The 'diet heart' hypothesis in secondary prevention of coronary heart disease

Mussel (Mytilus coruscus) Water Extract Containing Taurine Prevents LPS-Induced Inflammatory Responses in Zebrafish Model

Mussel (Mytilus coruscus) water extract had strong anti-inflammatory activities, but the effects and its mechanisms of mussel on anti-inflammatory properties in vivo remain to be determined. This study, therefore, was designed to investigate anti-inflammatory activities of mussel water extract containing a large amounts of taurine (151.96 nmol/mg) using the lipopolysaccharide (LPS)-induced inflammatory zebrafish model. In this study, mussel water extract containing taurine shows potent protective effects against the cell death stimulated by LPS exposure in zebrafish embryos. In addition, zebrafish subjected to LPS treatment exhibited significantly increased reactive oxygen species (ROS) and nitric oxide (NO) levels. However, mussel water extract markedly suppressed LPS-induced ROS and NO production. Our results indicate that mussel water extract attenuated inflammation by inhibiting the LPS-induced intracellular ROS and NO production in zebrafish embryos. These findings could demonstrate the anti-inflammatory activity of mussel water extract containing taurine, which might have a protective effects on inflammatory diseases.

Milk-derived bioactive peptides and their health promoting effects: a potential role in atherosclerosis

Bioactive peptides derived from milk proteins are food components that, in addition to their nutritional value, retain many biological properties and have therapeutic effects in several health disorders, including cardiovascular disease. Amongst these, atherosclerosis is the underlying cause of heart attack and strokes. It is a progressive dyslipidaemic and inflammatory disease where accumulation of oxidized lipids and inflammatory cells leads to the formation of an atherosclerotic plaque in the vessel wall. Milk-derived bioactive peptides can be released during gastrointestinal digestion, food processing or by enzymatic and bacterial fermentation and are considered to promote diverse beneficial effects such as lipid lowering, antihypertensive, immnomodulating, anti-inflammatory and antithrombotic effects. In this review, an overview of the diverse biological effects of these compounds is given, particularly focusing on their beneficial properties on cardiovascular disease and proposing novel mechanisms of action responsible for their bioactivity. Attempts to prevent cardiovascular diseases target modifications of several risk factors such as high blood pressure, obesity, high blood concentrations of lipids or insulin resistance. Milk-derived bioactive peptides are a source of health-enhancing components and the potential health benefit of these compounds has a growing commercial potential. Consequently, they have been incorporated as ingredients in functional foods, as dietary supplements and as pharmaceuticals to promote health and reduce risk of chronic diseases.

Purification of a novel peptide derived from a shellfish, Crassostrea gigas, and evaluation of its anticancer property

A novel anticancer peptide was purified from Crassostrea gigas and investigated for its cytotoxic activity. To prepare the peptide, eight proteases were employed for enzymatic hydrolysis. Flavourzyme hydrolysate, which showed clearly superior cytotoxic activity on prostate cancer cells, was further purified using a membrane system and consecutive chromatographic methods. Finally, a novel anticancer peptide was obtained, and the sequence was partially purified as His-Phe-Asn-Ile-Gly-Asn-Arg-Cys-Leu-Cys at the N-terminus. The peptide purified from C. gigas effectively induced the death of prostate, breast, and lung cancer cells but not normal liver cells. This is the first report of an anticancer peptide derived from the enzymatic hydrolysates of C. gigas.

Purification of a novel nitric oxide inhibitory peptide derived from enzymatic hydrolysates of Mytilus coruscus

Shellfish contain significant levels of high quality protein and are therefore a potential source for biofunctional high-value peptides. To purify a novel anti-inflammatory peptide from Mytilus coruscus (M. coruscus), we applied enzymatic hydrolysis and tangential flow filtration (TFF) and investigated its nitric oxide inhibitory property. To prepare the peptide, eight proteases were employed for enzymatic hydrolysis. Flavouzyme hydrolysates, which showed clearly superior nitric oxide inhibitory activity on lipopolysaccharide (LPS)-stimulated RAW264.7, were further purified using a TFF system and consecutive chromatographic methods. Finally, a novel anti-inflammatory peptide composed of 10 amino acid residues was obtained, and the sequence was identified as Gly-Val-Ser-Leu-Leu-Gln-Gln-Phe-Phe-Leu at N-terminal position. The peptide from M. coruscus effectively inhibited nitric oxide production on macrophage cells. This is the first report of an anti-inflammatory peptide derived from the hydrolysates of M. coruscus.

Purification of a novel peptide derived from Mytilus coruscus and in vitro/in vivo evaluation of its bioactive properties

Excess oxidant can promote inflammatory responses. Moreover, chronic inflammation accompanied by oxidative stress is connected various steps involved in many diseases. From the aspect, we investigated an antioxidant peptide to prevent inflammatory response against oxidant overexpression. To prepare the peptide, eight proteases were employed for enzymatic hydrolysis, and the antioxidant properties of the hydrolysates were investigated using free radical scavenging activity by electron spin resonance (ESR) spectrometry. Papain hydrolysates, which showed clearly superior free radical scavenging activity, were further purified using consecutive chromatographic methods. Finally, a novel antioxidant peptide was obtained, and the sequence was identified as Ser-Leu-Pro-Ile-Gly-Leu-Met-Ile-Ala-Met at N-terminal. Oral administration of the peptide to mice effectively inhibited malondialdehyde (MDA) levels in a thiobarbituric acid reactive substances (TBARS) assay, and we also confirmed the antioxidative enzyme activities in superoxide dismutase (SOD) and glutathione-s-transferase (GST) assays. This is the first report of an antioxidant peptide derived from the hydrolysate of Mytilus coruscus, and also these results suggest that the peptide possesses potent antioxidant activity, and potential to enhance anti-inflammatory response.

Mediterranean diet in secondary prevention of CHD

OBJECTIVE

To summarise our present knowledge on the Mediterranean diet in secondary prevention of CHD.

DESIGN

Review of literature.

SETTING

Adult coronary patients.

SUBJECTS

CHD patients at high risk of cardiac death.

RESULTS

The two main causes of death in these patients are sudden cardiac death (SCD) and chronic heart failure (CHF). The main mechanism underlying recurrent cardiac events is coronary thrombosis resulting from atherosclerotic plaque erosion or ulceration. The occurrence of thrombosis is usually associated with plaque weakness in relation to high lipid content of the lesion where cholesterol only represents a very small part compared with other lipids (i.e. fatty acids). Thus, the three main aims of the preventive strategy are to prevent coronary thrombosis, malignant ventricular arrhythmia and the development of left ventricular dysfunction (and CHF) and finally to minimise the risk of plaque erosion and ulceration. There is now a consensus about recommending the Mediterranean diet pattern for the secondary prevention of CHD because no other dietary pattern has been successfully tested so far in these patients. The most important aspect, in contrast with the pharmacological prevention of CHD (including cholesterol lowering), is that the Mediterranean diet results in a striking effect on survival.

CONCLUSIONS

The traditional Mediterranean diet is effective in reducing both coronary atherosclerosis/thrombosis and the risk of fatal complications such as SCD and heart failure.

Session 4: CVD, diabetes and cancer Evidence for the use of the Mediterranean diet in patients with CHD

Diet is associated with the development of CHD. The incidence of CHD is lower in southern European countries than in northern European countries and it has been proposed that this difference may be a result of diet. The traditional Mediterranean diet emphasises a high intake of fruits, vegetables, bread, other forms of cereals, potatoes, beans, nuts and seeds. It includes olive oil as a major fat source and dairy products, fish and poultry are consumed in low to moderate amounts. Many observational studies have shown that the Mediterranean diet is associated with reduced risk of CHD, and this result has been confirmed by meta-analysis, while a single randomised controlled trial, the Lyon Diet Heart study, has shown a reduction in CHD risk in subjects following the Mediterranean diet in the secondary prevention setting. However, it is uncertain whether the benefits of the Mediterranean diet are transferable to other non-Mediterranean populations and whether the effects of the Mediterranean diet will still be feasible in light of the changes in pharmacological therapy seen in patients with CHD since the Lyon Diet Heart study was conducted. Further randomised controlled trials are required and if the risk-reducing effect is confirmed then the best methods to effectively deliver this public health message worldwide need to be considered.

The Mediterranean diet: rationale and evidence for its benefit

There is now a consensus about recommending the Mediterranean diet pattern for the prevention of coronary heart disease (CHD) and cancer. The most important aspect of this treatment decision, in contrast with the pharmacologic prevention of CHD (including cholesterol lowering), is that the Mediterranean diet has a striking effect on survival. The main explanation for this is that the Mediterranean diet is protective not only against CHD and cancers but also against other various chronic diseases. Furthermore, the Mediterranean diet appears to be effective at reducing atherosclerosis and the risk of fatal complications (ie, sudden cardiac death and heart failure) of atherosclerosis. Finally, unlike drug therapies, no harmful side effect has been reported following the adoption of this dietary pattern. Many micro- and macronutrients characteristic of the Mediterranean diet interact in a synergistic way to induce states of resistance to chronic diseases. More research is required to understand these complex interplays.

Interactions of ethanol drinking withn-3 fatty acids in rats: potential consequences for the cardiovascular system

Moderate ethanol drinking (ED) andn-3 fatty acids have both been associated with low cardiac mortality. However, there are few data evaluating the interactions of ED withn-3. We recently reported that moderate ED results in increasedn-3 in cardiac patients. The main aim of the present study was, through a well-controlled experimental model, to confirm that chronic ED actually results in increasedn-3. Secondary aims were to examine the effects of chronic ED on cardiac mitochondria, cardiac function and experimental myocardial infarction. We studied the fatty acid profiles of plasma, cell membranes and cardiac mitochondria phospholipids in a rat model of chronic ED. In plasma and cell membranes, ED actually resulted in highern-3 (P = 0·005). In mitochondria phospholipids of ED rats,n-3 were also increased (P < 0·05) but quite modestly. Cardiac mitochondrial function and left ventricular function were not significantly different in ED and control rats, while infarct size after 30 min ischaemia and reperfusion was smaller (P < 0·0001) in ED rats. This is the first animal study confirming interaction of alcohol drinking withn-3. We found no harmful effect of chronic ED on the heart in that model but a significant cardioprotection. Further studies are warranted to investigate the mechanisms by which moderate ED alters the metabolism ofn-3 and whethern-3 are the mediators of the ED-induced cardioprotection.

Sex-specific interaction between APOE genotype and carbohydrate intake affects plasma HDL-C levels: the Strong Heart Family Study

Low plasma levels of high-density lipoprotein cholesterol (HDL-C) are identified as a risk factor for cardiovascular disease (CVD). Sexual dimorphism, however, is widely reported in both HDL-C and CVD, with the underlying explanations of these sexual differences not fully understood. HDL-C is a complex trait influenced by both genes and dietary factors. Here we examine evidence for a sex-specific effect of APOE and the macronutrient carbohydrate on HDL-C, triglycerides (TG) and apoprotein A-1 (ApoA-1) in a sample of 326 male and 423 female participants of the Strong Heart Family Study (SHFS). Using general estimating equations in SAS to account for kinship correlations, stratifying by sex, and adjusting for age, body mass index (BMI) and SHS center, we examine the relationship between APOE genotype and carbohydrate intake on circulating levels of HDL-C, TG, and ApoA-1 through a series of carbohydrate-by-sex interactions and stratified analyses. APOE-by-carbohydrate intake shows significant sex-specific effects. All males had similar decreases in HDL-C levels associated with increased carbohydrate intake. However, only those females with APOE-4 alleles showed significantly lower HDL-C levels as their percent of carbohydrate intake increased, while no association was noted between carbohydrate intake and HDL-C in those females without an APOE-4 allele. These findings demonstrate the importance of understanding sex differences in gene-by-nutrient interaction when examining the complex architecture of HDL-C variation.

Low-density lipoprotein cholesterol lowering in the prevention of CHD: How low should we go?

The past 12 years have seen the publication of numerous randomized placebo-controlled studies using statins to lower low-density lipoprotein cholesterol (LDLC) to assess the efficacy of cholesterol lowering on cardiovascular events. Initial studies predominantly evaluated mortality or nonfatal myocardial infarctions and coronary heart disease (CHD) death in patients with known or presumed established coronary disease and moderately elevated to very elevated serum cholesterol concentrations. Subsequent investigations studied a broader spectrum of cardiovascular events as a composite primary end point in both primary and secondary prevention strategies in subjects with lower mean entry serum LDLC concentrations. These studies have generally shown a reduction in a composite end point of cardiovascular events, although not necessarily the more restricted end points used in previous studies. Although the LDLC mantra "lower is better" has been popularized in advertising and continuing medical education and suggested as an option in "very high risk" patients by the National Cholesterol Education Program Adult Treatment Panel, the precise target level for LDLC for optimal treatment has not been rigorously defined. Serum LDLC less than 100 mg/dL seems reasonable for patients with known atherosclerosis or at high risk for atherosclerosis (diabetes or presence of multiple risk factors). Serum LDLC less than 70 mg/dL may be a reasonable goal in the setting of acute coronary syndromes, but there are many problems with the data on which this recommendation is made. Furthermore, many advocates of "lower is better" seem oblivious to the potential downsides of more aggressive lipid-lowering therapy. The LDLC target in lower risk primary prevention is less clear. What is obvious is that moderate-dose statin therapy can lower CHD risk in primary prevention and secondary prevention with minimal side effects, and with the imminent availability of several generic statins, with great cost-effectiveness.

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.

Alpha-linolenic acid and coronary heart disease

AIM

To summarize our present knowledge about vegetable omega-3 fatty acids.

DATA SYNTHESIS

Alpha-linolenic acid (ALA) is one of the two essential fatty acids in humans. Epidemiological studies and dietary trials strongly suggest that this fatty acid is important in relation with the pathogenesis (and prevention) of coronary heart disease. Like other n-3 fatty acids from marine origin, it may prevent cardiac arrhythmias and sudden cardiac death. The optimal dietary intake of alpha-linolenic acid seems to be about 2 g per day or 0.6 to 1% of total energy intake. Obtaining an optimal ratio of the two essential fatty acids, linoleic and alpha-linolenic acids--ie a ratio of less than 4 to 1 in the diet--is a major issue. The main sources of alpha-linolenic acid for the European population should be canola oil (and canola-oil based margarine if available), nuts (English walnut), ground linseeds and green leafy vegetables such as purslane.

CONCLUSIONS

Epidemiological studies and dietary trials in humans suggest that alpha-linolenic acid is a major cardio-protective nutrient.

The dietary prevention and treatment of coronary heart disease in the new millennium

Dietary changes can reduce the risk of coronary artery disease by 50%-70%. By understanding the mechanism, we can begin explaining why coronary heart disease has been the leading cause of mortality in most industrialized nations over the last century.

Risk factor modification through nonpharmacological interventions in patients with coronary heart disease

Coronary heart disease (CHD) is still the main cause of death in developed countries. Because of improved treatment, many patients survive the acute phase of a myocardial infarction, which makes secondary prevention of CHD of major importance. Most risk factors responsible for the development and progression of CHD are associated with behavior. Therefore, interventions aimed at behavior change may contribute to risk factor modification and secondary prevention of CHD. The effects of separate risk factor modification efforts by means of randomized, controlled clinical trials of nonpharmacological interventions in patients suffering from CHD are reviewed. Interventions aimed at healthy lifestyles may stimulate smoking cessation rates, reduce elevated serum total and low-density lipoprotein (LDL)-cholesterol concentrations, and favorably modify type A behavior in CHD patients. Moreover, reduction of coronary atherosclerosis has been reported after intensive lifestyle and exercise interventions, whereas exercise and type A interventions may also lead to reduced CHD morbidity and mortality. As for hypertension and obesity, studies aimed at secondary prevention are lacking.

Role of arginine, taurine and homocysteine in cardiovascular diseases

Arginine, taurine and homocysteine are amino acids which have been shown to affect the risk factors of cardiovascular diseases in humans. Arginine and taurine may protect against cardiovascular diseases while homocysteine may be a risk factor for them. Both arginine and taurine seem to lower blood pressure, arginine may also inhibit atherogenesis, and taurine may have antioxidant properties. However, the evidence of the beneficial effects of arginine and taurine supplementation from human studies is insufficient. Elevated levels of plasma homocysteine may be associated with atherosclerotic and thromboembolic cardiovascular diseases. Supplementation with folic acid seems to be effective in reducing hyperhomocysteinaemia, but there is an insufficient number of studies showing that lowering of homocysteine levels with vitamin supplementation will reduce the risk of cardiovascular diseases. In conclusion, further research is needed to determine the optimal levels for taurine and arginine in the human diet in order to decrease the risk factors for cardiovascular diseases, and to whom supplementation with folic acid should possibly be recommended to reduce hyperhomocysteinaemia. Even though the use of arginine and taurine supplements to reduce cardiovascular risk factors is an interesting possibility, the reported health-promoting effects and the safety of such a supplementation should first be confirmed.

Primary and secondary prevention of coronary artery disease: a follow-up on clinical controlled trials

Most probably the decennia of the 1990s will be called the 'statin decennia' in the history of coronary heart disease prevention. Statins are effective, both in primary and secondary prevention of coronary heart disease, in middle-aged and older (< 76 years) men and women, in both diabetics and non-diabetics with coronary heart disease. Statins used in secondary prevention of coronary heart disease significantly reduce the risk of stroke. They also reduce daily attacks of myocardial ischemia. Pathogenetic pathways leading to 'biological plausibilities' of the statins favourable effects are multiple, which explains their rapid (less than 1 year) influence on coronary events. Until the results from new event trials become available, fibrates have very few indications as first line drug therapy in dyslipidemia. They should be considered in combined therapy with statins. The scientific evidence with statins is overwhelming and the question is no longer 'who should we treat?' but 'who can society afford to treat?'. Health economics are indeed pivotal in the use of statins and public health authorities have to find answers according to their resources or innovative strategies, including new aspects in dietary advice (the 'Mediterranean diet'?).

Do codeine and caffeine enhance the analgesic effect of aspirin?--A systematic overview

OBJECTIVE

To assess whether codeine and caffeine enhance the analgesic effect of aspirin in post-operative pain.

METHOD

Systematic overview of the literature and meta-analysis of published randomized controlled trials (RCTs).

RESULTS

Codeine 60 mg leads to a small increase in the analgesic effect of 650 mg of aspirin when total pain relief score (TOTPAR%) is used as a efficacy end-point. This increased effect was not seen when sum of pain intensity (SPID%) and proportions of patients responding with moderate to excellent pain relief were used as outcome measures. Caffeine did not enhance the analgesic effect of aspirin.

CONCLUSION

Codeine 60 mg may produce a small increase in the analgesic effect of aspirin 650 mg. However, this effect is not clinically meaningful. Caffeine has no adjuvant analgesic effect. At over-the-counter (OTC) doses, caffeine and codeine are not useful in aspirin formulations.

Non-pharmacological modification of cardiac risk factors: Part 2. The role of diet

A high intake of saturated fats and cholesterol is associated with an increased risk of developing and dying from coronary artery disease (CHD), particularly if other risk factors are present. However, although a reduction in the consumption of the amounts of saturated fat and cholesterol may reduce the incidence of primary and secondary CHD in susceptible individuals, other dietary measures may also be important. These include an increased consumption of poly- and monounsaturated fatty acids, fresh fruit, fish and fibre.