Omega-6 fatty acid

Omega-6 fatty acids are fatty acids where the term "omega-6" signifies that the first double bond in the carbon backbone of the fatty acid, occurs in the omega minus 6 position; that is, the sixth carbon from the end of the fatty acid. See essential fatty acids for more detail on the naming system.

The biological effects of the ω-6 fatty acids are largely mediated by their interactions with the ω-3 fatty acids, see Essential fatty acid interactions for detail.

Linoleic acid (18:2), the shortest chain omega-6 fatty acid is an essential fatty acid. Arachidonic acid (20:4) is a physiologically significant n-6 fatty acid and is the precursor for prostaglandins and other physiologically active molecules.

Some medical research has suggested that excessive levels of omega-6 acids, relative to Omega-3 fatty acids, may increase the probability of a number of diseases and depression. Modern Western diets typically have ratios of omega-6 to omega-3 in excess of 10 to 1, some as high as 30 to 1. The optimal ratio is thought to be 4 to 1 or lower. 

Dietary sources of omega-6 fatty acids include:
 * nuts
 * cereals
 * whole-grain breads
 * most vegetable oils
 * eggs and poultry
 * baked goods.