Linolenic acid is an essential fatty acid required by all mammals but not produced in the body, so it must be ingested via diet. There are two forms of linolenic acid: alpha linolenic acid and gamma linolenic acid. Both provide the body with essential nutrients and help to provide protection against some medical conditions.
Alpha linolenic acid (ALA) is an omega-3 polyunsaturated fatty acid. Gamma linolenic acid (GLA) is an omega-6 unsaturated fatty acid. These forms of fatty acids are also closely related to the omega-3 fatty acids found in fish oil, which are called eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). Linolenic acid contains three double bonds, and although there are slight differences in all of these fatty acids, they all share the fact that they have a double bond in the omega-3 position. All of these fatty acids are related and connected by metabolic steps within the body.
The food sources of linolenic acids are very important to mammals, since they must ingest this essential fatty acid. ALA is found most commonly in plant and nut oils such as the seeds of chia, perilla, flax, purslane, ligonberry, hemp and even English walnuts. EPA and DHA are found in fish oils, especially salmon. GLA is actually produced in the body through the metabolism of linolenic acids consumed. There are also supplements of GLA made from the oils of evening primrose, borage and black currant plants.
Although it is known that linolenic acids are essential fatty acids, called such because they are not produced within the body, the exact function is still under debate. They are believed to be involved with brain development and function, but more scientific evidence is needed to substantiate the theory. The most widely studied function is the protection omega-3 fatty acids provide in heart disease. Many studies have shown that DHA and EPA can lower triglycerides, decrease plaque buildup in the arteries, lower blood pressure and reduce the risk of heart attacks and stroke in patients with heart disease.
Alpha Linolenic Acids
Although the omega-3 fatty acids from fish oil have received most of the attention, alpha linolenic acids from plant sources are also believed to have a beneficial effect against heart disease. Scientists are still studying ALA to determine if it can reduce the risks of heart disease or whether it is more likely that ALA is metabolized into EPA and DHA in the body, which then provides the beneficial protection. Either way, a diet enriched by vegetable oils like flaxseed oil can help to reduce cholesterol and blood triglycerides.
Gamma Linolenic Acids
Gamma linolenic acid in the body is used in the production of prostaglandins, which are hormone-like substances that are believed to aid in regulating the immune system. GLA has also been shown to slow the growth of certain types of cancer cells. Although this has not been proven, there are many studies being done to determine the possible benefits of GLA. Because of these possibilities, there are many GLA supplements available.
Linolenic acids in the various forms are all important essential fatty acids. Although all of the health benefits are still not completely known, it is a good idea to consume foods rich in these omega-3 fatty acids.