The body cannot produce its own supply of Omega-3 or EPA. Supplementing the diet with fish oil helps to balance the effects of Omega-6 fatty acids, which are found in most vegetable oils and are relatively abundant in the diet of most Americans. Most fish oil supplements are 18% EPA and 12% DHA, or a total of 30% omega-3. Balanced supplements help restore the body's natural balance of fatty acids. When these two groups of fatty acids are out of balance, the body releases chemicals that promote inflammation.