Omega-6 fatty acids belong to a group of "good" fats called polyunsaturated fatty acids. Unlike such "bad" fats as cholesterol and saturated fatty acids (which contribute to the worsening of a host of ailments including heart disease and other degenerative conditions), omega-6s can actually be beneficial to your health.

Omega-6 fatty acids are one of two types of essential fatty acids (EFAs) that people need to consume to stay healthy. Omega-3s are the other. Both are considered "essential" because the body can't produce them on its own; it can only get them through foods.

There are several different types of omega-6 fatty acids. Most omega-6 fatty acids are consumed in the diet from vegetable oils as linoleic acid (LA; be careful not to confuse this with alpha-linolenic acid [ALA] which is an omega-3 fatty acid). Linoleic acid is converted to gamma-linolenic acid (GLA) in the body and then further broken down to arachidonic acid (AA). AA can also be consumed directly from meat, and GLA can be ingested from several plant-based oils including evening primrose oil (EPO), borage oil, and black currant seed oil.

Excess amounts of LA and AA are unhealthy because they promote inflammation, thereby leading to several of the diseases described above. In contrast, GLA may actually reduce inflammation. Much of the GLA taken as a supplement is not converted to AA, but rather to a substance called dihomogamma-linolenic acid (DGLA). DGLA competes with AA and prevents the negative inflammatory effects that AA would otherwise cause in the body. In addition, DGLA becomes part of a particular series of substances, called prostaglandins, that can reduce inflammation. Having adequate amounts of certain nutrients in the body (including magnesium, zinc, and vitamins C, B3, and B6) helps promote the conversion of GLA to DGLA rather than AA.

It is important to know that many experts feel that the science supporting the use of omega-3 fatty acids to reduce inflammation and prevent diseases is much stronger than the information regarding use of GLA for these purposes.

If you take omega-6s in borage oil supplements over several months, you need to be under a doctor's supervision. In some cases, periodic liver function tests may be necessary. Although borage oil is a possible alternative to evening primrose oil for omega-6s, far less information is available on its safety and effectiveness.

The American diet provides more than 10 times the needed amount of omega-6 oils in the form of linoleic acid (LA). This is because it comprises the primary oil ingredient added to most processed foods and is found in commonly used cooking oils, including sunflower, safflower, corn, cottonseed, and soybean oils. Omega-6 fatty acids in the form of gamma linolenic acid (GLA) and LA are found in the plant seed oils of evening primrose, black currant, borage, and fungal oils. Arachidonic acid (AA) of the omega-6 series is found in egg yolk, meats in general, particularly organ meats, and other animal-based foods.