Omega 3 oils of plant baseed origin, flaxseed, soybean, linseed, walnut oils and canola oils can all be converted in the body to DHA and EPA (the substances of fish oil)...giving you similar lowering effects on tryglycerides, so fish oil might have a lot of what is necessary, but if you are already eating many omegas/essential oil (linoliec fatty acids) - did you know eggs contain a great deal of these omega 6? and (alpha linoliec fatty acids) - as listed above, you will also reap many benefits.
The major debate left is saturated fats, but even beef fat contains Omega 6 linoliec fatty acids- it's all about getting the RIGHT BALANCE of these essential fatty acids. They are all necessary, it's just that we are supposed to be getting more omega 3/than omega 6s. So go for the fish and plant/nut/seed based fats when you can, then the animal/diary protein (saturated omega 6). Balance is the key...it's not an all or nothing thing.
Walnuts
Fatty fish - coldwater /salmon trout, mackeral, fresh tuna, shark
herring, mahi mahi
Flaxseed
Canola
Soybean oil
walnut oil
Linsead oil
even if you aren't eating fish, increase in intake of essential fatty acids will improve your health in many ways.
Also excess carbohydrate increases tryglycerides...when I was living on bagel and potatos with no real fat my tryglycerides were downright frightening, now they are fine.