When taking fish oil, more is not always better. Remember that you want it to stay in a balanced ratio with omega-6 fats. For most people, I recommend a 1,000-milligram dose of fish oil daily as a good amount and the most scientifically studied dosage. I highly recommend not taking more than that unless directed to under the supervision of a doctor.

Several large trials have evaluated the effect of fish or fish oils on heart disease. In the Gruppo Italiano per lo Studio della Sopravvivenza nell’Infarto Miocardio (known as the GISSI Prevention Trial), heart attack survivors who took a 1-gram capsule of omega-3 fats every day for three years were less likely to have a repeat heart attack, stroke, or die of sudden death than those who took a placebo. (2) Notably, the risk of sudden cardiac death was reduced by about 50 percent. In the more recent Japan EPA Lipid Intervention Study (JELIS), participants who took EPA plus a cholesterol-lowering statin were less likely to have a major coronary event (sudden cardiac death, fatal or nonfatal heart attack, unstable angina, or a procedure to open or bypass a narrowed or blocked coronary artery) than those who took a statin alone. (3)
The reason why fish oil could increase a man’s risk of prostate cancer is IMBALANCE. Like I said earlier, omega-6 fatty acids aren’t bad for you. In fact, if your diet contains too many omega-3 fatty acids, your immune system wouldn’t work very well because omega-3 and omega-6 fatty acids are meant to work in a system of checks and balances. Omega-3 fatty acids suppress inflammation, and omega-6 fatty acids promote inflammation, which actually supports your body’s natural system of defense like activating your white blood cells.

Jump up ^ Martins, Julian G (2009). "EPA but Not DHA Appears to Be Responsible for the Efficacy of Omega-3 Long Chain Polyunsaturated Fatty Acid Supplementation in Depression: Evidence from a Meta-Analysis of Randomized Controlled Trials". Journal of the American College of Nutrition. 28 (5): 525–42. doi:10.1080/07315724.2009.10719785. PMID 20439549.
Fish oil is also used for diabetes, prediabetes, asthma, a movement and coordination disorder called dyspraxia, dyslexia, eczema, autism, obesity, weak bones (osteoporosis), rheumatoid arthritis (RA), osteoarthritis, psoriasis, an autoimmune disease called systemic lupus erythematosus (SLE), multiple sclerosis, HIV/AIDS, cystic fibrosis, gum disease, Lyme disease, sickle cell disease, and preventing weight loss caused by some cancer drugs.
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