Lynette,

Check this webpage out:

http://afterthediet.com/omega3.htm

"Omega-3 fatty acids are a subcategory of polyunsaturated fatty acids that have been found to have unique and important health benefits. The three main types of omega-3s important to humans are alpha-linolenic acid (ALA), eicosapentanoic acid (EPA), and docosahexanoic acid (DHA). Each of these omega-3's has unique and important functions that are not interchangeable. For example, flax, a source of ALA, has important health benefits. However, it does not substitute for EPA or DHA. There is some conversion of flax to EPA and DHA, but it is not an efficient conversion and it is generally agreed upon by omega-3 specialists that all three of these fatty acids must be consumed in order to gain the most benefit."