The fish oil Omega 3 content has a lot of benefits, including the effect on the cardiovascular disease. The consumption of fish and fish oil is associated with lower rates of CHD (Coronary heart disease) in many epidemiological studies. Seminal findings in Eskimos have been confirmed and extended to Western populations,and in most studies there is an inverse relationship between the intake of fish or n-3 fatty acids and total mortality or cardiovascular mortality. However, some studies have not shown any benefit, possibly because fish intake was higher in the studied population as a whole.
Intervention studies, in which the intake of fish or fish oil was increased, have also shown beneficial effects. One classic study investigated 2000 Welsh men who had just recovered from their first heart attack. The men were randomised to a ‘fish dvice group’, in which they were asked to eat at least two portions of oily fish a week, or failing this fish oil in capsule form, or a ‘no fish advice group’. After 2 years, there was a 29% reduction in mortality in the fish/fish oil group, which was attributable to a reduction in CHD deaths. However, although there were fewer fatal heart attacks in the fish group, the total number of heart attacks did not decrease.
In a double-blind, placebo-controlled study in India, 360 patients with suspected myocardial infarction were randomised to receive fish oil (1.09 g EPA/DHA daily), mustard oil (2.9 g alpha-linolenic acid daily) or placebo for 1 year. Total cardiac events, including cardiac arrhythmias, and also angina pectoris and left ventricular enlargement, were significantly reduced in both the fish oil and mustard oil groups compared with placebo. Fish oil, but not mustard oil, was significantly correlated with fewer cardiac deaths than placebo. Overall, a consistent body of evidence derived from several hundred studies has indicated that a daily ingestion of at least 1 g of EPA and DHA results in a reduction in total mortality, cardiovascular mortality and morbidity.
So the fish oil Omega 3 content is useful in cardiovascular disease.
2011. január 4., kedd
2011. január 2., vasárnap
Fish oil dosage
Let's see the recommended fish oil dosage. The fish oil Omega 3 containing supplements are available in the form of capsules and liquids. The dose is not established. Dietary supplements provide 100–1500 mg combined fish oil Omega 3 (EPA/DHA) per dose, clinical trials of fish oil supplements showing beneficial effects have often used 3–4 g daily (combined EPA/DHA), but doses of 1–2 g daily may be adequate.
Important: Intake of cod liver oil should not be increased above the doses recommended on the product label to achieve higher intakes of EPA/DHA (risk of vitamin A and D toxicity). Several capsules of cod liver oil could be required to provide the same amount of EPA/DHA as a single dose of cod liver oil liquid. There is no risk of vitamin toxicity with one dose of cod liver oil liquid, but toxicity is likely if several capsules are ingested (vitamin concentration is usually higher in capsules).
It is also important to know, thatfFish oil supplements are not identical, they provide different amounts of omega 3 fish oils (EPA/DHA).
Important: Intake of cod liver oil should not be increased above the doses recommended on the product label to achieve higher intakes of EPA/DHA (risk of vitamin A and D toxicity). Several capsules of cod liver oil could be required to provide the same amount of EPA/DHA as a single dose of cod liver oil liquid. There is no risk of vitamin toxicity with one dose of cod liver oil liquid, but toxicity is likely if several capsules are ingested (vitamin concentration is usually higher in capsules).
It is also important to know, thatfFish oil supplements are not identical, they provide different amounts of omega 3 fish oils (EPA/DHA).
Fish oil side effects
Fish oil and Fish oil containig products has a lot of benefits. But what about the fish oil side effects?
Vitamin A and D toxicity (fish liver oil only). The unpleasant taste of fish liver oil liquids may be masked by mixing with fruit juice or milk. Fish oil omega 3 supplements are generally safe, and in one prospective study involving 295 people aged 18–76 years, 10–20 ml of fish oil providing 1.8–3.6 g EPA/DHA for 7 years was not associated with any serious adverse effects. The safety of n-3 fatty acids from fish oil (derived from menhaden) was reviewed by the US Food and Drug Administration (FDA) in 1997. After reviewing more than 2600 articles, the FDA concluded that dietary intakes of up to 3 g daily of the 2 fish oil omega 3 (EPA/DHA) from menhaden oil were generally regarded as safe (GRAS). The FDA came to this conclusion after considering three main issues related to the safety of fish oils:
- firstly, the risk of deteriorating glycaemic control in type 2 diabetes;
- secondly, prolonged bleeding times;
- thirdly, the risk of increasing LDL levels in patients with hypertriglyceridaemia.
Many fish oil supplements (e.g. cod liver oil, halibut liver oil) contain vitamin A and vitamin D – that are fat-soluble vitamins that can be toxic in excessive amounts. However, the amount of these vitamins contained, for example, in an average multivitamin supplement containing no more than 100% of the RDAs together with the amounts in a recommended dose of, say, ordinary cod liver oil are unlikely to be harmful. However, care should be taken in pregnancy not to take excessive amounts of vitamin A, and product labels should be checked. Other safety concerns expressed in relation to fish oils include the potential to increase bleeding time (a beneficial effect in relation to prevention of CHD) and the possibly of altering glycaemic control in diabetes. However, it is unlikely that any of these effects is a problem, particularly with intakes of <3g EPA/DHA daily. Nevertheless, patients taking anticoagulant medication or those with blood clotting disorders should be monitored while taking fish oils. This does not mean that such patients have to avoid fish oils – just that their doctor should be aware of it. There is also concern about industrial contaminants in fish oil supplements. These include dioxins and polychlorinated biphenyls (PCBs). There is no immediate danger to health, but risks come from long exposure to high levels. In 2001, the UK Committee on Toxicity (COT) set a tolerable daily intake for dioxins and dioxin-like PCBs of 2 pg TEQ/kg/bw/day. (For comparison the EU Scientific Committee on Food (SCF) set a tolerable weekly intake of 14 pg/kg/body weight). Since July 2002 it has been an offence to place on the market any fish oil supplements containing higher contaminant levels.
Vitamin A and D toxicity (fish liver oil only). The unpleasant taste of fish liver oil liquids may be masked by mixing with fruit juice or milk. Fish oil omega 3 supplements are generally safe, and in one prospective study involving 295 people aged 18–76 years, 10–20 ml of fish oil providing 1.8–3.6 g EPA/DHA for 7 years was not associated with any serious adverse effects. The safety of n-3 fatty acids from fish oil (derived from menhaden) was reviewed by the US Food and Drug Administration (FDA) in 1997. After reviewing more than 2600 articles, the FDA concluded that dietary intakes of up to 3 g daily of the 2 fish oil omega 3 (EPA/DHA) from menhaden oil were generally regarded as safe (GRAS). The FDA came to this conclusion after considering three main issues related to the safety of fish oils:
- firstly, the risk of deteriorating glycaemic control in type 2 diabetes;
- secondly, prolonged bleeding times;
- thirdly, the risk of increasing LDL levels in patients with hypertriglyceridaemia.
Many fish oil supplements (e.g. cod liver oil, halibut liver oil) contain vitamin A and vitamin D – that are fat-soluble vitamins that can be toxic in excessive amounts. However, the amount of these vitamins contained, for example, in an average multivitamin supplement containing no more than 100% of the RDAs together with the amounts in a recommended dose of, say, ordinary cod liver oil are unlikely to be harmful. However, care should be taken in pregnancy not to take excessive amounts of vitamin A, and product labels should be checked. Other safety concerns expressed in relation to fish oils include the potential to increase bleeding time (a beneficial effect in relation to prevention of CHD) and the possibly of altering glycaemic control in diabetes. However, it is unlikely that any of these effects is a problem, particularly with intakes of <3g EPA/DHA daily. Nevertheless, patients taking anticoagulant medication or those with blood clotting disorders should be monitored while taking fish oils. This does not mean that such patients have to avoid fish oils – just that their doctor should be aware of it. There is also concern about industrial contaminants in fish oil supplements. These include dioxins and polychlorinated biphenyls (PCBs). There is no immediate danger to health, but risks come from long exposure to high levels. In 2001, the UK Committee on Toxicity (COT) set a tolerable daily intake for dioxins and dioxin-like PCBs of 2 pg TEQ/kg/bw/day. (For comparison the EU Scientific Committee on Food (SCF) set a tolerable weekly intake of 14 pg/kg/body weight). Since July 2002 it has been an offence to place on the market any fish oil supplements containing higher contaminant levels.
2010. december 30., csütörtök
Fish oil - omega 3 - mechanism of action
The action of fish oil omega 3 fatty acids is may be the following:
- modulation of pro-inflammatory and prothrombotic eicosanoid (prostaglandin, thromboxane and leukotriene) production
- reduction in interleukin-1 and other cytokines.
The effects of omega 3 fatty acids are thought to be due to the partial replacement of arachidonic acid with EPA in cell membrane lipids. This leads to increased production of PG3 series prostaglandins, thromboxane A3 and series 5 leukotrienes at the expense of PG2 series
prostaglandins, thromboxane A2 and series 4 leukotrienes . Thromboxane A3 (produced from EPA) is less effective at stimulating platelet aggregation than thromboxane A2 (produced from
arachidonic acid). Prostaglandins of the PG3 series have less potent inflammatory effects than prostaglandins of the PG2 series. In addition, DHA inhibits the formation of the more inflammatory prostaglandins of the PG2 series, while EPA acts as a substrate for the synthesis of the less inflammatory prostaglandins of the PG3 series. Series 5 leukotrienes (produced by EPA) have weaker inflammatory effects than series 4 leukotrienes (produced by arachidonic acid).
- modulation of pro-inflammatory and prothrombotic eicosanoid (prostaglandin, thromboxane and leukotriene) production
- reduction in interleukin-1 and other cytokines.
The effects of omega 3 fatty acids are thought to be due to the partial replacement of arachidonic acid with EPA in cell membrane lipids. This leads to increased production of PG3 series prostaglandins, thromboxane A3 and series 5 leukotrienes at the expense of PG2 series
prostaglandins, thromboxane A2 and series 4 leukotrienes . Thromboxane A3 (produced from EPA) is less effective at stimulating platelet aggregation than thromboxane A2 (produced from
arachidonic acid). Prostaglandins of the PG3 series have less potent inflammatory effects than prostaglandins of the PG2 series. In addition, DHA inhibits the formation of the more inflammatory prostaglandins of the PG2 series, while EPA acts as a substrate for the synthesis of the less inflammatory prostaglandins of the PG3 series. Series 5 leukotrienes (produced by EPA) have weaker inflammatory effects than series 4 leukotrienes (produced by arachidonic acid).
2010. december 29., szerda
Effects of fish oil Omega 3 fatty acids
Fish oil omega 3 fatty acids have a lot of benefits, they have several effects on the human body. The fish oil omega 3 benefits are the following:
- Fish oil omega 3 fatty acids has effect on alteration of lipoprotein metabolism. Fish oils reduce both fasting and post-prandial plasma triacylglycerols and VLDL cholesterol. With moderate intakes of fish oils, both HDL and LDL cholesterol tend to increase. High intakes reduce HDL cholesterol and may increase LDL in some patients. A meta-analysis of published human trials (that each provided 7 g daily of fish oils for at least 2 weeks) showed that serum cholesterol is unaffected by long-chain n-3 fatty acid consumption. However, triacylglycerols fell by 25–30%, LDL increased by 5–10% and HDL fell by 1–3%.
- Further fish oil omega 3 benefits are the prevention of thrombosis. Thrombosis is a major complication of coronary atherosclerosis, which can lead to myocardial infarction. The n-3 fatty acids have anti-thrombotic actions through inhibiting the synthesis of thromboxane A2 from arachidonic acids in platelets. Thromboxane A2 causes platelet aggregation and vasoconstriction and as a result fish oil increases bleeding time and reduces the ‘stickiness’ of the platelets. Fish oil also enhances the production of prostacyclin, which leads to vasodilatation and less ‘sticky’ platelets. These effects help to reduce the risk of thrombosis.
- The next benefits of fish oil omega 3 are inhibition of atherosclerosis. Fish oils reduce the plasma concentrations of several atherogenic lipoproteins (see above), but other mechanisms may be important. Thus, these effects may be associated with reduced synthesis of cytokines and interleukin 1α and through stimulation of the endothelial production of nitric oxide.
- Omega 3 fish oils can reduction in heart rate. A meta-analysis of 30 RCTs found that fish oil decreased heart rate by 1.6 beats per minute compared with placebo. In trials where initial heart beat was high and/or the study period was long, reduction in heart rate averaged 2.5 beats per minute. Heart rate reduction did not significantly vary with dosage of fish oil.
- Inhibition of inflammation. Diets rich in omega-3 fatty acids appear to reduce the inflammatory response.
- Inhibition of the immune response. Immune reactivity is generally reduced by omega-3
fatty acids.
- Fish oil omega 3 fatty acids have influence on arrhythmias. Fish oil may reduce the incidence of lethal myocardial infarction and sudden death. This may be due to the prevention of fatal cardiac arrhythmias. Evidence from some studies indicates an anti-arrhythmic action of fish oil, while evidence from other studies does not. In patients undergoing coronary artery bypass surgery (CABG), omega-3 fatty acids (2 g daily) substantially reduced the incidence of post-operative atrial fibrillation. In a further study in patients with a recent episode of sustained ventricular arrhythmia and an implantable cardioverter defibrillator (ICD), fish oil did not reduce the risk of ventricular tachycardia and ventricular fibrillation and there was evidence of a pro-arrhythmic effect in some patients.
- Fish oil omega 3 fatty acids has effect on alteration of lipoprotein metabolism. Fish oils reduce both fasting and post-prandial plasma triacylglycerols and VLDL cholesterol. With moderate intakes of fish oils, both HDL and LDL cholesterol tend to increase. High intakes reduce HDL cholesterol and may increase LDL in some patients. A meta-analysis of published human trials (that each provided 7 g daily of fish oils for at least 2 weeks) showed that serum cholesterol is unaffected by long-chain n-3 fatty acid consumption. However, triacylglycerols fell by 25–30%, LDL increased by 5–10% and HDL fell by 1–3%.
- Further fish oil omega 3 benefits are the prevention of thrombosis. Thrombosis is a major complication of coronary atherosclerosis, which can lead to myocardial infarction. The n-3 fatty acids have anti-thrombotic actions through inhibiting the synthesis of thromboxane A2 from arachidonic acids in platelets. Thromboxane A2 causes platelet aggregation and vasoconstriction and as a result fish oil increases bleeding time and reduces the ‘stickiness’ of the platelets. Fish oil also enhances the production of prostacyclin, which leads to vasodilatation and less ‘sticky’ platelets. These effects help to reduce the risk of thrombosis.
- The next benefits of fish oil omega 3 are inhibition of atherosclerosis. Fish oils reduce the plasma concentrations of several atherogenic lipoproteins (see above), but other mechanisms may be important. Thus, these effects may be associated with reduced synthesis of cytokines and interleukin 1α and through stimulation of the endothelial production of nitric oxide.
- Omega 3 fish oils can reduction in heart rate. A meta-analysis of 30 RCTs found that fish oil decreased heart rate by 1.6 beats per minute compared with placebo. In trials where initial heart beat was high and/or the study period was long, reduction in heart rate averaged 2.5 beats per minute. Heart rate reduction did not significantly vary with dosage of fish oil.
- Inhibition of inflammation. Diets rich in omega-3 fatty acids appear to reduce the inflammatory response.
- Inhibition of the immune response. Immune reactivity is generally reduced by omega-3
fatty acids.
- Fish oil omega 3 fatty acids have influence on arrhythmias. Fish oil may reduce the incidence of lethal myocardial infarction and sudden death. This may be due to the prevention of fatal cardiac arrhythmias. Evidence from some studies indicates an anti-arrhythmic action of fish oil, while evidence from other studies does not. In patients undergoing coronary artery bypass surgery (CABG), omega-3 fatty acids (2 g daily) substantially reduced the incidence of post-operative atrial fibrillation. In a further study in patients with a recent episode of sustained ventricular arrhythmia and an implantable cardioverter defibrillator (ICD), fish oil did not reduce the risk of ventricular tachycardia and ventricular fibrillation and there was evidence of a pro-arrhythmic effect in some patients.
2010. december 28., kedd
Fish oil omega 3 - EPA and DHA - how much do I need
The two main fish oil Omega 3 fatty acids, the EPA and DHA in small amounts can be synthesised in the body from alpha-linolenic acid (contained in vegetable oils, e.g. soya bean, linseed and rapeseed oils). However, this conversion
may be inefficient in some individuals so other sources would be necessary.
The recommended daily DHA/EPA intake in different coutries are different. The recommended very-long-chain n-3 (omega 3) fatty acids (EPA/DHA):
- UK Department of Heath: 1 200 mg daily
- British Nutrition Foundation: 2 1250 mg daily
- International Society for the Study of Fatty Acids and Lipids: 650 mg daily
- The Danish Ministry of Health: 300 mg daily
- Deutsche Gesellschaft fur Ernahrung (DGE): 1500 mg daily
Fish oil in Wikipedia
Some information about fish oil in Wikipedia
http://en.wikipedia.org/wiki/Fish_oil
may be inefficient in some individuals so other sources would be necessary.
The recommended daily DHA/EPA intake in different coutries are different. The recommended very-long-chain n-3 (omega 3) fatty acids (EPA/DHA):
- UK Department of Heath: 1 200 mg daily
- British Nutrition Foundation: 2 1250 mg daily
- International Society for the Study of Fatty Acids and Lipids: 650 mg daily
- The Danish Ministry of Health: 300 mg daily
- Deutsche Gesellschaft fur Ernahrung (DGE): 1500 mg daily
Fish oil in Wikipedia
Some information about fish oil in Wikipedia
http://en.wikipedia.org/wiki/Fish_oil
2010. december 27., hétfő
Fish oil omega 3 content - the sources and ingredients
The fish oil omega 3 content is realized to be very important recenty. Generealy there are two types of fish oil supplements:
- The first is : fish liver oil - this is generally obtained from the liver of the cod, halibut or shark.
- The second is fish body oil - this is normally derived from the flesh of the herring, sardine or anchovy.
Let's see the fish liver oil. Fish liver oil is rich in vitamins A and D. Concentrations in cod liver oil liquids normally range between 750 and 1200 μg (2500–4000 units) vitamin A per 10 ml and 2.5–10 μg(100–400 units) vitamin D per 10 ml. Halibut and shark liver oils are more concentrated sources of these vitamins.
And the fish body oil. Fish body oil is low in vitamins A and D. Vitamin E is also present in both types of fish oil and extra vitamin E is normally added to supplements.
Both fish liver oil and fish body oil are sources of polyunsaturated fatty acids (PUFAs) of the omega-3 series [eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA)]. These fish oil omega 3 fatty acids are may the most important parts of the oil, the fish oil benefits are connected to them.
EPA and DPA are 20- and 22-carbon molecules, respectively, with five double bonds D5,8,11,14,17, while DHA is a 22- carbon and six double-bond molecule D5,8,11,14,17,20.
All fatty acids (FA) in the fish oil omega 3 family are characterized by having their first double bond at the 3rd position counting from the terminal (o or nth) methyl group in the molecule. As with the omega 6 family, omega 3 fatty acid cannot be synthesized de novo by mammals and must be obtained from the diet.
The structure of the first fish oil omega 3: DHA
The structure of the second fish oil omega 3: EPA
Omega3 and fish oil in BBC
In BBC a short summary about fish oils and omega3 and their effect on brainpower
http://www.bbc.co.uk/science/humanbody/mind/articles/intelligenceandmemory/omega_three.shtml
- The first is : fish liver oil - this is generally obtained from the liver of the cod, halibut or shark.
- The second is fish body oil - this is normally derived from the flesh of the herring, sardine or anchovy.
Let's see the fish liver oil. Fish liver oil is rich in vitamins A and D. Concentrations in cod liver oil liquids normally range between 750 and 1200 μg (2500–4000 units) vitamin A per 10 ml and 2.5–10 μg(100–400 units) vitamin D per 10 ml. Halibut and shark liver oils are more concentrated sources of these vitamins.
And the fish body oil. Fish body oil is low in vitamins A and D. Vitamin E is also present in both types of fish oil and extra vitamin E is normally added to supplements.
Both fish liver oil and fish body oil are sources of polyunsaturated fatty acids (PUFAs) of the omega-3 series [eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA)]. These fish oil omega 3 fatty acids are may the most important parts of the oil, the fish oil benefits are connected to them.
EPA and DPA are 20- and 22-carbon molecules, respectively, with five double bonds D5,8,11,14,17, while DHA is a 22- carbon and six double-bond molecule D5,8,11,14,17,20.
All fatty acids (FA) in the fish oil omega 3 family are characterized by having their first double bond at the 3rd position counting from the terminal (o or nth) methyl group in the molecule. As with the omega 6 family, omega 3 fatty acid cannot be synthesized de novo by mammals and must be obtained from the diet.
The structure of the first fish oil omega 3: DHA
The structure of the second fish oil omega 3: EPA
Omega3 and fish oil in BBC
In BBC a short summary about fish oils and omega3 and their effect on brainpower
http://www.bbc.co.uk/science/humanbody/mind/articles/intelligenceandmemory/omega_three.shtml
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