It's essential for eye health, especially in a developing fetus. In adults it helps prevent macular degeneration. It's also essential for preventing brain degeneration as we age. During pregnancy, most women's brains shrink because they have to cannabilise omega 3 for the baby.
Omega 3 is also a powerful anti-inflammatory (helpful in preventing or alleviating rheumatoid arthritis, and helps prevent/alleviate depression (some clinical trials have shown it to be more effective than SSRIs).
It also keeps skin healthy and slows down aging of the skin.
Excess triglycerides are associated with raised blood pressure, cardiovascular disease and diabetes. That's why lowering them is a good thing.
So omega 3's not the answer to everything but it's pretty damned powerful stuff.
F 5 ft 3. HW: 196 lbs. Primal SW (May 2011): 182 lbs (42% BF)... W June '12: 160 lbs (29% BF) (UK size 12, US size 8). GW: ~24% BF - have ditched the scales til I fit into a pair of UK size 10 bootcut jeans. Currently aligning towards 'The Perfect Health Diet' having swapped some fat for potatoes.