The three types of omega−3 fatty acids involved in human physiology are α-linolenic acid (ALA), found in plant oils, and eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), both commonly found in marine oils. Marine algae and phytoplankton are primary sources of omega−3 fatty acids. Common sources of plant oils containing ALA include walnut, edible seeds, clary sage seed oil, algal oil, flaxseed oil, Sacha Inchi oil, Echium oil, and hemp oil, while sources of animal omega−3 fatty acids EPA and DHA include fish, fish oils, eggs from chickens fed EPA and DHA, squid oils, and krill oil. Dietary supplementation with omega−3 fatty acids does not appear to affect the risk of death, cancer or heart disease. Furthermore, fish oil supplement studies have failed to support claims of preventing heart attacks or strokes or any vascular disease outcomes.
To date, no studies have assessed mortality or nonfatal MI in diabetic patients treated with fish oil.52–54 A recent comprehensive meta-analysis analyzed the effect of fish oil supplements on metabolic parameters when added to usual care in patients with type 2 diabetes mellitus or impaired glucose tolerance.54 The meta-analysis included a total of 23 small, randomized trials with over 1000 patients that were assessed for lipid and insulin resistance parameters. At a mean follow-up of approximately 9 weeks, triglyceride reduction was accomplished but no significant changes were seen in total cholesterol, high-density lipoprotein-cholesterol, HgA1c levels, fasting glucose levels, fasting insulin, or in body weight. The largest randomized trial to date assessed approximately 400 patients with impaired glucose tolerance or insulin-dependent diabetes mel-litus, and as reflected in the larger meta-analysis, found no effect of moderate to high doses of fish oil on diabetic parameters.55 There are insufficient randomized data to comment on the combination of fish oil and specific diabetes medications and related mortality and/or morbidity.
Three omega−3 fatty acids are important in human physiology, α-linolenic acid (18:3, n-3; ALA), eicosapentaenoic acid (20:5, n-3; EPA), and docosahexaenoic acid (22:6, n-3; DHA). These three polyunsaturates have either 3, 5, or 6 double bonds in a carbon chain of 18, 20, or 22 carbon atoms, respectively. As with most naturally-produced fatty acids, all double bonds are in the cis-configuration, in other words, the two hydrogen atoms are on the same side of the double bond; and the double bonds are interrupted by methylene bridges (-CH
Good points, Miroslav. Focusing on your 4th point, with so many different formulations on the market that contain various preservatives, only looking at the blood levels of omega-3’s as the flag for increased risk for prostate cancer tends to ignore the fact that certain populations in coastal regions maintain a diet high in omega fish oils and don’t have a marked increase level of prostate cancer, pointing to the fact that another agent may be to blame here.
The National Institutes of Health (NIH) has created a website, NIH Clinical Research Trials and You, to help people learn about clinical trials, why they matter, and how to participate. The site includes questions and answers about clinical trials, guidance on how to find clinical trials through ClinicalTrials.gov and other resources, and stories about the personal experiences of clinical trial participants. Clinical trials are necessary to find better ways to prevent, diagnose, and treat diseases.
Anxiety, the most commonly experienced psychiatric symptom, is a psychological state derived from inappropriate or exaggerated fear leading to distress or impairment. The lifetime prevalence of any anxiety disorder is reported to be approximately 1 in 3.1 Anxiety is often comorbid with depressive disorders2 and is associated with lower health-related quality of life3 and increased risk of all-cause mortality.4 Treatment options include psychological treatments, such as cognitive-behavioral therapy and pharmacological treatments, mainly with selective serotonin reuptake inhibitors.5 Individuals with anxiety and related disorders tend to be more concerned about the potential adverse effects of pharmacological treatments (eg, sedation or drug dependence) and may be reluctant to engage in psychological treatments that can be time-consuming and costly, as well as sometimes limited in availability.6 Thus, evidence-based and safer treatments are required, especially for anxious patients with comorbid medical conditions.
Another small study had all volunteers consume the same exact control diet and substituted fish oil for visible fats (things like butter and cream). The volunteers consumed six grams of fish oil each day for three weeks. They found that body fat mass decreased with the intake of fish oil. The researchers conclude that dietary fish oil reduces body fat and stimulates the use of fatty acids for the production of energy in healthy adults. (33a)
While fish for dinner is one way to get EPA and DHA, most people don’t eat the suggested two to three servings of oily fish per week to reap the benefits of omega-3s. What’s more, there are extremely few food sources, aside from fish, that naturally provide EPA and DHA. With all the benefits that can come from fish oil, it’s no surprise that these supplements are increasing in popularity.
Some people who are hypersensitive to fish or have a known allergy to fish products may have a negative reaction to fatty acids which were derived from fish. Some fish oil tablets are also produced with alpha-linolenic acids which come from nuts, which may aggravate those which have an allergy to these products. In many cases these allergies will manifest themselves as a skin rash, but the symptoms could be more severe depending on the severity of your allergies. People with this concern will need to avoid using these products.
Australian researchers published results of a study examining the effects of fish oil on weight loss in combination with diet and exercise in the May 2007 issue of American Journal of Clinical Nutrition. The results show that a combination of fish oil supplements and regular exercise can reduce body fat while also improving heart and metabolic health. The fish supplementation group had lowered triglycerides, increased HDL cholesterol and improved blood flow. Overall, adding fish oil to a current exercise program (and a overall healthy lifestyle) looks like it can decrease body fat as well as cardiovascular disease risk. (32)
My optometrist explained to me how important a good quality fish oil was to my eye health because I have dry eye due to inflammation. Little did I realize that it would be go for so many other things. Since I have been taking this product, not only have I had improvement with my dry eyes, but I have less joint pain from my osteoarthritis! I am so happy I found this and plan to continue it as part of my regular supplement routine! Thanks BioScience Nutrition!
One meta-analysis concluded that omega−3 fatty acid supplementation demonstrated a modest effect for improving ADHD symptoms. A Cochrane review of PUFA (not necessarily omega−3) supplementation found "there is little evidence that PUFA supplementation provides any benefit for the symptoms of ADHD in children and adolescents", while a different review found "insufficient evidence to draw any conclusion about the use of PUFAs for children with specific learning disorders". Another review concluded that the evidence is inconclusive for the use of omega−3 fatty acids in behavior and non-neurodegenerative neuropsychiatric disorders such as ADHD and depression.
As mentioned above, the omega-3 index has been suggested as a predictor of the risk of coronary heart disease and other cardiovascular events. One study on a population in Seattle found that people with low omega-3 index levels were 10 times as likely to die from sudden cardiac death compared to people with higher omega-3 index levels (13). The NIH-funded Framingham study referenced above showed that the people with the highest omega-3 index levels had a 33% reduction in risk of death from any cause compared to the people with the lowest levels (2). In addition, a new study focused on individuals age 25 to 41 found that higher omega-3 index levels were associated with lower blood pressure in healthy adults (14).
For dry eye: Fish oil supplements providing EPA 360-1680 mg and DHA 240-560 mg have been used for 4-12 weeks. Some people used the specific product (PRN Dry Eye Omega Benefits softgels). A specific combination product containing EPA 450 mg, DHA 300 mg, and flaxseed oil 1000 mg (TheraTears Nutrition, Advanced Nutrition Research; Caruso’s Natural Health UltraMAX fish oil, Sydney, New South Wales, Australia) has been used once daily for 90 days.
Ramakrishnan, U., Stein, A. D., Parra-Cabrera, S., Wang, M., Imhoff-Kunsch, B., Juarez-Marquez, S., Rivera, J., and Martorell, R. Effects of docosahexaenoic acid supplementation during pregnancy on gestational age and size at birth: randomized, double-blind, placebo-controlled trial in Mexico. Food Nutr Bull 2010;31(2 Suppl):S108-S116. View abstract.
Why would someone foul a perfectly good box of rotini with omega 3 oils? This is based on the belief that omega 3 fatty acids reduce heart disease and vascular risk, probably through reducing blood pressure and cholesterol. This is a plausible claim, but as we see over and over again in medicine, plausibility (while nice) is insufficient as a basis for clinical claims.
Widenhorn-Müller K, Schwanda S, Scholz E, Spitzer M, Bode H. Effect of supplementation with long-chain ω-3 polyunsaturated fatty acids on behavior and cognition in children with attention deficit/hyperactivity disorder (ADHD): a randomized placebo-controlled intervention trial. Prostaglandins Leukot Essent Fatty Acids. 2014;91(1-2):49-60. doi:10.1016/j.plefa.2014.04.004PubMedGoogle ScholarCrossref
The various enzymes (COX and LOX) that make inflammatory eicosanoids can accommodate both AA and EPA, but again due to the greater spatial size of DHA, these enzymes will have difficulty in converting DHA into eicosanoids. This makes DHA a poor substrate for these key inflammatory enzymes. Thus DHA again has little effect on cellular inflammation whereas EPA can have a powerful impact.
Human diet has changed rapidly in recent centuries resulting in a reported increased diet of omega−6 in comparison to omega−3. The rapid evolution of human diet away from a 1:1 omega−3 and omega−6 ratio, such as during the Neolithic Agricultural Revolution, has presumably been too fast for humans to have adapted to biological profiles adept at balancing omega−3 and omega−6 ratios of 1:1. This is commonly believed to be the reason why modern diets are correlated with many inflammatory disorders. While omega−3 polyunsaturated fatty acids may be beneficial in preventing heart disease in humans, the level of omega−6 polyunsaturated fatty acids (and, therefore, the ratio) does not matter.
Thanks to fatdog11 for that informative post about PCB’s in fish-oil supplements. Are these same toxicity levels found in fish themselves, or possibly are these levels so high only in highly concentrated fish-oil products? Also, can fatdog11 please inform us more about algae-derived omega-3. What are the DHA and EPA levels in these capsules? What is the cost, and where can they be purchased?
Most people get far too little omega-3s in their diet. In fact, research consistently indicates that the majority of Americans have just slightly more than half the amount of EPA and DHA in their tissues than they need for optimum brain and body health. This is partly due to a high dietary intake of unhealthy fats combined with an inadequate intake of EPA and DHA.
Nakamura, N., Hamazaki, T., Ohta, M., Okuda, K., Urakaze, M., Sawazaki, S., Yamazaki, K., Satoh, A., Temaru, R., Ishikura, Y., Takata, M., Kishida, M., and Kobayashi, M. Joint effects of HMG-CoA reductase inhibitors and eicosapentaenoic acids on serum lipid profile and plasma fatty acid concentrations in patients with hyperlipidemia. Int J Clin Lab Res 1999;29(1):22-25. View abstract.
More than 30 clinical trials have tested different omega-3 preparations in people with depression. Most studies have used omega-3s as add-on therapy for people who are taking prescription antidepressants with limited or no benefit. Fewer studies have examined omega-3 therapy alone. Clinical trials typically use EPA alone or a combination of EPA plus DHA, at doses from 0.5 to 1 gram per day to 6 to 10 grams per day. To give some perspective, 1 gram per day would correspond to eating three salmon meals per week.
If you get your omega-3 index measured, you’ll know if your current efforts are sufficient. And this knowledge is especially important given that even health-conscious people are not always self-aware. One survey found that in a group of people with omega-3 index levels in the intermediate risk range, some 30% believed they were consuming enough omega-3s (11). One registered dietitian wrote a compelling story about exactly this experience. She discovered she was in the intermediate range, in spite of her intentions to eat enough fish.
There are three types of omega-3 fatty acids, which include EPA, DHA and ALA, which is alpha-linoleic acid. Although EPA and DHA are found to have high amounts from animal sources, ALA is found in rich concentrations in plant sources, including certain vegetable oils and flaxseeds, although fatty fish and shellfish are the best sources of EPA and DHA, according to the National Center for Complementary and Alternative Medicine. Examples of these fatty fish and shellfish include salmon, tuna, trout, crab, oysters and mussels.
Bianconi, L., Calo, L., Mennuni, M., Santini, L., Morosetti, P., Azzolini, P., Barbato, G., Biscione, F., Romano, P., and Santini, M. n-3 polyunsaturated fatty acids for the prevention of arrhythmia recurrence after electrical cardioversion of chronic persistent atrial fibrillation: a randomized, double-blind, multicentre study. Europace. 2011;13(2):174-181. View abstract.
Could you be deficient in omega-3s? The University of Maryland Medical Center says that the symptoms “include fatigue, poor memory, dry skin, heart problems, mood swings or depression, and poor circulation.” They also warn against a poor omega-3 to omega-6 ratio, cautioning readers that it may be “associated with worsening inflammation over time.” (6)
Children: Fish oil is POSSIBLY SAFE when taken by mouth appropriately. Fish oil has been used safely through feeding tubes in infants for up to 9 months. But young children should not eat more than two ounces of fish per week. Fish oil is also POSSIBLY SAFE when given in the vein by a health care professional to infants who cannot take food by mouth. Fish oil is POSSIBLY UNSAFE when consumed from dietary sources in large amounts. Fatty fish contain toxins such as mercury. Eating contaminated fish frequently can cause brain damage, mental retardation, blindness and seizures in children.