On the other hand, there is currently little evidence that plant-based oils like flaxseed oil and echium oil help lower high triglyceride levels. These oils contain the omega-3 fatty acid ALA (only a small percentage of which gets converted in the body into EPA and DHA) as well as various other fatty acids. Studies have generally not shown a benefit from flaxseed oil for reducing triglyceride levels. And while there is some evidence that supplementation with echium oil may decrease triglyceride levels (and LDL cholesterol) in healthy people -- there do not appear to be any studies on echium oil supplementation in people with high triglycerides.
A note of caution if you also have high cholesterol
If you are considering taking fish oil or algal oil, be aware that some studies suggest these oils can potentially increase LDL cholesterol — which is also often a concern for people with high triglyceride levels. Interestingly, one study found that supplementation with fresh, non-oxidized fish oil modestly lowered "bad" LDL cholesterol, while supplementation with an oxidized fish oil increased LDL, suggesting that the freshness of your fish oil may matter when it comes to its effects on cholesterol.
Additionally, some prescription fish oils have the potential to increase LDL cholesterol, but one particular prescription fish oil has been found lower to triglyceride levels without increasing LDL cholesterol.
ConsumerLab.com tests fish oil supplements for freshness, and you can see the results for popular products in the Results table in the Review.
Also, it's important to note that neither fish oil from supplements nor flaxseed oil appear to reduce the risk of cardiovascular disease or stroke — except in people who have recently had a heart attack. However, eating fish regularly may lower the risk of cardiovascular disease, and eating ground flaxseeds may help to lower blood pressure.
For other proposed natural treatments, see the Encyclopedia article about High Triglycerides.
Learn More About Supplements for Lowering Cholesterol