T Nation

Possible to get an Omega 6 to 3 ratio from USDA database?

I was wondering if anyone knows if it is possible to get an accurate ratio of Omega-6’s to Omega-3’s from the USDA nutrient database, or any other database (free) for that matter.

The USDA database lists EPA’s & DHA’s (both Omega-3’s), but the 18:2 and 18:3 acids are listed as “undifferentiated”. I thought all 18:2 acids are Omega-6’s (maybe not?), but it seems that 18:3 acids come in both Omega-3’s and Omega-6’s (alpha-linolenic and gamma-linolenic, respectively). If they are undifferentiated, I presume it is impossible to get an accurate ratio of Omega-6’s to Omega-3’s?

If anyone knows the answer to this, or if you know of a database where I could find accurate ratios for various foods, your help would be much appreciated.