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Essential Fatty Acids: Battle of the "Good Fats"
Essential fatty acids (EFAs) are the "good fats" that have recently been taking the media by storm because of their claimed positive health benefits. They are essential to human health, but cannot be synthesized by the body and therefore must be obtained through diet. There are two types of essential fatty acids: Omega-3s and Omega-6s. This article will show the alleged benefits of these essential fatty acids as well as investigate the different sources of these EFAs in hopes to determine the source that is most beneficial to the claims being made.
There are three major types of omega 3 fatty acids that are ingested in foods and used by the body: alpha-linolenic acid (ALA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA). When consumed, the body converts ALA to EPA and DHA, the two types of omega-3 fatty acids more readily used by the body. http://en.wikipedia.org/wiki/Essential_fatty_acid
Research indicates that omega-3 fatty acids reduce inflammation and help prevent certain chronic diseases. Among this list of chronic diseases are heart disease, stroke, arthritis, skin disorders, diabetes, high cholesterol, high blood pressure, breast, colon and prostate cancer, and depression as these "essential fatty acids are highly concentrated in the brain and appear to be particularly important for cognitive and behavioral function."
Fish oils and plant oils are the primary dietary source of omega-3 fatty acids. EPA and DHA are found in cold-water fish such as salmon, mackerel, halibut, sardines, and herring. ALA is found in flaxseeds, flaxseed oil, canola oil, soybeans, soybean oil, pumpkin seeds, pumpkin seed oil, purslane, perilla seed oil, walnuts, and walnut oil. ALA is also found in dark green leafy vegetable such as spinach and broccoli. In addition to the dietary sources described, EPA and DHA can be taken in the form of fish oil capsules.
Linoleic Acid is the primary Omega-6 fatty acid. A person of good health and fit nutrition will convert linoleic acid into gamma linolenic acid (GLA), which will later be manufactured with EPA from the Omega-3 group into eicosanoids (the body’s cellular check and balance system.). These essential fatty acids have shown to play a fundamental role in several physiological functions.
Safflower, Sunflower, Corn, Soya, Evening primrose, Pumpkin, and Wheatgerm are the primary sources of omega-6 fatty acids.
Research is stressing the importance of maintaining a balance between omega-3 and omega-6 fatty acids in the diet. An improper balance of these essential fatty acids contributes to the development of disease while a proper balance helps maintain and even improve health. A healthy diet should consist of roughly one to four times more omega-6 fatty acids than omega-3 fatty acids. The typical American diet tends to contain 11 to 30 times more omega-6 fatty acids than omega-3 fatty acids. According to many researchers, this imbalance is a significant factor in the rising rate of disorders in the United States.
For most Americans, the emphasis now needs to be on increasing omega-3 fatty acids to make the ratio more even. Increasing the intake of omega-3 fatty acids naturally brings the ratio of omega-3 and omega-6 fatty acids back into a healthier balance or an optimally 1-1 balance that was believed to be present in our ancestors. This is best achieved by reducing the consumption of omega-6-rich foods, while at the same time increasing the intake of omega-3-rich foods or supplements. http://www.advance-health.com/efa.html
Battle of the Best Omega 3 Sources
Dietary Sources: Marine vs. Plant
As stated before, marine sources of Omega-3s are of a different type than those found in plants. The source of plants, ALA, needs to be converted by the body into EPA and DHA. Since this conversion is somewhat slow (only about 15% of EPA and 5% DHA converted from DHA), and very inconsistent due to a lot of factors that inhibit conversion such as diet, drugs, alcohol, high intake, etc. some claim that fish sources are best because of the lack of conversion process.
According to Dr. Rudin, author of Omega-3 Oils; A practical Guide, plant-based Omega 3s are more beneficial. Because the body can make EPA and DHA from ALA, and because "ALA is an essential compound needed by the body for numerous essential long-term functions", he claims that plant-based Omega 3s are a better source.
DHA remains the most important brain fat throughout life.
Low levels of DHA are associated with an increased risk of memory loss. Dr.
Michael A. Schmidt reports in Smart Fats that, according to data collected in
the long-term Framingham Heart Study, adults with low levels of DHA have a
greater likelihood of developing dementia in their later years. These adults
are twice as likely to develop dementia as those with high levels of DHA.
The memory Solution by Dr Julian Whitaker, page 120
When it comes to providing protection for the brain and encouraging overall brain health, DHA may be the more important fatty acid. DHA supplementation significantly decreased the number of reference memory errors and working memory errors.
Disease Prevention And Treatment by Life Extension Foundation, page 22
The safety question is based on several studies showing fish oil supplements to be contaminated with toxic derivatives known as lipid peroxides. While extra vitamin E and other antioxident nutrients offer some protection against these compounds, in general, it is a good idea to avoid the intake of lipid peroxides.
For a general essential fatty acid supplement, flaxseed oil may be the best choice for most people. Flaxseed oil is a remarkable food that can easily be incorporated into the diet at an affordable price. Rich in the omega-3 oil alpha-linolenic acid, flaxseed oil is gaining popularity as the preferred oil by leading experts in health and nutrition. Because it's high in lignan flaxseed oil, it may offer the greatest benefit.
In one study, fifty-seven normal, healthy male subjects aged 35–60 years were recruited to compare the effects of three diets using a randomized, single-blind parallel dietary design. Subjects were randomly assigned to one of three diets enriched either with flaxseed oil, sunflower oil, or sunflower oil with fish-oil for 12 weeks. The outcome of this study indicates that the dietary ALA is not equivalent to dietary EPA and DHA in its effects on CVD risk factors, including fish-oil-induced changes in HDL cholesterol (good cholesterol) and LDL (bad cholesterol) subclasses. Nevertheless, a diet enriched with ALA had no deleterious effects on markers of CVD risk, and reproduced the cholesterol-lowering effects of a high-linoleic acid (Omega-6) diet. Atherosclerosis Volume 181, Issue 1 , July 2005, Pages 115-124
Studies from MEDLINE and other sources that were of one year or longer in duration reported estimates of fish oil and plant based omega 3-s intakes and cardiovascular disease outcomes. Secondary prevention was addressed in 14 randomized controlled trials of fish-oil supplements or of diets high in ALA omega-3 fatty acids and one prospective cohort study. Most trials reported that fish oil significantly reduced all-cause mortality, myocardial infarction, cardiac and sudden death, or stroke. Primary prevention of cardiovascular disease was reported in 1 randomized controlled trial, in 25 prospective cohort studies, and in 7 case-control studies. Most cohort studies reported that fish consumption was associated with lower rates of all-cause mortality and adverse cardiac outcomes. The effects on stroke were inconsistent. Evidence suggests that increased consumption of omega-3 fatty acids from fish or fish-oil supplements, but not of alpha-linolenic acid (plant based ALA), reduces the rates of all-cause mortality, cardiac and sudden death, and possibly stroke. The evidence for the benefits of fish oil is stronger in secondary- than in primary-prevention settings. Am J Clin Nutr. 2006 Jul; 84(1):5-17.
Another study compared the effects of the different essential fatty acids on cognitive dysfunction. They concluded that DHA supplementation can improve the cognitive dysfunction due to organic brain damages or aging. Neurosci Res. 2006 Aug 11; [Epub ahead of print]
These studies, all in all, give the general consensus that EPA and DHA are the two most important essential Omega-3 fatty acids. Although ALA indeed does break down into EPA and DHA, it is obvious from the results of several studies that this conversion is not efficient enough to produce the same results as direct EPA and DHA supplementation in all areas of omega-3 benefits on health in humans.
I Don't Eat Fish…What Can I Do???
Even if you don't eat fish, you can still obtain the same benefits of the essential fatty acids through supplementation. One of the claimed disadvantages of obtaining essential fatty acids through fish is the scare of digesting other toxins and contaminants, such as mercury and PCB, in fish these days. When taking fish oil supplements, make sure that the supplements you are taking are pharmaceutical grade fish oil. This will ensure that you’re getting quality fish oil supplements without getting any toxins left in the fish.
Fish Oil Still Isn't For Me…
If fish or fish oil still doesn't work for you, (if you're a vegetarian, allergic or some other factor) plant based sources listed above, especially flaxseed and flaxseed oil are still well worth taking.
Flaxseed and flaxseed oil are both high-quality sources of healthy omega-3 fats, with slightly different characteristics. Flaxseed oil is a more concentrated source of omega-3 fats than flax seeds, but contains only the alpha-linolenic acid component of flaxseed, and not the fiber or lignan components contained in the seeds themselves (though some oils have lignans as well). Therefore, flaxseed oil may share the heart-healthy properties of flaxseed, but not the additional fiber and anti-cancer benefits provided by the actual seeds. The lignan compounds have been studied by the National Cancer Institute for their cancer preventative properties. The SDG lignan in flaxseed not only has anti-cancer properties, it has anti-viral, anti-bacterial, and anti-fungal properties. It is also a powerful anti-oxidant. Most of the SDGs tested for their anti-oxidant activity have shown themselves to be 5 time greater in activity than Vitamin E. http://www.wildernessfamilynaturals.com/high_lignan_flax.htm
Flax seeds may have a slight leg up on flaxseed oil, overall, but remember that the seeds must be ground in order for your body to reap the health benefits.
It is also important to recognize that we all get the omega-6 fat we need from food. There is no need to take any supplements for these fats. Many of the omega fat supplements found in health food stores can potentially worsen your health, not improve it, as they contain omega-6 fats that will only worsen your omega-6 to omega-3 ratio.
EPA and DHA
Fish oil supplements
100 grams of raw flaxseed provides 22,800 mg of ALA
Flax is rich in ALA, the essential omega-3 fat. Flax also contains dietary fiber and lignans for further health benefits. Fish on the other hand are sources of high-quality protein and contain direct sources of omega-3 fats. Both flax and fish contain important nutrients and belong in a healthy eating plan.
However, in the battle between marine sources vs. plant sources, or more specifically, fish vs. flax, the most beneficial source of essential fatty acids is the marine or fish sources. Both have their benefits and both are proven to improve health. However, research shows that the direct intake of EPA and DHA from marine sources produce better, more rapid results due to the lack of a conversion process involved in plant source consumption of ALA.
Omega-3 Picture: http://www.mdsg.umd.edu/Extension/msgsnn/msgsnn03_2/omega3fa.gif
Donald Rudin, MD, and Clara Felix. Omega-3 Oils; A practical Guide. US: Avery, 1996.
Am J Clin Nutr. 2006 Jul; 84(1):5-17.
Am J Clin Nutr. 2001 Mar;73(3):539-48.
Neurosci Res. 2006 Aug 11; [Epub ahead of print]
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