Like omega-3 fatty acids, omega-6 fats are essential, which means your body cannot make them and they must come from food. Gamma-linolenic acid, or GLA, refers to the omega-6 fatty acids found in plant foods. Very few foods you normally eat contain GLA, according to NYU Langone Medical Center, but you may be able to up your intake by including hemp oil, spirulina or borage oil. Consult your doctor before supplementing your diet with these foods.
GLA Versus LA
Most of your omega-6 fatty acids come from vegetable oils in the form or linoleic acid, or LA. Your body converts the LA in the vegetable oils to GLA in your body, which is then converted into arachidonic acid, or AA. There is concern that high intakes of omega-6 fatty acids in the form or LA and AA increase inflammation, according to the University of Maryland Medical Center. However, getting your omega-6s from foods rich in GLA may reduce inflammation.
Compared to other oils such as olive or safflower oil, hemp oil contains the highest amount of GLA. Two to 4 percent of the unsaturated fats in hemp oil come from its GLA content. Because of the high amounts of unsaturated fats found in hemp oil, it should not be used as a cooking oil, but you can add it to salad or drizzle it over grains or cooked veggies for flavor.
Also known as blue-green algae, spirulina -- a source of GLA -- is eaten in other parts of the world but is usually taken as a supplement in the United States. You can mix spirulina powder or flakes into a smoothie, sprinkle it on a salad or add it to a grain dish. Some sources of spirulina may contain bacteria or heavy metals, which can be harmful to your health. To reduce your risk, look for spirulina that has been tested for contaminants.
Borage oil is the richest source of GLA, according to the NYU Langone Medical Center. Like spirulina, borage oil is more of a supplement than a food. It comes from the bee plant and is also sometimes referred to as starflower oil. Borage oil contains amabiline, which is a pyrrolizidine alkaloid that is toxic to your liver. The more borage oil you take, the greater the risk of liver damage, according to the Memorial Sloan Kettering Cancer Center. Look for borage oil certified free of unsaturated pyrrolizidine alkaloids to reduce your risk.
- University of Maryland Medical Center: Gamma-Linolenic Acid
- NYU Langone Medical Center: Gamma-Linolenic Acid (GLA)
- Nutiva: Nutritional Composition of Hemp Seed and Oil
- U.S. Department of Agriculture: Industrial Hemp in the United States: Seed Markets
- Memorial Sloan Kettering Cancer Center: Blue-Green Algae
- MedlinePlus: Blue-Green Algae
- Memorial Sloan Kettering Cancer Center: Borage