Fish oil supplementation in healthy subjects is associated with improved endothelial function and decreased resting heart rate

In a randomized, blinded, placebo-controlled trial, 26 subjects, average age 31, received a supplement providing 1g of fish oil or a placebo (corn oil) for 14 days. Fish oil supplementation resulted in a significant increase in endothelium-dependent brachial artery flow-mediated vasodilatation (EDV, a measure of the function of arteries and blood flow through them) and a significant decrease in resting heart rate. The authors conclude: “fish oil supplementation in healthy subjects is associated with improved endothelial function and decreased resting HR”.  The mechanism behind this effect is thought to be the production of specific hormone like substances, part of a group known as eicosanoids, from EPA. 

 

Click here to view the study abstract

 

Low blood omega-3 fats is associated with increased risk of acute coronary syndromes (ACS)    

Researchers measured the blood cell content of EPA and DHA in 768 ACS patients and 768 age, sex and race matched controls. The omega-3 content was 20% lower in cases than controls; the odds for ACS case status increased correspondingly as the EPA and DHA content decreased suggesting that low omega-3 status may be associated with increased risk for ACS. This is a well designed study that suggests the beneficial effects of the eicosanoids metabolised from EPA and the effect of DHA on cell membrane fluidity.

 

Click here to view the study abstract.

 

DHA supplementation may improve cardiovascular health by lowering concentrations of triacylglycerols and LDL cholesterol in hypertriglyceridemic men

The effects of docosahexaenoic acid (DHA) on the mean size and concentrations of VLDL, LDL, and HDL cholesterol have not been previously studied. 34 hypertriglyceridemic men received no supplements for the first 8 days, they then received either 7.5 g DHA oil/day (3 g DHA/day) or olive oil (placebo) for 90 days. Supplementation for 45 d significantly decreased concentrations of fasting triacylglycerol (24%), postprandial samples (0-6 h) yielded similar results, with the addition that the number of small dense LDL particles decreased significantly (21%).

 

Click here to view the abstract  

 

Omega-3 fatty acids as secondary prevention against cardiovascular events in patients who undergo chronic hemodialysis

Patients who are treated with chronic hemodialysis (HD) are at high risk of  premature cardiovascular disease, mortality rates among these patients are high. To investigate the efficacy of omega-3fatty acids in reducing this risk a total of 206 patients were randomly assigned to treatment with n-3 PUFA or a placebo and followed for 2 years. In the n-3 PUFA group, a significant reduction was seen in the number of myocardial infarctions (four versus 13). However, treatment with n-3 PUFA did not reduce the total number of cardiovascular events and death. Although limited by the small numbers involved this study may be of significant clinical interest.

 

Click here to view the abstract

 

Highly purified omega-3 polyunsaturated fatty acids are effective as adjunct therapy for secondary prevention of myocardial infarction

This is the first large randomised trial to produce evidence that a pharmaceutical preparation of highly purified omega-3 fatty acids, administered as an adjunct to other accepted interventions, had a favourable effect on clinical end-points in post-myocardial infarction patients. A 20% reduction in all-cause mortality was recorded following the intervention, a result attributed to a 45% reduction in sudden death, an  outcome that traditionally has proved resistant to intervention. The beneficial effects of omega-3 PUFA treatment were observed on top of standard, secondary pharmacological prevention therapy like anti-platelet agents, statins, beta-blockers and angiotensin-converting enzyme (ACE) inhibitors; the benefits were apparent in patients at all standards of adherence to a healthy diet and in patients with diabetes. The results were obtained with an omega-3 PUFA dose of just 1 g/day.

 

Click here to view the abstract

 

Omega-3 PUFA may contribute to the prevention and control of adverse blood pressure levels

Data are lacking on food omega-3 PFA and blood pressure in general populations. Data was examined from the International Study of Macro- and Micro-nutrients and Blood Pressure (INTERMAP), a study of 4680 men and women ages 40 to 59 from 17 groups in China, Japan, the United Kingdom and the United States. Higher intakes of omega-3 PUFA (measured from four 24 hour recalls) were associated with lower systolic (contraction of the heart ventricle) and diastolic (relaxation of the heart ventricle) blood pressure, even in non-hypertensive participants. 17 variables were adjusted for in the analysis, increasing the accuracy of the results. The authors conclude that “food omega-3 PUFA may contribute to prevention and control of adverse blood pressure levels”.

 

Click here to view the abstract.

 

Long-term fish consumption is associated with protection against arrhythmia in healthy persons

During 2001 and 2002, 1514 men (18-87 y old) and 1528 women (18-89 y old) randomly enrolled in order to investigate whether a diet rich in fish and n-3 fatty acid consumption is associated with a reduced incidence of arrhythmia (abnormal heart rhythm, measured by QT duration on a resting electrocardiogram). Diet was assessed with validated food frequency questionnaires, QT duration was measured and heart rate-corrected QT (QTc) was calculated. Compared with fish nonconsumers, those who consumed 300 g or more of fish/week had a mean 13.6% lower QTc; furthermore, compared with fish nonconsumers, those who consumed 300 g fish or more a week had a 29.2% lower likelihood of having QTc intervals greater than 0.45 (a delayed interval is associated with the development of cardiac arrhythmias). The findings were confirmed after adjustment for age, sex, physical activity status, BMI, smoking habits, intake of nuts, and other confounders. The conclusion: “fish intake seems to provide antiarrhythmic protection at a population level”.  

 

Click here to view the abstract.  

 

 

Prescription omega-3 fatty acids are valuable for the medical management of hypertriglyceridemia

A prescription form of omega-3 fatty acids has been approved by the United States Food and Drug Administration as an adjunct to diet for the treatment of very high triglyceride levels. The total EPA and DHA dose recommended for triglyceride lowering is approximately 2-4 g/day. In patients with triglyceride levels above 500 mg/dl, approximately 4 g/day of EPA and DHA reduces triglyceride levels 45% and VLDL cholesterol levels by more than 50%; although LDL cholesterol levels may increase depending on the baseline triglyceride level the net effect is an overall reduction in non-high-density lipoprotein cholesterol level. Omega-3 fatty acids are omega-3 fatty acids were well tolerated, with a low rate of both adverse events and treatment-associated discontinuations. Thus the “availability of prescription omega-3 fatty acids, which ensures consistent quality and purity, should prove to be valuable for the medical management of hypertriglyceridemia”. The UK government has voiced its intention to make omega-3 fatty acid supplements available on prescription for patients who have had a myocardial infarction.

 

Click here to view the abstract.

 

Oily fish reduces plasma triacylglycerols in overweight men and women

One hundred forty-two subjects were assigned to a control group or one of four interventions, to investigate the effect on cardiovascular risk markers of  reducing the dietary ratio of omega-6:omega-3 PUFA consumption and/or increasing intake of omega-3 PUFA. The study investigated whether decreases in LA (omega-6 precursor):LNA (omega-3 precursor) modulate the effects of  omega-3 PUFA. Intervention groups received two portions of oily fish (4.5 g EPA/DHA) or white fish (0.7g EPA/DHA) per week, and replaced habitual household fats with ones high in sunflower (high LA:LNA) or rapeseed (low LA:LNA) oil; the intervention lasted 24 weeks. At 24 weeks the control and two oily fish groups showed lower blood triacylglycerols (TAG) than did the white fish/sunflower group; the effects of the oily fish were maximized when combined with lower dietary LA:LNA. This is study is fascinating, revealing the vital importance of dietary balance in fat intake; simply increasing omega-3 intake will not be as effective as increasing omeg-3 consumption whilst also decreasing LA consumption (LA is found in vegetable oils).

 

Click here to view the abstract

 

Omega-3 fatty acid consumption, a new predictor of risk for sudden cardiac death?

Two groups were compared, subjects who had been taking fish oil daily during the last 6 years, and subjects who had not been taking fish oil. High intake of omega-3 fatty acids has been found to have a strong protective effect against sudden cardiac death. An index showing the relationship between different fatty acids in the blood could be an important risk indicator for sudden cardiac death. Two groups were compared: subjects who had been taking fish oil daily during the last 6 years, and subjects who had not been taking fish oil; scores on the index were calculated. 70% of the fish oil consumers had an index > or =50. Based on current knowledge about the relationship between blood levels of omega-3 fatty acids and sudden cardiac death (based on studies of 14,000 individuals), a subject with an index below 50 should be advised to increase his/her intake of omega-3 fatty acids.

 

Click here to view the abstract.

 

Omega-3 as a favourable impact on atherosclerosis, haemostasis and vascular status in patients with combined hyperlipoproteinemia

A double-blind pilot study was designed to address the impact of n-3 PUFA on atherosclerosis (chronic inflammatory response in the walls of arteries), haemostasis (coagulation) and vascular status in patients with combined hyperlipoproteinemia (elevated blood fats and lipoproteins, proteins which carry fats and cholesterol). 64 patients with combined hyperlipoproteinemia received a placebo or an n-3 PUFA (6 g/day) supplement for 2 years. A fall of triglycerides, accompanied by a rise of high- and low-density lipoprotein cholesterol (HDL and LDL), was observed in the active treated group. Platelet function was significantly reduced by n-3 PUFA, a beneficial effect (high levels predispose to blood clots).  Results also showed a favourable effect of n-3 PUFA on carotid intima-media thickness (C-IMT) and the texture of intima-media complex (T-IMC); although this result did not reach statistical significance the authors point out that is merits further study. The authors remark “despite the small sample size, the beneficial effect of n-3 PUFA on platelet function, triglycerides and HDL-C is clearly highlighted.”

 

Click here to view the abstract.

Fish oil supplementation in healthy subjects is associated with improved endothelial function and decreased resting heart rate

In a randomized, blinded, placebo-controlled trial, 26 subjects, average age 31, received a supplement providing 1g of fish oil or a placebo (corn oil) for 14 days. Fish oil supplementation resulted in a significant increase in endothelium-dependent brachial artery flow-mediated vasodilatation (EDV, a measure of the function of arteries and blood flow through them) and a significant decrease in resting heart rate. The authors conclude: “fish oil supplementation in healthy subjects is associated with improved endothelial function and decreased resting HR”.  The mechanism behind this effect is thought to be the production of specific hormone like substances, part of a group known as eicosanoids, from EPA. 

 

Click here to view the study abstract

 

Low blood omega-3 fats is associated with increased risk of acute coronary syndromes (ACS)    

Researchers measured the blood cell content of EPA and DHA in 768 ACS patients and 768 age, sex and race matched controls. The omega-3 content was 20% lower in cases than controls; the odds for ACS case status increased correspondingly as the EPA and DHA content decreased suggesting that low omega-3 status may be associated with increased risk for ACS. This is a well designed study that suggests the beneficial effects of the eicosanoids metabolised from EPA and the effect of DHA on cell membrane fluidity.

 

Click here to view the study abstract.

 

DHA supplementation may improve cardiovascular health by lowering concentrations of triacylglycerols and LDL cholesterol in hypertriglyceridemic men

The effects of docosahexaenoic acid (DHA) on the mean size and concentrations of VLDL, LDL, and HDL cholesterol have not been previously studied. 34 hypertriglyceridemic men received no supplements for the first 8 days, they then received either 7.5 g DHA oil/day (3 g DHA/day) or olive oil (placebo) for 90 days. Supplementation for 45 d significantly decreased concentrations of fasting triacylglycerol (24%), postprandial samples (0-6 h) yielded similar results, with the addition that the number of small dense LDL particles decreased significantly (21%).

 

Click here to view the abstract  

 

Omega-3 fatty acids as secondary prevention against cardiovascular events in patients who undergo chronic hemodialysis

Patients who are treated with chronic hemodialysis (HD) are at high risk of  premature cardiovascular disease, mortality rates among these patients are high. To investigate the efficacy of omega-3fatty acids in reducing this risk a total of 206 patients were randomly assigned to treatment with n-3 PUFA or a placebo and followed for 2 years. In the n-3 PUFA group, a significant reduction was seen in the number of myocardial infarctions (four versus 13). However, treatment with n-3 PUFA did not reduce the total number of cardiovascular events and death. Although limited by the small numbers involved this study may be of significant clinical interest.

 

Click here to view the abstract

 

Highly purified omega-3 polyunsaturated fatty acids are effective as adjunct therapy for secondary prevention of myocardial infarction

This is the first large randomised trial to produce evidence that a pharmaceutical preparation of highly purified omega-3 fatty acids, administered as an adjunct to other accepted interventions, had a favourable effect on clinical end-points in post-myocardial infarction patients. A 20% reduction in all-cause mortality was recorded following the intervention, a result attributed to a 45% reduction in sudden death, an  outcome that traditionally has proved resistant to intervention. The beneficial effects of omega-3 PUFA treatment were observed on top of standard, secondary pharmacological prevention therapy like anti-platelet agents, statins, beta-blockers and angiotensin-converting enzyme (ACE) inhibitors; the benefits were apparent in patients at all standards of adherence to a healthy diet and in patients with diabetes. The results were obtained with an omega-3 PUFA dose of just 1 g/day.

 

Click here to view the abstract

 

Omega-3 PUFA may contribute to the prevention and control of adverse blood pressure levels

Data are lacking on food omega-3 PFA and blood pressure in general populations. Data was examined from the International Study of Macro- and Micro-nutrients and Blood Pressure (INTERMAP), a study of 4680 men and women ages 40 to 59 from 17 groups in China, Japan, the United Kingdom and the United States. Higher intakes of omega-3 PUFA (measured from four 24 hour recalls) were associated with lower systolic (contraction of the heart ventricle) and diastolic (relaxation of the heart ventricle) blood pressure, even in non-hypertensive participants. 17 variables were adjusted for in the analysis, increasing the accuracy of the results. The authors conclude that “food omega-3 PUFA may contribute to prevention and control of adverse blood pressure levels”.

 

Click here to view the abstract.

 

Long-term fish consumption is associated with protection against arrhythmia in healthy persons

During 2001 and 2002, 1514 men (18-87 y old) and 1528 women (18-89 y old) randomly enrolled in order to investigate whether a diet rich in fish and n-3 fatty acid consumption is associated with a reduced incidence of arrhythmia (abnormal heart rhythm, measured by QT duration on a resting electrocardiogram). Diet was assessed with validated food frequency questionnaires, QT duration was measured and heart rate-corrected QT (QTc) was calculated. Compared with fish nonconsumers, those who consumed 300 g or more of fish/week had a mean 13.6% lower QTc; furthermore, compared with fish nonconsumers, those who consumed 300 g fish or more a week had a 29.2% lower likelihood of having QTc intervals greater than 0.45 (a delayed interval is associated with the development of cardiac arrhythmias). The findings were confirmed after adjustment for age, sex, physical activity status, BMI, smoking habits, intake of nuts, and other confounders. The conclusion: “fish intake seems to provide antiarrhythmic protection at a population level”.  

 

Click here to view the abstract.  

 

 

Prescription omega-3 fatty acids are valuable for the medical management of hypertriglyceridemia

A prescription form of omega-3 fatty acids has been approved by the United States Food and Drug Administration as an adjunct to diet for the treatment of very high triglyceride levels. The total EPA and DHA dose recommended for triglyceride lowering is approximately 2-4 g/day. In patients with triglyceride levels above 500 mg/dl, approximately 4 g/day of EPA and DHA reduces triglyceride levels 45% and VLDL cholesterol levels by more than 50%; although LDL cholesterol levels may increase depending on the baseline triglyceride level the net effect is an overall reduction in non-high-density lipoprotein cholesterol level. Omega-3 fatty acids are omega-3 fatty acids were well tolerated, with a low rate of both adverse events and treatment-associated discontinuations. Thus the “availability of prescription omega-3 fatty acids, which ensures consistent quality and purity, should prove to be valuable for the medical management of hypertriglyceridemia”. The UK government has voiced its intention to make omega-3 fatty acid supplements available on prescription for patients who have had a myocardial infarction.

 

Click here to view the abstract.

 

Oily fish reduces plasma triacylglycerols in overweight men and women

One hundred forty-two subjects were assigned to a control group or one of four interventions, to investigate the effect on cardiovascular risk markers of  reducing the dietary ratio of omega-6:omega-3 PUFA consumption and/or increasing intake of omega-3 PUFA. The study investigated whether decreases in LA (omega-6 precursor):LNA (omega-3 precursor) modulate the effects of  omega-3 PUFA. Intervention groups received two portions of oily fish (4.5 g EPA/DHA) or white fish (0.7g EPA/DHA) per week, and replaced habitual household fats with ones high in sunflower (high LA:LNA) or rapeseed (low LA:LNA) oil; the intervention lasted 24 weeks. At 24 weeks the control and two oily fish groups showed lower blood triacylglycerols (TAG) than did the white fish/sunflower group; the effects of the oily fish were maximized when combined with lower dietary LA:LNA. This is study is fascinating, revealing the vital importance of dietary balance in fat intake; simply increasing omega-3 intake will not be as effective as increasing omeg-3 consumption whilst also decreasing LA consumption (LA is found in vegetable oils).

 

Click here to view the abstract

 

Omega-3 fatty acid consumption, a new predictor of risk for sudden cardiac death?

Two groups were compared, subjects who had been taking fish oil daily during the last 6 years, and subjects who had not been taking fish oil. High intake of omega-3 fatty acids has been found to have a strong protective effect against sudden cardiac death. An index showing the relationship between different fatty acids in the blood could be an important risk indicator for sudden cardiac death. Two groups were compared: subjects who had been taking fish oil daily during the last 6 years, and subjects who had not been taking fish oil; scores on the index were calculated. 70% of the fish oil consumers had an index > or =50. Based on current knowledge about the relationship between blood levels of omega-3 fatty acids and sudden cardiac death (based on studies of 14,000 individuals), a subject with an index below 50 should be advised to increase his/her intake of omega-3 fatty acids.

 

Click here to view the abstract.

 

Omega-3 as a favourable impact on atherosclerosis, haemostasis and vascular status in patients with combined hyperlipoproteinemia

A double-blind pilot study was designed to address the impact of n-3 PUFA on atherosclerosis (chronic inflammatory response in the walls of arteries), haemostasis (coagulation) and vascular status in patients with combined hyperlipoproteinemia (elevated blood fats and lipoproteins, proteins which carry fats and cholesterol). 64 patients with combined hyperlipoproteinemia received a placebo or an n-3 PUFA (6 g/day) supplement for 2 years. A fall of triglycerides, accompanied by a rise of high- and low-density lipoprotein cholesterol (HDL and LDL), was observed in the active treated group. Platelet function was significantly reduced by n-3 PUFA, a beneficial effect (high levels predispose to blood clots).  Results also showed a favourable effect of n-3 PUFA on carotid intima-media thickness (C-IMT) and the texture of intima-media complex (T-IMC); although this result did not reach statistical significance the authors point out that is merits further study. The authors remark “despite the small sample size, the beneficial effect of n-3 PUFA on platelet function, triglycerides and HDL-C is clearly highlighted.”

 

Click here to view the abstract.