OMEGA 3 OIL – A COLLECTION OF STUDIES
25th February 2007 by Arrow Durfee Posted in Uncategorized
These studies were collected up by Chuck. Thanks for your good work, Chuck.
Importance of Omega Three Fats in Health and Disease
By Dr. William Connor
Interest in omega-3 fatty acids began some 30 years ago and there are now several thousand papers in the scientific literature supporting their benefits.
There is little doubt that omega-3 fatty acids are important in human nutrition. They are significant structural components of the cell membranes of tissues throughout the body and are especially rich in the retina, brain, and sperm, in which docosahexaenoic acid (DHA) constitutes 36.4% of total fatty acids
Membrane fluidity is essential for proper functioning of these tissues. In the retina, where omega-3 fatty acids are especially important, deficiency can result in decreased vision and abnormal electroretinogram results.
Omega-3 Fatty acids are essential fatty acids, necessary from conception through pregnancy and infancy and, undoubtedly, throughout life.
The ratio of omega-6 to omega-3 fatty acids has increased in industrialized societies because of increased consumption of vegetable oils rich in omega-6 fatty acids, ie, linoleic acid, and reduced consumption of foods rich in omega-3 fatty acids.
Another important feature of omega-3 fatty acids is their role in the prevention and modulation of certain diseases that are common in Western civilization.
The following is a partial list of diseases that may be prevented or ameliorated with omega-3 fatty acids, in descending order of the strength of the available evidence as perceived by this reviewer:
Coronary heart disease and stroke;
Essential fatty acid deficiency in infancy (retinal and brain development);
Autoimmune disorders (e.g., lupus and nephropathy);
Cancers of the breast, colon, and prostate;
Mild hypertension; and
Cardiovascular Benefits Of Omega-3 Fatty Acids
The strongest evidence of a relation between omega-3 fatty acids and disease is the inverse relation between the amount of omega-3 fatty acids in the diet and in blood and tissues and the occurrence of coronary heart disease and its many complications. Effects of omega-3 fatty acids on coronary heart disease have been shown in hundreds of experiments in animals, humans, tissue culture studies, and clinical trials.
Omega-3 fatty acids from fish have been shown to be protective of heart disease and, by a variety of mechanisms, prevent deaths from coronary disease, particularly cardiac arrest. The unique properties of these fatty acids in coronary heart disease first became apparent in the investigations of the health status of Greenland Eskimos who consumed diets very high in fat from seals, whales, and fish and yet had a low rate of coronary heart disease.
Further studies clarified this paradox. The fat the Eskimos consumed contained large quantities of the very-long-chain and highly polyunsaturated fatty acids of EPA and DHA, which are abundant in fish, shellfish, and sea mammals and are scarce or absent in land animals and plants. EPA and DHA are synthesized by phytoplankton, which are the plants of the waters and the base of the food chain for marine life.
Dietary omega-3 fatty acids act to prevent heart disease through a variety of actions. They:
Prevent arrhythmias (ventricular tachycardia and fibrillation),
Prostaglandin and leukotriene precursors,
Have anti-inflammatory properties,
Inhibit synthesis of cytokines and mitogens,
Stimulate endothelial-derived nitric oxide,
Have hypolipidemic properties with effects on triglycerides and VLDLs, and
EPA and DHA have strong antiarrhythmic action on the heart. In experimental animals and tissue culture systems, EPA and DHA prevent the development of ventricular tachycardia and fibrillation. Even total mortality has been improved in several studies in which the omega-3 fatty acid intake was increased. In one study, men who consumed salmon 1 time/wk had a 70% less likelihood of cardiac arrest.
In another study overall mortality was decreased by 29% in men with overt cardiovascular disease who consumed omega-3 fatty acids from fish or fish oil, probably because of the reduction in cardiac arrests.
The most recent data on fish consumption and risk of sudden cardiac death were from the Physician’s Health Study in the United States in 20551 male physicians. Consumption of 1 fish meal/week was associated with a 52% lower risk of sudden cardiac death compared with consumption of >>>>>>>>>>>>>>>>>>>>
More from study in The Lancet February 8, 2003; 361(9356);477-485
Doctors have discovered how oily fish protects against heart disease and stroke. Researchers at Southampton University have found that omega-3 oils stop the build up of fatty deposits in the arteries. If left unchecked these deposits can block key routes to the heart or brain triggering an attack or stroke. The findings add to growing evidence that eating oily fish or taking fish oil supplements reduce the risks of this happening.
Professor Philip Calder and colleagues based their findings on a study of 162 patients who were waiting to have surgery to remove dangerously high levels of fatty build-up or plaques in their arteries.
The patients were divided into three groups and were asked to take either omega-3 fish-oil capsules, sunflower-oil capsules or a dummy capsule six times a day. On average, they took the capsules for 42 days.
After the patients underwent surgery, doctors examined their plaques.
They found that there were far fewer inflammatory cells in the plaques of patients who had taken the omega-3 fish oil capsules. This meant that they were less likely to rupture and to trigger a heart attack or stroke.
Professor Calder hailed the results saying they offered hope to the hundreds of thousands of people who die from arterial disease every year. He suggested that people should eat more oily fish or take fish-oil supplements. “I have no hesitation in recommending that people increase their consumption of omega-3s, even if they are not ill, because they are protective,” he said.
Flax Seed Oil Actually Increases Prostate Cancer While Fish Oil Decreases It
A recent study of about 47,000 men has found the ALA omega-3 fatty acids stimulate the growth of prostate tumors in men. Of the men monitored over 14 years, some 3,000 struggled with prostate cancer and about one in seven were suffering from the advanced stages of the disease.
Researchers found men who were suffering from advanced prostate cancer had higher quantities of ALA from non-animal as well as meat and dairy sources.
Scientists also found EPA and DHA could reduce the risk of total and advanced prostate cancer too. How does EPA and DHA work to prevent prostate cancer? Researchers offered these possibilities:
modification of membrane phospholipid composition
alteration of cell signaling and receptor activity
interference with androgen activity
American Journal of Clinical Nutrition July 2004 80(1);204-216
Dietary intake of n–3 and n–6 fatty acids and the risk of prostate cancer1,2,3
Michael F Leitzmann, Meir J Stampfer, Dominique S Michaud, Katarina Augustsson, Graham C Colditz, Walter C Willett and Edward L Giovannucci
1 From the Nutritional Epidemiology Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, NIH, DHHS, Bethesda, MD (MFL and DSM); the Departments of Epidemiology and Nutrition, Harvard School of Public Health, Boston (MJS, WCW, and ELG); the Channing Laboratory, Department of Medicine, Harvard Medical School and Brigham and Women’s Hospital, Boston (MJS, GCC, WCW, and ELG); and the Department of Medical Epidemiology, Karolinska Institutet, Stockholm (KA)
Background: Laboratory studies have shown that n–3 fatty acids inhibit and n–6 fatty acids stimulate prostate tumor growth, but whether the dietary intake of these fatty acids affects prostate cancer risk in humans remains unclear.
Objective: We prospectively evaluated the association between intakes of -linolenic (ALA; 18:3n–3), eicosapentaenoic (EPA; 20:5n–3), docosahexaenoic (DHA; 22:6n–3), linoleic (LA; 18:2n–6), and arachidonic (AA; 20:4n–6) acids and prostate cancer risk.
Design: A cohort of 47 866 US men aged 40–75 y with no cancer history in 1986 was followed for 14 y.
Results: During follow-up, 2965 new cases of total prostate cancer were ascertained, 448 of which were advanced prostate cancer. ALA intake was unrelated to the risk of total prostate cancer. In contrast, the multivariate relative risks (RRs) of advanced prostate cancer from comparisons of extreme quintiles of ALA from nonanimal sources and ALA from meat and dairy sources were 2.02 (95% CI: 1.35, 3.03) and 1.53 (0.88, 2.66), respectively. EPA and DHA intakes were related to lower prostate cancer risk. The multivariate RRs of total and advanced prostate cancer from comparisons of extreme quintiles of the combination of EPA and DHA were 0.89 (0.77, 1.04) and 0.74 (0.49, 1.08), respectively. LA and AA intakes were unrelated to the risk of prostate cancer. The multivariate RR of advanced prostate cancer from a comparison of extreme quintiles of the ratio of LA to ALA was 0.62 (0.45, 0.86).
Conclusions: Increased dietary intakes of ALA may increase the risk of advanced prostate cancer. In contrast, EPA and DHA intakes may reduce the risk of total and advanced prostate cancer.
Fish Oil More Useful for Treating Inflammation Than Flax Seed Oil
While all omega-3 fats possess immune-boosting qualities, omega-3 fats from fish oil, EPA and DHA, are more biologically potent than omega-3 fat ALA, found in plant sources such as flax seeds.
These fats have also been found, by many animal and clinical studies, to have anti-inflammatory properties, indicating that they might be beneficial to managing diseases such as coronary heart disease, depression and cancer. Omega-3 fats many also help with aging.
Clinical trials have also assessed the benefits of supplementing the diet with fish oils and results showed a decrease in diseases including rheumatoid arthritis, Crohn’s disease, ulcerative colitis, psoriasis, lupus erythematosus, multiple sclerosis and migraine headaches.
Journal American College Nutrition December 2002;21(6):495-505
Omega-3 fatty acids in inflammation and autoimmune diseases.
Among the fatty acids, it is the omega-3 polyunsaturated fatty acids (PUFA) which possess the most potent immunomodulatory activities, and among the omega-3 PUFA, those from fish oil-eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA)–are more biologically potent than alpha-linolenic acid (ALA). Some of the effects of omega-3 PUFA are brought about by modulation of the amount and types of eicosanoids made, and other effects are elicited by eicosanoid-independent mechanisms, including actions upon intracellular signaling pathways, transcription factor activity and gene expression. Animal experiments and clinical intervention studies indicate that omega-3 fatty acids have anti-inflammatory properties and, therefore, might be useful in the management of inflammatory and autoimmune diseases. Coronary heart disease, major depression, aging and cancer are characterized by an increased level of interleukin 1 (IL-1), a proinflammatory cytokine. Similarly, arthritis, Crohn’s disease, ulcerative colitis and lupus erythematosis are autoimmune diseases characterized by a high level of IL-1 and the proinflammatory leukotriene LTB(4) produced by omega-6 fatty acids. There have been a number of clinical trials assessing the benefits of dietary supplementation with fish oils in several inflammatory and autoimmune diseases in humans, including rheumatoid arthritis, Crohn’s disease, ulcerative colitis, psoriasis, lupus erythematosus, multiple sclerosis and migraine headaches. Many of the placebo-controlled trials of fish oil in chronic inflammatory diseases reveal significant benefit, including decreased disease activity and a lowered use of anti-inflammatory drugs.