Most any food or compound you consume can elicit undesirable reactions. Fish oil provides a well-documented plethora of healthful benefits and is reputed to have few side effects. However, if you've started taking fish oil supplements and then simultaneously started to experience insomnia, you may be among the few who have a side effect. Insomnia as a side effect of fish oil can improve over time and the potential benefits of fish oil can more than compensate for your initial discomfort.
Fish oil contains nutrients your body can't synthesize: omega-3 fatty acids called docosahexaenoic acid, or DHA, and eicosapentaenoic acid, or EPA. You must obtain EPA and DHA from your diet. Found in significant quantities in fish and seafood, as well as flaxseed, walnuts and algae, omega-3 fatty acids function as anti-inflammatory agents. They naturally decrease your immune system's inflammatory response. Western diets tend to have 20 to 30 times the amount of pro-inflammatory omega-6 fatty acids as omega-3 fatty acids, creating an imbalance that promotes inflammation. For this reason, many people supplement their dietary intake of omega-3 fatty acids using fish oil supplements.
EPA and DHA in fish oil lower triglycerides and reduce your risk of cardiovascular disease. Substantial evidence also suggests that EPA and DHA can improve or reduce the risk of other conditions, including high cholesterol, high blood pressure, macular degeneration, diabetes, osteoporosis, rheumatoid arthritis, inflammatory bowel disease, menstrual pain, psoriasis, asthma, lupus, kidney problems, asthma and some forms of cancer, such as breast, prostate, colon and endometrial.
Mental Health Benefits
Fatty acids make up about 60 percent of your brain's mass. They compose 70 percent of the myelin sheath that surrounds neurons and most of the cell membrane that contains and protects the cell bodies. Fatty acids also contribute to the brain's biochemical dopamine and serotonin communication system, so deficits in omega-3 fatty acids can contribute to varied cognitive and mental health problems. Supplementing with fish oil can improve the symptoms of depression, schizophrenia and bipolar disorder, according to the University of Maryland Medical Center and Medline Plus, an online resource of the National Institutes of Health.
Several studies suggest that fish oil can improve sleep. Pregnant mothers with high levels of DHA have infants who sleep better, reports researcher Sunita Cheruku in the September 2002 "American Journal of Clinical Nutrition." Cheruku suggests that improved sleep might indicate advanced maturation of the central nervous system. In a 2002 study published in the "Archives of General Psychiatry," researcher Malcolm Peet evaluated the effect of fish oil on depressed patients who weren't responding to medications. Patients who took 1 g each day of EPA supplements showed improvement in symptoms of depression and reported increased quality of sleep. Omega-3 fatty acids might improve sleep by enhancing the release of melatonin, a hormone that regulates the sleep cycle. Although more research is needed to clearly establish that fish oil enhances sleep, data currently available indicates fish oil generally improves sleep patterns.
Fish Oil Sleep Side Effects
Sleep-related side effects from fish oil, such as sleepiness or insomnia, don't occur commonly, and when they do they usually improve within a couple of weeks as your body adjusts to the influx of omega-3 fatty acids. If you experience insomnia, try taking the fish oil earlier during the day, and start out at lower dosages and increase it slowly. Speak with your doctor before starting fish oil supplements to make sure it doesn't interact with any of your current conditions or medications. For example, fish can have a thinning effect on blood and can interact with blood thinners, including warfarin, clopedigrel and aspirin. Fish oil can lower blood sugar and your doctor might need to make adjustments in diabetes medications, such as flipizide, glyburide, metformin and insulin. If you experience side effects such as arm, jaw or back pain, shortness of breath, nausea, sweating or chest pain, speak with your physician immediately.
- “American Journal of Clinical Nutrition”; Higher Maternal Plasma Docosahexaenoic Acid During Pregnancy is Associated With More Mature Neonatal Sleep-state Patterning; Sunita Cheruku, et al.; September 2002
- “Archives of General Psychiatry”; A Dose-Ranging Study of the Effects of Ethyl-Eicosapentaenoate in Patients With Ongoing Depression Despite Apparently Adequate Treatment With Standard Drugs; Malcolm Peet and David Horrobin; October 2002
- Mayo Clinic: Omega-3-Acid Ethyl Esters (Oral Route)
- MedlinePlus: Fish Oil
- Reuters.com: Can Fish Oil Help Guard Against Schizophrenia?; Anne Harding; February 1, 2010
- The Franklin Institute: The Human Brain