What are Omega 3 fatty acids ?
Omega-3 Fatty Acids are a family of essential fatty acids, with the other family being Omega-6 Fatty Acids. While Omega-6s are found in some common food sources, Omega-3s may be a bit harder to come by. It is important to understand this distinction since Omega-3s and Omega-6s are required by our body for optimum health and well-being. For instance, Omega-3s have been widely noted to help in reducing the risk of heart disease.Fish Oil is full of Omega-3 Fatty Acids that are said to be good for the heart as well as for the brain and the bones.
Two of the most important Omega-3 Fatty Acids Eicosapentaenoic Acid (EPA) and Docosahexaenoic Acid (DHA). DHA is the most abundant essential fatty acid in the brain and retina. As such, DHA may have the most significant effect on brain composition. The purported health benefits of supplementing one’s diet with Fish Oil may be popularly known. For example, DHA deficiency has been found to be closely associated with cognitive decline.
Similarly, Eicosapentaenoic acid (EPA) may have broad effects on one’s mental health. Studies suggest that a diet rich in EPA may help people combat such psychologically debilitating conditions as depression. Furthermore, EPA is also a precursor to DHA. As such, a diet rich in EPA may be very important in maintaining not only good mental health but also a better cardiovascular system.
Essential fatty acids, or EFAs, are fatty acids that cannot be constructed within an organism (generally all references are to humans) from other components by any known chemical pathways, and therefore must be obtained from the diet.There are two families of EFAs: ?-3 (or omega-3 or n-3) and ?-6 (omega-6, n-6).
n-3 fatty acids (popularly referred to as ?-3 fatty acids or omega-3 fatty acids) are a family of unsaturated fatty acids that have in common a final carbon–carbon double bond in the n-3 position; that is, the third bond from the methyl end of the fatty acid.
Important nutritionally-essential n-3 fatty acids are: a-linolenic acid (ALA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA), all of which are polyunsaturated. The human body cannot synthesize n-3 fatty acids de novo, but it can form 20-carbon unsaturated n-3 fatty acids (like EPA) and 22-carbon unsaturated n-3 fatty acids (like DHA) from the eighteen-carbon n-3 fatty acid a-linolenic acid. These conversions occur competitively with n-6 fatty acids, which are essential closely related chemical analogues that are derived from linoleic acid. Both the n-3 a-linolenic acid and n-6 linoleic acid are essential nutrients which must be obtained from food. Synthesis of the longer n-3 fatty acids from linolenic acid within the body is competitively slowed by the n-6 analogues. Thus accumulation of long-chain n-3 fatty acids in tissues is more effective when they are obtained directly from food or when competing amounts of n-6 analogs do not greatly exceed the amounts of n-3.
Chemistry
About ALA
Chemical structure of alpha-linolenic acid (ALA), an essential n-3 fatty acid, (18:3?9c,12c,15c, which means a chain of 18 carbons with 3 double bonds on carbons numbered 9, 12 and 15). Although chemists count from the carbonyl carbon (Blue Numbering), physiologists count from the n (?) carbon (red numbering). Note that from the n end (diagram right), the first double bond appears as the third carbon-carbon bond (line segment), hence the name "n-3". This is explained by the fact that the n end is almost never changed during physiologic transformations in the human body, as it is more stable energetically, and other carbohydrates compounds can be synthesized from the other carbonyl end, for example in glycerides, or from double bonds in the middle of the chain.
About EPA
Eicosapentaenoic acid (EPA or also icosapentaenoic acid) is an omega-3 fatty acid. In physiological literature, it is given the name 20:5(n-3). It also has the trivial name timnodonic acid. In chemical structure, EPA is a carboxylic acid with a 20-carbon chain and five cis double bonds; the first double bond is located at the third carbon from the omega end.
About DHA
Docosahexaenoic acid (DHA) is an omega-3 fatty acid. In chemical structure, DHA is a carboxylic acid with a 22-carbon chain and six cis double bonds; the first double bond is located at the third carbon from the omega end. Its trivial name is cervonic acid, its systematic name is all-cis-docosa-4,7,10,13,16,19-hexa-enoic acid, and its shorthand name is 22:6(n-3) in the nomenclature of fatty acids.
Consumption :
The American Heart Association recommends eating fish (particularly fatty fish such as mackerel, lake trout, herring, sardines, albacore tuna, and salmon) at least 2 times a week.The Mediterranean diet does not include much meat (which is high in omega-6 fatty acids) and emphasizes foods rich in omega-3 fatty acids, including whole grains, fresh fruits and vegetables, fish, olive oil, garlic, as well as moderate wine consumption.
Adults
Do not take more than 3 grams daily of omega-3 fatty acids from capsules without the supervision of a health care provider, due to an increased risk of bleeding.
• For healthy adults with no history of heart disease: The American Heart Association recommends eating fish at least 2 times per week.
• For adults with coronary heart disease: The American Heart Association recommends an omega-3 fatty acid supplement (as fish oils), 1 gram daily of EPA and DHA. It may take 2 - 3 weeks for benefits of fish oil supplements to be seen.
• For adults with high cholesterol levels: The American Heart Association recommends an omega-3 fatty acid supplement (as fish oils), 2 - 4 grams daily of EPA and DHA. It may take 2 - 3 weeks for benefits of fish oil supplements to be seen.
The American Heart Association recommends eating fish (particularly fatty fish such as mackerel, lake trout, herring, sardines, albacore tuna, and salmon) at least 2 times a week.The Mediterranean diet does not include much meat (which is high in omega-6 fatty acids) and emphasizes foods rich in omega-3 fatty acids, including whole grains, fresh fruits and vegetables, fish, olive oil, garlic, as well as moderate wine consumption.
Adults
Do not take more than 3 grams daily of omega-3 fatty acids from capsules without the supervision of a health care provider, due to an increased risk of bleeding.
• For healthy adults with no history of heart disease: The American Heart Association recommends eating fish at least 2 times per week.
• For adults with coronary heart disease: The American Heart Association recommends an omega-3 fatty acid supplement (as fish oils), 1 gram daily of EPA and DHA. It may take 2 - 3 weeks for benefits of fish oil supplements to be seen.
• For adults with high cholesterol levels: The American Heart Association recommends an omega-3 fatty acid supplement (as fish oils), 2 - 4 grams daily of EPA and DHA. It may take 2 - 3 weeks for benefits of fish oil supplements to be seen.
Health benefits :
People with certain circulatory problems, such as varicose veins, benefit from such supplements containing EPA and DHA which stimulate blood circulation, increase the breakdown of fibrin, a compound involved in clot and scar formation, and additionally have been shown to reduce blood pressure.There is strong scientific evidence that n-3 fatty acids reduce blood triglyceride levels and regular intake reduces the risk of secondary and primary heart attack.Some benefits have been reported in conditions such as rheumatoid arthritis and cardiac arrhythmias.
There is preliminary evidence that n-3 fatty acids supplementation might be helpful in cases of depression and anxiety. Studies report highly significant improvement from n-3 fatty acids supplementation alone and in conjunction with medication. Some research suggests that fish oil intake may reduce the risk of ischemic and thrombotic stroke.
Several studies report possible anti-cancer effects of n-3 fatty acids (particularly breast, colon and prostate cancer). Omega-3 fatty acids reduced prostate tumor growth, slowed histopathological progression, and increased survival. Among n-3 fatty acids [omega-3], neither long-chain nor short-chain forms were consistently associated with breast cancer risk. High levels of docosahexaenoic acid, however, the most abundant n-3 PUFA [omega-3] in erythrocyte membranes, were associated with a reduced risk of breast cancer. A 2009 trial found that a supplement of eicosapentaenoic acid helped cancer patients retain muscle mass.
Another study regarding fish oil was published in the Journal of Nutrition in April 2007. Sixty four healthy Danish infants from nine to twelve months of age received either cow's milk or infant formula alone or with fish oil. It was found that those infants supplemented with fish oil had improvement in immune function maturation with no apparent reduction in immune activation.
Several clinical studies suggest that diets or fish oil supplements rich in omega-3 fatty acids lower blood pressure in people with hypertension. An analysis of 17 clinical studies using fish oil supplements found that taking 3 or more grams of fish oil daily may reduce blood pressure in people with untreated hypertension.
One of the best ways to help prevent heart disease is to eat a diet low in saturated fat and to eat foods that are rich in monounsaturated and polyunsaturated fats (including omega-3 fatty acids). Clinical evidence suggests that EPA and DHA (eicosapentaenoic acid and docosahexaenoic acid, the two omega-3 fatty acids found in fish oil) help reduce risk factors for heart disease, including high cholesterol and high blood pressure. Fish oil has been shown to lower levels of triglycerides (fats in the blood), and to lower risk of death, heart attack, stroke, and abnormal heart rhythms in people who have already had a heart attack. Fish oil also appears to help prevent and treat atherosclerosis (hardening of the arteries) by slowing the development of plaque and blood clots, which can clog arteries.
People with certain circulatory problems, such as varicose veins, benefit from such supplements containing EPA and DHA which stimulate blood circulation, increase the breakdown of fibrin, a compound involved in clot and scar formation, and additionally have been shown to reduce blood pressure.There is strong scientific evidence that n-3 fatty acids reduce blood triglyceride levels and regular intake reduces the risk of secondary and primary heart attack.Some benefits have been reported in conditions such as rheumatoid arthritis and cardiac arrhythmias.
There is preliminary evidence that n-3 fatty acids supplementation might be helpful in cases of depression and anxiety. Studies report highly significant improvement from n-3 fatty acids supplementation alone and in conjunction with medication. Some research suggests that fish oil intake may reduce the risk of ischemic and thrombotic stroke.
Several studies report possible anti-cancer effects of n-3 fatty acids (particularly breast, colon and prostate cancer). Omega-3 fatty acids reduced prostate tumor growth, slowed histopathological progression, and increased survival. Among n-3 fatty acids [omega-3], neither long-chain nor short-chain forms were consistently associated with breast cancer risk. High levels of docosahexaenoic acid, however, the most abundant n-3 PUFA [omega-3] in erythrocyte membranes, were associated with a reduced risk of breast cancer. A 2009 trial found that a supplement of eicosapentaenoic acid helped cancer patients retain muscle mass.
Another study regarding fish oil was published in the Journal of Nutrition in April 2007. Sixty four healthy Danish infants from nine to twelve months of age received either cow's milk or infant formula alone or with fish oil. It was found that those infants supplemented with fish oil had improvement in immune function maturation with no apparent reduction in immune activation.
Several clinical studies suggest that diets or fish oil supplements rich in omega-3 fatty acids lower blood pressure in people with hypertension. An analysis of 17 clinical studies using fish oil supplements found that taking 3 or more grams of fish oil daily may reduce blood pressure in people with untreated hypertension.
One of the best ways to help prevent heart disease is to eat a diet low in saturated fat and to eat foods that are rich in monounsaturated and polyunsaturated fats (including omega-3 fatty acids). Clinical evidence suggests that EPA and DHA (eicosapentaenoic acid and docosahexaenoic acid, the two omega-3 fatty acids found in fish oil) help reduce risk factors for heart disease, including high cholesterol and high blood pressure. Fish oil has been shown to lower levels of triglycerides (fats in the blood), and to lower risk of death, heart attack, stroke, and abnormal heart rhythms in people who have already had a heart attack. Fish oil also appears to help prevent and treat atherosclerosis (hardening of the arteries) by slowing the development of plaque and blood clots, which can clog arteries.
SOURCES
Fish Sources
The most widely available source of EPA and DHA is cold water oily fish such as salmon, herring, mackerel, anchovies and sardines. Oils from these fish have a profile of around seven times as much n-3 as n-6. Other oily fish such as tuna also contain n-3 in somewhat lesser amounts. Consumers of oily fish should be aware of the potential presence of heavy metals and fat-soluble pollutants like PCBs and dioxin which may accumulate up the food chain.
Flax Source
Flax seeds produce linseed oil, which has a very high n-3 content Six times richer than most fish oils in n-3, Flax (aka linseed) (Linum usitatissimum) and its oil are perhaps the most widely available botanical source of n-3. Flax seed oil consists of approximately 55% ALA (alpha-linolenic acid). Flax, like chia, contains approximately three times as much n-3 as n-6. 15 grams of flaxseed oil provides ca. 8 grams of ALA, which is converted in the body to EPA and then DHA at an efficiency of 2–15% and 2–5%, respectively.
Egg Source
Eggs produced by chickens fed a diet of greens and insects produce higher levels of n-3 fatty acids (mostly ALA) than chickens fed corn or soybeans. In addition to feeding chickens insects and greens, fish oils may be added to their diet to increase the amount of fatty acid concentrations in eggs. The addition of flax and canola seeds to the diet of chickens, both good sources of alpha-linolenic acid, increases the omega-3 content of the eggs.
Dairy Source
Milk and cheese from grass-fed cows may also be good sources of n-3. One UK study showed that half a pint of milk provides 10% of the recommended daily intake (RDI) of ALA, while a piece of organic cheese the size of a matchbox may provide up to 88%".
Fish Sources
The most widely available source of EPA and DHA is cold water oily fish such as salmon, herring, mackerel, anchovies and sardines. Oils from these fish have a profile of around seven times as much n-3 as n-6. Other oily fish such as tuna also contain n-3 in somewhat lesser amounts. Consumers of oily fish should be aware of the potential presence of heavy metals and fat-soluble pollutants like PCBs and dioxin which may accumulate up the food chain.
Flax Source
Flax seeds produce linseed oil, which has a very high n-3 content Six times richer than most fish oils in n-3, Flax (aka linseed) (Linum usitatissimum) and its oil are perhaps the most widely available botanical source of n-3. Flax seed oil consists of approximately 55% ALA (alpha-linolenic acid). Flax, like chia, contains approximately three times as much n-3 as n-6. 15 grams of flaxseed oil provides ca. 8 grams of ALA, which is converted in the body to EPA and then DHA at an efficiency of 2–15% and 2–5%, respectively.
Egg Source
Eggs produced by chickens fed a diet of greens and insects produce higher levels of n-3 fatty acids (mostly ALA) than chickens fed corn or soybeans. In addition to feeding chickens insects and greens, fish oils may be added to their diet to increase the amount of fatty acid concentrations in eggs. The addition of flax and canola seeds to the diet of chickens, both good sources of alpha-linolenic acid, increases the omega-3 content of the eggs.
Dairy Source
Milk and cheese from grass-fed cows may also be good sources of n-3. One UK study showed that half a pint of milk provides 10% of the recommended daily intake (RDI) of ALA, while a piece of organic cheese the size of a matchbox may provide up to 88%".
