A prospective randomised trial to determine the efficacy of a low glycaemic index diet given in addition to healthy eating and weight loss advice in patients with coronary heart disease

OBJECTIVE: Recent epidemiological and prospective trial evidence suggests that consumption of a low glycaemic index (LGI) diet will reduce coronary risk. We hypothesise that introduction of an LGI diet will improve the metabolic profile of patients who have undergone coronary artery bypass grafting. DESIGN: We conducted a randomised parallel group trial comparing a control group (n=29, age 61.8+/-9 y), who received currently advocated healthy eating dietary advice only, to an intervention group, who received healthy eating advice emphasising LGI carbohydrates (n=26, age 63.6+/-9.4 y) over a 12-week period in free-living patients with coronary heart disease. Outcome measures included fasting glucose, insulin, total cholesterol, high-density lipoprotein cholesterol, very low-density lipoprotein cholesterol, low density lipoprotein cholesterol and triglycerides. RESULTS: A significant lower dietary glycaemic index was achieved in the group assigned to an LGI diet compared to the healthy eating control group (71+/-1 vs 81+/-1); fibre intake was also higher in the LGI group (20+/-1 vs 15+/-1 g). All biochemical markers of glucose and lipid metabolism measured were similar after 12 weeks of the LGI diet or control diet. DISCUSSION: The LGI group achieved a significant LGI and a higher dietary fibre intake. However, there was no measurable significant effect of either the LGI diet or the health eating diet on lipid levels; this may have been hidden by concurrent drug therapy.     

A simple method of assessing the effect of dietary advice to reduce plasma cholesterol

A simple eight-item questionnaire was used to assess the saturated fat content of the diet of participants in a multifactorial trial of the prevention of coronary heart disease. The questionnaire was found to have good repeatability, and a score derived from it correlated significantly with a more lengthy dietary recall method (the 3-day diary) in assessing the amount of saturated fat in the diet: high scores reflected a low saturated fat intake. The score was higher among those advised to reduce their saturated fat intake (suggesting that they had taken the advice) than among those who had been given no advice. Men given personal counseling had higher scores than those who were only sent letters and leaflets containing essentially the same information by post. Among unadvised control men there was no correlation between the score and the plasma cholesterol level; but among the men given advice, the higher their score the greater was the fall in their plasma cholesterol. This highlights the paradox that an individual's current saturated fat intake cannot predict his plasma cholesterol level, yet a change in this level is readily predicted by even a crude assessment of change in dietary fat.     

Unscrambling the research: Eggs, serum cholesterol and coronary heart disease

The role of dietary cholesterol in raising plasma cholesterol levels has been debated over the past 25 years. Consequently, eggs, as a food high in dietary cholesterol, have been targeted as a food to limit when advising patients on a diet to lower serum cholesterol levels. The aim of the present review was to evaluate the literature to address the effects of dietary cholesterol from eggs on serum cholesterol levels and risk of coronary heart disease. An increase in dietary cholesterol from eggs by 100 mg daily, equivalent to half a medium egg or three to four eggs a week, results in an increase of approximately 0.05 mmol/L in LDL cholesterol. Adding 100 mg of cholesterol per day (equivalent to three to four eggs a week) to a high saturated fat diet caused an increase in LDL cholesterol of 0.061 ± 0.006 mmol/L, whereas adding the same quantity of cholesterol to a low saturated fat diet caused an increase in LDL cholesterol of only 0.036 ± 0.004 mmol/L (P = 0.03). Despite the small increase in LDL‐cholesterol levels with increasing egg intake, most epidemiological studies have shown little or no association between egg intake and risk of coronary heart disease. However, the impact of dietary cholesterol for people with type 2 diabetes has been poorly studied. In conclusion, in a healthy Western population, there is insufficient evidence to excessively restrict egg intake as part of a healthy diet. Eggs should be considered in a similar way as other protein‐rich foods and selected as part of a varied diet that is low in saturated fat and contains a variety of cardio‐protective foods such as fish, wholegrains, fruits, vegetables, legumes and nuts.     

‘We work in silos’: Exploring clinicians' perspectives on the dietary management of coronary heart disease and type 2 diabetes in an Australian public hospital and community health service

Aims

This study explored clinicians' perspectives on roles, practices and service delivery in the dietary management of coronary heart disease and type 2 diabetes in a public health service.

Methods

Semi-structured individual interviews were conducted with 57 clinicians (21 nurses, 19 doctors, 13 dietitians and 4 physiotherapists) involved in the care of relevant patients across hospital and post-acute community settings in a metropolitan health service in Australia. Interviews were audio-recorded, transcribed verbatim and analysed using inductive thematic analysis.

Results

A total of 3 themes with 10 subthemes were identified. (a) ‘Treatment prioritisation’: important role of nutrition in risk factor management; competing priorities with complex patients; weight loss as a priority; and dietitians individualise. (b) ‘Diverse roles in providing diet advice’: a tension between nutrients, restrictions and diet quality; patients seek and trust advice from non-dietitians; and providing nutrition information materials crosses professions. (c) ‘Dietitian access’: variable integration and resourcing; access governed by clinician discretion and perceived patient interest; and bespoke application of referral pathways.

Conclusions

Time and resource constraints, variable access and referral to dietitians, and inconsistent advice were key challenges in the dietary management of coronary heart disease and type 2 diabetes. Models of care may be improved with greater investment and integration of dietitians, including to provide professional support across disciplines and disease specialties.     

Dietetic guidelines: diet in secondary prevention of cardiovascular disease (first update, June 2003)

AIM: To update dietetic guidelines summarizing the systematic review evidence on dietary advice to prevent further events in people with existing cardiovascular disease (CVD) (secondary prevention). METHODS: The Cochrane Library, MEDLINE and EMBASE were comprehensively searched to November 2002 for systematic reviews on aspects of diet and heart health. Reviews were included if they searched systematically for randomised controlled trials relating to diet and secondary prevention of CVD. Two members of the UK Heart Health and Thoracic Dietitians Group critically appraised each review. The quality and results of each review were discussed and summarized in a meeting of the whole group. RESULTS: Providing evidence-based dietary information (including increasing omega-3 fat intake) to all people who have had a myocardial infarction will save more lives than concentrating dietary advice on just those in need of weight loss or lipid lowering. The practice of prioritizing dietetic time in secondary prevention to those with raised lipids is out of date since the advent of statin therapy. However, effective dietary advice for those with angina, stroke, peripheral vascular disease or heart failure is less clear. CONCLUSION: There is good systematic review evidence that dietary advice to those with coronary heart disease can reduce mortality and morbidity as well as modify some risk factors. Dietary advice that does this most effectively should be prioritized.     

Eggs and dietary cholesterol – dispelling the myth

Dietary cholesterol in foods such as eggs has only a small and clinically insignificant effect on blood cholesterol, especially when compared with the much greater effects of dietary saturated fatty acids on blood cholesterol. These facts are now well established and, as a consequence, recommendations from major food and health bodies concerning dietary cholesterol have been relaxed in the UK and elsewhere in recent years. However, in the minds of the public, cholesterol in the diet, specifically from eggs, continues to be viewed with suspicion and that view is still reflected in the advice of some professionals.     

Subject Index to Volume 6

The nutrient composition of dry beans makes them ideally suited to meet two major dietary recommendations for good health–increased intake of starches and complex carbohydrates and decreased consumption of fat. Dry beans supply protein, complex carbohydrate, fiber and essential vitamins and minerals to the diet, yet are low in fat and sodium and contain no cholesterol. Both protective and therapeutic effects of bean intake have been documented. The antinutritional effects of dry beans, while minor, are of interest to nutrition professionals. Dry beans are an excellent way to increase dietary fiber consumption and most individuals can incorporate beans into their diet without difficulty if they do so gradually. Including dry beans in a health-promoting diet is especially important in meeting the major dietary recommendations to reduce risk for chronic diseases such as coronary heart disease, diabetes mellitus, obesity and cancer.     

Difficulties in changing the diet in relation to dietary fat intake among patients with coronary heart disease

OBJECTIVE: To study barriers in following nutritional advice among coronary heart disease patients in relation to dietary fat intake. DESIGN: A cross-sectional study using 4-day food records and a questionnaire with regard to barriers to or difficulties in following dietary advice. SUBJECTS: Altogether, 362 male subjects with coronary heart disease from two separate patient populations (91 + 271) were included in the study, with the mean age of 50 years and 60 years, respectively. The patients were classified into low (< or = 30 E%) or high (> 30 E%) fat intake groups. The patients with low dietary fat intake obtained on an average 10 E% less energy from fat as compared to the high dietary fat intake group. RESULTS: Overall, most patients with coronary heart disease reported difficulties in following nutritional advice when eating in social situations. Patients with high dietary fat intake reported more frequently than patients with low fat intake that they eat like other people without thinking about what they eat. On the other hand, there were no differences between the high and low fat intake groups in the barriers: eating at work, food price, shopping, taste or knowledge of nutrition. CONCLUSIONS: Our results suggest that the sensitivity to social influence is an important factor explaining noncompliance with dietary advice among patients with high dietary fat intake.     

Oily fish and fish oil supplements in the prevention of coronary heart disease

Dietary advice for the reduction of coronary heart disease events emphasizes the importance of a low-fat diet and advice on the consumption of oily fish may also be given. This report reviews the evidence linking fish consumption with coronary risk. On the basis of available evidence, a target of two to three portions of oily fish per week (200–400 g, 7–14 oz) is considered reasonable, particularly for secondary prevention. For those who cannot achieve the suggested dietary intake of oily fish, the partial or complete substitution of fish oil supplements may be appropriate. A range of suitable types of fish oil supplements is given, but an awareness of the potential adverse effects of fish oil supplementation is considered important. Further studies are needed to define the role of fish intake in coronary heart disease.     

Improvements in circulating cholesterol, antioxidants, and homocysteine after dietary intervention in an Australian Aboriginal community

BACKGROUND: Poor nutrition contributes to high rates of coronary heart disease among Australian Aboriginal populations. Since late 1993, the Aboriginal community described here has operated a healthy lifestyle program aimed at reducing the risk of chronic disease. OBJECTIVE: We evaluated the effectiveness of a community-directed intervention program to reduce coronary heart disease risk through dietary modification. DESIGN: Intervention processes included store management policy changes, health promotion activities, and nutrition education aimed at high-risk individuals. Dietary advice was focused on decreasing saturated fat and sugar intake and increasing fruit and vegetable intake. Evaluation of the program included conducting sequential, cross-sectional risk factor surveys at 2-y intervals; measuring fasting cholesterol, lipid-soluble antioxidants, and homocysteine concentrations; and assessing smoking status. Nutrient intakes were estimated from analysis of food turnover in the single community store. RESULTS: There was a significant reduction in the prevalence of hypercholesterolemia (age-adjusted prevalences were 31%, 21%, and 15% at baseline, 2 y, and 4 y, respectively; P < 0.001). There were significant increases in plasma concentrations of alpha-tocopherol, lutein and zeaxanthin, cryptoxanthin, and beta-carotene across the population. Retinol and lycopene concentrations did not change significantly. Mean plasma homocysteine concentrations decreased by 3 micromol/L. There was no significant change in smoking prevalence between the 2 follow-up surveys. There was an increase in the density of fresh fruit and vegetables and carotenoids in the food supply at the community store. CONCLUSION: This community-directed dietary intervention program reduced the prevalence of coronary heart disease risk factors related to diet.     

脂肪饮食与相关疾病关系的调查分析

通过对荤食组与素食组(和尚)临床对比分析,发现两组在相关疾病如胆石症、冠心病、高脂血症、高血压、肥胖症、癌症、糖尿病的发病率有非常显著性差异(P<0.005,P<0.001).两组的血脂水平亦有着显著性差别(P<0.005)、P<0.001).结果表明不同饮食结构的人群的相关疾病的发病率有着显著的不同.证明早期限制脂肪饮食的摄入是预防相关疾病的最重要措施.     

What are the health effects of fat?

In order to answer the question which health benefits are to be expected from dietary fat, we have to differentiate between different kinds of fat with varying fatty acid composition. Saturated fatty acids are commonly judged to have a negative health impact as they lead to increased serum cholesterol levels and a higher risk of coronary heart disease. Therefore, all recommendations stress the importance to limit the intake of saturated fatty acids. Monounsaturated fatty acids, on the other hand, have a positive impact on the serum lipid profile, lead to decreased LDL-oxidation and favorably influence the metabolism of diabetics. However, it is essential that monounsaturated fatty acids be mainly supplied by plant oils like rape seed or olive oil and not by foods that are simultaneously rich in saturated fatty acids. Concerning polyunsaturated fatty acids, it is important to increase the supply of n-3 fatty acids (ratio of n-6:n-3: about 5:1) as there is substantial evidence for their protective effects. If the fatty acid composition of the diet is optimized, even a total dietary fat content of 35% of total energy intake can be adequate as long as there is enough physical activity and the diet is rich in plant-derived foods like vegetables, fruits, cereals, potatoes, beans and legumes.     

Effect of media coverage and physician advice on utilization of breast cancer screening by women 40 years and older

The purpose of this study is to examine the relative importance of media coverage and physician advice on the decision of women 40 years and older to obtain a mammogram. Five theoretical models, by which media coverage and physician advice may interact to affect individual health behavior, are presented. These models are tested with time-series regression analysis based on national-level data on mammography utilization and physician advice from the Behavioral Risk Factor Surveillance System (BRFSS) and content analysis of mammography-related national news coverage. Results suggest that although physician advice plays a key role in women's decisions to have mammograms, media coverage of mammography screening also contributes to mammography utilization by women. In particular, media coverage seems to be important for women who do not have regular contact with a physician or access to physicians. A possible conclusion is that mass media and physician advice complement one another in persuading individuals to adopt preventive health behavior.     

The good, the bad, and the ugly: weighing the risks and benefits of seafood consumption

The health benefits that long chain omega-3 fatty acids contribute in the reduction of coronary heart disease are well established through a number of scientific publications. A number of studies are also examining their potential role in mitigating other diseases and health conditions such as Alzheimer's and mental disorders. Some of the latest research have shown the importance of omega-3 fatty acids such as docosahexaenoic acid in cognitive development in infants. Extensive scientific research and recommendations to consume fish regularly from professional societies, health organizations, and government agencies consistently support dietary guidance to consume fish regularly. Nevertheless, increasingly consumers are being warned to eliminate or minimize their consumption of certain species. The warnings, which have been issued due to risks associated with chemical contaminates such as mercury, PCB, and dioxin in fish, have received extensive coverage in news articles and stories in popular magazines. There have been a series of mixed messages to the consumer about the benefits or risks in eating seafood. In some cases, the warnings have been issued by government agencies such as the Food and Drug Administration and Environmental Protection Agency's Joint Fish Advisory on methylmercury. In other cases, the warnings have come from advocacy groups and others. Unfortunately, the advice is often miscommunicated and misunderstood by consumers. The emerging news about the benefits and risks of fish consumption will be discussed in the context of their impacts on consumer's health and well-being.     

The National Cholesterol Education Program: implications for dietetic practitioners from the Adult Treatment Panel recommendations

The National Cholesterol Education Program (NCEP) was initiated to contribute to the prevention of illness and death from coronary heart disease by reducing the prevalence of high blood cholesterol. The report of an expert panel of this program provides guidelines for the treatment of high blood cholesterol in adults 20 years of age and over. Dietary therapy is the primary treatment. The goal of the recommended dietary therapy is to lower the LDL-cholesterol concentration, although measurement of total blood cholesterol can be used to monitor the response to diet. Dietary modification involves a progressive decrease in intake of saturated fatty acids and cholesterol. The Step-One Diet calls for an intake of total fat less than 30% of calories, saturated fatty acids less than 10% of calories, and cholesterol less than 300 mg/day. If the desired decrease in LDL-cholesterol is not achieved with that dietary change, then the Step-Two Diet is begun. It requires a reduction in saturated fatty acids to less than 7% of calories and cholesterol to less than 200 mg/day. This article provides background information on the organization and objectives of the NCEP and focuses on the recommendations of the Adult Treatment Panel (ATP), e.g., classification of risk for developing coronary heart disease based on total and low-density-lipoprotein cholesterol levels and recommendations for treatment of patients with high blood cholesterol. The emphasis of the discussion is on dietary treatment. The implications of the recommendations for the dietetic practitioner are discussed. These include an expanded leadership role to meet the education needs of health professionals and patients.     

Should foods or nutrients be the focus of guidelines to promote healthful eating?

A variety of different dietary patterns can achieve the nutrient goals for a given population and therefore be considered as healthful. This means that guidelines for a healthy diet can be tailored to suit different cultures and food preferences. Although food‐based dietary guidelines are used worldwide, there is also authoritative dietary advice in relation to single nutrients, especially those of public health relevance. This includes recommendations to eat less salt, free sugars and ‘saturates’ as well as more fibre. However, it can be difficult for consumers to make simultaneous reductions in salt, sugars and saturated fatty acids as well as increases in dietary fibre, given that food choices are made according to a variety of considerations, including taste preferences, culture, convenience and cost, as well as health. In addition, media coverage of new scientific findings, especially those that challenge current dietary guidelines, can confuse consumers and hamper efforts to eat healthfully. Both food‐based dietary guidelines and recommended nutrient intakes can help consumers eat healthfully, providing they are supported by sound nutrition science, communicated well and delivered in a way that promotes beneficial changes in behaviour.     

Diet, prevalence and 10-year mortality from coronary heart disease in 871 middle-aged men. The Zutphen Study

The Zutphen Study is a longitudinal investigation among middle-aged men of relationships between diet, other risk characteristics, and coronary heart disease (CHD). In 1960, dietary data were collected by the cross-check dietary history method. CHD mortality data were collected during 10 years of follow-up. The 14 men with CHD at baseline consumed 524 kcal/day less than the 857 CHD-free men. During 10 years of follow-up, 30 men who were initially free of CHD died from CHD. Those men consumed 273 kcal/day less than men who did not die from CHD. The inverse relationship between energy intake and CHD became stronger when energy intake was expressed per kg of body weight. Dietary cholesterol per 1000 kcal was significantly positively related to CHD, while vegetable protein, polysaccharides, and dietary fiber were significantly inversely related to CHD. These relationships were no longer statistically significant when energy intake per kg of body weight was added to the logistic model. The inverse relationship between energy intake per kg of body weight and CHD became insignificant when subscapular skinfold and serum cholesterol were added to the logistic model. It is concluded that the influence of energy intake per kg of body weight on CHD is mediated through other risk characteristics: subscapular skinfold and serum cholesterol.     

Dietary cholesterol provided by eggs and plasma lipoproteins in healthy populations

PURPOSE OF REVIEW: Extensive research has not clearly established a link between egg consumption and risk for coronary heart disease. The effects of egg intake on plasma lipids and low-density lipoprotein (LDL) atherogenicity in healthy populations need to be addressed. RECENT FINDINGS: The lack of connection between heart disease and egg intake could partially be explained by the fact that dietary cholesterol increases the concentrations of both circulating LDL and high-density lipoprotein (HDL) cholesterol in those individuals who experience an increase in plasma cholesterol following egg consumption (hyperresponders). It is also important to note that 70% of the population experiences a mild increase or no alterations in plasma cholesterol concentrations when challenged with high amounts of dietary cholesterol (hyporesponders). Egg intake has been shown to promote the formation of large LDL, in addition to shifting individuals from the LDL pattern B to pattern A, which is less atherogenic. Eggs are also good sources of antioxidants known to protect the eye; therefore, increased plasma concentrations of lutein and zeaxanthin in individuals consuming eggs are also of interest, especially in those populations susceptible to developing macular degeneration and eye cataracts. SUMMARY: For these reasons, dietary recommendations aimed at restricting egg consumption should not be generalized to include all individuals. We need to acknowledge that diverse healthy populations experience no risk in developing coronary heart disease by increasing their intake of cholesterol but, in contrast, they may have multiple beneficial effects by the inclusion of eggs in their regular diet.     

Effect of unsaturated fats and cholesterol on serum and fecal lipids. A study of healthy middle-aged men.

Modification of the Western diet, with an intake of 2,500 kcal per day and a decrease in cholesterol and fat intake to 33 per cent of calories with a P:S of 0.40, failed to alter serum lipids significantly. Evidence suggested that increasing the daily intake of cholesterol resulted in deposition in the body tissues. However, when the fatty acid composition and the P:S ratio of dietary fat were adjusted, lower serum lipids and a compensatory increase in fecal sterols occurred when cholesterol was added to the diet. Changes in serum lipoproteins in the subjects fed a "prudent" or a common diet indicate an increase in the proportion of HDL-cholesterol which may be beneficial in reducing coronary heart disease. Evidence suggests that, in absence of caloric excess, lowering of serum lipids and increased removal of fecal sterols is possible on a prudent diet without major modification of the customary foods, but that a high P:S ratio is required.     

Sending a message: Ecstasy,equasy and the media politics of drug classification

In February 2009, the UK government's Advisory Council on the Misuse of Drugs (ACMD) published a review of MDMA (ecstasy) which recommended a reclassification from the highest class A to the ‘intermediate category’ class B, on the basis of a review of recent scientific research. This became a matter of news attention alongside a recent journal article by Professor David Nutt, the chairman of the ACMD, in which ecstasy consumption was suggested to be no more dangerous than horse-riding. The home secretary Jacqui Smith rejected the recommendations and Professor Nutt was forced to apologise for making the comparison. Some sections of the media coverage around this topic contrasted the (implicitly irrational) political response to the review with the authority of the scientific evidence it represented, while other media accounts characterised Nutt either as an ‘out of touch’, or ‘immoral’ academic or as having a politically motivated social agenda. In this way, risk issues are played out in, and through, media discourses of science and political authority. This paper analyses the national newspaper coverage of the debate around the risks of ecstasy use and drug classification in the context of the political imperatives within media accounts, and identifies the key discursive strategies employed by those engaged in the media debate. The paper briefly discusses the relevance of a number of risk theories before focusing on the governmentality approach to risk in order to explain how, despite the conservatism inherent in recent drug policy, the neo-liberal managerialism evident in recent UK governmental discourses largely sets the agenda in the media coverage.