population of patients hospitalized with acute coronary syndrome (ACS). BACKGROUND: Early and intensive statin therapy in ACS was shown to reduce cardiovascular morbidity and mortality. Utilization and predictors of LLT among hospitalized ACS patients are not known. METHODS: The GWTG database was analyzed for ACS-related hospitalizations from 2005 to 2009. The use of LLT (defined as dose of statin or combination therapy likely to produce>50% reductions in low-density lipoprotein [LDL]) and less intensive LLT at discharge was assessed. Baseline characteristics and temporal trends in LLT were compared in these 2 treatment groups. RESULTS: Of 65,396 patients receiving LLT, only 25,036 (38.3%) were treated with an LLT regimen. Mean total cholesterol, LDL, and triglycerides were significantly higher in the LLT group. Even among those with LDL>130 mg/dL, 50% or less received LLT. Predictors of LLT at discharge included LLT before admission, hyperlipidemia, prior coronary artery disease, increasing body mass index, and in-hospital percutaneous coronary intervention. Although there was some temporal improvement in the rate of LLT from 2005 to 2007, a decline in use of LLT was noted in 2008 and 2009. This was attributed to a sharp reduction in use of ezetimibe in combination with statin, without corresponding increases in intensive statin monotherapy. CONCLUSIONS: In a large cohort of patients admitted with ACS, most of the eligible patients were not discharged on LLT. These data suggest the need for better implementation of guideline-recommended intensive statin therapy in patients with ACS. Published by Mosby, Inc.
In this third installment of the series, we point out that the absence of an explicit, detailed and plausible hypothesis linking hypercholesterolemia to the events in the artery wall was probably an important reason for continuing skepticism and for failure to treat elevated blood cholesterol levels. The rapid advances in understanding of lipoprotein metabolism in the 1950s and 1960s and the application of modern cellular biology in the 1970s provided the context for a modern consensus on pathogenetic mechanisms of atherogenesis.
BACKGROUND: Several epidemiologic studies found no effect of egg consumption on the risk of coronary heart disease. It is possible that the adverse effect of eggs on LDL-cholesterol is offset by their favorable effect on HDL cholesterol. OBJECTIVE: The objective was to review the effect of dietary cholesterol on the ratio of total to HDL cholesterol. DESIGN: Studies were identified by MEDLINE and Biological s searches (from 1974 to June 1999) and by reviewing reference lists. In addition, we included data from a more recently published study. Studies were included if they had a crossover or parallel design with a control group, if the experimental diets differed only in the amount of dietary cholesterol or number of eggs and were fed for > or =14 d, and if HDL-cholesterol concentrations were reported. Of the 222 studies identified, 17 studies involving 556 subjects met these criteria. RESULTS: The addition of 100 mg dietary cholesterol/d increased the ratio of total to HDL cholesterol by 0.020 units (95% CI: 0.010, 0.030), total cholesterol concentrations by 0.056 mmol/L (2.2 mg/dL) (95% CI: 0.046, 0.065 mmol/L; 1.8, 2.5 mg/dL), and HDL-cholesterol concentrations by 0.008 mmol/L (0.3 mg/dL) (95% CI: 0.005, 0.010 mmol/L; 0.2, 0.4 mg/dL). CONCLUSIONS: Dietary cholesterol raises the ratio of total to HDL cholesterol and, therefore, adversely affects the cholesterol profile. The advice to limit cholesterol intake by reducing consumption of eggs and other cholesterol-rich foods may therefore still be valid.
BACKGROUND: Ischemic heart disease (IHD) is a leading cause of death in India. Dietary changes could reduce risk, but few studies have addressed the association between diet and IHD risk in India. OBJECTIVE: The goal was to address the association between diet and IHD risk among Indians in New Delhi (northern India) and Bangalore (southern India). DESIGN: We collected data from 350 cases of acute myocardial infarction and 700 controls matched on the basis of age, sex, and hospital as part of a hospital-based case-control study in 8 hospitals. Long-term dietary intake was assessed by using food-frequency questionnaires developed for New Delhi and Bangalore. We used conditional logistic regression to control for the matching factors and other predictors of risk. RESULTS: We observed a significant and dose-dependent inverse association between vegetable intake and IHD risk. The inverse association was stronger for green leafy vegetables; in multivariate analysis, persons consuming a median of 3.5 servings/wk had a 67% lower relative risk (RR: 0.33; 95% CI: 0.17, 0.64; P for trend = 0.0001) than did those consuming 0.5 servings/wk. Controlling for other dietary covariates did not alter the association. Cereal intake was also associated with a lower risk. Use of mustard oil, which is rich in alpha-linolenic acid, was associated with a lower risk than was use of sunflower oil [for use in cooking: RR: 0.49 (95% CI: 0.24, 0.99); for use in frying, RR: 0.29 (95% CI: 0.13, 0.64)]. CONCLUSION: Diets rich in vegetables and use of mustard oil could contribute to the lower risk of IHD among Indians.
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. Résumé Une idée fausse et généralisée se répand au sein du public canadien et des médecins, qui pensent de plus en plus que la consommation de cholestérol alimentaire et de jaunes d’œuf est inoffensive. Les recommandations de longue date qui préconisent de limiter le cholestérol alimentaire à moins de 200 mg/jour reposent sur de bonnes raisons. Un seul gros jaune d’œuf contient environ 275 mg de cholestérol (plus que la portion quotidienne de cholestérol). Même si certaines études ont démontré que la consommation d’œufs n’est pas nuisible chez les personnes en santé, ce résultat peut découler de l’absence de capacité à déceler des augmentations pertinentes sur le plan clinique au sein d’une population à faible risque. De plus, les mêmes études ont révélé que chez les participants devenus diabétiques pendant la période d’observation, la consommation d’un œuf par jour doublait leur risque par rapport à la consommation de moins d’un œuf par semaine. Le régime ne vise pas à éviter le cholestérol, mais surtout les effets postprandiaux du cholestérol, des gras saturés, du stress oxydant et de l’inflammation. Le fait de se concentrer à tort sur les lipides à jeun occulte trois enjeux. Le cholestérol alimentaire accroît la susceptibilité des lipoprotéines à faible densité à l’oxydation, accroît la lipémie postprandiale et potentialise les effets secondaires des graisses saturées alimentaires. Le cholestérol alimentaire, y compris les jaunes d’œuf, est nuisible pour les artères. Les patients vulnérables aux maladies cardiovasculaires devraient limiter leur consommation de cholestérol. Le fait d’arrêter de consommer des jaunes d’œuf après un accident vasculaire cérébral ou un infarctus du myocarde s’apparenterait à arrêter de fumer après un diagnostic de cancer du poumon : c’est un geste nécessaire, mais entrepris tardivement. D’après les données probantes présentées dans la présente analyse, la perception généralisée du public et des professionnels de la santé selon laquelle le cholestérol alimentaire est un mal bénin est une idée fausse, et une meilleure information s’impose pour la corriger.
Metabolomics studies hold promise for discovery of pathways linked to disease processes. Cardiovascular disease (CVD) represents the leading cause of death and morbidity worldwide. A metabolomics approach was used to generate unbiased small molecule metabolic profiles in plasma that predict risk for CVD. Three metabolites of the dietary lipid phosphatidylcholine, namely choline, trimethylamine N-oxide (TMAO), and betaine, were identified and then shown to predict risk for CVD in an independent large clinical cohort. Dietary supplementation of mice with choline, TMAO or betaine promoted up-regulation of multiple macrophage scavenger receptors linked to atherosclerosis, and supplementation with choline or TMAO promoted atherosclerosis. Studies using germ-free mice confirmed a critical role for dietary choline and gut flora in TMAO production, augmented macrophage cholesterol accumulation and foam cell formation. Suppression of intestinal microflora in atherosclerosis-prone mice inhibited dietary choline-enhanced atherosclerosis. Genetic variations controlling expression of flavin monooxygenases (FMOs), an enzymatic source of TMAO, segregated with atherosclerosis in hyperlipidemic mice. Discovery of a relationship between gut flora-dependent metabolism of dietary phosphatidylcholine and CVD pathogenesis provides opportunities for development of both novel diagnostic tests and therapeutic approaches for atherosclerotic heart disease.
BACKGROUND Recent studies in animals have shown a mechanistic link between intestinal microbial metabolism of the choline moiety in dietary phosphatidylcholine (lecithin) and coronary artery disease through the production of a proatherosclerotic metabolite, trimethylamine-N-oxide (TMAO). We investigated the relationship among intestinal microbiota-dependent metabolism of dietary phosphatidylcholine, TMAO levels, and adverse cardiovascular events in humans. METHODS We quantified plasma and urinary levels of TMAO and plasma choline and betaine levels by means of liquid chromatography and online tandem mass spectrometry after a phosphatidylcholine challenge (ingestion of two hard-boiled eggs and deuterium [d9]-labeled phosphatidylcholine) in healthy participants before and after the suppression of intestinal microbiota with oral broad-spectrum antibiotics. We further examined the relationship between fasting plasma levels of TMAO and incident major adverse cardiovascular events (death, myocardial infarction, or stroke) during 3 years of follow-up in 4007 patients undergoing elective coronary angiography. RESULTS Time-dependent increases in levels of both TMAO and its d9 isotopologue, as well as other choline metabolites, were detected after the phosphatidylcholine challenge. Plasma levels of TMAO were markedly suppressed after the administration of antibiotics and then reappeared after withdrawal of antibiotics. Increased plasma levels of TMAO were associated with an increased risk of a major adverse cardiovascular event (hazard ratio for highest vs. lowest TMAO quartile, 2.54; 95% confidence interval, 1.96 to 3.28; P<0.001). An elevated TMAO level predicted an increased risk of major adverse cardiovascular events after adjustment for traditional risk factors (P<0.001), as well as in lower-risk subgroups. CONCLUSIONS The production of TMAO from dietary phosphatidylcholine is dependent on metabolism by the intestinal microbiota. Increased TMAO levels are associated with an increased risk of incident major adverse cardiovascular events. (Funded by the National Institutes of Health and others.)
The first four reviews in this series (Steinberg, D. 2004. J. Lipid Res. 45: 1583-1593; Steinberg, D. 2005. J. Lipid Res. 46: 179-190; Steinberg, D. 2005. J. Lipid Res. 46: 2037-2051; Steinberg, D. 2006. J. Lipid Res. 47: 1-14) traced the gradual accumulation of evidence, evidence of several different kinds, supporting the lipid hypothesis. They tracked the history from Anitschkow's 1913 classic work on the cholesterol-fed rabbit model to the breakthrough 1984 Coronary Primary Prevention Trial, the first large, randomized, double-blind primary intervention trial showing that decreasing blood cholesterol (using cholestyramine) significantly reduces coronary heart disease events. At that point, for the first time, decreasing blood cholesterol levels became an official national public health goal. Still, only a small fraction of patients at high risk were getting appropriate cholesterol-lowering treatment, and a number of important clinical questions remained unanswered. This final review in the series traces the early studies that led to the discovery of the statins and briefly reviews the now familiar large-scale clinical trials demonstrating their safety and their remarkable effectiveness in reducing coronary heart disease morbidity and mortality.
Several nutrition and non-nutritional pathways are recognised in the development and occurrence of cardiovascular disease. In many populations, high intakes of saturated fat are associated with elevated serum cholesterol concentrations and increased coronary heart disease (CHD) mortality. However, several studies report that hyperlipidaemia and heart diseases are not common among populations who consume coconut, a source of saturated fat. A case-control study was conducted among the Minangkabau known to be high coconut consumers to examine the difference in food patterns and risk of coronary heart disease (CHD) between the coronary cases and their gender- and age-matched apparently healthy counterparts serving as controls. Eligible subjects with CHD were identified through the co-operation of five participating hospitals located in Padang and Bukittinggi in West Sumatra, Indonesia. A total of 93 eligible cases (62 men and 31 women) in the Case group and 189 subjects (113 men and 76 women) in the Control group were recruited. Information on the intakes of individual foods and dishes over the preceding 12 months was obtained using a semi-quantitative food frequency questionnaire. The Case groups had significantly higher intakes of meats, eggs, sugar, tea, coffee and fruits, but lower intakes of soy products, rice and cereals compared to the controls. Coconut consumption as flesh or milk was not different between cases and controls. The cases had significantly higher intakes of protein and cholesterol, but lower intake of carbohydrate. Similar intakes of saturated and unsaturated fatty acids between the cases and controls indicated that the consumption of total fat or saturated fat, including that from coconut, was not a predictor for CHD in this food culture. However, the intakes of animal foods, total protein, dietary cholesterol and less plant derived carbohydrates were predictors of CHD.
Olive oil is well known for its cardioprotective properties; however, epidemiological data showing that olive oil consumption reduces incident CHD events are still limited. Therefore, we studied the association between olive oil and CHD in the European Prospective Investigation into Cancer and Nutrition (EPIC) Spanish cohort study. The analysis included 40 142 participants (38 % male), free of CHD events at baseline, recruited from five EPIC-Spain centres from 1992 to 1996 and followed up until 2004. Baseline dietary and lifestyle information was collected using interview-administered questionnaires. Cox proportional regression models were used to assess the relationship between validated incident CHD events and olive oil intake (energy-adjusted quartiles and each 10 g/d per 8368 kJ (2000 kcal) increment), while adjusting for potential confounders. During a 10·4-year follow-up, 587 (79 % male) CHD events were recorded. Olive oil intake was negatively associated with CHD risk after excluding dietary mis-reporters (hazard ratio (HR) 0·93; 95 % CI 0·87, 1·00 for each 10 g/d per 8368 kJ (2000 kcal) and HR 0·78; 95 % CI 0·59, 1·03 for upper v. lower quartile). The inverse association between olive oil intake (per 10 g/d per 8368 kJ (2000 kcal)) and CHD was more pronounced in never smokers (11 % reduced CHD risk (P = 0·048)), in never/low alcohol drinkers (25 % reduced CHD risk (P < 0·001)) and in virgin olive oil consumers (14 % reduced CHD risk (P = 0·072)). In conclusion, olive oil consumption was related to a reduced risk of incident CHD events. This emphasises the need to conserve the traditional culinary use of olive oil within the Mediterranean diet to reduce the CHD burden.
Meat protein is associated with an increase in risk of heart disease. Recent data have shown that meat protein appeared to be associated with weight gain over 6.5 years, with 1 kg of weight increase per 125 g of meat per day. In the Nurses' Health Study, diets low in red meat, containing nuts, low-fat dairy, poultry, or fish, were associated with a 13% to 30% lower risk of CHD compared with diets high in meat. Low-carbohydrate diets high in animal protein were associated with a 23% higher total mortality rate whereas low-carbohydrate diets high in vegetable protein were associated with a 20% lower total mortality rate. Recent soy interventions have been assessed by the American Heart Association and found to be associated with only small reductions in LDL cholesterol. Although dairy intake has been associated with a lower weight and lower insulin resistance and metabolic syndrome, the only long-term (6 months) dairy intervention performed so far has shown no effects on these parameters.
OBJECTIVE: To describe changes in negative emotions among participants of a cholesterol-lowering study. DESIGN: Cohort study. Quantitative evaluation of changes in negative emotions in relation to diet and plasma cholesterol levels before and after a 5-year dietary intervention program aimed at reducing plasma cholesterol levels. SETTING: Community-dwelling families of the Family Heart Study, Portland, Oregon. PARTICIPANTS: One hundred forty-nine men and 156 women from 233 families (mean age, 37.7 years). MEASUREMENTS: Changes in negative emotions including depression and aggressive hostility as measured by the Hopkins Symptom Checklist (SCL-90). RESULTS: Improvement in overall emotional state was noted for the entire sample. Those who consumed a low-fat, high complex-carbohydrate diet at the end of the study showed significantly greater improvements in depression (P = 0.044; difference in improvement, 2.9 points) and aggressive hostility (P = 0.035; difference in improvement, 3.3 points) as well as a reduction in their plasma cholesterol levels (P = 0.024; difference in improvement, 2.7%) compared with those who ate a high-fat "American diet." CONCLUSIONS: Participation in a cholesterol-lowering program may not be associated with a worsening in emotional state. To the contrary, improvements in diet appear to be associated with reductions in depression and aggressive hostility as well as with lowered plasma cholesterol levels.
The hypothesis that plasma chylomicrons in persons who ingest a cholesterol-rich diet are atherogenic is evaluated. Evidence is presented that in humans, and experimental animals, chylomicron remnants as well as low-density lipoproteins are taken up by arterial cells. In persons who do not have familial hyperlipoproteinemia, atherogenesis may occur during the postprandial period. Research directions that may contribute to the evaluation of chylomicron remnants as a risk factor for atherogenesis are discussed. Lipoprotein studies after administration of a test meal containing fat and cholesterol are urgently needed.
We assessed the relation of risk factors for cardiovascular disease to early atherosclerotic lesions in the aorta and coronary arteries in 35 persons (mean age at death, 18 years). Aortic involvement with fatty streaks was greater in blacks than in whites (37 vs. 17 percent, P less than 0.01). However, aortic fatty streaks were strongly related to antemortem levels of both total and low-density lipoprotein cholesterol (r = 0.67, P less than 0.0001 for each association), independently of race, sex, and age, and were inversely correlated with the ratio of high-density lipoprotein cholesterol to low-density plus very-low-density lipoprotein cholesterol (r = -0.35, P = 0.06). Coronary-artery fatty streaks were correlated with very-low-density lipoprotein cholesterol (r = 0.41, P = 0.04). Mean systolic blood-pressure levels also tended to be higher in the four subjects with coronary-artery fibrous plaques than in those without them: 112 mm Hg as compared with 104 (P = 0.09). These results document the importance of risk-factor levels to early anatomical changes in the aorta and coronary arteries. The progression of fatty streaks to fibrous plaques is uncertain, but these data suggest that a rational approach to the prevention of cardiovascular disease should begin early in life.
Background and Aims Studies evaluating the effect of legume consumption on cholesterol have focused on soybeans, however non-soy legumes, such as a variety of beans, peas, and some seeds, are commonly consumed in Western countries. We conducted a meta-analysis of randomized controlled trials evaluating the effects of non-soy legume consumption on blood lipids. Methods and Results Studies were retrieved by searching MEDLINE (from January 1966 through July 2009), EMBASE (from January 1980 to July 2009), and the Cochrane Collaboration's Central Register of Controlled Clinical Trials using the following terms as medical subject headings and keywords: fabaceae not soybeans not isoflavones and diet or dietary fiber and cholesterol or hypercholesterolemia or triglycerides or cardiovascular diseases. Bibliographies of all retrieved articles were also searched. From 140 relevant reports, 10 randomized clinical trials were selected which compared a non-soy legume diet to control, had a minimum duration of 3 weeks, and reported blood lipid changes during intervention and control. Data on sample size, participant characteristics, study design, intervention methods, duration, and treatment results were independently abstracted by 2 investigators using a standardized protocol. Data from 10 trials representing 268 participants were examined using a random-effects model. Pooled mean net change in total cholesterol for those treated with a legume diet compared to control was −11.8 mg/dL (95% confidence interval [CI], −16.1 to −7.5); mean net change in low density lipoprotein cholesterol was −8.0 mg/dL (95% CI, −11.4 to −4.6). Conclusion These results indicate that a diet rich in legumes other than soy decreases total and LDL cholesterol.
The good news about coronary atherosclerosis is that it takes an awful lot of plaque before symptoms of myocardial ischemia occur. The bad news is that despite the need for large quantities of plaque for symptoms to occur, nevertheless nearly half of us in the United States eventually have the necessary quantity. Atherosclerosis is infrequently hereditary in origin. Most of us get atherosclerosis because we consume too much fat, cholesterol, and calories. The consequence is an elevated ( > 150 mg/dl) serum total cholesterol level, and the higher the number is above 150, the greater is the quantity of plaque deposited in our arteries. If the serum total cholesterol level can be prevented from rising to more than 150 mg/dl, plaques are not laid down; if elevated levels are lowered to 150 mg/dl, further plaque does not form, and parts of those present may vanish. A fruit-vegetarian-starch diet is necessary as a rule to achieve the 150 mg/dl level in most adults. Lipid-lowering drugs are required in the patients with familial hypercholesterolemia and in most patients with atherosclerotic events. The best news about atherosclerosis is that it can be prevented in those without the hereditary form, and it can be arrested by lowering elevated serum total (and LDL) cholesterol to the 150 mg/dl level.
The inverse association of nut consumption and risk markers of coronary heart disease (lipids) has sparked the interest of the scientific and lay community. The objective of this study was to conduct a systematic review to investigate the effects of nuts on the lipid profile. Medline and Web of Science databases were searched from the start of the database to August 2004 and supplemented by cross-checking reference lists of relevant publications. Human intervention trials with the objective of investigating independent effects of nuts on lipid concentrations were included. From the literature search, 415 publications were screened and 23 studies were included. These papers received a rating based upon the methodology as it appeared in the publication. No formal statistical analysis was performed due to the large differences in study designs of the dietary intervention trials. The results of 3 almond (50-100 g/d), 2 peanut (35-68 g/d), 1 pecan nut (72 g/d), and 4 walnut (40-84 g/d) studies showed decreases in total cholesterol between 2 and 16% and LDL cholesterol between 2 and 19% compared with subjects consuming control diets. Consumption of macadamia nuts (50-100 g/d) produced less convincing results. In conclusion, consumption of approximately 50-100 g (approximately 1.5-3.5 servings) of nuts > or = 5 times/wk as part of a heart-healthy diet with total fat content (high in mono- and/or polyunsaturated fatty acids) of approximately 35% of energy may significantly decrease total cholesterol and LDL cholesterol in normo- and hyperlipidemic individuals.
OBJECTIVE: To determine effects of daily intake of 1/2 cup pinto beans, black-eyed peas or carrots (placebo) on risk factors for coronary heart disease (CHD) and diabetes mellitus (DM) in free-living, mildly insulin resistant adults over an 8 week period. METHODS: Randomized, crossover 3x3 block design. Sixteen participants (7 men, 9 women) received each treatment for eight-weeks with two-week washouts. Fasting blood samples collected at beginning and end of periods were analyzed for total cholesterol (TC), low density lipoprotein cholesterol (LDL-C), high density lipoprotein cholesterol, triacylglycerols, high-sensitivity C-reactive protein, insulin, glucose, and hemoglobin A1c. RESULTS: A significant treatment-by-time effect impacted serum TC (p = 0.026) and LDL (p = 0.033) after eight weeks. Paired t-tests indicated that pinto beans were responsible for this effect (p = 0.003; p = 0.008). Mean change of serum TC for pinto bean, black-eyed pea and placebo were -19 +/- 5, 2.5 +/- 6, and 1 +/- 5 mg/dL, respectively (p = 0.011). Mean change of serum LDL-C for pinto bean, black-eyed pea and placebo were -14 +/- 4, 4 +/- 5, and 1 +/- 4 mg/dL, in that order (p = 0.013). Pinto beans differed significantly from placebo (p = 0.021). No significant differences were seen with other blood concentrations across the 3 treatment periods. CONCLUSIONS: Pinto bean intake should be encouraged to lower serum TC and LDL-C, thereby reducing risk for CHD.
PURPOSE OF REVIEW: The perceived notion that dietary cholesterol is associated with increased risk for coronary heart disease (CHD) has led to dietary recommendations of no more than 300  mg/day for healthy populations in the USA. This study will review the recent evidence that challenges the current dietary restrictions regarding cholesterol while it presents some beneficial effects of eggs (an icon for dietary cholesterol) in healthy individuals. RECENT FINDINGS: The European countries, Australia, Canada, New Zealand, Korea and India among others do not have an upper limit for cholesterol intake in their dietary guidelines. Further, existing epidemiological data have clearly demonstrated that dietary cholesterol is not correlated with increased risk for CHD. Although numerous clinical studies have shown that dietary cholesterol challenges may increase plasma LDL cholesterol in certain individuals, who are more sensitive to dietary cholesterol (about one-quarter of the population), HDL cholesterol also rises resulting in the maintenance of the LDL/HDL cholesterol ratio, a key marker of CHD risk. SUMMARY: The lines of evidence coming from current epidemiological studies and from clinical interventions utilizing different types of cholesterol challenges support the notion that the recommendations limiting dietary cholesterol should be reconsidered.
BACKGROUND: Because of egg cholesterol content, reduction in egg consumption is generally recommended to reduce risk of cardiovascular disease. Recently, however, evidence has been accumulating to suggest that dietary cholesterol is less relevant to cardiovascular risk than dietary saturated fat. This randomized controlled crossover trial was conducted to determine the effects of egg ingestion on endothelial function, a reliable index of cardiovascular risk. METHODS: Forty-nine healthy adults (mean age 56 years, 40% females) underwent a baseline brachial artery reactivity study (BARS), and were assigned to two eggs or oats daily for 6 weeks in random sequence with a 4-week washout. A BARS was done at the end of each treatment phase, measuring flow-mediated vasodilation (FMD) in the brachial artery using a high-frequency ultrasound. RESULTS: FMD was stable in both egg and oat groups, and between-treatment differences were not significant (egg -0.96%, oatmeal -0.79%; p value >0.05). Six weeks of egg ingestion had no effect on total cholesterol (baseline: 203.8 mg/dl; post-treatment: 205.3) or LDL (baseline: 124.8 mg/dl; post-treatment: 129.1). In contrast, 6 weeks of oats lowered total cholesterol (to 194 mg/dl; p = 0.0017) and LDL (to 116.6 mg/dl; p = 0.012). There were no differences in body mass index (BMI), triglyceride, HDL or SBP levels between egg and oat treatment assignments. CONCLUSION: Short-term egg consumption does not adversely affect endothelial function in healthy adults, supporting the view that dietary cholesterol may be less detrimental to cardiovascular health than previously thought.
Although there is a well-established relation between serum cholesterol and coronary artery disease risk, individual and national variations in this association suggest that other factors are involved in atherogenesis. High-fat diet associated triglyceride-rich lipoproteins have also been suggested to be atherogenic. To assess the direct effect of postprandial triglyceride-rich lipoproteins on endothelial function, an early factor in atherogenesis--10 healthy, normocholesterolemic volunteers--were studied before and for 6 hours after single isocaloric high- and low-fat meals (900 calorie; 50 and 0 g fat, respectively). Endothelial function, in the form of flow-mediated vasoactivity, was assessed in the brachial artery using 7.5-MHz ultrasound as percent arterial diameter change 1 minute after 5 minutes of upper-arm arterial occlusion. Serum lipoproteins and glucose were determined before eating and 2 and 4 hours postprandially. Serum triglycerides increased from 94 +/- 55 mg/dl preprandially to 147 +/- 80 mg/dl 2 hours after the high-fat meal (p = 0.05). Flow-dependent vasoactivity decreased from 21 +/- 5% preprandially to 11 +/- 4%, 11 +/- 6%, and 10 +/- 3% at 2, 3, and 4 hours after the high-fat meal, respectively (all p <0.05 compared with low-fat meal data). No changes in lipoproteins or flow-mediated vasoactivity were observed after the low-fat meal. Fasting low-density lipoprotein cholesterol correlated inversely (r = -0.47, p = 0.04) with preprandial flow-mediated vasoactivity, but triglyceride level did not. Mean change in postprandial flow-mediated vasoactivity at 2, 3, and 4 hours correlated with change in 2-hour serum triglycerides (r = -0.51, p = 0.02). These results demonstrate that a single high-fat meal transiently impairs endothelial function. These findings identify a potential process by which a high-fat diet may be atherogenic independent of induced changes in cholesterol.
Vegetarians have an apparent diminished risk for the development of ischemic coronary heart disease. This may be secondary to dietary effects of plasma lipids and lipoproteins, but platelets, which may also play a role, have also been observed to have aberrant functions in vegetarians. We measured plasma lipid and lipoprotein levels, platelet function, platelet fatty acid levels, and platelet active prostaglandins in ten strict vegetarians (vegans), 15 lactovegetarians, and 25 age- and sex-matched omnivorous controls. The most striking observations were a highly significant rise in platelet linoleic acid concentration and a decline in platelet arachidonic acid concentration in both vegetarian subgroups as compared with omnivorous controls. Serum thromboxane and prostacyclin levels as well as results of platelet aggregation studies did not differ among the groups tested. Cholesterol levels were significantly lower in both vegetarian groups as compared with controls, but plasma high- and low-density lipoprotein levels were lower only in the vegan subgroup as compared with omnivores. If diet produces these changes in platelet fatty acid and plasma lipid levels it may contribute to the decreased risk of coronary heart disease and possibly atherosclerosis in vegetarians.
Background Reduction in dietary cholesterol is recommended to prevent cardiovascular disease (CVD). Although eggs are important sources of cholesterol and other nutrients, limited and inconsistent data are available on the effects of egg consumption on the risk of CVD and mortality. Objectives To examine the association between egg consumption and the risk of CVD and mortality. Design Prospective cohort study of 21,327 participants from the Physicians' Health Study I. Egg consumption was assessed using a simple abbreviated food questionnaire. We used Cox regression to estimate relative risks. Results After an average follow up of 20 years, a total of 1,550 new myocardial infarction (MI), 1,342 incident strokes, and 5,169 deaths occurred in this cohort. Egg consumption was not associated with incident MI or stroke in a multivariable Cox regression. In contrast, adjusted hazard ratios (95% CI) for mortality were 1.0 (reference), 0.94 (0.87-1.02), 1.03 (0.95-1.11), 1.05 (0.93-1.19), and 1.23 (1.11-1.36) for egg consumption of <1, 1, 2-4, 5-6, and 7+ per week, respectively, (p for trend <0.0001). This association was stronger among diabetic subjects with a 2-fold increased risk of death comparing the highest to the lowest category of egg consumption than non-diabetic subjects (HR: 1.22 (1.09-1.35) (p for interaction 0.09). Conclusions Our data suggest that infrequent egg consumption does not influence the risk of CVD and only confers a modest increased risk for total mortality in male physicians. In addition, egg consumption was positively related to mortality and such relation was stronger among diabetic subjects in this selective population.
Prospective epidemiological studies have reported that a higher fruit and vegetable intake is associated with a lower risk of CHD. The aim of the present study was to examine associations between fruit and vegetable consumption, in particular the subgroupings citrus fruits, apples and cruciferous vegetables, and the risk of acute coronary syndrome (ACS). During a median follow-up of 7.7 years, 1075 incident ACS cases were identified among 53 383 men and women, aged 50-64 years at recruitment into the Diet, Cancer and Health cohort study in 1993-7. Fruit and vegetable intake was estimated from a validated FFQ, and ACS incidence rate ratios (IRR) were estimated using Cox proportional hazards models. Overall, a tendency towards a lower risk of ACS was observed for both men and women with higher fruit and vegetable consumption. For men, we found an inverse association for apple intake (IRR per 25 g/d: 0.97; 95 % CI 0.94, 0.99). This association was also seen among women, albeit borderline significant. However, a higher risk was seen among women with higher fruit juice intake (IRR per 25 g/d: 1.04; 95 % CI 1.00, 1.08). The present results provide some support for previously observed inverse associations between fresh fruit intake, particularly apples, and ACS risk.
Background: A Step I diet with lean beef compared with lean white meat both decrease LDL cholesterol. To our knowledge, no studies have evaluated a low–saturated fatty acid (SFA) (<7% calories) diet that contains lean beef. Objective: We studied the effect on LDL cholesterol of cholesterol-lowering diets with varying amounts of lean beef [ie, Dietary Approaches to Stop Hypertension (DASH): 28 g beef/d; Beef in an Optimal Lean Diet (BOLD): 113 g beef/d; and Beef in an Optimal Lean Diet plus additional protein (BOLD+): 153 g beef/d] compared with that of a healthy American diet (HAD). Design: Thirty-six hypercholesterolemic participants (with LDL-cholesterol concentrations >2.8 mmol/L) were randomly assigned to consume each of the 4 diets (HAD: 33% total fat, 12% SFA, 17% protein, and 20 g beef/d), DASH (27% total fat, 6% SFA, 18% protein, and 28 g beef/d), BOLD (28% total fat, 6% SFA, 19% protein, and 113 g beef/d), and BOLD+ (28% total fat, 6% SFA, 27% protein, and 153 g beef/d) for 5 wk. Results: There was a decrease in total cholesterol (TC) and LDL-cholesterol concentrations (P < 0.05) after consumption of the DASH (−0.49 ± 0.11 and −0.37 ± 0.09 mmol/L, respectively), BOLD (−0.48 ± 0.10 and −0.35 ± 0.9 mmol/L, respectively), and BOLD+ (−0.50 ± 0.10 and −0.345 ± 0.09 mmol/L, respectively) diets compared with after consumption of the HAD (−0.22 ± 0.10 and −0.14 ± 0.10 mmol/L, respectively). Apolipoprotein A-I, C-III, and C-III bound to apolipoprotein A1 particles decreased after BOLD and BOLD+ diets compared with after the HAD, and there was a greater decrease in apolipoprotein B after consumption of the BOLD+ diet than after consumption of the HAD (P < 0.05 for both). LDL cholesterol and TC decreased after consumption of the DASH, BOLD, and BOLD+ diets when the baseline C-reactive protein (CRP) concentration was <1 mg/L; LDL cholesterol and TC decreased when baseline CRP concentration was >1 mg/L with the BOLD and BOLD+ diets. Conclusions: Low-SFA, heart-healthy dietary patterns that contain lean beef elicit favorable effects on cardiovascular disease (CVD) lipid and lipoprotein risk factors that are comparable to those elicited by a DASH dietary pattern. These results, in conjunction with the beneficial effects on apolipoprotein CVD risk factors after consumption of the BOLD and BOLD+ diets, which were greater with the BOLD+ diet, provide support for including lean beef in a heart-healthy dietary pattern. This trial was registered at clinicaltrials.gov as NCT00937898.