Krill oil is a source of omega−3 fatty acids.[116] The effect of krill oil, at a lower dose of EPA + DHA (62.8%), was demonstrated to be similar to that of fish oil on blood lipid levels and markers of inflammation in healthy humans.[117] While not an endangered species, krill are a mainstay of the diets of many ocean-based species including whales, causing environmental and scientific concerns about their sustainability.[118][119][120]

The two key omega-3 fatty acids are docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA). Fatty fish like salmon, mackerel, and sardines are rich in these omega-3s. Some plants are rich in another type of omega-3 fatty acid, alpha-linolenic acid, which the body can convert to DHA and EPA. Good sources of these are flaxseeds, chia seeds, walnuts, pumpkin seeds, and canola oil.
Sangiovanni, J. P., Agron, E., Meleth, A. D., Reed, G. F., Sperduto, R. D., Clemons, T. E., and Chew, E. Y. {omega}-3 Long-chain polyunsaturated fatty acid intake and 12-y incidence of neovascular age-related macular degeneration and central geographic atrophy: AREDS report 30, a prospective cohort study from the Age-Related Eye Disease Study. Am J Clin Nutr 2009;90(6):1601-1607. View abstract.
My initial interest in omga-3 was an article by Dr Andrew Stoll in Harvard about May 99, One of my bipolar patients had extreme OCD related to HIV which was not relevant to her. I put her on 9.6g of fish oil and continued her on her regular medication. She was well for the next 3 years with no obvious mental health problem when she was attending here.

In your final paragraph, you suggest that a ratio of 2:1 EPA/DHA maybe best for reducing inflammation. Are you suggesting using two separate products to obtain that ratio? I can't see how it is achieveable through standard omega-3 products. Good fish oil brands are typically 60% or higher EPA, but never reach a 2:1 ratio in my product searches. According to case studies (link below), 1 gram of EPA per day (60% or more of the total omega-3 content) is sufficient and the highest efficacy.

Fish oils rich in omega 3 fatty acids help improve fertility and cell division. Preliminary research conducted on animals has shown that when males are fed a diet containing fish oil, the quality of the sperm is enhanced. After ejaculation, the sperm has increased survival against lipid peroxidative attacks in the female genital tract, thereby increasing the chances of conception. On the other hand, similar animal studies have shown inhibition in the synthesis of prostaglandin E and prostaglandin F, which are produced in large quantities by human seminal vesicles. The research, however, found no impact on the count and mobility of sperm.
Your retina contains quite a bit of DHA, making it necessary for that fatty acid to function. (90) The National Eye Institute, part of the National Institutes of Health, concludes that there is “consistent evidence” suggesting long-chain polyunsaturated fatty acids DHA and EPA are necessary for retinal health and may help protect the eyes from disease. (91)
Belalcazar, L. M., Reboussin, D. M., Haffner, S. M., Reeves, R. S., Schwenke, D. C., Hoogeveen, R. C., Pi-Sunyer, F. X., and Ballantyne, C. M. Marine omega-3 fatty acid intake: associations with cardiometabolic risk and response to weight loss intervention in the Look AHEAD (Action for Health in Diabetes) study. Diabetes Care 2010;33(1):197-199. View abstract.
Heart disease. Research suggests that eating fish can be effective for keeping people with healthy hearts free of heart disease. People who already have heart disease might also be able to lower their risk of dying from heart disease by eating fish. The picture is less clear for fish oil supplements. For people who already take heart medications such as a "statin" and those who already eat a decent amount of fish, adding on fish oil might not offer any additional benefit.
The Lyon Diet Heart Study, performed shortly after the DART study, was a prospective trial of 607 survivors of MI who were randomized to either a Mediterranean diet or a regular Western diet.49 At a mean follow-up of 27 months, the primary end point of death from cardiovascular causes and nonfatal deaths had a 73% relative risk reduction—a positive effect that continued at follow up assessment at a mean of 46 months.50 FA analysis of plasma lipids showed that in the patients randomized to a Mediterranean diet, there was a higher concentration of alpha-linolenic acid as well as EPA. Fish, however, was consumed in similar amounts by both the Western and Mediterranean diet groups. The higher blood level of EPA in the Mediterranean diet arm was attributed to its synthesis from alpha-linolenic acid, which was 60-times higher than the plasma concentration of EPA. In addition, the risk reduction that occurred in this trial could not be attributed to one particular diet intervention because as the consumption of fruits and vegetables increased, the consumption of monounsaturated fat increased, while saturated fat and cholesterol were decreased.
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.
Irving, G. F., Freund-Levi, Y., Eriksdotter-Jonhagen, M., Basun, H., Brismar, K., Hjorth, E., Palmblad, J., Vessby, B., Vedin, I., Wahlund, L. O., and Cederholm, T. Omega-3 fatty acid supplementation effects on weight and appetite in patients with Alzheimer's disease: the omega-3 Alzheimer's disease study. J Am Geriatr Soc 2009;57(1):11-17. View abstract.
Fish oil is also extremely beneficial for pregnant women and their children. Throughout pregnancy and also while breastfeeding, a woman’s omega-3 needs are even higher than usual. According to the American Pregnancy Association, most U.S. women are deficient in EPA and especially DHA going into pregnancy and get even more depleted during pregnancy, as the placenta supplies the fetus with DHA from the mother’s tissue. Omega-3 DHA is a critical building block of the fetal brain, eyes and nervous system. Once the baby is born, omega-3s continue to be vital to healthy brain development and immune function. (30)
CONDITIONS OF USE AND IMPORTANT INFORMATION: This information is meant to supplement, not replace advice from your doctor or healthcare provider and is not meant to cover all possible uses, precautions, interactions or adverse effects. This information may not fit your specific health circumstances. Never delay or disregard seeking professional medical advice from your doctor or other qualified health care provider because of something you have read on WebMD. You should always speak with your doctor or health care professional before you start, stop, or change any prescribed part of your health care plan or treatment and to determine what course of therapy is right for you.
The Cochrane researchers found that increasing long-chain omega 3 provides little if any benefit on most outcomes that they looked at. They found high certainty evidence that long-chain omega 3 fats had little or no meaningful effect on the risk of death from any cause. The risk of death from any cause was 8.8% in people who had increased their intake of omega 3 fats, compared with 9% in people in the control groups.
Sangiovanni, J. P., Agron, E., Meleth, A. D., Reed, G. F., Sperduto, R. D., Clemons, T. E., and Chew, E. Y. {omega}-3 Long-chain polyunsaturated fatty acid intake and 12-y incidence of neovascular age-related macular degeneration and central geographic atrophy: AREDS report 30, a prospective cohort study from the Age-Related Eye Disease Study. Am J Clin Nutr 2009;90(6):1601-1607. View abstract.

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.
The supplements contain omega-3 fatty acids, the polyunsaturated oils prominent in fatty cold water fish like salmon, sardines and mackerel. In many observational studies, people who regularly consumed fish two or more times a week were less likely to suffer heart attacks, strokes and cardiovascular deaths than those who ate fish infrequently or not at all.
Kabir, M., Skurnik, G., Naour, N., Pechtner, V., Meugnier, E., Rome, S., Quignard-Boulange, A., Vidal, H., Slama, G., Clement, K., Guerre-Millo, M., and Rizkalla, S. W. Treatment for 2 mo with n 3 polyunsaturated fatty acids reduces adiposity and some atherogenic factors but does not improve insulin sensitivity in women with type 2 diabetes: a randomized controlled study. Am.J.Clin.Nutr. 2007;86(6):1670-1679. View abstract.
Some studies reported better psychomotor development at 30 months of age in infants whose mothers received fish oil supplements for the first four months of lactation.[45] In addition, five-year-old children whose mothers received modest algae based docosahexaenoic acid supplementation for the first 4 months of breastfeeding performed better on a test of sustained attention. This suggests that docosahexaenoic acid intake during early infancy confers long-term benefits on specific aspects of neurodevelopment.[45]
Damage to the kidneys caused the drug cyclosporine. Cyclosporine is a medication that reduces the chance of organ rejection after an organ transplant. Taking fish oil seems to prevent kidney damage in people taking this drug. Fish oil also seems to improve kidney function during the recovery phase following the rejection of a transplanted organ in people taking cyclosporine.