There are very few sources of EPA in the diet. It can be made from the omega-3 oil alpha-linolenic acid found in large amounts in flax oil, in moderate amounts in canola oil and walnuts or in small amounts in green leafy vegetables. Only about 3 – 5% of the alpha-linolenic acid consumed becomes EPA or DHA in healthy individuals. This process is hindered in various disease states and requires that some people get EPA from their diet or supplementally.
The average American’s diet, however, is now low in EPA, resulting from a declining consumption of dietary sources of EPA such as fatty fish and animal organ meats. Vegetarians have lower blood levels of EPA due to its absence in foods of plant origin. Fish obtain their DHA and EPA ultimately from the consumption of algae.
Fish oils contain both EPA and DHA in varying ratios, usually with about twice as much EPA as DHA. Some conditions are treated predominantly with EPA and others with DHA. Since EPA and DHA seem to compete with each other, taking a blend of the two has proven not to produce the expected benefits in some conditions. In other words, DHA should be taken separately from EPA in some conditions and a high EPA /DHA ratio product should be used in other conditions.
A study on elderly Japanese patients demonstrated that blood levels of the omega-3 fatty acids EPA and DHA increase after prolonged consumption of ALA from a plant-based oil. The change is slow and requires about 10 months of supplementation. However, the result of the study suggests that supplementation with ALA from flax oil may to some degree have the same beneficial role as supplementation with fish oil. This news may be particularly interesting to people following a vegetarian diet or for those who do not eat fish products.
Sources with a high EPA/DHA ratio are prepared from fish oils. There is currently no product available which contains EPA without any DHA. Supplemental sources with high DHA/EPA ratios are now available that have been derived from algae. Eggs are now available which contain EPA and DHA when the chickens have been fed special diets containing these fatty acids or flax seed. Therapeutic EPA doses are in the range of 500 to 2,500mg per day, depending on the condition being treated.
Krill oil is another very good source of EPA and DHA and is becoming more readily available as a valuable source of these Omega-3 fatty acids. It is also high in protective phospholipids and potent antioxidants, which make it an ideal source of Omega-3 essential fatty acids, which are subject to rancidity. Fish oil and flax are weak in antioxidant content. Further, the phospholipids found in krill oil aid in the absorption of the essential fatty acids which are present. So, fish oil is good, but krill oil is even better, though more expensive. Krill oil has more EPA than DHA in a ratio of about 3 to 2.
EPA (eicosapentanoic acid) can help with the following
Hypercoagulation (Thickened Blood)
EPA from fish oils (or as a metabolite from omega 3 fatty acid metabolism) can make your blood thinner and less sticky.
Increased Risk of Stroke
EPA reduces platelet aggregation and thus helps prevent those strokes that are due to an abnormal clotting tendency.
Depression
There is an increasing body of evidence that indicates that fish oils, in particular those with high EPA to DHA ratios, have a major role to play in helping people maintain good mental health and to avoid mood swings and mild depression. Currently the only available source of EPA without equal amounts of DHA being present is “EPA rich” fish oil.
Ethyl-eicosapentaenoate (ethyl-EPA – 1gm per day), in addition to conventional antidepressant medication, improved measures of depression in a study of 70 patients with persistant depression despite ongoing treatment with conventional antidepressant drugs. Higher doses had no effect on measures of depression. [Arch Gen Psychiatry 2002;59(10): pp.913-9]
Bipolar Disorder, Manic-Depressive
Several studies have shown that essential fatty acids may be beneficial in treating Bipolar Disorder. The omega-3 metabolite responsible is believed to be EPA. At least one study found DHA, the other common metabolite, to be ineffective. This means if you were using a fish oil product, it shoud have a high EPA/DHA ratio; in other words, be EPA rich. [Omega-3 Fatty Acids in Bipolar Disorder: A Preliminary Double-blind, Placebo-controlled Trial. Arch Gen Psychiatry. 1999;56: pp.407-412]
Schizophrenia
Treatment with ethyl-eicosapentaenoic acid (ethyl-EPA) for 3 months, along with conventional antipsychotic drugs improved evaluation scores in a study of 40 schizophrenia patients with persistent symptoms after at least six months of stable antipsychotic drug treatment. [Am J Psychiatry 2002;159(9): pp.1596-1598]
EPA is one of the downline metabolites of alpha-linolenic acid (ALA, 18:3(n-3)), an Omega3 acid available in the diet. Schizophrenic patients who eat more (n-3) fatty acids in their normal diet have less severe symptoms. As those with pyroluria may worsen with n-3 fatty acids, red blood cell essential fatty acid testing could be important to determine which oils to use for treatment.
Psoriasis
Several double-blind clinical studies have demonstrated that supplementing the diet with 10 to 12gm of EPA results in significant improvement. This would be equivalent to the amount of EPA in about 150gm of mackerel or herring. It must be kept in mind that the presence of DHA in fish oil may reduce the effectiveness of the EPA. A high EPA fish oil is recommended.
Key
| May do some good |
| Likely to help |
Glossary
EPA
Environmental Protection Agency. Also: Eicosapentanoic Acid. A metabolite of the omega-3 fatty acid alpha-linolenic acid.
Flax
Flax Seed or Flax Oil. Flax oil is nutty-flavored oil that is pressed out of flax seeds and is one of the richest sources of Essential Fatty Acids (especially Omega-3 oil), a vital element for good health. The oil making process removes many of the seed's phytoestrogens which offer several health-related benefits including reducing the risk of cancer and alleviating menopausal symptoms. Many choose to use the whole seed because of its fiber and lignan content. Flaxseed oil is light- and temperature-sensitive and must be stored in the refrigerator.
DHA
Docosahexanoic Acid. A metabolite of the omega-3 fatty acid alpha-linolenic acid.
Fatty Acids
Chemical chains of carbon, hydrogen, and oxygen atoms that are part of a fat (lipid) and are the major component of triglycerides. Depending on the number and arrangement of these atoms, fatty acids are classified as either saturated, polyunsaturated, or monounsaturated. They are nutritional substances found in nature which include cholesterol, prostaglandins, and stearic, palmitic, linoleic, linolenic, eicosapentanoic (EPA), and decohexanoic acids. Important nutritional lipids include lecithin, choline, gamma-linoleic acid, and inositol.
Milligram
(mg): 1/1,000 of a gram by weight.
Antioxidant
A chemical compound that slows or prevents oxygen from reacting with other compounds. Some antioxidants have been shown to have cancer-protecting potential because they neutralize free radicals. Examples include vitamins C and E, alpha lipoic acid, beta carotene, the minerals selenium, zinc, and germanium, superoxide dismutase (SOD), coenzyme Q10, catalase, and some amino acids, like cystiene. Other nutrient sources include grape seed extract, curcumin, gingko, green tea, olive leaf, policosanol and pycnogenol.
Essential Fatty Acid
(EFA): A substance that the human body cannot manufacture and therefore must be supplied in the diet.