The primary essential fatty acids in our diet are omega-3 & omega-6 fatty acids. Dietary sources of omega-3 fatty acids include fish oil and certain plant & nut oils. Fish oil contains both docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), while some nuts (such as English walnuts) and vegetable oils (such as soybean, flaxseed,canola, linseed and olive oils) contain alpha-linolenic acid (ALA).
In a new study, researchers recruited 25 obese boys & girls between 14- 17 years. Participants randomly received either a 1.2 gram omega-3 fatty acid capsule or a placebo for three months. Six weeks later, each subject received the opposite treatment for another three months. The investigators collected data on fasting blood glucose, cholesterol and insulin levels. They also conducted glucose tolerance tests & skeletal muscle biopsies.
Research showed that in girls, omega-3 supplementation restored blood sugar concentration by 34% and improved glucose tolerance by 39%. However, these effects were not seen in boys.
The team concluded that supplementation with omega-3 fatty acids may benefit obese adolescent girls by improving their blood sugar control. However, more evidence is needed to confirm these findings.
There is supportive evidence from multiple studies that suggests the intake of recommended amounts of DHA and EPA in the form of dietary fish or fish oil supplements lowers triglycerides; reduces the risk of death, heart attack, dangerous abnormal heart rhythms & strokes in people with known cardiovascular disease; slows the buildup of atherosclerotic plaques ("hardening of the arteries") and lowers blood pressure slightly.
However, high doses may have harmful effects, such as an increased risk of bleeding. Although similar benefits have been proposed for alpha-linolenic acid, the scientific evidence is less compelling, and the beneficial effects may be less pronounced.
1 May 2012