Geographic and climate based variation in essential fatty acid content of Canadian canola.

Linoleic (LA) and α-linolenic acid (ALA) are the essential N-3 and N-6 fatty acids in the human diet. During the 20th century soybean and canola oils became the primary sources of these of essential nutrients in the North American diet, however the LA and ALA content of these oils in the food supply is changing with cultivar and climate. In this project fatty acid composition data obtained from the Canadian Grain Commission for the years 2010-2022 across the provinces of Manitoba, Saskatchewan, and Alberta showed the average concentration of ALA in samples decreased from a high of 9.93 g/100 g ± 0.78 g/100 g (average ± standard deviation) in 2010, to a low of 8.16 g/100 g ± 0.46 g/100 g in 2022.  LA concentration was less variable with a high of 19.21 g/100 g ± 0.52 g/100 g in 2012, and a low in 2022 of 18.06 g/100 g ± 0.32 g/100 g.  Paired with geospatial metadata, it was clear that these data represented two geographically distinct populations of canola, Northern Plains Canola (NPC), and Southern Plains Canola (SPC) which could vary in ALA content by as much as 30% (7.57 g/100 g versus 9.96 g/100 g) while LA routinely varied by less than 5%.  Further we demonstrate that ALA content exhibits a sensitivity to high growing temperatures that LA does not.  Changes in climate and agricultural practice represent challenges to the assessment of N-3 and N-6 intake in the food system.