Omega-3 fatty acids can help lower triglyceride levels significantly. This fat is found in fish, such as salmon, sardines, mackerel, tuna, and tilapia. Try to eat fatty fish at least twice a week. Omega-3 fatty acids are also found in walnuts, flax seeds, canola oil, and foods made with soy. Fish oil or omega-3 supplements are also available and may be an excellent addition to your care regimen. A diet high in vegetables and fruits can help lower triglyceride levels.