[mitb6]

Rapeseed oil has been used for cooking in Japan for hundreds of year. The 1950s saw a shift to non domestic production.

https://www.tokyofoundation.org/research/detail.php?id=241

I shouldn't have used canola to refer to both.

Mustard oil is traditional and still very common cooking oil in South Asia that is even higher in erucic acid than rapeseed. People have used high erucic acid seed as good for a long time.