Ample evidence from animal studies supports regular supplementation with omega-3 oils as a means of lowering long-term cardiovascular risk. This may be due to omega-3 fatty acids’ effects on reducing inflammation, lowering triglycerides, reducing blood pressure, improving endothelial function, inducing new blood vessel formation after heart attack or stroke, and favorable modification of obesity-related inflammatory molecules.35-39
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)
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.
Fish oil has only a small benefit on the risk of premature birth. A 2015 meta-analysis of the effect of omega−3 supplementation during pregnancy did not demonstrate a decrease in the rate of preterm birth or improve outcomes in women with singleton pregnancies with no prior preterm births. A systematic review and meta-analysis published the same year reached the opposite conclusion, specifically, that omega−3 fatty acids were effective in "preventing early and any preterm delivery".
The use of DHA by persons with epilepsy could decrease the frequency of their seizures. Studies have shown that children with epilepsy had a major improvement, i.e. decrease in the frequency of their seizures, but another study showed mixed results with 57 adults taking DHA supplementation. The 57 subjects demonstrated a decreased frequency of seizures for the first six weeks of the study, but for some, it was just a temporary improvement (R).
A 2012 study involved children from 6 to 12 years of age with ADHD who were being treated with methylphenidate and standard behavior therapy for more than six months. The parents of these children reported no improvement in behavior and academic learning using these standard treatments. The researchers randomly gave some of the children an omega-3 and omega-6 acid supplementation or a placebo. They found “statistically significant improvement” for the omega group in the following categories: restlessness, aggressiveness, completing work and academic performance. (5)
Omega−3 fatty acids are formed in the chloroplasts of green leaves and algae. While seaweeds and algae are the source of omega−3 fatty acids present in fish, grass is the source of omega−3 fatty acids present in grass fed animals. When cattle are taken off omega−3 fatty acid rich grass and shipped to a feedlot to be fattened on omega−3 fatty acid deficient grain, they begin losing their store of this beneficial fat. Each day that an animal spends in the feedlot, the amount of omega−3 fatty acids in its meat is diminished.
“The review provides good evidence that taking long-chain omega 3 (fish oil, EPA or DHA) supplements does not benefit heart health or reduce our risk of stroke or death from any cause. The most trustworthy studies consistently showed little or no effect of long-chain omega 3 fats on cardiovascular health. On the other hand, while oily fish is a healthy food, it is unclear from the small number of trials whether eating more oily fish is protective of our hearts.
EPA and DHA are vital nutrients and may be taken to maintain healthy function of the following: brain and retina: DHA is a building block of tissue in the brain and retina of the eye. It helps with forming neural transmitters, such as phosphatidylserine, which is important for brain function. DHA is found in the retina of the eye and taking DHA may be necessary for maintaining healthy levels of DHA for normal eye function.
The systematic review suggests that eating more ALA through food or supplements probably has little or no effect on cardiovascular deaths or deaths from any cause. However, eating more ALA probably reduces the risk of heart irregularities from 3.3 to 2.6%. The review team found that reductions in cardiovascular events with ALA were so small that about 1000 people would need to increase consumption of ALA for one of them to benefit. Similar results were found for cardiovascular death. They did not find enough data from the studies to be able to measure the risk of bleeding or blood clots from using ALA.
Rogers, P. J., Appleton, K. M., Kessler, D., Peters, T. J., Gunnell, D., Hayward, R. C., Heatherley, S. V., Christian, L. M., McNaughton, S. A., and Ness, A. R. No effect of n-3 long-chain polyunsaturated fatty acid (EPA and DHA) supplementation on depressed mood and cognitive function: a randomised controlled trial. Br J Nutr 2008;99(2):421-431. View abstract.
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.