Omega-3 Fatty Acids and Cardiovascular Benefits: Plant Based ALA or Marine Based DHA and EPA?
Several scientific studies support the beneficial role of marine based omega-3 fatty acids, namely DHA (docosahexaenoic acid) and EPA (eicosapetenoic acid), in reducing the risk of heart attack, death, life-threatening abnormal heart rhythms and strokes in people with known cardiovascular disease.
These fish based omega-3 acids also slow the atherosclerotic plaque build up in arteries and help lower blood pressure.
However scientific evidence supporting similar benefits from ALA (alpha-linolenic acid), a shorter chain cousin, is less pronounced.
ALA is an essential polyunsaturated fatty acid for humans.
It cannot be synthesized by the human body and must be obtained from food sources.
It is found in certain plant oils, especially flaxseed oil, constituting almost 50% of its fatty acid content.
Other plant oil sources include soybean, mustard, linseed and olive oil.
English walnuts are also high in ALA.
Smaller amounts are present in green leafy vegetables and chocolate, tree nuts other than walnuts and corn.
ALA is the precursor to EPA and DHA.
However the conversion into these longer-chain cousins is limited and this may explain its relative inefficiency in cardiovascular protection.
Several scientific studies have suggested that ALA may be cardioprotective.
The two major randomized prospective studies, the Lyon Diet Heart Study(Mediterranean Diet Study) and a study by Singh and associates suggested that ALA was cardiovascular protective.
However in these studies it has been difficult to ascribe the cardiovascular benefit to ALA alone.
A study by Luc Djoussé, MD and published in Circulation in 2005 showed that people with higher ALA intake had lower sub-clinical atherosclerosis.
A recent prospective study and published in 2011, reviewed the cardiovascular outcomes in a Dutch population of 20,069 healthy adults enrolled in the European Prospective Investigation into Cancer and Nutrition (EPIC) study.
They were monitored for up to 13 years.
The researchers found that intake of ALA in this population had a protective effect on stroke and a further, although borderline, reduction of other cardiovascular events in women.
ALA has been used therapeutically in rheumatoid arthritis, multiple sclerosis, diabetes, renal disease, and inflammatory bowel diseases such as ulcerative colitis, and Crohn's disease.
Patients with chronic obstructive pulmonary disease, migraines, skin cancer, and depression, may also benefit from its intake.
Supplementation has also shown to help inflammatory conditions such as psoriasis and eczema.
ALA is safe to take in its natural form.
It is readily available in health food stores.
It use is rarely associated with any side effects.
However, there is a suggestion that there may be a small increase in the risk of prostate cancer associated with its intake.
Marine oils rich in DHA and EPA are expensive and subject to limitation due to dwindling fish stocks.
Plant sources of ALA are more numerous and maybe inexhaustible, but conclusive proof of ALA's role as a cardiovascular protective agent remains only suggestive, and not persuasive.
Further studies will hopefully establish a more conclusive intake-benefit connection of this essential fatty acid.
Present scientific data continues to support the use of marine based omega-3 fatty acids for cardiovascular benefits.
However, individuals unable or unwilling to consume marine based products may use ALA as a substitute for EPA and DHA.
These fish based omega-3 acids also slow the atherosclerotic plaque build up in arteries and help lower blood pressure.
However scientific evidence supporting similar benefits from ALA (alpha-linolenic acid), a shorter chain cousin, is less pronounced.
ALA is an essential polyunsaturated fatty acid for humans.
It cannot be synthesized by the human body and must be obtained from food sources.
It is found in certain plant oils, especially flaxseed oil, constituting almost 50% of its fatty acid content.
Other plant oil sources include soybean, mustard, linseed and olive oil.
English walnuts are also high in ALA.
Smaller amounts are present in green leafy vegetables and chocolate, tree nuts other than walnuts and corn.
ALA is the precursor to EPA and DHA.
However the conversion into these longer-chain cousins is limited and this may explain its relative inefficiency in cardiovascular protection.
Several scientific studies have suggested that ALA may be cardioprotective.
The two major randomized prospective studies, the Lyon Diet Heart Study(Mediterranean Diet Study) and a study by Singh and associates suggested that ALA was cardiovascular protective.
However in these studies it has been difficult to ascribe the cardiovascular benefit to ALA alone.
A study by Luc Djoussé, MD and published in Circulation in 2005 showed that people with higher ALA intake had lower sub-clinical atherosclerosis.
A recent prospective study and published in 2011, reviewed the cardiovascular outcomes in a Dutch population of 20,069 healthy adults enrolled in the European Prospective Investigation into Cancer and Nutrition (EPIC) study.
They were monitored for up to 13 years.
The researchers found that intake of ALA in this population had a protective effect on stroke and a further, although borderline, reduction of other cardiovascular events in women.
ALA has been used therapeutically in rheumatoid arthritis, multiple sclerosis, diabetes, renal disease, and inflammatory bowel diseases such as ulcerative colitis, and Crohn's disease.
Patients with chronic obstructive pulmonary disease, migraines, skin cancer, and depression, may also benefit from its intake.
Supplementation has also shown to help inflammatory conditions such as psoriasis and eczema.
ALA is safe to take in its natural form.
It is readily available in health food stores.
It use is rarely associated with any side effects.
However, there is a suggestion that there may be a small increase in the risk of prostate cancer associated with its intake.
Marine oils rich in DHA and EPA are expensive and subject to limitation due to dwindling fish stocks.
Plant sources of ALA are more numerous and maybe inexhaustible, but conclusive proof of ALA's role as a cardiovascular protective agent remains only suggestive, and not persuasive.
Further studies will hopefully establish a more conclusive intake-benefit connection of this essential fatty acid.
Present scientific data continues to support the use of marine based omega-3 fatty acids for cardiovascular benefits.
However, individuals unable or unwilling to consume marine based products may use ALA as a substitute for EPA and DHA.
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