Question

What is the difference between omega-3 and omega-6 fatty acids?

Answer

All fats are comprised of fatty acids that are linked together in long chains by chemical bonds. The number of bonds that join fatty acids to one another determines if a fat is saturated or unsaturated. Saturated fats are solid at room temperature and are derived from animal tissues or dairy products. In contrast, unsaturated fats are liquid at room temperature. Unsaturated fats can be further separated into monounsaturated and polyunsaturated fats, which are obtained from fatty fish and plants.

Polyunsaturated fats are rich in two distinct families of fatty acids: the omega-3 family and the omega-6 family. The omega-3 family stems from alpha-linolenic acid (ALA), and the omega-6 family originates from linoleic acid (LA). ALAand LA are considered “essential fatty acids” because they cannot be manufactured in the body and must be obtained from dietary sources.

Significant members of the omega-3 family are eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA).

Interestingly, the horse’s body can convert ALAto EPA and DHA when insufficient quantities of ALAare consumed. The lack of EPA and DHA in equine diets is understandable, as these two fatty acids are found almost exclusively in fish. The fish, namely cold-water species, are at the top of a food chain based largely on algae that manufacture EPA and DHA. ALA, on the other hand, is found predominantly in leafy plants, more traditional components of equine diets than fish by-products (fishmeal or fish oil).

Linseed oil is also a rich source of omega-3 fatty acids. The primary source of omega-6 fatty acids in the diet is LA derived from the oils of seeds and grains. Corn, sunflower, and safflower oil contain abundant quantities of LA.