Flax seed oil is a substance extracted from the flax plant which contains a high level of omega 3 essential fatty acids and flax seed oil supplementation is often used as an alternative to fish oil supplementation for vegetarians. Flax seed oil also has many other benefits due to its other properties which fish oil does not necessarily give.
Due to its high level of omega 3 fatty acids flax seed oil supplementation has been known to have positive effects on high cholesterol and high blood pressure. Some fish oils may be high in mercury and although providing a high level of omega 3 fatty acids are not suitable for high blood pressure due to the high mercury content. Flax seed oil on the other hand provides the benefits of omega 3 fatty acid supplementation to patients suffering from high blood pressure without the problems associated with mercury.